/src/backend/postmaster/postmaster.c
C | 6093 lines | 3424 code | 772 blank | 1897 comment | 801 complexity | 85a6cfbd16d163cf65289491934ca360 MD5 | raw file
Possible License(s): AGPL-3.0
- /*-------------------------------------------------------------------------
- *
- * postmaster.c
- * This program acts as a clearing house for requests to the
- * POSTGRES system. Frontend programs send a startup message
- * to the Postmaster and the postmaster uses the info in the
- * message to setup a backend process.
- *
- * The postmaster also manages system-wide operations such as
- * startup and shutdown. The postmaster itself doesn't do those
- * operations, mind you --- it just forks off a subprocess to do them
- * at the right times. It also takes care of resetting the system
- * if a backend crashes.
- *
- * The postmaster process creates the shared memory and semaphore
- * pools during startup, but as a rule does not touch them itself.
- * In particular, it is not a member of the PGPROC array of backends
- * and so it cannot participate in lock-manager operations. Keeping
- * the postmaster away from shared memory operations makes it simpler
- * and more reliable. The postmaster is almost always able to recover
- * from crashes of individual backends by resetting shared memory;
- * if it did much with shared memory then it would be prone to crashing
- * along with the backends.
- *
- * When a request message is received, we now fork() immediately.
- * The child process performs authentication of the request, and
- * then becomes a backend if successful. This allows the auth code
- * to be written in a simple single-threaded style (as opposed to the
- * crufty "poor man's multitasking" code that used to be needed).
- * More importantly, it ensures that blockages in non-multithreaded
- * libraries like SSL or PAM cannot cause denial of service to other
- * clients.
- *
- *
- * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- *
- * IDENTIFICATION
- * src/backend/postmaster/postmaster.c
- *
- * NOTES
- *
- * Initialization:
- * The Postmaster sets up shared memory data structures
- * for the backends.
- *
- * Synchronization:
- * The Postmaster shares memory with the backends but should avoid
- * touching shared memory, so as not to become stuck if a crashing
- * backend screws up locks or shared memory. Likewise, the Postmaster
- * should never block on messages from frontend clients.
- *
- * Garbage Collection:
- * The Postmaster cleans up after backends if they have an emergency
- * exit and/or core dump.
- *
- * Error Reporting:
- * Use write_stderr() only for reporting "interactive" errors
- * (essentially, bogus arguments on the command line). Once the
- * postmaster is launched, use ereport().
- *
- *-------------------------------------------------------------------------
- */
- #include "postgres.h"
- #include <unistd.h>
- #include <signal.h>
- #include <time.h>
- #include <sys/wait.h>
- #include <ctype.h>
- #include <sys/stat.h>
- #include <sys/socket.h>
- #include <fcntl.h>
- #include <sys/param.h>
- #include <netinet/in.h>
- #include <arpa/inet.h>
- #include <netdb.h>
- #include <limits.h>
- #ifdef HAVE_SYS_SELECT_H
- #include <sys/select.h>
- #endif
- #ifdef USE_BONJOUR
- #include <dns_sd.h>
- #endif
- #include "access/transam.h"
- #include "access/xlog.h"
- #include "bootstrap/bootstrap.h"
- #include "catalog/pg_control.h"
- #include "lib/ilist.h"
- #include "libpq/auth.h"
- #include "libpq/ip.h"
- #include "libpq/libpq.h"
- #include "libpq/pqsignal.h"
- #include "miscadmin.h"
- #include "pg_getopt.h"
- #include "pgstat.h"
- #include "postmaster/autovacuum.h"
- #include "postmaster/bgworker_internals.h"
- #include "postmaster/fork_process.h"
- #include "postmaster/pgarch.h"
- #include "postmaster/postmaster.h"
- #include "postmaster/syslogger.h"
- #include "replication/walsender.h"
- #include "storage/fd.h"
- #include "storage/ipc.h"
- #include "storage/pg_shmem.h"
- #include "storage/pmsignal.h"
- #include "storage/proc.h"
- #include "tcop/tcopprot.h"
- #include "utils/builtins.h"
- #include "utils/datetime.h"
- #include "utils/dynamic_loader.h"
- #include "utils/memutils.h"
- #include "utils/ps_status.h"
- #include "utils/timeout.h"
- #ifdef EXEC_BACKEND
- #include "storage/spin.h"
- #endif
- /*
- * Possible types of a backend. Beyond being the possible bkend_type values in
- * struct bkend, these are OR-able request flag bits for SignalSomeChildren()
- * and CountChildren().
- */
- #define BACKEND_TYPE_NORMAL 0x0001 /* normal backend */
- #define BACKEND_TYPE_AUTOVAC 0x0002 /* autovacuum worker process */
- #define BACKEND_TYPE_WALSND 0x0004 /* walsender process */
- #define BACKEND_TYPE_BGWORKER 0x0008 /* bgworker process */
- #define BACKEND_TYPE_ALL 0x000F /* OR of all the above */
- #define BACKEND_TYPE_WORKER (BACKEND_TYPE_AUTOVAC | BACKEND_TYPE_BGWORKER)
- /*
- * List of active backends (or child processes anyway; we don't actually
- * know whether a given child has become a backend or is still in the
- * authorization phase). This is used mainly to keep track of how many
- * children we have and send them appropriate signals when necessary.
- *
- * "Special" children such as the startup, bgwriter and autovacuum launcher
- * tasks are not in this list. Autovacuum worker and walsender are in it.
- * Also, "dead_end" children are in it: these are children launched just for
- * the purpose of sending a friendly rejection message to a would-be client.
- * We must track them because they are attached to shared memory, but we know
- * they will never become live backends. dead_end children are not assigned a
- * PMChildSlot.
- *
- * Background workers that request shared memory access during registration are
- * in this list, too.
- */
- typedef struct bkend
- {
- pid_t pid; /* process id of backend */
- long cancel_key; /* cancel key for cancels for this backend */
- int child_slot; /* PMChildSlot for this backend, if any */
- /*
- * Flavor of backend or auxiliary process. Note that BACKEND_TYPE_WALSND
- * backends initially announce themselves as BACKEND_TYPE_NORMAL, so if
- * bkend_type is normal, you should check for a recent transition.
- */
- int bkend_type;
- bool dead_end; /* is it going to send an error and quit? */
- bool bgworker_notify; /* gets bgworker start/stop notifications */
- dlist_node elem; /* list link in BackendList */
- } Backend;
- static dlist_head BackendList = DLIST_STATIC_INIT(BackendList);
- #ifdef EXEC_BACKEND
- static Backend *ShmemBackendArray;
- #endif
- BackgroundWorker *MyBgworkerEntry = NULL;
- /* The socket number we are listening for connections on */
- int PostPortNumber;
- /* The directory names for Unix socket(s) */
- char *Unix_socket_directories;
- /* The TCP listen address(es) */
- char *ListenAddresses;
- /*
- * ReservedBackends is the number of backends reserved for superuser use.
- * This number is taken out of the pool size given by MaxBackends so
- * number of backend slots available to non-superusers is
- * (MaxBackends - ReservedBackends). Note what this really means is
- * "if there are <= ReservedBackends connections available, only superusers
- * can make new connections" --- pre-existing superuser connections don't
- * count against the limit.
- */
- int ReservedBackends;
- /* The socket(s) we're listening to. */
- #define MAXLISTEN 64
- static pgsocket ListenSocket[MAXLISTEN];
- /*
- * Set by the -o option
- */
- static char ExtraOptions[MAXPGPATH];
- /*
- * These globals control the behavior of the postmaster in case some
- * backend dumps core. Normally, it kills all peers of the dead backend
- * and reinitializes shared memory. By specifying -s or -n, we can have
- * the postmaster stop (rather than kill) peers and not reinitialize
- * shared data structures. (Reinit is currently dead code, though.)
- */
- static bool Reinit = true;
- static int SendStop = false;
- /* still more option variables */
- bool EnableSSL = false;
- int PreAuthDelay = 0;
- int AuthenticationTimeout = 60;
- bool log_hostname; /* for ps display and logging */
- bool Log_connections = false;
- bool Db_user_namespace = false;
- bool enable_bonjour = false;
- char *bonjour_name;
- bool restart_after_crash = true;
- /* PIDs of special child processes; 0 when not running */
- static pid_t StartupPID = 0,
- BgWriterPID = 0,
- CheckpointerPID = 0,
- WalWriterPID = 0,
- WalReceiverPID = 0,
- AutoVacPID = 0,
- PgArchPID = 0,
- PgStatPID = 0,
- SysLoggerPID = 0;
- /* Startup/shutdown state */
- #define NoShutdown 0
- #define SmartShutdown 1
- #define FastShutdown 2
- #define ImmediateShutdown 3
- static int Shutdown = NoShutdown;
- static bool FatalError = false; /* T if recovering from backend crash */
- static bool RecoveryError = false; /* T if WAL recovery failed */
- /*
- * We use a simple state machine to control startup, shutdown, and
- * crash recovery (which is rather like shutdown followed by startup).
- *
- * After doing all the postmaster initialization work, we enter PM_STARTUP
- * state and the startup process is launched. The startup process begins by
- * reading the control file and other preliminary initialization steps.
- * In a normal startup, or after crash recovery, the startup process exits
- * with exit code 0 and we switch to PM_RUN state. However, archive recovery
- * is handled specially since it takes much longer and we would like to support
- * hot standby during archive recovery.
- *
- * When the startup process is ready to start archive recovery, it signals the
- * postmaster, and we switch to PM_RECOVERY state. The background writer and
- * checkpointer are launched, while the startup process continues applying WAL.
- * If Hot Standby is enabled, then, after reaching a consistent point in WAL
- * redo, startup process signals us again, and we switch to PM_HOT_STANDBY
- * state and begin accepting connections to perform read-only queries. When
- * archive recovery is finished, the startup process exits with exit code 0
- * and we switch to PM_RUN state.
- *
- * Normal child backends can only be launched when we are in PM_RUN or
- * PM_HOT_STANDBY state. (We also allow launch of normal
- * child backends in PM_WAIT_BACKUP state, but only for superusers.)
- * In other states we handle connection requests by launching "dead_end"
- * child processes, which will simply send the client an error message and
- * quit. (We track these in the BackendList so that we can know when they
- * are all gone; this is important because they're still connected to shared
- * memory, and would interfere with an attempt to destroy the shmem segment,
- * possibly leading to SHMALL failure when we try to make a new one.)
- * In PM_WAIT_DEAD_END state we are waiting for all the dead_end children
- * to drain out of the system, and therefore stop accepting connection
- * requests at all until the last existing child has quit (which hopefully
- * will not be very long).
- *
- * Notice that this state variable does not distinguish *why* we entered
- * states later than PM_RUN --- Shutdown and FatalError must be consulted
- * to find that out. FatalError is never true in PM_RECOVERY_* or PM_RUN
- * states, nor in PM_SHUTDOWN states (because we don't enter those states
- * when trying to recover from a crash). It can be true in PM_STARTUP state,
- * because we don't clear it until we've successfully started WAL redo.
- * Similarly, RecoveryError means that we have crashed during recovery, and
- * should not try to restart.
- */
- typedef enum
- {
- PM_INIT, /* postmaster starting */
- PM_STARTUP, /* waiting for startup subprocess */
- PM_RECOVERY, /* in archive recovery mode */
- PM_HOT_STANDBY, /* in hot standby mode */
- PM_RUN, /* normal "database is alive" state */
- PM_WAIT_BACKUP, /* waiting for online backup mode to end */
- PM_WAIT_READONLY, /* waiting for read only backends to exit */
- PM_WAIT_BACKENDS, /* waiting for live backends to exit */
- PM_SHUTDOWN, /* waiting for checkpointer to do shutdown
- * ckpt */
- PM_SHUTDOWN_2, /* waiting for archiver and walsenders to
- * finish */
- PM_WAIT_DEAD_END, /* waiting for dead_end children to exit */
- PM_NO_CHILDREN /* all important children have exited */
- } PMState;
- static PMState pmState = PM_INIT;
- /* Start time of abort processing at immediate shutdown or child crash */
- static time_t AbortStartTime;
- #define SIGKILL_CHILDREN_AFTER_SECS 5
- static bool ReachedNormalRunning = false; /* T if we've reached PM_RUN */
- bool ClientAuthInProgress = false; /* T during new-client
- * authentication */
- bool redirection_done = false; /* stderr redirected for syslogger? */
- /* received START_AUTOVAC_LAUNCHER signal */
- static volatile sig_atomic_t start_autovac_launcher = false;
- /* the launcher needs to be signalled to communicate some condition */
- static volatile bool avlauncher_needs_signal = false;
- /* set when there's a worker that needs to be started up */
- static volatile bool StartWorkerNeeded = true;
- static volatile bool HaveCrashedWorker = false;
- /*
- * State for assigning random salts and cancel keys.
- * Also, the global MyCancelKey passes the cancel key assigned to a given
- * backend from the postmaster to that backend (via fork).
- */
- static unsigned int random_seed = 0;
- static struct timeval random_start_time;
- #ifdef USE_BONJOUR
- static DNSServiceRef bonjour_sdref = NULL;
- #endif
- /*
- * postmaster.c - function prototypes
- */
- static void unlink_external_pid_file(int status, Datum arg);
- static void getInstallationPaths(const char *argv0);
- static void checkDataDir(void);
- static Port *ConnCreate(int serverFd);
- static void ConnFree(Port *port);
- static void reset_shared(int port);
- static void SIGHUP_handler(SIGNAL_ARGS);
- static void pmdie(SIGNAL_ARGS);
- static void reaper(SIGNAL_ARGS);
- static void sigusr1_handler(SIGNAL_ARGS);
- static void startup_die(SIGNAL_ARGS);
- static void dummy_handler(SIGNAL_ARGS);
- static void StartupPacketTimeoutHandler(void);
- static void CleanupBackend(int pid, int exitstatus);
- static bool CleanupBackgroundWorker(int pid, int exitstatus);
- static void HandleChildCrash(int pid, int exitstatus, const char *procname);
- static void LogChildExit(int lev, const char *procname,
- int pid, int exitstatus);
- static void PostmasterStateMachine(void);
- static void BackendInitialize(Port *port);
- static void BackendRun(Port *port) __attribute__((noreturn));
- static void ExitPostmaster(int status) __attribute__((noreturn));
- static int ServerLoop(void);
- static int BackendStartup(Port *port);
- static int ProcessStartupPacket(Port *port, bool SSLdone);
- static void processCancelRequest(Port *port, void *pkt);
- static int initMasks(fd_set *rmask);
- static void report_fork_failure_to_client(Port *port, int errnum);
- static CAC_state canAcceptConnections(void);
- static long PostmasterRandom(void);
- static void RandomSalt(char *md5Salt);
- static void signal_child(pid_t pid, int signal);
- static bool SignalSomeChildren(int signal, int targets);
- static bool SignalUnconnectedWorkers(int signal);
- static void TerminateChildren(int signal);
- #define SignalChildren(sig) SignalSomeChildren(sig, BACKEND_TYPE_ALL)
- static int CountChildren(int target);
- static int CountUnconnectedWorkers(void);
- static void maybe_start_bgworker(void);
- static bool CreateOptsFile(int argc, char *argv[], char *fullprogname);
- static pid_t StartChildProcess(AuxProcType type);
- static void StartAutovacuumWorker(void);
- static void InitPostmasterDeathWatchHandle(void);
- #ifdef EXEC_BACKEND
- #ifdef WIN32
- #define WNOHANG 0 /* ignored, so any integer value will do */
- static pid_t waitpid(pid_t pid, int *exitstatus, int options);
- static void WINAPI pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired);
- static HANDLE win32ChildQueue;
- typedef struct
- {
- HANDLE waitHandle;
- HANDLE procHandle;
- DWORD procId;
- } win32_deadchild_waitinfo;
- #endif /* WIN32 */
- static pid_t backend_forkexec(Port *port);
- static pid_t internal_forkexec(int argc, char *argv[], Port *port);
- /* Type for a socket that can be inherited to a client process */
- #ifdef WIN32
- typedef struct
- {
- SOCKET origsocket; /* Original socket value, or PGINVALID_SOCKET
- * if not a socket */
- WSAPROTOCOL_INFO wsainfo;
- } InheritableSocket;
- #else
- typedef int InheritableSocket;
- #endif
- /*
- * Structure contains all variables passed to exec:ed backends
- */
- typedef struct
- {
- Port port;
- InheritableSocket portsocket;
- char DataDir[MAXPGPATH];
- pgsocket ListenSocket[MAXLISTEN];
- long MyCancelKey;
- int MyPMChildSlot;
- #ifndef WIN32
- unsigned long UsedShmemSegID;
- #else
- HANDLE UsedShmemSegID;
- #endif
- void *UsedShmemSegAddr;
- slock_t *ShmemLock;
- VariableCache ShmemVariableCache;
- Backend *ShmemBackendArray;
- #ifndef HAVE_SPINLOCKS
- PGSemaphore SpinlockSemaArray;
- #endif
- LWLockPadded *MainLWLockArray;
- slock_t *ProcStructLock;
- PROC_HDR *ProcGlobal;
- PGPROC *AuxiliaryProcs;
- PGPROC *PreparedXactProcs;
- PMSignalData *PMSignalState;
- InheritableSocket pgStatSock;
- pid_t PostmasterPid;
- TimestampTz PgStartTime;
- TimestampTz PgReloadTime;
- pg_time_t first_syslogger_file_time;
- bool redirection_done;
- bool IsBinaryUpgrade;
- int max_safe_fds;
- int MaxBackends;
- #ifdef WIN32
- HANDLE PostmasterHandle;
- HANDLE initial_signal_pipe;
- HANDLE syslogPipe[2];
- #else
- int postmaster_alive_fds[2];
- int syslogPipe[2];
- #endif
- char my_exec_path[MAXPGPATH];
- char pkglib_path[MAXPGPATH];
- char ExtraOptions[MAXPGPATH];
- } BackendParameters;
- static void read_backend_variables(char *id, Port *port);
- static void restore_backend_variables(BackendParameters *param, Port *port);
- #ifndef WIN32
- static bool save_backend_variables(BackendParameters *param, Port *port);
- #else
- static bool save_backend_variables(BackendParameters *param, Port *port,
- HANDLE childProcess, pid_t childPid);
- #endif
- static void ShmemBackendArrayAdd(Backend *bn);
- static void ShmemBackendArrayRemove(Backend *bn);
- #endif /* EXEC_BACKEND */
- #define StartupDataBase() StartChildProcess(StartupProcess)
- #define StartBackgroundWriter() StartChildProcess(BgWriterProcess)
- #define StartCheckpointer() StartChildProcess(CheckpointerProcess)
- #define StartWalWriter() StartChildProcess(WalWriterProcess)
- #define StartWalReceiver() StartChildProcess(WalReceiverProcess)
- /* Macros to check exit status of a child process */
- #define EXIT_STATUS_0(st) ((st) == 0)
- #define EXIT_STATUS_1(st) (WIFEXITED(st) && WEXITSTATUS(st) == 1)
- #ifndef WIN32
- /*
- * File descriptors for pipe used to monitor if postmaster is alive.
- * First is POSTMASTER_FD_WATCH, second is POSTMASTER_FD_OWN.
- */
- int postmaster_alive_fds[2] = {-1, -1};
- #else
- /* Process handle of postmaster used for the same purpose on Windows */
- HANDLE PostmasterHandle;
- #endif
- /*
- * Postmaster main entry point
- */
- void
- PostmasterMain(int argc, char *argv[])
- {
- int opt;
- int status;
- char *userDoption = NULL;
- bool listen_addr_saved = false;
- int i;
- char *output_config_variable = NULL;
- MyProcPid = PostmasterPid = getpid();
- MyStartTime = time(NULL);
- IsPostmasterEnvironment = true;
- /*
- * for security, no dir or file created can be group or other accessible
- */
- umask(S_IRWXG | S_IRWXO);
- /*
- * By default, palloc() requests in the postmaster will be allocated in
- * the PostmasterContext, which is space that can be recycled by backends.
- * Allocated data that needs to be available to backends should be
- * allocated in TopMemoryContext.
- */
- PostmasterContext = AllocSetContextCreate(TopMemoryContext,
- "Postmaster",
- ALLOCSET_DEFAULT_MINSIZE,
- ALLOCSET_DEFAULT_INITSIZE,
- ALLOCSET_DEFAULT_MAXSIZE);
- MemoryContextSwitchTo(PostmasterContext);
- /* Initialize paths to installation files */
- getInstallationPaths(argv[0]);
- /*
- * Set up signal handlers for the postmaster process.
- *
- * CAUTION: when changing this list, check for side-effects on the signal
- * handling setup of child processes. See tcop/postgres.c,
- * bootstrap/bootstrap.c, postmaster/bgwriter.c, postmaster/walwriter.c,
- * postmaster/autovacuum.c, postmaster/pgarch.c, postmaster/pgstat.c,
- * postmaster/syslogger.c, postmaster/bgworker.c and
- * postmaster/checkpointer.c.
- */
- pqinitmask();
- PG_SETMASK(&BlockSig);
- pqsignal(SIGHUP, SIGHUP_handler); /* reread config file and have
- * children do same */
- pqsignal(SIGINT, pmdie); /* send SIGTERM and shut down */
- pqsignal(SIGQUIT, pmdie); /* send SIGQUIT and die */
- pqsignal(SIGTERM, pmdie); /* wait for children and shut down */
- pqsignal(SIGALRM, SIG_IGN); /* ignored */
- pqsignal(SIGPIPE, SIG_IGN); /* ignored */
- pqsignal(SIGUSR1, sigusr1_handler); /* message from child process */
- pqsignal(SIGUSR2, dummy_handler); /* unused, reserve for children */
- pqsignal(SIGCHLD, reaper); /* handle child termination */
- pqsignal(SIGTTIN, SIG_IGN); /* ignored */
- pqsignal(SIGTTOU, SIG_IGN); /* ignored */
- /* ignore SIGXFSZ, so that ulimit violations work like disk full */
- #ifdef SIGXFSZ
- pqsignal(SIGXFSZ, SIG_IGN); /* ignored */
- #endif
- /*
- * Options setup
- */
- InitializeGUCOptions();
- opterr = 1;
- /*
- * Parse command-line options. CAUTION: keep this in sync with
- * tcop/postgres.c (the option sets should not conflict) and with the
- * common help() function in main/main.c.
- */
- while ((opt = getopt(argc, argv, "A:B:bc:C:D:d:EeFf:h:ijk:lN:nOo:Pp:r:S:sTt:W:-:")) != -1)
- {
- switch (opt)
- {
- case 'A':
- SetConfigOption("debug_assertions", optarg, PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'B':
- SetConfigOption("shared_buffers", optarg, PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'b':
- /* Undocumented flag used for binary upgrades */
- IsBinaryUpgrade = true;
- break;
- case 'C':
- output_config_variable = strdup(optarg);
- break;
- case 'D':
- userDoption = strdup(optarg);
- break;
- case 'd':
- set_debug_options(atoi(optarg), PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'E':
- SetConfigOption("log_statement", "all", PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'e':
- SetConfigOption("datestyle", "euro", PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'F':
- SetConfigOption("fsync", "false", PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'f':
- if (!set_plan_disabling_options(optarg, PGC_POSTMASTER, PGC_S_ARGV))
- {
- write_stderr("%s: invalid argument for option -f: \"%s\"\n",
- progname, optarg);
- ExitPostmaster(1);
- }
- break;
- case 'h':
- SetConfigOption("listen_addresses", optarg, PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'i':
- SetConfigOption("listen_addresses", "*", PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'j':
- /* only used by interactive backend */
- break;
- case 'k':
- SetConfigOption("unix_socket_directories", optarg, PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'l':
- SetConfigOption("ssl", "true", PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'N':
- SetConfigOption("max_connections", optarg, PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'n':
- /* Don't reinit shared mem after abnormal exit */
- Reinit = false;
- break;
- case 'O':
- SetConfigOption("allow_system_table_mods", "true", PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'o':
- /* Other options to pass to the backend on the command line */
- snprintf(ExtraOptions + strlen(ExtraOptions),
- sizeof(ExtraOptions) - strlen(ExtraOptions),
- " %s", optarg);
- break;
- case 'P':
- SetConfigOption("ignore_system_indexes", "true", PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'p':
- SetConfigOption("port", optarg, PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'r':
- /* only used by single-user backend */
- break;
- case 'S':
- SetConfigOption("work_mem", optarg, PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 's':
- SetConfigOption("log_statement_stats", "true", PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'T':
- /*
- * In the event that some backend dumps core, send SIGSTOP,
- * rather than SIGQUIT, to all its peers. This lets the wily
- * post_hacker collect core dumps from everyone.
- */
- SendStop = true;
- break;
- case 't':
- {
- const char *tmp = get_stats_option_name(optarg);
- if (tmp)
- {
- SetConfigOption(tmp, "true", PGC_POSTMASTER, PGC_S_ARGV);
- }
- else
- {
- write_stderr("%s: invalid argument for option -t: \"%s\"\n",
- progname, optarg);
- ExitPostmaster(1);
- }
- break;
- }
- case 'W':
- SetConfigOption("post_auth_delay", optarg, PGC_POSTMASTER, PGC_S_ARGV);
- break;
- case 'c':
- case '-':
- {
- char *name,
- *value;
- ParseLongOption(optarg, &name, &value);
- if (!value)
- {
- if (opt == '-')
- ereport(ERROR,
- (errcode(ERRCODE_SYNTAX_ERROR),
- errmsg("--%s requires a value",
- optarg)));
- else
- ereport(ERROR,
- (errcode(ERRCODE_SYNTAX_ERROR),
- errmsg("-c %s requires a value",
- optarg)));
- }
- SetConfigOption(name, value, PGC_POSTMASTER, PGC_S_ARGV);
- free(name);
- if (value)
- free(value);
- break;
- }
- default:
- write_stderr("Try \"%s --help\" for more information.\n",
- progname);
- ExitPostmaster(1);
- }
- }
- /*
- * Postmaster accepts no non-option switch arguments.
- */
- if (optind < argc)
- {
- write_stderr("%s: invalid argument: \"%s\"\n",
- progname, argv[optind]);
- write_stderr("Try \"%s --help\" for more information.\n",
- progname);
- ExitPostmaster(1);
- }
- /*
- * Locate the proper configuration files and data directory, and read
- * postgresql.conf for the first time.
- */
- if (!SelectConfigFiles(userDoption, progname))
- ExitPostmaster(2);
- if (output_config_variable != NULL)
- {
- /*
- * permission is handled because the user is reading inside the data
- * dir
- */
- puts(GetConfigOption(output_config_variable, false, false));
- ExitPostmaster(0);
- }
- /* Verify that DataDir looks reasonable */
- checkDataDir();
- /* And switch working directory into it */
- ChangeToDataDir();
- /*
- * Check for invalid combinations of GUC settings.
- */
- if (ReservedBackends >= MaxConnections)
- {
- write_stderr("%s: superuser_reserved_connections must be less than max_connections\n", progname);
- ExitPostmaster(1);
- }
- if (max_wal_senders >= MaxConnections)
- {
- write_stderr("%s: max_wal_senders must be less than max_connections\n", progname);
- ExitPostmaster(1);
- }
- if (XLogArchiveMode && wal_level == WAL_LEVEL_MINIMAL)
- ereport(ERROR,
- (errmsg("WAL archival (archive_mode=on) requires wal_level \"archive\", \"hot_standby\" or \"logical\"")));
- if (max_wal_senders > 0 && wal_level == WAL_LEVEL_MINIMAL)
- ereport(ERROR,
- (errmsg("WAL streaming (max_wal_senders > 0) requires wal_level \"archive\", \"hot_standby\" or \"logical\"")));
- /*
- * Other one-time internal sanity checks can go here, if they are fast.
- * (Put any slow processing further down, after postmaster.pid creation.)
- */
- if (!CheckDateTokenTables())
- {
- write_stderr("%s: invalid datetoken tables, please fix\n", progname);
- ExitPostmaster(1);
- }
- /*
- * Now that we are done processing the postmaster arguments, reset
- * getopt(3) library so that it will work correctly in subprocesses.
- */
- optind = 1;
- #ifdef HAVE_INT_OPTRESET
- optreset = 1; /* some systems need this too */
- #endif
- /* For debugging: display postmaster environment */
- {
- extern char **environ;
- char **p;
- ereport(DEBUG3,
- (errmsg_internal("%s: PostmasterMain: initial environment dump:",
- progname)));
- ereport(DEBUG3,
- (errmsg_internal("-----------------------------------------")));
- for (p = environ; *p; ++p)
- ereport(DEBUG3,
- (errmsg_internal("\t%s", *p)));
- ereport(DEBUG3,
- (errmsg_internal("-----------------------------------------")));
- }
- /*
- * Create lockfile for data directory.
- *
- * We want to do this before we try to grab the input sockets, because the
- * data directory interlock is more reliable than the socket-file
- * interlock (thanks to whoever decided to put socket files in /tmp :-().
- * For the same reason, it's best to grab the TCP socket(s) before the
- * Unix socket(s).
- */
- CreateDataDirLockFile(true);
- /*
- * Initialize SSL library, if specified.
- */
- #ifdef USE_SSL
- if (EnableSSL)
- secure_initialize();
- #endif
- /*
- * process any libraries that should be preloaded at postmaster start
- */
- process_shared_preload_libraries();
- /*
- * Now that loadable modules have had their chance to register background
- * workers, calculate MaxBackends.
- */
- InitializeMaxBackends();
- /*
- * Establish input sockets.
- */
- for (i = 0; i < MAXLISTEN; i++)
- ListenSocket[i] = PGINVALID_SOCKET;
- if (ListenAddresses)
- {
- char *rawstring;
- List *elemlist;
- ListCell *l;
- int success = 0;
- /* Need a modifiable copy of ListenAddresses */
- rawstring = pstrdup(ListenAddresses);
- /* Parse string into list of hostnames */
- if (!SplitIdentifierString(rawstring, ',', &elemlist))
- {
- /* syntax error in list */
- ereport(FATAL,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("invalid list syntax in parameter \"%s\"",
- "listen_addresses")));
- }
- foreach(l, elemlist)
- {
- char *curhost = (char *) lfirst(l);
- if (strcmp(curhost, "*") == 0)
- status = StreamServerPort(AF_UNSPEC, NULL,
- (unsigned short) PostPortNumber,
- NULL,
- ListenSocket, MAXLISTEN);
- else
- status = StreamServerPort(AF_UNSPEC, curhost,
- (unsigned short) PostPortNumber,
- NULL,
- ListenSocket, MAXLISTEN);
- if (status == STATUS_OK)
- {
- success++;
- /* record the first successful host addr in lockfile */
- if (!listen_addr_saved)
- {
- AddToDataDirLockFile(LOCK_FILE_LINE_LISTEN_ADDR, curhost);
- listen_addr_saved = true;
- }
- }
- else
- ereport(WARNING,
- (errmsg("could not create listen socket for \"%s\"",
- curhost)));
- }
- if (!success && elemlist != NIL)
- ereport(FATAL,
- (errmsg("could not create any TCP/IP sockets")));
- list_free(elemlist);
- pfree(rawstring);
- }
- #ifdef USE_BONJOUR
- /* Register for Bonjour only if we opened TCP socket(s) */
- if (enable_bonjour && ListenSocket[0] != PGINVALID_SOCKET)
- {
- DNSServiceErrorType err;
- /*
- * We pass 0 for interface_index, which will result in registering on
- * all "applicable" interfaces. It's not entirely clear from the
- * DNS-SD docs whether this would be appropriate if we have bound to
- * just a subset of the available network interfaces.
- */
- err = DNSServiceRegister(&bonjour_sdref,
- 0,
- 0,
- bonjour_name,
- "_postgresql._tcp.",
- NULL,
- NULL,
- htons(PostPortNumber),
- 0,
- NULL,
- NULL,
- NULL);
- if (err != kDNSServiceErr_NoError)
- elog(LOG, "DNSServiceRegister() failed: error code %ld",
- (long) err);
- /*
- * We don't bother to read the mDNS daemon's reply, and we expect that
- * it will automatically terminate our registration when the socket is
- * closed at postmaster termination. So there's nothing more to be
- * done here. However, the bonjour_sdref is kept around so that
- * forked children can close their copies of the socket.
- */
- }
- #endif
- #ifdef HAVE_UNIX_SOCKETS
- if (Unix_socket_directories)
- {
- char *rawstring;
- List *elemlist;
- ListCell *l;
- int success = 0;
- /* Need a modifiable copy of Unix_socket_directories */
- rawstring = pstrdup(Unix_socket_directories);
- /* Parse string into list of directories */
- if (!SplitDirectoriesString(rawstring, ',', &elemlist))
- {
- /* syntax error in list */
- ereport(FATAL,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("invalid list syntax in parameter \"%s\"",
- "unix_socket_directories")));
- }
- foreach(l, elemlist)
- {
- char *socketdir = (char *) lfirst(l);
- status = StreamServerPort(AF_UNIX, NULL,
- (unsigned short) PostPortNumber,
- socketdir,
- ListenSocket, MAXLISTEN);
- if (status == STATUS_OK)
- {
- success++;
- /* record the first successful Unix socket in lockfile */
- if (success == 1)
- AddToDataDirLockFile(LOCK_FILE_LINE_SOCKET_DIR, socketdir);
- }
- else
- ereport(WARNING,
- (errmsg("could not create Unix-domain socket in directory \"%s\"",
- socketdir)));
- }
- if (!success && elemlist != NIL)
- ereport(FATAL,
- (errmsg("could not create any Unix-domain sockets")));
- list_free_deep(elemlist);
- pfree(rawstring);
- }
- #endif
- /*
- * check that we have some socket to listen on
- */
- if (ListenSocket[0] == PGINVALID_SOCKET)
- ereport(FATAL,
- (errmsg("no socket created for listening")));
- /*
- * If no valid TCP ports, write an empty line for listen address,
- * indicating the Unix socket must be used. Note that this line is not
- * added to the lock file until there is a socket backing it.
- */
- if (!listen_addr_saved)
- AddToDataDirLockFile(LOCK_FILE_LINE_LISTEN_ADDR, "");
- /*
- * Set up shared memory and semaphores.
- */
- reset_shared(PostPortNumber);
- /*
- * Estimate number of openable files. This must happen after setting up
- * semaphores, because on some platforms semaphores count as open files.
- */
- set_max_safe_fds();
- /*
- * Set reference point for stack-depth checking.
- */
- set_stack_base();
- /*
- * Initialize pipe (or process handle on Windows) that allows children to
- * wake up from sleep on postmaster death.
- */
- InitPostmasterDeathWatchHandle();
- #ifdef WIN32
- /*
- * Initialize I/O completion port used to deliver list of dead children.
- */
- win32ChildQueue = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 1);
- if (win32ChildQueue == NULL)
- ereport(FATAL,
- (errmsg("could not create I/O completion port for child queue")));
- #endif
- /*
- * Record postmaster options. We delay this till now to avoid recording
- * bogus options (eg, NBuffers too high for available memory).
- */
- if (!CreateOptsFile(argc, argv, my_exec_path))
- ExitPostmaster(1);
- #ifdef EXEC_BACKEND
- /* Write out nondefault GUC settings for child processes to use */
- write_nondefault_variables(PGC_POSTMASTER);
- #endif
- /*
- * Write the external PID file if requested
- */
- if (external_pid_file)
- {
- FILE *fpidfile = fopen(external_pid_file, "w");
- if (fpidfile)
- {
- fprintf(fpidfile, "%d\n", MyProcPid);
- fclose(fpidfile);
- /* Make PID file world readable */
- if (chmod(external_pid_file, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) != 0)
- write_stderr("%s: could not change permissions of external PID file \"%s\": %s\n",
- progname, external_pid_file, strerror(errno));
- }
- else
- write_stderr("%s: could not write external PID file \"%s\": %s\n",
- progname, external_pid_file, strerror(errno));
- on_proc_exit(unlink_external_pid_file, 0);
- }
- /*
- * If enabled, start up syslogger collection subprocess
- */
- SysLoggerPID = SysLogger_Start();
- /*
- * Reset whereToSendOutput from DestDebug (its starting state) to
- * DestNone. This stops ereport from sending log messages to stderr unless
- * Log_destination permits. We don't do this until the postmaster is
- * fully launched, since startup failures may as well be reported to
- * stderr.
- *
- * If we are in fact disabling logging to stderr, first emit a log message
- * saying so, to provide a breadcrumb trail for users who may not remember
- * that their logging is configured to go somewhere else.
- */
- if (!(Log_destination & LOG_DESTINATION_STDERR))
- ereport(LOG,
- (errmsg("ending log output to stderr"),
- errhint("Future log output will go to log destination \"%s\".",
- Log_destination_string)));
- whereToSendOutput = DestNone;
- /*
- * Initialize stats collection subsystem (this does NOT start the
- * collector process!)
- */
- pgstat_init();
- /*
- * Initialize the autovacuum subsystem (again, no process start yet)
- */
- autovac_init();
- /*
- * Load configuration files for client authentication.
- */
- if (!load_hba())
- {
- /*
- * It makes no sense to continue if we fail to load the HBA file,
- * since there is no way to connect to the database in this case.
- */
- ereport(FATAL,
- (errmsg("could not load pg_hba.conf")));
- }
- if (!load_ident())
- {
- /*
- * We can start up without the IDENT file, although it means that you
- * cannot log in using any of the authentication methods that need a
- * user name mapping. load_ident() already logged the details of error
- * to the log.
- */
- }
- /*
- * Remove old temporary files. At this point there can be no other
- * Postgres processes running in this directory, so this should be safe.
- */
- RemovePgTempFiles();
- /*
- * Remember postmaster startup time
- */
- PgStartTime = GetCurrentTimestamp();
- /* PostmasterRandom wants its own copy */
- gettimeofday(&random_start_time, NULL);
- /*
- * We're ready to rock and roll...
- */
- StartupPID = StartupDataBase();
- Assert(StartupPID != 0);
- pmState = PM_STARTUP;
- /* Some workers may be scheduled to start now */
- maybe_start_bgworker();
- status = ServerLoop();
- /*
- * ServerLoop probably shouldn't ever return, but if it does, close down.
- */
- ExitPostmaster(status != STATUS_OK);
- abort(); /* not reached */
- }
- /*
- * on_proc_exit callback to delete external_pid_file
- */
- static void
- unlink_external_pid_file(int status, Datum arg)
- {
- if (external_pid_file)
- unlink(external_pid_file);
- }
- /*
- * Compute and check the directory paths to files that are part of the
- * installation (as deduced from the postgres executable's own location)
- */
- static void
- getInstallationPaths(const char *argv0)
- {
- DIR *pdir;
- /* Locate the postgres executable itself */
- if (find_my_exec(argv0, my_exec_path) < 0)
- elog(FATAL, "%s: could not locate my own executable path", argv0);
- #ifdef EXEC_BACKEND
- /* Locate executable backend before we change working directory */
- if (find_other_exec(argv0, "postgres", PG_BACKEND_VERSIONSTR,
- postgres_exec_path) < 0)
- ereport(FATAL,
- (errmsg("%s: could not locate matching postgres executable",
- argv0)));
- #endif
- /*
- * Locate the pkglib directory --- this has to be set early in case we try
- * to load any modules from it in response to postgresql.conf entries.
- */
- get_pkglib_path(my_exec_path, pkglib_path);
- /*
- * Verify that there's a readable directory there; otherwise the Postgres
- * installation is incomplete or corrupt. (A typical cause of this
- * failure is that the postgres executable has been moved or hardlinked to
- * some directory that's not a sibling of the installation lib/
- * directory.)
- */
- pdir = AllocateDir(pkglib_path);
- if (pdir == NULL)
- ereport(ERROR,
- (errcode_for_file_access(),
- errmsg("could not open directory \"%s\": %m",
- pkglib_path),
- errhint("This may indicate an incomplete PostgreSQL installation, or that the file \"%s\" has been moved away from its proper location.",
- my_exec_path)));
- FreeDir(pdir);
- /*
- * XXX is it worth similarly checking the share/ directory? If the lib/
- * directory is there, then share/ probably is too.
- */
- }
- /*
- * Validate the proposed data directory
- */
- static void
- checkDataDir(void)
- {
- char path[MAXPGPATH];
- FILE *fp;
- struct stat stat_buf;
- Assert(DataDir);
- if (stat(DataDir, &stat_buf) != 0)
- {
- if (errno == ENOENT)
- ereport(FATAL,
- (errcode_for_file_access(),
- errmsg("data directory \"%s\" does not exist",
- DataDir)));
- else
- ereport(FATAL,
- (errcode_for_file_access(),
- errmsg("could not read permissions of directory \"%s\": %m",
- DataDir)));
- }
- /* eventual chdir would fail anyway, but let's test ... */
- if (!S_ISDIR(stat_buf.st_mode))
- ereport(FATAL,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("specified data directory \"%s\" is not a directory",
- DataDir)));
- /*
- * Check that the directory belongs to my userid; if not, reject.
- *
- * This check is an essential part of the interlock that prevents two
- * postmasters from starting in the same directory (see CreateLockFile()).
- * Do not remove or weaken it.
- *
- * XXX can we safely enable this check on Windows?
- */
- #if !defined(WIN32) && !defined(__CYGWIN__)
- if (stat_buf.st_uid != geteuid())
- ereport(FATAL,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("data directory \"%s\" has wrong ownership",
- DataDir),
- errhint("The server must be started by the user that owns the data directory.")));
- #endif
- /*
- * Check if the directory has group or world access. If so, reject.
- *
- * It would be possible to allow weaker constraints (for example, allow
- * group access) but we cannot make a general assumption that that is
- * okay; for example there are platforms where nearly all users
- * customarily belong to the same group. Perhaps this test should be
- * configurable.
- *
- * XXX temporarily suppress check when on Windows, because there may not
- * be proper support for Unix-y file permissions. Need to think of a
- * reasonable check to apply on Windows.
- */
- #if !defined(WIN32) && !defined(__CYGWIN__)
- if (stat_buf.st_mode & (S_IRWXG | S_IRWXO))
- ereport(FATAL,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("data directory \"%s\" has group or world access",
- DataDir),
- errdetail("Permissions should be u=rwx (0700).")));
- #endif
- /* Look for PG_VERSION before looking for pg_control */
- ValidatePgVersion(DataDir);
- snprintf(path, sizeof(path), "%s/global/pg_control", DataDir);
- fp = AllocateFile(path, PG_BINARY_R);
- if (fp == NULL)
- {
- write_stderr("%s: could not find the database system\n"
- "Expected to find it in the directory \"%s\",\n"
- "but could not open file \"%s\": %s\n",
- progname, DataDir, path, strerror(errno));
- ExitPostmaster(2);
- }
- FreeFile(fp);
- }
- /*
- * Determine how long should we let ServerLoop sleep.
- *
- * In normal conditions we wait at most one minute, to ensure that the other
- * background tasks handled by ServerLoop get done even when no requests are
- * arriving. However, if there are background workers waiting to be started,
- * we don't actually sleep so that they are quickly serviced.
- */
- static void
- DetermineSleepTime(struct timeval * timeout)
- {
- TimestampTz next_wakeup = 0;
- /*
- * Normal case: either there are no background workers at all, or we're in
- * a shutdown sequence (during which we ignore bgworkers altogether).
- */
- if (Shutdown > NoShutdown ||
- (!StartWorkerNeeded && !HaveCrashedWorker))
- {
- if (AbortStartTime > 0)
- {
- /* time left to abort; clamp to 0 in case it already expired */
- timeout->tv_sec = Max(SIGKILL_CHILDREN_AFTER_SECS -
- (time(NULL) - AbortStartTime), 0);
- timeout->tv_usec = 0;
- }
- else
- {
- timeout->tv_sec = 60;
- timeout->tv_usec = 0;
- }
- return;
- }
- if (StartWorkerNeeded)
- {
- timeout->tv_sec = 0;
- timeout->tv_usec = 0;
- return;
- }
- if (HaveCrashedWorker)
- {
- slist_mutable_iter siter;
- /*
- * When there are crashed bgworkers, we sleep just long enough that
- * they are restarted when they request to be. Scan the list to
- * determine the minimum of all wakeup times according to most recent
- * crash time and requested restart interval.
- */
- slist_foreach_modify(siter, &BackgroundWorkerList)
- {
- RegisteredBgWorker *rw;
- TimestampTz this_wakeup;
- rw = slist_container(RegisteredBgWorker, rw_lnode, siter.cur);
- if (rw->rw_crashed_at == 0)
- continue;
- if (rw->rw_worker.bgw_restart_time == BGW_NEVER_RESTART
- || rw->rw_terminate)
- {
- ForgetBackgroundWorker(&siter);
- continue;
- }
- this_wakeup = TimestampTzPlusMilliseconds(rw->rw_crashed_at,
- 1000L * rw->rw_worker.bgw_restart_time);
- if (next_wakeup == 0 || this_wakeup < next_wakeup)
- next_wakeup = this_wakeup;
- }
- }
- if (next_wakeup != 0)
- {
- long secs;
- int microsecs;
- TimestampDifference(GetCurrentTimestamp(), next_wakeup,
- &secs, µsecs);
- timeout->tv_sec = secs;
- timeout->tv_usec = microsecs;
- /* Ensure we don't exceed one minute */
- if (timeout->tv_sec > 60)
- {
- timeout->tv_sec = 60;
- timeout->tv_usec = 0;
- }
- }
- else
- {
- timeout->tv_sec = 60;
- timeout->tv_usec = 0;
- }
- }
- /*
- * Main idle loop of postmaster
- */
- static int
- ServerLoop(void)
- {
- fd_set readmask;
- int nSockets;
- time_t now,
- last_touch_time;
- last_touch_time = time(NULL);
- nSockets = initMasks(&readmask);
- for (;;)
- {
- fd_set rmask;
- int selres;
- /*
- * Wait for a connection request to arrive.
- *
- * If we are in PM_WAIT_DEAD_END state, then we don't want to accept
- * any new connections, so we don't call select() at all; just sleep
- * for a little bit with signals unblocked.
- */
- memcpy((char *) &rmask, (char *) &readmask, sizeof(fd_set));
- PG_SETMASK(&UnBlockSig);
- if (pmState == PM_WAIT_DEAD_END)
- {
- pg_usleep(100000L); /* 100 msec seems reasonable */
- selres = 0;
- }
- else
- {
- /* must set timeout each time; some OSes change it! */
- struct timeval timeout;
- DetermineSleepTime(&timeout);
- selres = select(nSockets, &rmask, NULL, NULL, &timeout);
- }
- /*
- * Block all signals until we wait again. (This makes it safe for our
- * signal handlers to do nontrivial work.)
- */
- PG_SETMASK(&BlockSig);
- /* Now check the select() result */
- if (selres < 0)
- {
- if (errno != EINTR && errno != EWOULDBLOCK)
- {
- ereport(LOG,
- (errcode_for_socket_access(),
- errmsg("select() failed in postmaster: %m")));
- return STATUS_ERROR;
- }
- }
- /*
- * New connection pending on any of our sockets? If so, fork a child
- * process to deal with it.
- */
- if (selres > 0)
- {
- int i;
- for (i = 0; i < MAXLISTEN; i++)
- {
- if (ListenSocket[i] == PGINVALID_SOCKET)
- break;
- if (FD_ISSET(ListenSocket[i], &rmask))
- {
- Port *port;
- port = ConnCreate(ListenSocket[i]);
- if (port)
- {
- BackendStartup(port);
- /*
- * We no longer need the open socket or port structure
- * in this process
- */
- StreamClose(port->sock);
- ConnFree(port);
- }
- }
- }
- }
- /* If we have lost the log collector, try to start a new one */
- if (SysLoggerPID == 0 && Logging_collector)
- SysLoggerPID = SysLogger_Start();
- /*
- * If no background writer process is running, and we are not in a
- * state that prevents it, start one. It doesn't matter if this
- * fails, we'll just try again later. Likewise for the checkpointer.
- */
- if (pmState == PM_RUN || pmState == PM_RECOVERY ||
- pmState == PM_HOT_STANDBY)
- {
- if (CheckpointerPID == 0)
- CheckpointerPID = StartCheckpointer();
- if (BgWriterPID == 0)
- BgWriterPID = StartBackgroundWriter();
- }
- /*
- * Likewise, if we have lost the walwriter process, try to start a new
- * one. But this is needed only in normal operation (else we cannot
- * be writing any new WAL).
- */
- if (WalWriterPID == 0 && pmState == PM_RUN)
- WalWriterPID = StartWalWriter();
- /*
- * If we have lost the autovacuum launcher, try to start a new one. We
- * don't want autovacuum to run in binary upgrade mode because
- * autovacuum might update relfrozenxid for empty tables before the
- * physical files are put in place.
- */
- if (!IsBinaryUpgrade && AutoVacPID == 0 &&
- (AutoVacuumingActive() || start_autovac_launcher) &&
- pmState == PM_RUN)
- {
- AutoVacPID = StartAutoVacLauncher();
- if (AutoVacPID != 0)
- start_autovac_launcher = false; /* signal processed */
- }
- /* If we have lost the archiver, try to start a new one */
- if (XLogArchivingActive() && PgArchPID == 0 && pmState == PM_RUN)
- PgArchPID = pgarch_start();
- /* If we have lost the stats collector, try to start a new one */
- if (PgStatPID == 0 && pmState == PM_RUN)
- PgStatPID = pgstat_start();
- /* If we need to signal the autovacuum launcher, do so now */
- if (avlauncher_needs_signal)
- {
- avlauncher_needs_signal = false;
- if (AutoVacPID != 0)
- kill(AutoVacPID, SIGUSR2);
- }
- /* Get other worker processes running, if needed */
- if (StartWorkerNeeded || HaveCrashedWorker)
- maybe_start_bgworker();
- /*
- * Touch Unix socket and lock files every 58 minutes, to ensure that
- * they are not removed by overzealous /tmp-cleaning tasks. We assume
- * no one runs cleaners with cutoff times of less than an hour ...
- */
- now = time(NULL);
- if (now - last_touch_time >= 58 * SECS_PER_MINUTE)
- {
- TouchSocketFiles();
- TouchSocketLockFiles();
- last_touch_time = now;
- }
- /*
- * If we already sent SIGQUIT to children and they are slow to shut
- * down, it's time to send them SIGKILL. This doesn't happen
- * normally, but under certain conditions backends can get stuck while
- * shutting down. This is a last measure to get them unwedged.
- *
- * Note we also do this during recovery from a process crash.
- */
- if ((Shutdown >= ImmediateShutdown || (FatalError && !SendStop)) &&
- AbortStartTime > 0 &&
- now - AbortStartTime >= SIGKILL_CHILDREN_AFTER_SECS)
- {
- /* We were gentle with them before. Not anymore */
- TerminateChildren(SIGKILL);
- /* reset flag so we don't SIGKILL again */
- AbortStartTime = 0;
- /*
- * Additionally, unless we're recovering from a process crash,
- * it's now the time for postmaster to abandon ship.
- */
- if (!FatalError)
- ExitPostmaster(1);
- }
- }
- }
- /*
- * Initialise the masks for select() for the ports we are listening on.
- * Return the number of sockets to listen on.
- */
- static int
- initMasks(fd_set *rmask)
- {
- int maxsock = -1;
- int i;
- FD_ZERO(rmask);
- for (i = 0; i < MAXLISTEN; i++)
- {
- int fd = ListenSocket[i];
- if (fd == PGINVALID_SOCKET)
- break;
- FD_SET(fd, rmask);
- if (fd > maxsock)
- maxsock = fd;
- }
- return maxsock + 1;
- }
- /*
- * Read a client's startup packet and do something according to it.
- *
- * Returns STATUS_OK or STATUS_ERROR, or might call ereport(FATAL) and
- * not return at all.
- *
- * (Note that ereport(FATAL) stuff is sent to the client, so only use it
- * if that's what you want. Return STATUS_ERROR if you don't want to
- * send anything to the client, which would typically be appropriate
- * if we detect a communications failure.)
- */
- static int
- ProcessStartupPacket(Port *port, bool SSLdone)
- {
- int32 len;
- void *buf;
- ProtocolVersion proto;
- MemoryContext oldcontext;
- if (pq_getbytes((char *) &len, 4) == EOF)
- {
- /*
- * EOF after SSLdone probably means the client didn't like our
- * response to NEGOTIATE_SSL_CODE. That's not an error condition, so
- * don't clutter the log with a complaint.
- */
- if (!SSLdone)
- ereport(COMMERROR,
- (errcode(ERRCODE_PROTOCOL_VIOLATION),
- errmsg("incomplete startup packet")));
- return STATUS_ERROR;
- }
- len = ntohl(len);
- len -= 4;
- if (len < (int32) sizeof(ProtocolVersion) ||
- len > MAX_STARTUP_PACKET_LENGTH)
- {
- ereport(COMMERROR,
- (errcode(ERRCODE_PROTOCOL_VIOLATION),
- errmsg("invalid length of startup packet")));
- return STATUS_ERROR;
- }
- /*
- * Allocate at least the size of an old-style startup packet, plus one
- * extra byte, and make sure all are zeroes. This ensures we will have
- * null termination of all strings, in both fixed- and variable-length
- * packet layouts.
- */
- if (len <= (int32) sizeof(StartupPacket))
- buf = palloc0(sizeof(StartupPacket) + 1);
- else
- buf = palloc0(len + 1);
- if (pq_getbytes(buf, len) == EOF)
- {
- ereport(COMMERROR,
- (errcode(ERRCODE_PROTOCOL_VIOLATION),
- errmsg("incomplete startup packet")));
- return STATUS_ERROR;
- }
- /*
- * The first field is either a protocol version number or a special
- * request code.
- */
- port->proto = proto = ntohl(*((ProtocolVersion *) buf));
- if (proto == CANCEL_REQUEST_CODE)
- {
- processCancelRequest(port, buf);
- /* Not really an error, but we don't want to proceed further */
- return STATUS_ERROR;
- }
- if (proto == NEGOTIATE_SSL_CODE && !SSLdone)
- {
- char SSLok;
- #ifdef USE_SSL
- /* No SSL when disabled or on Unix sockets */
- if (!EnableSSL || IS_AF_UNIX(port->laddr.addr.ss_family))
- SSLok = 'N';
- else
- SSLok = 'S'; /* Support for SSL */
- #else
- SSLok = 'N'; /* No support for SSL */
- #endif
- retry1:
- if (send(port->sock, &SSLok, 1, 0) != 1)
- {
- if (errno == EINTR)
- goto retry1; /* if interrupted, just retry */
- ereport(COMMERROR,
- (errcode_for_socket_access(),
- errmsg("failed to send SSL negotiation response: %m")));
- return STATUS_ERROR; /* close the connection */
- }
- #ifdef USE_SSL
- if (SSLok == 'S' && secure_open_server(port) == -1)
- return STATUS_ERROR;
- #endif
- /* regular startup packet, cancel, etc packet should follow... */
- /* but not another SSL negotiation request */
- return ProcessStartupPacket(port, true);
- }
- /* Could add additional special packet types here */
- /*
- * Set FrontendProtocol now so that ereport() knows what format to send if
- * we fail during startup.
- */
- FrontendProtocol = proto;
- /* Check we can handle the protocol the frontend is using. */
- if (PG_PROTOCOL_MAJOR(proto) < PG_PROTOCOL_MAJOR(PG_PROTOCOL_EARLIEST) ||
- PG_PROTOCOL_MAJOR(proto) > PG_PROTOCOL_MAJOR(PG_PROTOCOL_LATEST) ||
- (PG_PROTOCOL_MAJOR(proto) == PG_PROTOCOL_MAJOR(PG_PROTOCOL_LATEST) &&
- PG_PROTOCOL_MINOR(proto) > PG_PROTOCOL_MINOR(PG_PROTOCOL_LATEST)))
- ereport(FATAL,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("unsupported frontend protocol %u.%u: server supports %u.0 to %u.%u",
- PG_PROTOCOL_MAJOR(proto), PG_PROTOCOL_MINOR(proto),
- PG_PROTOCOL_MAJOR(PG_PROTOCOL_EARLIEST),
- PG_PROTOCOL_MAJOR(PG_PROTOCOL_LATEST),
- PG_PROTOCOL_MINOR(PG_PROTOCOL_LATEST))));
- /*
- * Now fetch parameters out of startup packet and save them into the Port
- * structure. All data structures attached to the Port struct must be
- * allocated in TopMemoryContext so that they will remain available in a
- * running backend (even after PostmasterContext is destroyed). We need
- * not worry about leaking this storage on failure, since we aren't in the
- * postmaster process anymore.
- */
- oldcontext = MemoryContextSwitchTo(TopMemoryContext);
- if (PG_PROTOCOL_MAJOR(proto) >= 3)
- {
- int32 offset = sizeof(ProtocolVersion);
- /*
- * Scan packet body for name/option pairs. We can assume any string
- * beginning within the packet body is null-terminated, thanks to
- * zeroing extra byte above.
- */
- port->guc_options = NIL;
- while (offset < len)
- {
- char *nameptr = ((char *) buf) + offset;
- int32 valoffset;
- char *valptr;
- if (*nameptr == '\0')
- break; /* found packet terminator */
- valoffset = offset + strlen(nameptr) + 1;
- if (valoffset >= len)
- break; /* missing value, will complain below */
- valptr = ((char *) buf) + valoffset;
- if (strcmp(nameptr, "database") == 0)
- port->database_name = pstrdup(valptr);
- else if (strcmp(nameptr, "user") == 0)
- port->user_name = pstrdup(valptr);
- else if (strcmp(nameptr, "options") == 0)
- port->cmdline_options = pstrdup(valptr);
- else if (strcmp(nameptr, "replication") == 0)
- {
- /*
- * Due to backward compatibility concerns the replication
- * parameter is a hybrid beast which allows the value to be
- * either boolean or the string 'database'. The latter
- * connects to a specific database which is e.g. required for
- * logical decoding while.
- */
- if (strcmp(valptr, "database") == 0)
- {
- am_walsender = true;
- am_db_walsender = true;
- }
- else if (!parse_bool(valptr, &am_walsender))
- ereport(FATAL,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("invalid value for parameter \"replication\""),
- errhint("Valid values are: false, 0, true, 1, database.")));
- }
- else
- {
- /* Assume it's a generic GUC option */
- port->guc_options = lappend(port->guc_options,
- pstrdup(nameptr));
- port->guc_options = lappend(port->guc_options,
- pstrdup(valptr));
- }
- offset = valoffset + strlen(valptr) + 1;
- }
- /*
- * If we didn't find a packet terminator exactly at the end of the
- * given packet length, complain.
- */
- if (offset != len - 1)
- ereport(FATAL,
- (errcode(ERRCODE_PROTOCOL_VIOLATION),
- errmsg("invalid startup packet layout: expected terminator as last byte")));
- }
- else
- {
- /*
- * Get the parameters from the old-style, fixed-width-fields startup
- * packet as C strings. The packet destination was cleared first so a
- * short packet has zeros silently added. We have to be prepared to
- * truncate the pstrdup result for oversize fields, though.
- */
- StartupPacket *packet = (StartupPacket *) buf;
- port->database_name = pstrdup(packet->database);
- if (strlen(port->database_name) > sizeof(packet->database))
- port->database_name[sizeof(packet->database)] = '\0';
- port->user_name = pstrdup(packet->user);
- if (strlen(port->user_name) > sizeof(packet->user))
- port->user_name[sizeof(packet->user)] = '\0';
- port->cmdline_options = pstrdup(packet->options);
- if (strlen(port->cmdline_options) > sizeof(packet->options))
- port->cmdline_options[sizeof(packet->options)] = '\0';
- port->guc_options = NIL;
- }
- /* Check a user name was given. */
- if (port->user_name == NULL || port->user_name[0] == '\0')
- ereport(FATAL,
- (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
- errmsg("no PostgreSQL user name specified in startup packet")));
- /* The database defaults to the user name. */
- if (port->database_name == NULL || port->database_name[0] == '\0')
- port->database_name = pstrdup(port->user_name);
- if (Db_user_namespace)
- {
- /*
- * If user@, it is a global user, remove '@'. We only want to do this
- * if there is an '@' at the end and no earlier in the user string or
- * they may fake as a local user of another database attaching to this
- * database.
- */
- if (strchr(port->user_name, '@') ==
- port->user_name + strlen(port->user_name) - 1)
- *strchr(port->user_name, '@') = '\0';
- else
- {
- /* Append '@' and dbname */
- port->user_name = psprintf("%s@%s", port->user_name, port->database_name);
- }
- }
- /*
- * Truncate given database and user names to length of a Postgres name.
- * This avoids lookup failures when overlength names are given.
- */
- if (strlen(port->database_name) >= NAMEDATALEN)
- port->database_name[NAMEDATALEN - 1] = '\0';
- if (strlen(port->user_name) >= NAMEDATALEN)
- port->user_name[NAMEDATALEN - 1] = '\0';
- /*
- * Normal walsender backends, e.g. for streaming replication, are not
- * connected to a particular database. But walsenders used for logical
- * replication need to connect to a specific database. We allow streaming
- * replication commands to be issued even if connected to a database as it
- * can make sense to first make a basebackup and then stream changes
- * starting from that.
- */
- if (am_walsender && !am_db_walsender)
- port->database_name[0] = '\0';
- /*
- * Done putting stuff in TopMemoryContext.
- */
- MemoryContextSwitchTo(oldcontext);
- /*
- * If we're going to reject the connection due to database state, say so
- * now instead of wasting cycles on an authentication exchange. (This also
- * allows a pg_ping utility to be written.)
- */
- switch (port->canAcceptConnections)
- {
- case CAC_STARTUP:
- ereport(FATAL,
- (errcode(ERRCODE_CANNOT_CONNECT_NOW),
- errmsg("the database system is starting up")));
- break;
- case CAC_SHUTDOWN:
- ereport(FATAL,
- (errcode(ERRCODE_CANNOT_CONNECT_NOW),
- errmsg("the database system is shutting down")));
- break;
- case CAC_RECOVERY:
- ereport(FATAL,
- (errcode(ERRCODE_CANNOT_CONNECT_NOW),
- errmsg("the database system is in recovery mode")));
- break;
- case CAC_TOOMANY:
- ereport(FATAL,
- (errcode(ERRCODE_TOO_MANY_CONNECTIONS),
- errmsg("sorry, too many clients already")));
- break;
- case CAC_WAITBACKUP:
- /* OK for now, will check in InitPostgres */
- break;
- case CAC_OK:
- break;
- }
- return STATUS_OK;
- }
- /*
- * The client has sent a cancel request packet, not a normal
- * start-a-new-connection packet. Perform the necessary processing.
- * Nothing is sent back to the client.
- */
- static void
- processCancelRequest(Port *port, void *pkt)
- {
- CancelRequestPacket *canc = (CancelRequestPacket *) pkt;
- int backendPID;
- long cancelAuthCode;
- Backend *bp;
- #ifndef EXEC_BACKEND
- dlist_iter iter;
- #else
- int i;
- #endif
- backendPID = (int) ntohl(canc->backendPID);
- cancelAuthCode = (long) ntohl(canc->cancelAuthCode);
- /*
- * See if we have a matching backend. In the EXEC_BACKEND case, we can no
- * longer access the postmaster's own backend list, and must rely on the
- * duplicate array in shared memory.
- */
- #ifndef EXEC_BACKEND
- dlist_foreach(iter, &BackendList)
- {
- bp = dlist_container(Backend, elem, iter.cur);
- #else
- for (i = MaxLivePostmasterChildren() - 1; i >= 0; i--)
- {
- bp = (Backend *) &ShmemBackendArray[i];
- #endif
- if (bp->pid == backendPID)
- {
- if (bp->cancel_key == cancelAuthCode)
- {
- /* Found a match; signal that backend to cancel current op */
- ereport(DEBUG2,
- (errmsg_internal("processing cancel request: sending SIGINT to process %d",
- backendPID)));
- signal_child(bp->pid, SIGINT);
- }
- else
- /* Right PID, wrong key: no way, Jose */
- ereport(LOG,
- (errmsg("wrong key in cancel request for process %d",
- backendPID)));
- return;
- }
- }
- /* No matching backend */
- ereport(LOG,
- (errmsg("PID %d in cancel request did not match any process",
- backendPID)));
- }
- /*
- * canAcceptConnections --- check to see if database state allows connections.
- */
- static CAC_state
- canAcceptConnections(void)
- {
- CAC_state result = CAC_OK;
- /*
- * Can't start backends when in startup/shutdown/inconsistent recovery
- * state.
- *
- * In state PM_WAIT_BACKUP only superusers can connect (this must be
- * allowed so that a superuser can end online backup mode); we return
- * CAC_WAITBACKUP code to indicate that this must be checked later. Note
- * that neither CAC_OK nor CAC_WAITBACKUP can safely be returned until we
- * have checked for too many children.
- */
- if (pmState != PM_RUN)
- {
- if (pmState == PM_WAIT_BACKUP)
- result = CAC_WAITBACKUP; /* allow superusers only */
- else if (Shutdown > NoShutdown)
- return CAC_SHUTDOWN; /* shutdown is pending */
- else if (!FatalError &&
- (pmState == PM_STARTUP ||
- pmState == PM_RECOVERY))
- return CAC_STARTUP; /* normal startup */
- else if (!FatalError &&
- pmState == PM_HOT_STANDBY)
- result = CAC_OK; /* connection OK during hot standby */
- else
- return CAC_RECOVERY; /* else must be crash recovery */
- }
- /*
- * Don't start too many children.
- *
- * We allow more connections than we can have backends here because some
- * might still be authenticating; they might fail auth, or some existing
- * backend might exit before the auth cycle is completed. The exact
- * MaxBackends limit is enforced when a new backend tries to join the
- * shared-inval backend array.
- *
- * The limit here must match the sizes of the per-child-process arrays;
- * see comments for MaxLivePostmasterChildren().
- */
- if (CountChildren(BACKEND_TYPE_ALL) >= MaxLivePostmasterChildren())
- result = CAC_TOOMANY;
- return result;
- }
- /*
- * ConnCreate -- create a local connection data structure
- *
- * Returns NULL on failure, other than out-of-memory which is fatal.
- */
- static Port *
- ConnCreate(int serverFd)
- {
- Port *port;
- if (!(port = (Port *) calloc(1, sizeof(Port))))
- {
- ereport(LOG,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("out of memory")));
- ExitPostmaster(1);
- }
- if (StreamConnection(serverFd, port) != STATUS_OK)
- {
- if (port->sock != PGINVALID_SOCKET)
- StreamClose(port->sock);
- ConnFree(port);
- return NULL;
- }
- /*
- * Precompute password salt values to use for this connection. It's
- * slightly annoying to do this long in advance of knowing whether we'll
- * need 'em or not, but we must do the random() calls before we fork, not
- * after. Else the postmaster's random sequence won't get advanced, and
- * all backends would end up using the same salt...
- */
- RandomSalt(port->md5Salt);
- /*
- * Allocate GSSAPI specific state struct
- */
- #ifndef EXEC_BACKEND
- #if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
- port->gss = (pg_gssinfo *) calloc(1, sizeof(pg_gssinfo));
- if (!port->gss)
- {
- ereport(LOG,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("out of memory")));
- ExitPostmaster(1);
- }
- #endif
- #endif
- return port;
- }
- /*
- * ConnFree -- free a local connection data structure
- */
- static void
- ConnFree(Port *conn)
- {
- #ifdef USE_SSL
- secure_close(conn);
- #endif
- if (conn->gss)
- free(conn->gss);
- free(conn);
- }
- /*
- * ClosePostmasterPorts -- close all the postmaster's open sockets
- *
- * This is called during child process startup to release file descriptors
- * that are not needed by that child process. The postmaster still has
- * them open, of course.
- *
- * Note: we pass am_syslogger as a boolean because we don't want to set
- * the global variable yet when this is called.
- */
- void
- ClosePostmasterPorts(bool am_syslogger)
- {
- int i;
- #ifndef WIN32
- /*
- * Close the write end of postmaster death watch pipe. It's important to
- * do this as early as possible, so that if postmaster dies, others won't
- * think that it's still running because we're holding the pipe open.
- */
- if (close(postmaster_alive_fds[POSTMASTER_FD_OWN]))
- ereport(FATAL,
- (errcode_for_file_access(),
- errmsg_internal("could not close postmaster death monitoring pipe in child process: %m")));
- postmaster_alive_fds[POSTMASTER_FD_OWN] = -1;
- #endif
- /* Close the listen sockets */
- for (i = 0; i < MAXLISTEN; i++)
- {
- if (ListenSocket[i] != PGINVALID_SOCKET)
- {
- StreamClose(ListenSocket[i]);
- ListenSocket[i] = PGINVALID_SOCKET;
- }
- }
- /* If using syslogger, close the read side of the pipe */
- if (!am_syslogger)
- {
- #ifndef WIN32
- if (syslogPipe[0] >= 0)
- close(syslogPipe[0]);
- syslogPipe[0] = -1;
- #else
- if (syslogPipe[0])
- CloseHandle(syslogPipe[0]);
- syslogPipe[0] = 0;
- #endif
- }
- #ifdef USE_BONJOUR
- /* If using Bonjour, close the connection to the mDNS daemon */
- if (bonjour_sdref)
- close(DNSServiceRefSockFD(bonjour_sdref));
- #endif
- }
- /*
- * reset_shared -- reset shared memory and semaphores
- */
- static void
- reset_shared(int port)
- {
- /*
- * Create or re-create shared memory and semaphores.
- *
- * Note: in each "cycle of life" we will normally assign the same IPC keys
- * (if using SysV shmem and/or semas), since the port number is used to
- * determine IPC keys. This helps ensure that we will clean up dead IPC
- * objects if the postmaster crashes and is restarted.
- */
- CreateSharedMemoryAndSemaphores(false, port);
- }
- /*
- * SIGHUP -- reread config files, and tell children to do same
- */
- static void
- SIGHUP_handler(SIGNAL_ARGS)
- {
- int save_errno = errno;
- PG_SETMASK(&BlockSig);
- if (Shutdown <= SmartShutdown)
- {
- ereport(LOG,
- (errmsg("received SIGHUP, reloading configuration files")));
- ProcessConfigFile(PGC_SIGHUP);
- SignalChildren(SIGHUP);
- SignalUnconnectedWorkers(SIGHUP);
- if (StartupPID != 0)
- signal_child(StartupPID, SIGHUP);
- if (BgWriterPID != 0)
- signal_child(BgWriterPID, SIGHUP);
- if (CheckpointerPID != 0)
- signal_child(CheckpointerPID, SIGHUP);
- if (WalWriterPID != 0)
- signal_child(WalWriterPID, SIGHUP);
- if (WalReceiverPID != 0)
- signal_child(WalReceiverPID, SIGHUP);
- if (AutoVacPID != 0)
- signal_child(AutoVacPID, SIGHUP);
- if (PgArchPID != 0)
- signal_child(PgArchPID, SIGHUP);
- if (SysLoggerPID != 0)
- signal_child(SysLoggerPID, SIGHUP);
- if (PgStatPID != 0)
- signal_child(PgStatPID, SIGHUP);
- /* Reload authentication config files too */
- if (!load_hba())
- ereport(WARNING,
- (errmsg("pg_hba.conf not reloaded")));
- if (!load_ident())
- ereport(WARNING,
- (errmsg("pg_ident.conf not reloaded")));
- #ifdef EXEC_BACKEND
- /* Update the starting-point file for future children */
- write_nondefault_variables(PGC_SIGHUP);
- #endif
- }
- PG_SETMASK(&UnBlockSig);
- errno = save_errno;
- }
- /*
- * pmdie -- signal handler for processing various postmaster signals.
- */
- static void
- pmdie(SIGNAL_ARGS)
- {
- int save_errno = errno;
- PG_SETMASK(&BlockSig);
- ereport(DEBUG2,
- (errmsg_internal("postmaster received signal %d",
- postgres_signal_arg)));
- switch (postgres_signal_arg)
- {
- case SIGTERM:
- /*
- * Smart Shutdown:
- *
- * Wait for children to end their work, then shut down.
- */
- if (Shutdown >= SmartShutdown)
- break;
- Shutdown = SmartShutdown;
- ereport(LOG,
- (errmsg("received smart shutdown request")));
- if (pmState == PM_RUN || pmState == PM_RECOVERY ||
- pmState == PM_HOT_STANDBY || pmState == PM_STARTUP)
- {
- /* autovac workers are told to shut down immediately */
- /* and bgworkers too; does this need tweaking? */
- SignalSomeChildren(SIGTERM,
- BACKEND_TYPE_AUTOVAC | BACKEND_TYPE_BGWORKER);
- SignalUnconnectedWorkers(SIGTERM);
- /* and the autovac launcher too */
- if (AutoVacPID != 0)
- signal_child(AutoVacPID, SIGTERM);
- /* and the bgwriter too */
- if (BgWriterPID != 0)
- signal_child(BgWriterPID, SIGTERM);
- /* and the walwriter too */
- if (WalWriterPID != 0)
- signal_child(WalWriterPID, SIGTERM);
- /*
- * If we're in recovery, we can't kill the startup process
- * right away, because at present doing so does not release
- * its locks. We might want to change this in a future
- * release. For the time being, the PM_WAIT_READONLY state
- * indicates that we're waiting for the regular (read only)
- * backends to die off; once they do, we'll kill the startup
- * and walreceiver processes.
- */
- pmState = (pmState == PM_RUN) ?
- PM_WAIT_BACKUP : PM_WAIT_READONLY;
- }
- /*
- * Now wait for online backup mode to end and backends to exit. If
- * that is already the case, PostmasterStateMachine will take the
- * next step.
- */
- PostmasterStateMachine();
- break;
- case SIGINT:
- /*
- * Fast Shutdown:
- *
- * Abort all children with SIGTERM (rollback active transactions
- * and exit) and shut down when they are gone.
- */
- if (Shutdown >= FastShutdown)
- break;
- Shutdown = FastShutdown;
- ereport(LOG,
- (errmsg("received fast shutdown request")));
- if (StartupPID != 0)
- signal_child(StartupPID, SIGTERM);
- if (BgWriterPID != 0)
- signal_child(BgWriterPID, SIGTERM);
- if (WalReceiverPID != 0)
- signal_child(WalReceiverPID, SIGTERM);
- SignalUnconnectedWorkers(SIGTERM);
- if (pmState == PM_RECOVERY)
- {
- /*
- * Only startup, bgwriter, walreceiver, unconnected bgworkers,
- * and/or checkpointer should be active in this state; we just
- * signaled the first four, and we don't want to kill
- * checkpointer yet.
- */
- pmState = PM_WAIT_BACKENDS;
- }
- else if (pmState == PM_RUN ||
- pmState == PM_WAIT_BACKUP ||
- pmState == PM_WAIT_READONLY ||
- pmState == PM_WAIT_BACKENDS ||
- pmState == PM_HOT_STANDBY)
- {
- ereport(LOG,
- (errmsg("aborting any active transactions")));
- /* shut down all backends and workers */
- SignalSomeChildren(SIGTERM,
- BACKEND_TYPE_NORMAL | BACKEND_TYPE_AUTOVAC |
- BACKEND_TYPE_BGWORKER);
- /* and the autovac launcher too */
- if (AutoVacPID != 0)
- signal_child(AutoVacPID, SIGTERM);
- /* and the walwriter too */
- if (WalWriterPID != 0)
- signal_child(WalWriterPID, SIGTERM);
- pmState = PM_WAIT_BACKENDS;
- }
- /*
- * Now wait for backends to exit. If there are none,
- * PostmasterStateMachine will take the next step.
- */
- PostmasterStateMachine();
- break;
- case SIGQUIT:
- /*
- * Immediate Shutdown:
- *
- * abort all children with SIGQUIT, wait for them to exit,
- * terminate remaining ones with SIGKILL, then exit without
- * attempt to properly shut down the data base system.
- */
- if (Shutdown >= ImmediateShutdown)
- break;
- Shutdown = ImmediateShutdown;
- ereport(LOG,
- (errmsg("received immediate shutdown request")));
- TerminateChildren(SIGQUIT);
- pmState = PM_WAIT_BACKENDS;
- /* set stopwatch for them to die */
- AbortStartTime = time(NULL);
- /*
- * Now wait for backends to exit. If there are none,
- * PostmasterStateMachine will take the next step.
- */
- PostmasterStateMachine();
- break;
- }
- PG_SETMASK(&UnBlockSig);
- errno = save_errno;
- }
- /*
- * Reaper -- signal handler to cleanup after a child process dies.
- */
- static void
- reaper(SIGNAL_ARGS)
- {
- int save_errno = errno;
- int pid; /* process id of dead child process */
- int exitstatus; /* its exit status */
- PG_SETMASK(&BlockSig);
- ereport(DEBUG4,
- (errmsg_internal("reaping dead processes")));
- while ((pid = waitpid(-1, &exitstatus, WNOHANG)) > 0)
- {
- /*
- * Check if this child was a startup process.
- */
- if (pid == StartupPID)
- {
- StartupPID = 0;
- /*
- * Startup process exited in response to a shutdown request (or it
- * completed normally regardless of the shutdown request).
- */
- if (Shutdown > NoShutdown &&
- (EXIT_STATUS_0(exitstatus) || EXIT_STATUS_1(exitstatus)))
- {
- pmState = PM_WAIT_BACKENDS;
- /* PostmasterStateMachine logic does the rest */
- continue;
- }
- /*
- * Unexpected exit of startup process (including FATAL exit)
- * during PM_STARTUP is treated as catastrophic. There are no
- * other processes running yet, so we can just exit.
- */
- if (pmState == PM_STARTUP && !EXIT_STATUS_0(exitstatus))
- {
- LogChildExit(LOG, _("startup process"),
- pid, exitstatus);
- ereport(LOG,
- (errmsg("aborting startup due to startup process failure")));
- ExitPostmaster(1);
- }
- /*
- * After PM_STARTUP, any unexpected exit (including FATAL exit) of
- * the startup process is catastrophic, so kill other children,
- * and set RecoveryError so we don't try to reinitialize after
- * they're gone. Exception: if FatalError is already set, that
- * implies we previously sent the startup process a SIGQUIT, so
- * that's probably the reason it died, and we do want to try to
- * restart in that case.
- */
- if (!EXIT_STATUS_0(exitstatus))
- {
- if (!FatalError)
- RecoveryError = true;
- HandleChildCrash(pid, exitstatus,
- _("startup process"));
- continue;
- }
- /*
- * Startup succeeded, commence normal operations
- */
- FatalError = false;
- Assert(AbortStartTime == 0);
- ReachedNormalRunning = true;
- pmState = PM_RUN;
- /*
- * Crank up the background tasks, if we didn't do that already
- * when we entered consistent recovery state. It doesn't matter
- * if this fails, we'll just try again later.
- */
- if (CheckpointerPID == 0)
- CheckpointerPID = StartCheckpointer();
- if (BgWriterPID == 0)
- BgWriterPID = StartBackgroundWriter();
- if (WalWriterPID == 0)
- WalWriterPID = StartWalWriter();
- /*
- * Likewise, start other special children as needed. In a restart
- * situation, some of them may be alive already.
- */
- if (!IsBinaryUpgrade && AutoVacuumingActive() && AutoVacPID == 0)
- AutoVacPID = StartAutoVacLauncher();
- if (XLogArchivingActive() && PgArchPID == 0)
- PgArchPID = pgarch_start();
- if (PgStatPID == 0)
- PgStatPID = pgstat_start();
- /* workers may be scheduled to start now */
- maybe_start_bgworker();
- /* at this point we are really open for business */
- ereport(LOG,
- (errmsg("database system is ready to accept connections")));
- continue;
- }
- /*
- * Was it the bgwriter? Normal exit can be ignored; we'll start a new
- * one at the next iteration of the postmaster's main loop, if
- * necessary. Any other exit condition is treated as a crash.
- */
- if (pid == BgWriterPID)
- {
- BgWriterPID = 0;
- if (!EXIT_STATUS_0(exitstatus))
- HandleChildCrash(pid, exitstatus,
- _("background writer process"));
- continue;
- }
- /*
- * Was it the checkpointer?
- */
- if (pid == CheckpointerPID)
- {
- CheckpointerPID = 0;
- if (EXIT_STATUS_0(exitstatus) && pmState == PM_SHUTDOWN)
- {
- /*
- * OK, we saw normal exit of the checkpointer after it's been
- * told to shut down. We expect that it wrote a shutdown
- * checkpoint. (If for some reason it didn't, recovery will
- * occur on next postmaster start.)
- *
- * At this point we should have no normal backend children
- * left (else we'd not be in PM_SHUTDOWN state) but we might
- * have dead_end children to wait for.
- *
- * If we have an archiver subprocess, tell it to do a last
- * archive cycle and quit. Likewise, if we have walsender
- * processes, tell them to send any remaining WAL and quit.
- */
- Assert(Shutdown > NoShutdown);
- /* Waken archiver for the last time */
- if (PgArchPID != 0)
- signal_child(PgArchPID, SIGUSR2);
- /*
- * Waken walsenders for the last time. No regular backends
- * should be around anymore.
- */
- SignalChildren(SIGUSR2);
- pmState = PM_SHUTDOWN_2;
- /*
- * We can also shut down the stats collector now; there's
- * nothing left for it to do.
- */
- if (PgStatPID != 0)
- signal_child(PgStatPID, SIGQUIT);
- }
- else
- {
- /*
- * Any unexpected exit of the checkpointer (including FATAL
- * exit) is treated as a crash.
- */
- HandleChildCrash(pid, exitstatus,
- _("checkpointer process"));
- }
- continue;
- }
- /*
- * Was it the wal writer? Normal exit can be ignored; we'll start a
- * new one at the next iteration of the postmaster's main loop, if
- * necessary. Any other exit condition is treated as a crash.
- */
- if (pid == WalWriterPID)
- {
- WalWriterPID = 0;
- if (!EXIT_STATUS_0(exitstatus))
- HandleChildCrash(pid, exitstatus,
- _("WAL writer process"));
- continue;
- }
- /*
- * Was it the wal receiver? If exit status is zero (normal) or one
- * (FATAL exit), we assume everything is all right just like normal
- * backends.
- */
- if (pid == WalReceiverPID)
- {
- WalReceiverPID = 0;
- if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
- HandleChildCrash(pid, exitstatus,
- _("WAL receiver process"));
- continue;
- }
- /*
- * Was it the autovacuum launcher? Normal exit can be ignored; we'll
- * start a new one at the next iteration of the postmaster's main
- * loop, if necessary. Any other exit condition is treated as a
- * crash.
- */
- if (pid == AutoVacPID)
- {
- AutoVacPID = 0;
- if (!EXIT_STATUS_0(exitstatus))
- HandleChildCrash(pid, exitstatus,
- _("autovacuum launcher process"));
- continue;
- }
- /*
- * Was it the archiver? If so, just try to start a new one; no need
- * to force reset of the rest of the system. (If fail, we'll try
- * again in future cycles of the main loop.). Unless we were waiting
- * for it to shut down; don't restart it in that case, and
- * PostmasterStateMachine() will advance to the next shutdown step.
- */
- if (pid == PgArchPID)
- {
- PgArchPID = 0;
- if (!EXIT_STATUS_0(exitstatus))
- LogChildExit(LOG, _("archiver process"),
- pid, exitstatus);
- if (XLogArchivingActive() && pmState == PM_RUN)
- PgArchPID = pgarch_start();
- continue;
- }
- /*
- * Was it the statistics collector? If so, just try to start a new
- * one; no need to force reset of the rest of the system. (If fail,
- * we'll try again in future cycles of the main loop.)
- */
- if (pid == PgStatPID)
- {
- PgStatPID = 0;
- if (!EXIT_STATUS_0(exitstatus))
- LogChildExit(LOG, _("statistics collector process"),
- pid, exitstatus);
- if (pmState == PM_RUN)
- PgStatPID = pgstat_start();
- continue;
- }
- /* Was it the system logger? If so, try to start a new one */
- if (pid == SysLoggerPID)
- {
- SysLoggerPID = 0;
- /* for safety's sake, launch new logger *first* */
- SysLoggerPID = SysLogger_Start();
- if (!EXIT_STATUS_0(exitstatus))
- LogChildExit(LOG, _("system logger process"),
- pid, exitstatus);
- continue;
- }
- /* Was it one of our background workers? */
- if (CleanupBackgroundWorker(pid, exitstatus))
- {
- /* have it be restarted */
- HaveCrashedWorker = true;
- continue;
- }
- /*
- * Else do standard backend child cleanup.
- */
- CleanupBackend(pid, exitstatus);
- } /* loop over pending child-death reports */
- /*
- * After cleaning out the SIGCHLD queue, see if we have any state changes
- * or actions to make.
- */
- PostmasterStateMachine();
- /* Done with signal handler */
- PG_SETMASK(&UnBlockSig);
- errno = save_errno;
- }
- /*
- * Scan the bgworkers list and see if the given PID (which has just stopped
- * or crashed) is in it. Handle its shutdown if so, and return true. If not a
- * bgworker, return false.
- *
- * This is heavily based on CleanupBackend. One important difference is that
- * we don't know yet that the dying process is a bgworker, so we must be silent
- * until we're sure it is.
- */
- static bool
- CleanupBackgroundWorker(int pid,
- int exitstatus) /* child's exit status */
- {
- char namebuf[MAXPGPATH];
- slist_iter iter;
- slist_foreach(iter, &BackgroundWorkerList)
- {
- RegisteredBgWorker *rw;
- rw = slist_container(RegisteredBgWorker, rw_lnode, iter.cur);
- if (rw->rw_pid != pid)
- continue;
- #ifdef WIN32
- /* see CleanupBackend */
- if (exitstatus == ERROR_WAIT_NO_CHILDREN)
- exitstatus = 0;
- #endif
- snprintf(namebuf, MAXPGPATH, "%s: %s", _("worker process"),
- rw->rw_worker.bgw_name);
- if (!EXIT_STATUS_0(exitstatus))
- {
- /* Record timestamp, so we know when to restart the worker. */
- rw->rw_crashed_at = GetCurrentTimestamp();
- }
- else
- {
- /* Zero exit status means terminate */
- rw->rw_crashed_at = 0;
- rw->rw_terminate = true;
- }
- /*
- * Additionally, for shared-memory-connected workers, just like a
- * backend, any exit status other than 0 or 1 is considered a crash
- * and causes a system-wide restart.
- */
- if ((rw->rw_worker.bgw_flags & BGWORKER_SHMEM_ACCESS) != 0)
- {
- if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
- {
- HandleChildCrash(pid, exitstatus, namebuf);
- return true;
- }
- }
- /*
- * We must release the postmaster child slot whether this worker
- * is connected to shared memory or not, but we only treat it as
- * a crash if it is in fact connected.
- */
- if (!ReleasePostmasterChildSlot(rw->rw_child_slot) &&
- (rw->rw_worker.bgw_flags & BGWORKER_SHMEM_ACCESS) != 0)
- {
- HandleChildCrash(pid, exitstatus, namebuf);
- return true;
- }
- /* Get it out of the BackendList and clear out remaining data */
- if (rw->rw_backend)
- {
- Assert(rw->rw_worker.bgw_flags & BGWORKER_BACKEND_DATABASE_CONNECTION);
- dlist_delete(&rw->rw_backend->elem);
- #ifdef EXEC_BACKEND
- ShmemBackendArrayRemove(rw->rw_backend);
- #endif
- /*
- * It's possible that this background worker started some OTHER
- * background worker and asked to be notified when that worker
- * started or stopped. If so, cancel any notifications destined
- * for the now-dead backend.
- */
- if (rw->rw_backend->bgworker_notify)
- BackgroundWorkerStopNotifications(rw->rw_pid);
- free(rw->rw_backend);
- rw->rw_backend = NULL;
- }
- rw->rw_pid = 0;
- rw->rw_child_slot = 0;
- ReportBackgroundWorkerPID(rw); /* report child death */
- LogChildExit(LOG, namebuf, pid, exitstatus);
- return true;
- }
- return false;
- }
- /*
- * CleanupBackend -- cleanup after terminated backend.
- *
- * Remove all local state associated with backend.
- *
- * If you change this, see also CleanupBackgroundWorker.
- */
- static void
- CleanupBackend(int pid,
- int exitstatus) /* child's exit status. */
- {
- dlist_mutable_iter iter;
- LogChildExit(DEBUG2, _("server process"), pid, exitstatus);
- /*
- * If a backend dies in an ugly way then we must signal all other backends
- * to quickdie. If exit status is zero (normal) or one (FATAL exit), we
- * assume everything is all right and proceed to remove the backend from
- * the active backend list.
- */
- #ifdef WIN32
- /*
- * On win32, also treat ERROR_WAIT_NO_CHILDREN (128) as nonfatal case,
- * since that sometimes happens under load when the process fails to start
- * properly (long before it starts using shared memory). Microsoft reports
- * it is related to mutex failure:
- * http://archives.postgresql.org/pgsql-hackers/2010-09/msg00790.php
- */
- if (exitstatus == ERROR_WAIT_NO_CHILDREN)
- {
- LogChildExit(LOG, _("server process"), pid, exitstatus);
- exitstatus = 0;
- }
- #endif
- if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
- {
- HandleChildCrash(pid, exitstatus, _("server process"));
- return;
- }
- dlist_foreach_modify(iter, &BackendList)
- {
- Backend *bp = dlist_container(Backend, elem, iter.cur);
- if (bp->pid == pid)
- {
- if (!bp->dead_end)
- {
- if (!ReleasePostmasterChildSlot(bp->child_slot))
- {
- /*
- * Uh-oh, the child failed to clean itself up. Treat as a
- * crash after all.
- */
- HandleChildCrash(pid, exitstatus, _("server process"));
- return;
- }
- #ifdef EXEC_BACKEND
- ShmemBackendArrayRemove(bp);
- #endif
- }
- if (bp->bgworker_notify)
- {
- /*
- * This backend may have been slated to receive SIGUSR1 when
- * some background worker started or stopped. Cancel those
- * notifications, as we don't want to signal PIDs that are not
- * PostgreSQL backends. This gets skipped in the (probably
- * very common) case where the backend has never requested any
- * such notifications.
- */
- BackgroundWorkerStopNotifications(bp->pid);
- }
- dlist_delete(iter.cur);
- free(bp);
- break;
- }
- }
- }
- /*
- * HandleChildCrash -- cleanup after failed backend, bgwriter, checkpointer,
- * walwriter, autovacuum, or background worker.
- *
- * The objectives here are to clean up our local state about the child
- * process, and to signal all other remaining children to quickdie.
- */
- static void
- HandleChildCrash(int pid, int exitstatus, const char *procname)
- {
- dlist_mutable_iter iter;
- slist_iter siter;
- Backend *bp;
- bool take_action;
- /*
- * We only log messages and send signals if this is the first process
- * crash and we're not doing an immediate shutdown; otherwise, we're only
- * here to update postmaster's idea of live processes. If we have already
- * signalled children, nonzero exit status is to be expected, so don't
- * clutter log.
- */
- take_action = !FatalError && Shutdown != ImmediateShutdown;
- if (take_action)
- {
- LogChildExit(LOG, procname, pid, exitstatus);
- ereport(LOG,
- (errmsg("terminating any other active server processes")));
- }
- /* Process background workers. */
- slist_foreach(siter, &BackgroundWorkerList)
- {
- RegisteredBgWorker *rw;
- rw = slist_container(RegisteredBgWorker, rw_lnode, siter.cur);
- if (rw->rw_pid == 0)
- continue; /* not running */
- if (rw->rw_pid == pid)
- {
- /*
- * Found entry for freshly-dead worker, so remove it.
- */
- (void) ReleasePostmasterChildSlot(rw->rw_child_slot);
- if (rw->rw_backend)
- {
- dlist_delete(&rw->rw_backend->elem);
- #ifdef EXEC_BACKEND
- ShmemBackendArrayRemove(rw->rw_backend);
- #endif
- free(rw->rw_backend);
- rw->rw_backend = NULL;
- }
- rw->rw_pid = 0;
- rw->rw_child_slot = 0;
- /* don't reset crashed_at */
- /* don't report child stop, either */
- /* Keep looping so we can signal remaining workers */
- }
- else
- {
- /*
- * This worker is still alive. Unless we did so already, tell it
- * to commit hara-kiri.
- *
- * SIGQUIT is the special signal that says exit without proc_exit
- * and let the user know what's going on. But if SendStop is set
- * (-s on command line), then we send SIGSTOP instead, so that we
- * can get core dumps from all backends by hand.
- */
- if (take_action)
- {
- ereport(DEBUG2,
- (errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) rw->rw_pid)));
- signal_child(rw->rw_pid, (SendStop ? SIGSTOP : SIGQUIT));
- }
- }
- }
- /* Process regular backends */
- dlist_foreach_modify(iter, &BackendList)
- {
- bp = dlist_container(Backend, elem, iter.cur);
- if (bp->pid == pid)
- {
- /*
- * Found entry for freshly-dead backend, so remove it.
- */
- if (!bp->dead_end)
- {
- (void) ReleasePostmasterChildSlot(bp->child_slot);
- #ifdef EXEC_BACKEND
- ShmemBackendArrayRemove(bp);
- #endif
- }
- dlist_delete(iter.cur);
- free(bp);
- /* Keep looping so we can signal remaining backends */
- }
- else
- {
- /*
- * This backend is still alive. Unless we did so already, tell it
- * to commit hara-kiri.
- *
- * SIGQUIT is the special signal that says exit without proc_exit
- * and let the user know what's going on. But if SendStop is set
- * (-s on command line), then we send SIGSTOP instead, so that we
- * can get core dumps from all backends by hand.
- *
- * We could exclude dead_end children here, but at least in the
- * SIGSTOP case it seems better to include them.
- *
- * Background workers were already processed above; ignore them
- * here.
- */
- if (bp->bkend_type == BACKEND_TYPE_BGWORKER)
- continue;
- if (take_action)
- {
- ereport(DEBUG2,
- (errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) bp->pid)));
- signal_child(bp->pid, (SendStop ? SIGSTOP : SIGQUIT));
- }
- }
- }
- /* Take care of the startup process too */
- if (pid == StartupPID)
- StartupPID = 0;
- else if (StartupPID != 0 && take_action)
- {
- ereport(DEBUG2,
- (errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) StartupPID)));
- signal_child(StartupPID, (SendStop ? SIGSTOP : SIGQUIT));
- }
- /* Take care of the bgwriter too */
- if (pid == BgWriterPID)
- BgWriterPID = 0;
- else if (BgWriterPID != 0 && take_action)
- {
- ereport(DEBUG2,
- (errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) BgWriterPID)));
- signal_child(BgWriterPID, (SendStop ? SIGSTOP : SIGQUIT));
- }
- /* Take care of the checkpointer too */
- if (pid == CheckpointerPID)
- CheckpointerPID = 0;
- else if (CheckpointerPID != 0 && take_action)
- {
- ereport(DEBUG2,
- (errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) CheckpointerPID)));
- signal_child(CheckpointerPID, (SendStop ? SIGSTOP : SIGQUIT));
- }
- /* Take care of the walwriter too */
- if (pid == WalWriterPID)
- WalWriterPID = 0;
- else if (WalWriterPID != 0 && take_action)
- {
- ereport(DEBUG2,
- (errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) WalWriterPID)));
- signal_child(WalWriterPID, (SendStop ? SIGSTOP : SIGQUIT));
- }
- /* Take care of the walreceiver too */
- if (pid == WalReceiverPID)
- WalReceiverPID = 0;
- else if (WalReceiverPID != 0 && take_action)
- {
- ereport(DEBUG2,
- (errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) WalReceiverPID)));
- signal_child(WalReceiverPID, (SendStop ? SIGSTOP : SIGQUIT));
- }
- /* Take care of the autovacuum launcher too */
- if (pid == AutoVacPID)
- AutoVacPID = 0;
- else if (AutoVacPID != 0 && take_action)
- {
- ereport(DEBUG2,
- (errmsg_internal("sending %s to process %d",
- (SendStop ? "SIGSTOP" : "SIGQUIT"),
- (int) AutoVacPID)));
- signal_child(AutoVacPID, (SendStop ? SIGSTOP : SIGQUIT));
- }
- /*
- * Force a power-cycle of the pgarch process too. (This isn't absolutely
- * necessary, but it seems like a good idea for robustness, and it
- * simplifies the state-machine logic in the case where a shutdown request
- * arrives during crash processing.)
- */
- if (PgArchPID != 0 && take_action)
- {
- ereport(DEBUG2,
- (errmsg_internal("sending %s to process %d",
- "SIGQUIT",
- (int) PgArchPID)));
- signal_child(PgArchPID, SIGQUIT);
- }
- /*
- * Force a power-cycle of the pgstat process too. (This isn't absolutely
- * necessary, but it seems like a good idea for robustness, and it
- * simplifies the state-machine logic in the case where a shutdown request
- * arrives during crash processing.)
- */
- if (PgStatPID != 0 && take_action)
- {
- ereport(DEBUG2,
- (errmsg_internal("sending %s to process %d",
- "SIGQUIT",
- (int) PgStatPID)));
- signal_child(PgStatPID, SIGQUIT);
- allow_immediate_pgstat_restart();
- }
- /* We do NOT restart the syslogger */
- if (Shutdown != ImmediateShutdown)
- FatalError = true;
- /* We now transit into a state of waiting for children to die */
- if (pmState == PM_RECOVERY ||
- pmState == PM_HOT_STANDBY ||
- pmState == PM_RUN ||
- pmState == PM_WAIT_BACKUP ||
- pmState == PM_WAIT_READONLY ||
- pmState == PM_SHUTDOWN)
- pmState = PM_WAIT_BACKENDS;
- /*
- * .. and if this doesn't happen quickly enough, now the clock is ticking
- * for us to kill them without mercy.
- */
- if (AbortStartTime == 0)
- AbortStartTime = time(NULL);
- }
- /*
- * Log the death of a child process.
- */
- static void
- LogChildExit(int lev, const char *procname, int pid, int exitstatus)
- {
- /*
- * size of activity_buffer is arbitrary, but set equal to default
- * track_activity_query_size
- */
- char activity_buffer[1024];
- const char *activity = NULL;
- if (!EXIT_STATUS_0(exitstatus))
- activity = pgstat_get_crashed_backend_activity(pid,
- activity_buffer,
- sizeof(activity_buffer));
- if (WIFEXITED(exitstatus))
- ereport(lev,
- /*------
- translator: %s is a noun phrase describing a child process, such as
- "server process" */
- (errmsg("%s (PID %d) exited with exit code %d",
- procname, pid, WEXITSTATUS(exitstatus)),
- activity ? errdetail("Failed process was running: %s", activity) : 0));
- else if (WIFSIGNALED(exitstatus))
- #if defined(WIN32)
- ereport(lev,
- /*------
- translator: %s is a noun phrase describing a child process, such as
- "server process" */
- (errmsg("%s (PID %d) was terminated by exception 0x%X",
- procname, pid, WTERMSIG(exitstatus)),
- errhint("See C include file \"ntstatus.h\" for a description of the hexadecimal value."),
- activity ? errdetail("Failed process was running: %s", activity) : 0));
- #elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST
- ereport(lev,
- /*------
- translator: %s is a noun phrase describing a child process, such as
- "server process" */
- (errmsg("%s (PID %d) was terminated by signal %d: %s",
- procname, pid, WTERMSIG(exitstatus),
- WTERMSIG(exitstatus) < NSIG ?
- sys_siglist[WTERMSIG(exitstatus)] : "(unknown)"),
- activity ? errdetail("Failed process was running: %s", activity) : 0));
- #else
- ereport(lev,
- /*------
- translator: %s is a noun phrase describing a child process, such as
- "server process" */
- (errmsg("%s (PID %d) was terminated by signal %d",
- procname, pid, WTERMSIG(exitstatus)),
- activity ? errdetail("Failed process was running: %s", activity) : 0));
- #endif
- else
- ereport(lev,
- /*------
- translator: %s is a noun phrase describing a child process, such as
- "server process" */
- (errmsg("%s (PID %d) exited with unrecognized status %d",
- procname, pid, exitstatus),
- activity ? errdetail("Failed process was running: %s", activity) : 0));
- }
- /*
- * Advance the postmaster's state machine and take actions as appropriate
- *
- * This is common code for pmdie(), reaper() and sigusr1_handler(), which
- * receive the signals that might mean we need to change state.
- */
- static void
- PostmasterStateMachine(void)
- {
- if (pmState == PM_WAIT_BACKUP)
- {
- /*
- * PM_WAIT_BACKUP state ends when online backup mode is not active.
- */
- if (!BackupInProgress())
- pmState = PM_WAIT_BACKENDS;
- }
- if (pmState == PM_WAIT_READONLY)
- {
- /*
- * PM_WAIT_READONLY state ends when we have no regular backends that
- * have been started during recovery. We kill the startup and
- * walreceiver processes and transition to PM_WAIT_BACKENDS. Ideally,
- * we might like to kill these processes first and then wait for
- * backends to die off, but that doesn't work at present because
- * killing the startup process doesn't release its locks.
- */
- if (CountChildren(BACKEND_TYPE_NORMAL) == 0)
- {
- if (StartupPID != 0)
- signal_child(StartupPID, SIGTERM);
- if (WalReceiverPID != 0)
- signal_child(WalReceiverPID, SIGTERM);
- pmState = PM_WAIT_BACKENDS;
- }
- }
- /*
- * If we are in a state-machine state that implies waiting for backends to
- * exit, see if they're all gone, and change state if so.
- */
- if (pmState == PM_WAIT_BACKENDS)
- {
- /*
- * PM_WAIT_BACKENDS state ends when we have no regular backends
- * (including autovac workers), no bgworkers (including unconnected
- * ones), and no walwriter, autovac launcher or bgwriter. If we are
- * doing crash recovery or an immediate shutdown then we expect the
- * checkpointer to exit as well, otherwise not. The archiver, stats,
- * and syslogger processes are disregarded since they are not
- * connected to shared memory; we also disregard dead_end children
- * here. Walsenders are also disregarded, they will be terminated
- * later after writing the checkpoint record, like the archiver
- * process.
- */
- if (CountChildren(BACKEND_TYPE_NORMAL | BACKEND_TYPE_WORKER) == 0 &&
- CountUnconnectedWorkers() == 0 &&
- StartupPID == 0 &&
- WalReceiverPID == 0 &&
- BgWriterPID == 0 &&
- (CheckpointerPID == 0 ||
- (!FatalError && Shutdown < ImmediateShutdown)) &&
- WalWriterPID == 0 &&
- AutoVacPID == 0)
- {
- if (Shutdown >= ImmediateShutdown || FatalError)
- {
- /*
- * Start waiting for dead_end children to die. This state
- * change causes ServerLoop to stop creating new ones.
- */
- pmState = PM_WAIT_DEAD_END;
- /*
- * We already SIGQUIT'd the archiver and stats processes, if
- * any, when we started immediate shutdown or entered
- * FatalError state.
- */
- }
- else
- {
- /*
- * If we get here, we are proceeding with normal shutdown. All
- * the regular children are gone, and it's time to tell the
- * checkpointer to do a shutdown checkpoint.
- */
- Assert(Shutdown > NoShutdown);
- /* Start the checkpointer if not running */
- if (CheckpointerPID == 0)
- CheckpointerPID = StartCheckpointer();
- /* And tell it to shut down */
- if (CheckpointerPID != 0)
- {
- signal_child(CheckpointerPID, SIGUSR2);
- pmState = PM_SHUTDOWN;
- }
- else
- {
- /*
- * If we failed to fork a checkpointer, just shut down.
- * Any required cleanup will happen at next restart. We
- * set FatalError so that an "abnormal shutdown" message
- * gets logged when we exit.
- */
- FatalError = true;
- pmState = PM_WAIT_DEAD_END;
- /* Kill the walsenders, archiver and stats collector too */
- SignalChildren(SIGQUIT);
- if (PgArchPID != 0)
- signal_child(PgArchPID, SIGQUIT);
- if (PgStatPID != 0)
- signal_child(PgStatPID, SIGQUIT);
- }
- }
- }
- }
- if (pmState == PM_SHUTDOWN_2)
- {
- /*
- * PM_SHUTDOWN_2 state ends when there's no other children than
- * dead_end children left. There shouldn't be any regular backends
- * left by now anyway; what we're really waiting for is walsenders and
- * archiver.
- *
- * Walreceiver should normally be dead by now, but not when a fast
- * shutdown is performed during recovery.
- */
- if (PgArchPID == 0 && CountChildren(BACKEND_TYPE_ALL) == 0 &&
- WalReceiverPID == 0)
- {
- pmState = PM_WAIT_DEAD_END;
- }
- }
- if (pmState == PM_WAIT_DEAD_END)
- {
- /*
- * PM_WAIT_DEAD_END state ends when the BackendList is entirely empty
- * (ie, no dead_end children remain), and the archiver and stats
- * collector are gone too.
- *
- * The reason we wait for those two is to protect them against a new
- * postmaster starting conflicting subprocesses; this isn't an
- * ironclad protection, but it at least helps in the
- * shutdown-and-immediately-restart scenario. Note that they have
- * already been sent appropriate shutdown signals, either during a
- * normal state transition leading up to PM_WAIT_DEAD_END, or during
- * FatalError processing.
- */
- if (dlist_is_empty(&BackendList) &&
- PgArchPID == 0 && PgStatPID == 0)
- {
- /* These other guys should be dead already */
- Assert(StartupPID == 0);
- Assert(WalReceiverPID == 0);
- Assert(BgWriterPID == 0);
- Assert(CheckpointerPID == 0);
- Assert(WalWriterPID == 0);
- Assert(AutoVacPID == 0);
- /* syslogger is not considered here */
- pmState = PM_NO_CHILDREN;
- }
- }
- /*
- * If we've been told to shut down, we exit as soon as there are no
- * remaining children. If there was a crash, cleanup will occur at the
- * next startup. (Before PostgreSQL 8.3, we tried to recover from the
- * crash before exiting, but that seems unwise if we are quitting because
- * we got SIGTERM from init --- there may well not be time for recovery
- * before init decides to SIGKILL us.)
- *
- * Note that the syslogger continues to run. It will exit when it sees
- * EOF on its input pipe, which happens when there are no more upstream
- * processes.
- */
- if (Shutdown > NoShutdown && pmState == PM_NO_CHILDREN)
- {
- if (FatalError)
- {
- ereport(LOG, (errmsg("abnormal database system shutdown")));
- ExitPostmaster(1);
- }
- else
- {
- /*
- * Terminate exclusive backup mode to avoid recovery after a clean
- * fast shutdown. Since an exclusive backup can only be taken
- * during normal running (and not, for example, while running
- * under Hot Standby) it only makes sense to do this if we reached
- * normal running. If we're still in recovery, the backup file is
- * one we're recovering *from*, and we must keep it around so that
- * recovery restarts from the right place.
- */
- if (ReachedNormalRunning)
- CancelBackup();
- /* Normal exit from the postmaster is here */
- ExitPostmaster(0);
- }
- }
- /*
- * If recovery failed, or the user does not want an automatic restart
- * after backend crashes, wait for all non-syslogger children to exit, and
- * then exit postmaster. We don't try to reinitialize when recovery fails,
- * because more than likely it will just fail again and we will keep
- * trying forever.
- */
- if (pmState == PM_NO_CHILDREN && (RecoveryError || !restart_after_crash))
- ExitPostmaster(1);
- /*
- * If we need to recover from a crash, wait for all non-syslogger children
- * to exit, then reset shmem and StartupDataBase.
- */
- if (FatalError && pmState == PM_NO_CHILDREN)
- {
- ereport(LOG,
- (errmsg("all server processes terminated; reinitializing")));
- /* allow background workers to immediately restart */
- ResetBackgroundWorkerCrashTimes();
- shmem_exit(1);
- reset_shared(PostPortNumber);
- StartupPID = StartupDataBase();
- Assert(StartupPID != 0);
- pmState = PM_STARTUP;
- /* crash recovery started, reset SIGKILL flag */
- AbortStartTime = 0;
- }
- }
- /*
- * Send a signal to a postmaster child process
- *
- * On systems that have setsid(), each child process sets itself up as a
- * process group leader. For signals that are generally interpreted in the
- * appropriate fashion, we signal the entire process group not just the
- * direct child process. This allows us to, for example, SIGQUIT a blocked
- * archive_recovery script, or SIGINT a script being run by a backend via
- * system().
- *
- * There is a race condition for recently-forked children: they might not
- * have executed setsid() yet. So we signal the child directly as well as
- * the group. We assume such a child will handle the signal before trying
- * to spawn any grandchild processes. We also assume that signaling the
- * child twice will not cause any problems.
- */
- static void
- signal_child(pid_t pid, int signal)
- {
- if (kill(pid, signal) < 0)
- elog(DEBUG3, "kill(%ld,%d) failed: %m", (long) pid, signal);
- #ifdef HAVE_SETSID
- switch (signal)
- {
- case SIGINT:
- case SIGTERM:
- case SIGQUIT:
- case SIGSTOP:
- case SIGKILL:
- if (kill(-pid, signal) < 0)
- elog(DEBUG3, "kill(%ld,%d) failed: %m", (long) (-pid), signal);
- break;
- default:
- break;
- }
- #endif
- }
- /*
- * Send a signal to bgworkers that did not request backend connections
- *
- * The reason this is interesting is that workers that did request connections
- * are considered by SignalChildren; this function complements that one.
- */
- static bool
- SignalUnconnectedWorkers(int signal)
- {
- slist_iter iter;
- bool signaled = false;
- slist_foreach(iter, &BackgroundWorkerList)
- {
- RegisteredBgWorker *rw;
- rw = slist_container(RegisteredBgWorker, rw_lnode, iter.cur);
- if (rw->rw_pid == 0)
- continue;
- /* ignore connected workers */
- if (rw->rw_backend != NULL)
- continue;
- ereport(DEBUG4,
- (errmsg_internal("sending signal %d to process %d",
- signal, (int) rw->rw_pid)));
- signal_child(rw->rw_pid, signal);
- signaled = true;
- }
- return signaled;
- }
- /*
- * Send a signal to the targeted children (but NOT special children;
- * dead_end children are never signaled, either).
- */
- static bool
- SignalSomeChildren(int signal, int target)
- {
- dlist_iter iter;
- bool signaled = false;
- dlist_foreach(iter, &BackendList)
- {
- Backend *bp = dlist_container(Backend, elem, iter.cur);
- if (bp->dead_end)
- continue;
- /*
- * Since target == BACKEND_TYPE_ALL is the most common case, we test
- * it first and avoid touching shared memory for every child.
- */
- if (target != BACKEND_TYPE_ALL)
- {
- /*
- * Assign bkend_type for any recently announced WAL Sender
- * processes.
- */
- if (bp->bkend_type == BACKEND_TYPE_NORMAL &&
- IsPostmasterChildWalSender(bp->child_slot))
- bp->bkend_type = BACKEND_TYPE_WALSND;
- if (!(target & bp->bkend_type))
- continue;
- }
- ereport(DEBUG4,
- (errmsg_internal("sending signal %d to process %d",
- signal, (int) bp->pid)));
- signal_child(bp->pid, signal);
- signaled = true;
- }
- return signaled;
- }
- /*
- * Send a termination signal to children. This considers all of our children
- * processes, except syslogger and dead_end backends.
- */
- static void
- TerminateChildren(int signal)
- {
- SignalChildren(signal);
- if (StartupPID != 0)
- signal_child(StartupPID, signal);
- if (BgWriterPID != 0)
- signal_child(BgWriterPID, signal);
- if (CheckpointerPID != 0)
- signal_child(CheckpointerPID, signal);
- if (WalWriterPID != 0)
- signal_child(WalWriterPID, signal);
- if (WalReceiverPID != 0)
- signal_child(WalReceiverPID, signal);
- if (AutoVacPID != 0)
- signal_child(AutoVacPID, signal);
- if (PgArchPID != 0)
- signal_child(PgArchPID, signal);
- if (PgStatPID != 0)
- signal_child(PgStatPID, signal);
- SignalUnconnectedWorkers(signal);
- }
- /*
- * BackendStartup -- start backend process
- *
- * returns: STATUS_ERROR if the fork failed, STATUS_OK otherwise.
- *
- * Note: if you change this code, also consider StartAutovacuumWorker.
- */
- static int
- BackendStartup(Port *port)
- {
- Backend *bn; /* for backend cleanup */
- pid_t pid;
- /*
- * Create backend data structure. Better before the fork() so we can
- * handle failure cleanly.
- */
- bn = (Backend *) malloc(sizeof(Backend));
- if (!bn)
- {
- ereport(LOG,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("out of memory")));
- return STATUS_ERROR;
- }
- /*
- * Compute the cancel key that will be assigned to this backend. The
- * backend will have its own copy in the forked-off process' value of
- * MyCancelKey, so that it can transmit the key to the frontend.
- */
- MyCancelKey = PostmasterRandom();
- bn->cancel_key = MyCancelKey;
- /* Pass down canAcceptConnections state */
- port->canAcceptConnections = canAcceptConnections();
- bn->dead_end = (port->canAcceptConnections != CAC_OK &&
- port->canAcceptConnections != CAC_WAITBACKUP);
- /*
- * Unless it's a dead_end child, assign it a child slot number
- */
- if (!bn->dead_end)
- bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
- else
- bn->child_slot = 0;
- /* Hasn't asked to be notified about any bgworkers yet */
- bn->bgworker_notify = false;
- #ifdef EXEC_BACKEND
- pid = backend_forkexec(port);
- #else /* !EXEC_BACKEND */
- pid = fork_process();
- if (pid == 0) /* child */
- {
- free(bn);
- /*
- * Let's clean up ourselves as the postmaster child, and close the
- * postmaster's listen sockets. (In EXEC_BACKEND case this is all
- * done in SubPostmasterMain.)
- */
- IsUnderPostmaster = true; /* we are a postmaster subprocess now */
- MyProcPid = getpid(); /* reset MyProcPid */
- MyStartTime = time(NULL);
- /* We don't want the postmaster's proc_exit() handlers */
- on_exit_reset();
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
- /* Perform additional initialization and collect startup packet */
- BackendInitialize(port);
- /* And run the backend */
- BackendRun(port);
- }
- #endif /* EXEC_BACKEND */
- if (pid < 0)
- {
- /* in parent, fork failed */
- int save_errno = errno;
- if (!bn->dead_end)
- (void) ReleasePostmasterChildSlot(bn->child_slot);
- free(bn);
- errno = save_errno;
- ereport(LOG,
- (errmsg("could not fork new process for connection: %m")));
- report_fork_failure_to_client(port, save_errno);
- return STATUS_ERROR;
- }
- /* in parent, successful fork */
- ereport(DEBUG2,
- (errmsg_internal("forked new backend, pid=%d socket=%d",
- (int) pid, (int) port->sock)));
- /*
- * Everything's been successful, it's safe to add this backend to our list
- * of backends.
- */
- bn->pid = pid;
- bn->bkend_type = BACKEND_TYPE_NORMAL; /* Can change later to WALSND */
- dlist_push_head(&BackendList, &bn->elem);
- #ifdef EXEC_BACKEND
- if (!bn->dead_end)
- ShmemBackendArrayAdd(bn);
- #endif
- return STATUS_OK;
- }
- /*
- * Try to report backend fork() failure to client before we close the
- * connection. Since we do not care to risk blocking the postmaster on
- * this connection, we set the connection to non-blocking and try only once.
- *
- * This is grungy special-purpose code; we cannot use backend libpq since
- * it's not up and running.
- */
- static void
- report_fork_failure_to_client(Port *port, int errnum)
- {
- char buffer[1000];
- int rc;
- /* Format the error message packet (always V2 protocol) */
- snprintf(buffer, sizeof(buffer), "E%s%s\n",
- _("could not fork new process for connection: "),
- strerror(errnum));
- /* Set port to non-blocking. Don't do send() if this fails */
- if (!pg_set_noblock(port->sock))
- return;
- /* We'll retry after EINTR, but ignore all other failures */
- do
- {
- rc = send(port->sock, buffer, strlen(buffer) + 1, 0);
- } while (rc < 0 && errno == EINTR);
- }
- /*
- * BackendInitialize -- initialize an interactive (postmaster-child)
- * backend process, and collect the client's startup packet.
- *
- * returns: nothing. Will not return at all if there's any failure.
- *
- * Note: this code does not depend on having any access to shared memory.
- * In the EXEC_BACKEND case, we are physically attached to shared memory
- * but have not yet set up most of our local pointers to shmem structures.
- */
- static void
- BackendInitialize(Port *port)
- {
- int status;
- int ret;
- char remote_host[NI_MAXHOST];
- char remote_port[NI_MAXSERV];
- char remote_ps_data[NI_MAXHOST];
- /* Save port etc. for ps status */
- MyProcPort = port;
- /*
- * PreAuthDelay is a debugging aid for investigating problems in the
- * authentication cycle: it can be set in postgresql.conf to allow time to
- * attach to the newly-forked backend with a debugger. (See also
- * PostAuthDelay, which we allow clients to pass through PGOPTIONS, but it
- * is not honored until after authentication.)
- */
- if (PreAuthDelay > 0)
- pg_usleep(PreAuthDelay * 1000000L);
- /* This flag will remain set until InitPostgres finishes authentication */
- ClientAuthInProgress = true; /* limit visibility of log messages */
- /* save process start time */
- port->SessionStartTime = GetCurrentTimestamp();
- MyStartTime = timestamptz_to_time_t(port->SessionStartTime);
- /* set these to empty in case they are needed before we set them up */
- port->remote_host = "";
- port->remote_port = "";
- /*
- * Initialize libpq and enable reporting of ereport errors to the client.
- * Must do this now because authentication uses libpq to send messages.
- */
- pq_init(); /* initialize libpq to talk to client */
- whereToSendOutput = DestRemote; /* now safe to ereport to client */
- /*
- * If possible, make this process a group leader, so that the postmaster
- * can signal any child processes too. (We do this now on the off chance
- * that something might spawn a child process during authentication.)
- */
- #ifdef HAVE_SETSID
- if (setsid() < 0)
- elog(FATAL, "setsid() failed: %m");
- #endif
- /*
- * We arrange for a simple exit(1) if we receive SIGTERM or SIGQUIT or
- * timeout while trying to collect the startup packet. Otherwise the
- * postmaster cannot shutdown the database FAST or IMMED cleanly if a
- * buggy client fails to send the packet promptly.
- */
- pqsignal(SIGTERM, startup_die);
- pqsignal(SIGQUIT, startup_die);
- InitializeTimeouts(); /* establishes SIGALRM handler */
- PG_SETMASK(&StartupBlockSig);
- /*
- * Get the remote host name and port for logging and status display.
- */
- remote_host[0] = '\0';
- remote_port[0] = '\0';
- if ((ret = pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
- remote_host, sizeof(remote_host),
- remote_port, sizeof(remote_port),
- (log_hostname ? 0 : NI_NUMERICHOST) | NI_NUMERICSERV)) != 0)
- ereport(WARNING,
- (errmsg_internal("pg_getnameinfo_all() failed: %s",
- gai_strerror(ret))));
- if (remote_port[0] == '\0')
- snprintf(remote_ps_data, sizeof(remote_ps_data), "%s", remote_host);
- else
- snprintf(remote_ps_data, sizeof(remote_ps_data), "%s(%s)", remote_host, remote_port);
- if (Log_connections)
- {
- if (remote_port[0])
- ereport(LOG,
- (errmsg("connection received: host=%s port=%s",
- remote_host,
- remote_port)));
- else
- ereport(LOG,
- (errmsg("connection received: host=%s",
- remote_host)));
- }
- /*
- * save remote_host and remote_port in port structure
- */
- port->remote_host = strdup(remote_host);
- port->remote_port = strdup(remote_port);
- /*
- * If we did a reverse lookup to name, we might as well save the results
- * rather than possibly repeating the lookup during authentication.
- *
- * Note that we don't want to specify NI_NAMEREQD above, because then we'd
- * get nothing useful for a client without an rDNS entry. Therefore, we
- * must check whether we got a numeric IPv4 or IPv6 address, and not save
- * it into remote_hostname if so. (This test is conservative and might
- * sometimes classify a hostname as numeric, but an error in that
- * direction is safe; it only results in a possible extra lookup.)
- */
- if (log_hostname &&
- ret == 0 &&
- strspn(remote_host, "0123456789.") < strlen(remote_host) &&
- strspn(remote_host, "0123456789ABCDEFabcdef:") < strlen(remote_host))
- port->remote_hostname = strdup(remote_host);
- /*
- * Ready to begin client interaction. We will give up and exit(1) after a
- * time delay, so that a broken client can't hog a connection
- * indefinitely. PreAuthDelay and any DNS interactions above don't count
- * against the time limit.
- *
- * Note: AuthenticationTimeout is applied here while waiting for the
- * startup packet, and then again in InitPostgres for the duration of any
- * authentication operations. So a hostile client could tie up the
- * process for nearly twice AuthenticationTimeout before we kick him off.
- *
- * Note: because PostgresMain will call InitializeTimeouts again, the
- * registration of STARTUP_PACKET_TIMEOUT will be lost. This is okay
- * since we never use it again after this function.
- */
- RegisterTimeout(STARTUP_PACKET_TIMEOUT, StartupPacketTimeoutHandler);
- enable_timeout_after(STARTUP_PACKET_TIMEOUT, AuthenticationTimeout * 1000);
- /*
- * Receive the startup packet (which might turn out to be a cancel request
- * packet).
- */
- status = ProcessStartupPacket(port, false);
- /*
- * Stop here if it was bad or a cancel packet. ProcessStartupPacket
- * already did any appropriate error reporting.
- */
- if (status != STATUS_OK)
- proc_exit(0);
- /*
- * Now that we have the user and database name, we can set the process
- * title for ps. It's good to do this as early as possible in startup.
- *
- * For a walsender, the ps display is set in the following form:
- *
- * postgres: wal sender process <user> <host> <activity>
- *
- * To achieve that, we pass "wal sender process" as username and username
- * as dbname to init_ps_display(). XXX: should add a new variant of
- * init_ps_display() to avoid abusing the parameters like this.
- */
- if (am_walsender)
- init_ps_display("wal sender process", port->user_name, remote_ps_data,
- update_process_title ? "authentication" : "");
- else
- init_ps_display(port->user_name, port->database_name, remote_ps_data,
- update_process_title ? "authentication" : "");
- /*
- * Disable the timeout, and prevent SIGTERM/SIGQUIT again.
- */
- disable_timeout(STARTUP_PACKET_TIMEOUT, false);
- PG_SETMASK(&BlockSig);
- }
- /*
- * BackendRun -- set up the backend's argument list and invoke PostgresMain()
- *
- * returns:
- * Shouldn't return at all.
- * If PostgresMain() fails, return status.
- */
- static void
- BackendRun(Port *port)
- {
- char **av;
- int maxac;
- int ac;
- long secs;
- int usecs;
- int i;
- /*
- * Don't want backend to be able to see the postmaster random number
- * generator state. We have to clobber the static random_seed *and* start
- * a new random sequence in the random() library function.
- */
- random_seed = 0;
- random_start_time.tv_usec = 0;
- /* slightly hacky way to convert timestamptz into integers */
- TimestampDifference(0, port->SessionStartTime, &secs, &usecs);
- srandom((unsigned int) (MyProcPid ^ (usecs << 12) ^ secs));
- /*
- * Now, build the argv vector that will be given to PostgresMain.
- *
- * The maximum possible number of commandline arguments that could come
- * from ExtraOptions is (strlen(ExtraOptions) + 1) / 2; see
- * pg_split_opts().
- */
- maxac = 2; /* for fixed args supplied below */
- maxac += (strlen(ExtraOptions) + 1) / 2;
- av = (char **) MemoryContextAlloc(TopMemoryContext,
- maxac * sizeof(char *));
- ac = 0;
- av[ac++] = "postgres";
- /*
- * Pass any backend switches specified with -o on the postmaster's own
- * command line. We assume these are secure. (It's OK to mangle
- * ExtraOptions now, since we're safely inside a subprocess.)
- */
- pg_split_opts(av, &ac, ExtraOptions);
- av[ac] = NULL;
- Assert(ac < maxac);
- /*
- * Debug: print arguments being passed to backend
- */
- ereport(DEBUG3,
- (errmsg_internal("%s child[%d]: starting with (",
- progname, (int) getpid())));
- for (i = 0; i < ac; ++i)
- ereport(DEBUG3,
- (errmsg_internal("\t%s", av[i])));
- ereport(DEBUG3,
- (errmsg_internal(")")));
- /*
- * Make sure we aren't in PostmasterContext anymore. (We can't delete it
- * just yet, though, because InitPostgres will need the HBA data.)
- */
- MemoryContextSwitchTo(TopMemoryContext);
- PostgresMain(ac, av, port->database_name, port->user_name);
- }
- #ifdef EXEC_BACKEND
- /*
- * postmaster_forkexec -- fork and exec a postmaster subprocess
- *
- * The caller must have set up the argv array already, except for argv[2]
- * which will be filled with the name of the temp variable file.
- *
- * Returns the child process PID, or -1 on fork failure (a suitable error
- * message has been logged on failure).
- *
- * All uses of this routine will dispatch to SubPostmasterMain in the
- * child process.
- */
- pid_t
- postmaster_forkexec(int argc, char *argv[])
- {
- Port port;
- /* This entry point passes dummy values for the Port variables */
- memset(&port, 0, sizeof(port));
- return internal_forkexec(argc, argv, &port);
- }
- /*
- * backend_forkexec -- fork/exec off a backend process
- *
- * Some operating systems (WIN32) don't have fork() so we have to simulate
- * it by storing parameters that need to be passed to the child and
- * then create a new child process.
- *
- * returns the pid of the fork/exec'd process, or -1 on failure
- */
- static pid_t
- backend_forkexec(Port *port)
- {
- char *av[4];
- int ac = 0;
- av[ac++] = "postgres";
- av[ac++] = "--forkbackend";
- av[ac++] = NULL; /* filled in by internal_forkexec */
- av[ac] = NULL;
- Assert(ac < lengthof(av));
- return internal_forkexec(ac, av, port);
- }
- #ifndef WIN32
- /*
- * internal_forkexec non-win32 implementation
- *
- * - writes out backend variables to the parameter file
- * - fork():s, and then exec():s the child process
- */
- static pid_t
- internal_forkexec(int argc, char *argv[], Port *port)
- {
- static unsigned long tmpBackendFileNum = 0;
- pid_t pid;
- char tmpfilename[MAXPGPATH];
- BackendParameters param;
- FILE *fp;
- if (!save_backend_variables(¶m, port))
- return -1; /* log made by save_backend_variables */
- /* Calculate name for temp file */
- snprintf(tmpfilename, MAXPGPATH, "%s/%s.backend_var.%d.%lu",
- PG_TEMP_FILES_DIR, PG_TEMP_FILE_PREFIX,
- MyProcPid, ++tmpBackendFileNum);
- /* Open file */
- fp = AllocateFile(tmpfilename, PG_BINARY_W);
- if (!fp)
- {
- /*
- * As in OpenTemporaryFileInTablespace, try to make the temp-file
- * directory
- */
- mkdir(PG_TEMP_FILES_DIR, S_IRWXU);
- fp = AllocateFile(tmpfilename, PG_BINARY_W);
- if (!fp)
- {
- ereport(LOG,
- (errcode_for_file_access(),
- errmsg("could not create file \"%s\": %m",
- tmpfilename)));
- return -1;
- }
- }
- if (fwrite(¶m, sizeof(param), 1, fp) != 1)
- {
- ereport(LOG,
- (errcode_for_file_access(),
- errmsg("could not write to file \"%s\": %m", tmpfilename)));
- FreeFile(fp);
- return -1;
- }
- /* Release file */
- if (FreeFile(fp))
- {
- ereport(LOG,
- (errcode_for_file_access(),
- errmsg("could not write to file \"%s\": %m", tmpfilename)));
- return -1;
- }
- /* Make sure caller set up argv properly */
- Assert(argc >= 3);
- Assert(argv[argc] == NULL);
- Assert(strncmp(argv[1], "--fork", 6) == 0);
- Assert(argv[2] == NULL);
- /* Insert temp file name after --fork argument */
- argv[2] = tmpfilename;
- /* Fire off execv in child */
- if ((pid = fork_process()) == 0)
- {
- if (execv(postgres_exec_path, argv) < 0)
- {
- ereport(LOG,
- (errmsg("could not execute server process \"%s\": %m",
- postgres_exec_path)));
- /* We're already in the child process here, can't return */
- exit(1);
- }
- }
- return pid; /* Parent returns pid, or -1 on fork failure */
- }
- #else /* WIN32 */
- /*
- * internal_forkexec win32 implementation
- *
- * - starts backend using CreateProcess(), in suspended state
- * - writes out backend variables to the parameter file
- * - during this, duplicates handles and sockets required for
- * inheritance into the new process
- * - resumes execution of the new process once the backend parameter
- * file is complete.
- */
- static pid_t
- internal_forkexec(int argc, char *argv[], Port *port)
- {
- STARTUPINFO si;
- PROCESS_INFORMATION pi;
- int i;
- int j;
- char cmdLine[MAXPGPATH * 2];
- HANDLE paramHandle;
- BackendParameters *param;
- SECURITY_ATTRIBUTES sa;
- char paramHandleStr[32];
- win32_deadchild_waitinfo *childinfo;
- /* Make sure caller set up argv properly */
- Assert(argc >= 3);
- Assert(argv[argc] == NULL);
- Assert(strncmp(argv[1], "--fork", 6) == 0);
- Assert(argv[2] == NULL);
- /* Set up shared memory for parameter passing */
- ZeroMemory(&sa, sizeof(sa));
- sa.nLength = sizeof(sa);
- sa.bInheritHandle = TRUE;
- paramHandle = CreateFileMapping(INVALID_HANDLE_VALUE,
- &sa,
- PAGE_READWRITE,
- 0,
- sizeof(BackendParameters),
- NULL);
- if (paramHandle == INVALID_HANDLE_VALUE)
- {
- elog(LOG, "could not create backend parameter file mapping: error code %lu",
- GetLastError());
- return -1;
- }
- param = MapViewOfFile(paramHandle, FILE_MAP_WRITE, 0, 0, sizeof(BackendParameters));
- if (!param)
- {
- elog(LOG, "could not map backend parameter memory: error code %lu",
- GetLastError());
- CloseHandle(paramHandle);
- return -1;
- }
- /* Insert temp file name after --fork argument */
- #ifdef _WIN64
- sprintf(paramHandleStr, "%llu", (LONG_PTR) paramHandle);
- #else
- sprintf(paramHandleStr, "%lu", (DWORD) paramHandle);
- #endif
- argv[2] = paramHandleStr;
- /* Format the cmd line */
- cmdLine[sizeof(cmdLine) - 1] = '\0';
- cmdLine[sizeof(cmdLine) - 2] = '\0';
- snprintf(cmdLine, sizeof(cmdLine) - 1, "\"%s\"", postgres_exec_path);
- i = 0;
- while (argv[++i] != NULL)
- {
- j = strlen(cmdLine);
- snprintf(cmdLine + j, sizeof(cmdLine) - 1 - j, " \"%s\"", argv[i]);
- }
- if (cmdLine[sizeof(cmdLine) - 2] != '\0')
- {
- elog(LOG, "subprocess command line too long");
- return -1;
- }
- memset(&pi, 0, sizeof(pi));
- memset(&si, 0, sizeof(si));
- si.cb = sizeof(si);
- /*
- * Create the subprocess in a suspended state. This will be resumed later,
- * once we have written out the parameter file.
- */
- if (!CreateProcess(NULL, cmdLine, NULL, NULL, TRUE, CREATE_SUSPENDED,
- NULL, NULL, &si, &pi))
- {
- elog(LOG, "CreateProcess call failed: %m (error code %lu)",
- GetLastError());
- return -1;
- }
- if (!save_backend_variables(param, port, pi.hProcess, pi.dwProcessId))
- {
- /*
- * log made by save_backend_variables, but we have to clean up the
- * mess with the half-started process
- */
- if (!TerminateProcess(pi.hProcess, 255))
- ereport(LOG,
- (errmsg_internal("could not terminate unstarted process: error code %lu",
- GetLastError())));
- CloseHandle(pi.hProcess);
- CloseHandle(pi.hThread);
- return -1; /* log made by save_backend_variables */
- }
- /* Drop the parameter shared memory that is now inherited to the backend */
- if (!UnmapViewOfFile(param))
- elog(LOG, "could not unmap view of backend parameter file: error code %lu",
- GetLastError());
- if (!CloseHandle(paramHandle))
- elog(LOG, "could not close handle to backend parameter file: error code %lu",
- GetLastError());
- /*
- * Reserve the memory region used by our main shared memory segment before
- * we resume the child process.
- */
- if (!pgwin32_ReserveSharedMemoryRegion(pi.hProcess))
- {
- /*
- * Failed to reserve the memory, so terminate the newly created
- * process and give up.
- */
- if (!TerminateProcess(pi.hProcess, 255))
- ereport(LOG,
- (errmsg_internal("could not terminate process that failed to reserve memory: error code %lu",
- GetLastError())));
- CloseHandle(pi.hProcess);
- CloseHandle(pi.hThread);
- return -1; /* logging done made by
- * pgwin32_ReserveSharedMemoryRegion() */
- }
- /*
- * Now that the backend variables are written out, we start the child
- * thread so it can start initializing while we set up the rest of the
- * parent state.
- */
- if (ResumeThread(pi.hThread) == -1)
- {
- if (!TerminateProcess(pi.hProcess, 255))
- {
- ereport(LOG,
- (errmsg_internal("could not terminate unstartable process: error code %lu",
- GetLastError())));
- CloseHandle(pi.hProcess);
- CloseHandle(pi.hThread);
- return -1;
- }
- CloseHandle(pi.hProcess);
- CloseHandle(pi.hThread);
- ereport(LOG,
- (errmsg_internal("could not resume thread of unstarted process: error code %lu",
- GetLastError())));
- return -1;
- }
- /*
- * Queue a waiter for to signal when this child dies. The wait will be
- * handled automatically by an operating system thread pool.
- *
- * Note: use malloc instead of palloc, since it needs to be thread-safe.
- * Struct will be free():d from the callback function that runs on a
- * different thread.
- */
- childinfo = malloc(sizeof(win32_deadchild_waitinfo));
- if (!childinfo)
- ereport(FATAL,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("out of memory")));
- childinfo->procHandle = pi.hProcess;
- childinfo->procId = pi.dwProcessId;
- if (!RegisterWaitForSingleObject(&childinfo->waitHandle,
- pi.hProcess,
- pgwin32_deadchild_callback,
- childinfo,
- INFINITE,
- WT_EXECUTEONLYONCE | WT_EXECUTEINWAITTHREAD))
- ereport(FATAL,
- (errmsg_internal("could not register process for wait: error code %lu",
- GetLastError())));
- /* Don't close pi.hProcess here - the wait thread needs access to it */
- CloseHandle(pi.hThread);
- return pi.dwProcessId;
- }
- #endif /* WIN32 */
- /*
- * SubPostmasterMain -- Get the fork/exec'd process into a state equivalent
- * to what it would be if we'd simply forked on Unix, and then
- * dispatch to the appropriate place.
- *
- * The first two command line arguments are expected to be "--forkFOO"
- * (where FOO indicates which postmaster child we are to become), and
- * the name of a variables file that we can read to load data that would
- * have been inherited by fork() on Unix. Remaining arguments go to the
- * subprocess FooMain() routine.
- */
- void
- SubPostmasterMain(int argc, char *argv[])
- {
- Port port;
- /* Do this sooner rather than later... */
- IsUnderPostmaster = true; /* we are a postmaster subprocess now */
- MyProcPid = getpid(); /* reset MyProcPid */
- MyStartTime = time(NULL);
- /*
- * make sure stderr is in binary mode before anything can possibly be
- * written to it, in case it's actually the syslogger pipe, so the pipe
- * chunking protocol isn't disturbed. Non-logpipe data gets translated on
- * redirection (e.g. via pg_ctl -l) anyway.
- */
- #ifdef WIN32
- _setmode(fileno(stderr), _O_BINARY);
- #endif
- /* Lose the postmaster's on-exit routines (really a no-op) */
- on_exit_reset();
- /* In EXEC_BACKEND case we will not have inherited these settings */
- IsPostmasterEnvironment = true;
- whereToSendOutput = DestNone;
- /* Setup essential subsystems (to ensure elog() behaves sanely) */
- InitializeGUCOptions();
- /* Read in the variables file */
- memset(&port, 0, sizeof(Port));
- read_backend_variables(argv[2], &port);
- /*
- * Set reference point for stack-depth checking
- */
- set_stack_base();
- /*
- * Set up memory area for GSS information. Mirrors the code in ConnCreate
- * for the non-exec case.
- */
- #if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
- port.gss = (pg_gssinfo *) calloc(1, sizeof(pg_gssinfo));
- if (!port.gss)
- ereport(FATAL,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("out of memory")));
- #endif
- /* Check we got appropriate args */
- if (argc < 3)
- elog(FATAL, "invalid subpostmaster invocation");
- /*
- * If appropriate, physically re-attach to shared memory segment. We want
- * to do this before going any further to ensure that we can attach at the
- * same address the postmaster used.
- */
- if (strcmp(argv[1], "--forkbackend") == 0 ||
- strcmp(argv[1], "--forkavlauncher") == 0 ||
- strcmp(argv[1], "--forkavworker") == 0 ||
- strcmp(argv[1], "--forkboot") == 0 ||
- strncmp(argv[1], "--forkbgworker=", 15) == 0)
- PGSharedMemoryReAttach();
- /* autovacuum needs this set before calling InitProcess */
- if (strcmp(argv[1], "--forkavlauncher") == 0)
- AutovacuumLauncherIAm();
- if (strcmp(argv[1], "--forkavworker") == 0)
- AutovacuumWorkerIAm();
- /*
- * Start our win32 signal implementation. This has to be done after we
- * read the backend variables, because we need to pick up the signal pipe
- * from the parent process.
- */
- #ifdef WIN32
- pgwin32_signal_initialize();
- #endif
- /* In EXEC_BACKEND case we will not have inherited these settings */
- pqinitmask();
- PG_SETMASK(&BlockSig);
- /* Read in remaining GUC variables */
- read_nondefault_variables();
- /*
- * Reload any libraries that were preloaded by the postmaster. Since we
- * exec'd this process, those libraries didn't come along with us; but we
- * should load them into all child processes to be consistent with the
- * non-EXEC_BACKEND behavior.
- */
- process_shared_preload_libraries();
- /* Run backend or appropriate child */
- if (strcmp(argv[1], "--forkbackend") == 0)
- {
- Assert(argc == 3); /* shouldn't be any more args */
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
- /*
- * Need to reinitialize the SSL library in the backend, since the
- * context structures contain function pointers and cannot be passed
- * through the parameter file.
- *
- * XXX should we do this in all child processes? For the moment it's
- * enough to do it in backend children.
- */
- #ifdef USE_SSL
- if (EnableSSL)
- secure_initialize();
- #endif
- /*
- * Perform additional initialization and collect startup packet.
- *
- * We want to do this before InitProcess() for a couple of reasons: 1.
- * so that we aren't eating up a PGPROC slot while waiting on the
- * client. 2. so that if InitProcess() fails due to being out of
- * PGPROC slots, we have already initialized libpq and are able to
- * report the error to the client.
- */
- BackendInitialize(&port);
- /* Restore basic shared memory pointers */
- InitShmemAccess(UsedShmemSegAddr);
- /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
- InitProcess();
- /*
- * Attach process to shared data structures. If testing EXEC_BACKEND
- * on Linux, you must run this as root before starting the postmaster:
- *
- * echo 0 >/proc/sys/kernel/randomize_va_space
- *
- * This prevents a randomized stack base address that causes child
- * shared memory to be at a different address than the parent, making
- * it impossible to attached to shared memory. Return the value to
- * '1' when finished.
- */
- CreateSharedMemoryAndSemaphores(false, 0);
- /* And run the backend */
- BackendRun(&port); /* does not return */
- }
- if (strcmp(argv[1], "--forkboot") == 0)
- {
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
- /* Restore basic shared memory pointers */
- InitShmemAccess(UsedShmemSegAddr);
- /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
- InitAuxiliaryProcess();
- /* Attach process to shared data structures */
- CreateSharedMemoryAndSemaphores(false, 0);
- AuxiliaryProcessMain(argc - 2, argv + 2); /* does not return */
- }
- if (strcmp(argv[1], "--forkavlauncher") == 0)
- {
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
- /* Restore basic shared memory pointers */
- InitShmemAccess(UsedShmemSegAddr);
- /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
- InitProcess();
- /* Attach process to shared data structures */
- CreateSharedMemoryAndSemaphores(false, 0);
- AutoVacLauncherMain(argc - 2, argv + 2); /* does not return */
- }
- if (strcmp(argv[1], "--forkavworker") == 0)
- {
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
- /* Restore basic shared memory pointers */
- InitShmemAccess(UsedShmemSegAddr);
- /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
- InitProcess();
- /* Attach process to shared data structures */
- CreateSharedMemoryAndSemaphores(false, 0);
- AutoVacWorkerMain(argc - 2, argv + 2); /* does not return */
- }
- if (strncmp(argv[1], "--forkbgworker=", 15) == 0)
- {
- int shmem_slot;
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
- /* Restore basic shared memory pointers */
- InitShmemAccess(UsedShmemSegAddr);
- /* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
- InitProcess();
- /* Attach process to shared data structures */
- CreateSharedMemoryAndSemaphores(false, 0);
- shmem_slot = atoi(argv[1] + 15);
- MyBgworkerEntry = BackgroundWorkerEntry(shmem_slot);
- StartBackgroundWorker();
- }
- if (strcmp(argv[1], "--forkarch") == 0)
- {
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
- /* Do not want to attach to shared memory */
- PgArchiverMain(argc, argv); /* does not return */
- }
- if (strcmp(argv[1], "--forkcol") == 0)
- {
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
- /* Do not want to attach to shared memory */
- PgstatCollectorMain(argc, argv); /* does not return */
- }
- if (strcmp(argv[1], "--forklog") == 0)
- {
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(true);
- /* Do not want to attach to shared memory */
- SysLoggerMain(argc, argv); /* does not return */
- }
- abort(); /* shouldn't get here */
- }
- #endif /* EXEC_BACKEND */
- /*
- * ExitPostmaster -- cleanup
- *
- * Do NOT call exit() directly --- always go through here!
- */
- static void
- ExitPostmaster(int status)
- {
- /* should cleanup shared memory and kill all backends */
- /*
- * Not sure of the semantics here. When the Postmaster dies, should the
- * backends all be killed? probably not.
- *
- * MUST -- vadim 05-10-1999
- */
- proc_exit(status);
- }
- /*
- * sigusr1_handler - handle signal conditions from child processes
- */
- static void
- sigusr1_handler(SIGNAL_ARGS)
- {
- int save_errno = errno;
- bool start_bgworker = false;
- PG_SETMASK(&BlockSig);
- /* Process background worker state change. */
- if (CheckPostmasterSignal(PMSIGNAL_BACKGROUND_WORKER_CHANGE))
- {
- BackgroundWorkerStateChange();
- start_bgworker = true;
- }
- /*
- * RECOVERY_STARTED and BEGIN_HOT_STANDBY signals are ignored in
- * unexpected states. If the startup process quickly starts up, completes
- * recovery, exits, we might process the death of the startup process
- * first. We don't want to go back to recovery in that case.
- */
- if (CheckPostmasterSignal(PMSIGNAL_RECOVERY_STARTED) &&
- pmState == PM_STARTUP && Shutdown == NoShutdown)
- {
- /* WAL redo has started. We're out of reinitialization. */
- FatalError = false;
- Assert(AbortStartTime == 0);
- /*
- * Crank up the background tasks. It doesn't matter if this fails,
- * we'll just try again later.
- */
- Assert(CheckpointerPID == 0);
- CheckpointerPID = StartCheckpointer();
- Assert(BgWriterPID == 0);
- BgWriterPID = StartBackgroundWriter();
- pmState = PM_RECOVERY;
- }
- if (CheckPostmasterSignal(PMSIGNAL_BEGIN_HOT_STANDBY) &&
- pmState == PM_RECOVERY && Shutdown == NoShutdown)
- {
- /*
- * Likewise, start other special children as needed.
- */
- Assert(PgStatPID == 0);
- PgStatPID = pgstat_start();
- ereport(LOG,
- (errmsg("database system is ready to accept read only connections")));
- pmState = PM_HOT_STANDBY;
- /* Some workers may be scheduled to start now */
- start_bgworker = true;
- }
- if (start_bgworker)
- maybe_start_bgworker();
- if (CheckPostmasterSignal(PMSIGNAL_WAKEN_ARCHIVER) &&
- PgArchPID != 0)
- {
- /*
- * Send SIGUSR1 to archiver process, to wake it up and begin archiving
- * next transaction log file.
- */
- signal_child(PgArchPID, SIGUSR1);
- }
- if (CheckPostmasterSignal(PMSIGNAL_ROTATE_LOGFILE) &&
- SysLoggerPID != 0)
- {
- /* Tell syslogger to rotate logfile */
- signal_child(SysLoggerPID, SIGUSR1);
- }
- if (CheckPostmasterSignal(PMSIGNAL_START_AUTOVAC_LAUNCHER) &&
- Shutdown == NoShutdown)
- {
- /*
- * Start one iteration of the autovacuum daemon, even if autovacuuming
- * is nominally not enabled. This is so we can have an active defense
- * against transaction ID wraparound. We set a flag for the main loop
- * to do it rather than trying to do it here --- this is because the
- * autovac process itself may send the signal, and we want to handle
- * that by launching another iteration as soon as the current one
- * completes.
- */
- start_autovac_launcher = true;
- }
- if (CheckPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER) &&
- Shutdown == NoShutdown)
- {
- /* The autovacuum launcher wants us to start a worker process. */
- StartAutovacuumWorker();
- }
- if (CheckPostmasterSignal(PMSIGNAL_START_WALRECEIVER) &&
- WalReceiverPID == 0 &&
- (pmState == PM_STARTUP || pmState == PM_RECOVERY ||
- pmState == PM_HOT_STANDBY || pmState == PM_WAIT_READONLY) &&
- Shutdown == NoShutdown)
- {
- /* Startup Process wants us to start the walreceiver process. */
- WalReceiverPID = StartWalReceiver();
- }
- if (CheckPostmasterSignal(PMSIGNAL_ADVANCE_STATE_MACHINE) &&
- (pmState == PM_WAIT_BACKUP || pmState == PM_WAIT_BACKENDS))
- {
- /* Advance postmaster's state machine */
- PostmasterStateMachine();
- }
- if (CheckPromoteSignal() && StartupPID != 0 &&
- (pmState == PM_STARTUP || pmState == PM_RECOVERY ||
- pmState == PM_HOT_STANDBY || pmState == PM_WAIT_READONLY))
- {
- /* Tell startup process to finish recovery */
- signal_child(StartupPID, SIGUSR2);
- }
- PG_SETMASK(&UnBlockSig);
- errno = save_errno;
- }
- /*
- * SIGTERM or SIGQUIT while processing startup packet.
- * Clean up and exit(1).
- *
- * XXX: possible future improvement: try to send a message indicating
- * why we are disconnecting. Problem is to be sure we don't block while
- * doing so, nor mess up SSL initialization. In practice, if the client
- * has wedged here, it probably couldn't do anything with the message anyway.
- */
- static void
- startup_die(SIGNAL_ARGS)
- {
- proc_exit(1);
- }
- /*
- * Dummy signal handler
- *
- * We use this for signals that we don't actually use in the postmaster,
- * but we do use in backends. If we were to SIG_IGN such signals in the
- * postmaster, then a newly started backend might drop a signal that arrives
- * before it's able to reconfigure its signal processing. (See notes in
- * tcop/postgres.c.)
- */
- static void
- dummy_handler(SIGNAL_ARGS)
- {
- }
- /*
- * Timeout while processing startup packet.
- * As for startup_die(), we clean up and exit(1).
- */
- static void
- StartupPacketTimeoutHandler(void)
- {
- proc_exit(1);
- }
- /*
- * RandomSalt
- */
- static void
- RandomSalt(char *md5Salt)
- {
- long rand;
- /*
- * We use % 255, sacrificing one possible byte value, so as to ensure that
- * all bits of the random() value participate in the result. While at it,
- * add one to avoid generating any null bytes.
- */
- rand = PostmasterRandom();
- md5Salt[0] = (rand % 255) + 1;
- rand = PostmasterRandom();
- md5Salt[1] = (rand % 255) + 1;
- rand = PostmasterRandom();
- md5Salt[2] = (rand % 255) + 1;
- rand = PostmasterRandom();
- md5Salt[3] = (rand % 255) + 1;
- }
- /*
- * PostmasterRandom
- */
- static long
- PostmasterRandom(void)
- {
- /*
- * Select a random seed at the time of first receiving a request.
- */
- if (random_seed == 0)
- {
- do
- {
- struct timeval random_stop_time;
- gettimeofday(&random_stop_time, NULL);
- /*
- * We are not sure how much precision is in tv_usec, so we swap
- * the high and low 16 bits of 'random_stop_time' and XOR them
- * with 'random_start_time'. On the off chance that the result is
- * 0, we loop until it isn't.
- */
- random_seed = random_start_time.tv_usec ^
- ((random_stop_time.tv_usec << 16) |
- ((random_stop_time.tv_usec >> 16) & 0xffff));
- }
- while (random_seed == 0);
- srandom(random_seed);
- }
- return random();
- }
- /*
- * Count up number of worker processes that did not request backend connections
- * See SignalUnconnectedWorkers for why this is interesting.
- */
- static int
- CountUnconnectedWorkers(void)
- {
- slist_iter iter;
- int cnt = 0;
- slist_foreach(iter, &BackgroundWorkerList)
- {
- RegisteredBgWorker *rw;
- rw = slist_container(RegisteredBgWorker, rw_lnode, iter.cur);
- if (rw->rw_pid == 0)
- continue;
- /* ignore connected workers */
- if (rw->rw_backend != NULL)
- continue;
- cnt++;
- }
- return cnt;
- }
- /*
- * Count up number of child processes of specified types (dead_end chidren
- * are always excluded).
- */
- static int
- CountChildren(int target)
- {
- dlist_iter iter;
- int cnt = 0;
- dlist_foreach(iter, &BackendList)
- {
- Backend *bp = dlist_container(Backend, elem, iter.cur);
- if (bp->dead_end)
- continue;
- /*
- * Since target == BACKEND_TYPE_ALL is the most common case, we test
- * it first and avoid touching shared memory for every child.
- */
- if (target != BACKEND_TYPE_ALL)
- {
- /*
- * Assign bkend_type for any recently announced WAL Sender
- * processes.
- */
- if (bp->bkend_type == BACKEND_TYPE_NORMAL &&
- IsPostmasterChildWalSender(bp->child_slot))
- bp->bkend_type = BACKEND_TYPE_WALSND;
- if (!(target & bp->bkend_type))
- continue;
- }
- cnt++;
- }
- return cnt;
- }
- /*
- * StartChildProcess -- start an auxiliary process for the postmaster
- *
- * xlop determines what kind of child will be started. All child types
- * initially go to AuxiliaryProcessMain, which will handle common setup.
- *
- * Return value of StartChildProcess is subprocess' PID, or 0 if failed
- * to start subprocess.
- */
- static pid_t
- StartChildProcess(AuxProcType type)
- {
- pid_t pid;
- char *av[10];
- int ac = 0;
- char typebuf[32];
- /*
- * Set up command-line arguments for subprocess
- */
- av[ac++] = "postgres";
- #ifdef EXEC_BACKEND
- av[ac++] = "--forkboot";
- av[ac++] = NULL; /* filled in by postmaster_forkexec */
- #endif
- snprintf(typebuf, sizeof(typebuf), "-x%d", type);
- av[ac++] = typebuf;
- av[ac] = NULL;
- Assert(ac < lengthof(av));
- #ifdef EXEC_BACKEND
- pid = postmaster_forkexec(ac, av);
- #else /* !EXEC_BACKEND */
- pid = fork_process();
- if (pid == 0) /* child */
- {
- IsUnderPostmaster = true; /* we are a postmaster subprocess now */
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
- /* Lose the postmaster's on-exit routines and port connections */
- on_exit_reset();
- /* Release postmaster's working memory context */
- MemoryContextSwitchTo(TopMemoryContext);
- MemoryContextDelete(PostmasterContext);
- PostmasterContext = NULL;
- AuxiliaryProcessMain(ac, av);
- ExitPostmaster(0);
- }
- #endif /* EXEC_BACKEND */
- if (pid < 0)
- {
- /* in parent, fork failed */
- int save_errno = errno;
- errno = save_errno;
- switch (type)
- {
- case StartupProcess:
- ereport(LOG,
- (errmsg("could not fork startup process: %m")));
- break;
- case BgWriterProcess:
- ereport(LOG,
- (errmsg("could not fork background writer process: %m")));
- break;
- case CheckpointerProcess:
- ereport(LOG,
- (errmsg("could not fork checkpointer process: %m")));
- break;
- case WalWriterProcess:
- ereport(LOG,
- (errmsg("could not fork WAL writer process: %m")));
- break;
- case WalReceiverProcess:
- ereport(LOG,
- (errmsg("could not fork WAL receiver process: %m")));
- break;
- default:
- ereport(LOG,
- (errmsg("could not fork process: %m")));
- break;
- }
- /*
- * fork failure is fatal during startup, but there's no need to choke
- * immediately if starting other child types fails.
- */
- if (type == StartupProcess)
- ExitPostmaster(1);
- return 0;
- }
- /*
- * in parent, successful fork
- */
- return pid;
- }
- /*
- * StartAutovacuumWorker
- * Start an autovac worker process.
- *
- * This function is here because it enters the resulting PID into the
- * postmaster's private backends list.
- *
- * NB -- this code very roughly matches BackendStartup.
- */
- static void
- StartAutovacuumWorker(void)
- {
- Backend *bn;
- /*
- * If not in condition to run a process, don't try, but handle it like a
- * fork failure. This does not normally happen, since the signal is only
- * supposed to be sent by autovacuum launcher when it's OK to do it, but
- * we have to check to avoid race-condition problems during DB state
- * changes.
- */
- if (canAcceptConnections() == CAC_OK)
- {
- bn = (Backend *) malloc(sizeof(Backend));
- if (bn)
- {
- /*
- * Compute the cancel key that will be assigned to this session.
- * We probably don't need cancel keys for autovac workers, but
- * we'd better have something random in the field to prevent
- * unfriendly people from sending cancels to them.
- */
- MyCancelKey = PostmasterRandom();
- bn->cancel_key = MyCancelKey;
- /* Autovac workers are not dead_end and need a child slot */
- bn->dead_end = false;
- bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
- bn->bgworker_notify = false;
- bn->pid = StartAutoVacWorker();
- if (bn->pid > 0)
- {
- bn->bkend_type = BACKEND_TYPE_AUTOVAC;
- dlist_push_head(&BackendList, &bn->elem);
- #ifdef EXEC_BACKEND
- ShmemBackendArrayAdd(bn);
- #endif
- /* all OK */
- return;
- }
- /*
- * fork failed, fall through to report -- actual error message was
- * logged by StartAutoVacWorker
- */
- (void) ReleasePostmasterChildSlot(bn->child_slot);
- free(bn);
- }
- else
- ereport(LOG,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("out of memory")));
- }
- /*
- * Report the failure to the launcher, if it's running. (If it's not, we
- * might not even be connected to shared memory, so don't try to call
- * AutoVacWorkerFailed.) Note that we also need to signal it so that it
- * responds to the condition, but we don't do that here, instead waiting
- * for ServerLoop to do it. This way we avoid a ping-pong signalling in
- * quick succession between the autovac launcher and postmaster in case
- * things get ugly.
- */
- if (AutoVacPID != 0)
- {
- AutoVacWorkerFailed();
- avlauncher_needs_signal = true;
- }
- }
- /*
- * Create the opts file
- */
- static bool
- CreateOptsFile(int argc, char *argv[], char *fullprogname)
- {
- FILE *fp;
- int i;
- #define OPTS_FILE "postmaster.opts"
- if ((fp = fopen(OPTS_FILE, "w")) == NULL)
- {
- elog(LOG, "could not create file \"%s\": %m", OPTS_FILE);
- return false;
- }
- fprintf(fp, "%s", fullprogname);
- for (i = 1; i < argc; i++)
- fprintf(fp, " \"%s\"", argv[i]);
- fputs("\n", fp);
- if (fclose(fp))
- {
- elog(LOG, "could not write file \"%s\": %m", OPTS_FILE);
- return false;
- }
- return true;
- }
- /*
- * MaxLivePostmasterChildren
- *
- * This reports the number of entries needed in per-child-process arrays
- * (the PMChildFlags array, and if EXEC_BACKEND the ShmemBackendArray).
- * These arrays include regular backends, autovac workers, walsenders
- * and background workers, but not special children nor dead_end children.
- * This allows the arrays to have a fixed maximum size, to wit the same
- * too-many-children limit enforced by canAcceptConnections(). The exact value
- * isn't too critical as long as it's more than MaxBackends.
- */
- int
- MaxLivePostmasterChildren(void)
- {
- return 2 * (MaxConnections + autovacuum_max_workers + 1 +
- max_worker_processes);
- }
- /*
- * Connect background worker to a database.
- */
- void
- BackgroundWorkerInitializeConnection(char *dbname, char *username)
- {
- BackgroundWorker *worker = MyBgworkerEntry;
- /* XXX is this the right errcode? */
- if (!(worker->bgw_flags & BGWORKER_BACKEND_DATABASE_CONNECTION))
- ereport(FATAL,
- (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
- errmsg("database connection requirement not indicated during registration")));
- InitPostgres(dbname, InvalidOid, username, NULL);
- /* it had better not gotten out of "init" mode yet */
- if (!IsInitProcessingMode())
- ereport(ERROR,
- (errmsg("invalid processing mode in background worker")));
- SetProcessingMode(NormalProcessing);
- }
- /*
- * Block/unblock signals in a background worker
- */
- void
- BackgroundWorkerBlockSignals(void)
- {
- PG_SETMASK(&BlockSig);
- }
- void
- BackgroundWorkerUnblockSignals(void)
- {
- PG_SETMASK(&UnBlockSig);
- }
- #ifdef EXEC_BACKEND
- static pid_t
- bgworker_forkexec(int shmem_slot)
- {
- char *av[10];
- int ac = 0;
- char forkav[MAXPGPATH];
- snprintf(forkav, MAXPGPATH, "--forkbgworker=%d", shmem_slot);
- av[ac++] = "postgres";
- av[ac++] = forkav;
- av[ac++] = NULL; /* filled in by postmaster_forkexec */
- av[ac] = NULL;
- Assert(ac < lengthof(av));
- return postmaster_forkexec(ac, av);
- }
- #endif
- /*
- * Start a new bgworker.
- * Starting time conditions must have been checked already.
- *
- * This code is heavily based on autovacuum.c, q.v.
- */
- static void
- do_start_bgworker(RegisteredBgWorker *rw)
- {
- pid_t worker_pid;
- ereport(LOG,
- (errmsg("starting background worker process \"%s\"",
- rw->rw_worker.bgw_name)));
- #ifdef EXEC_BACKEND
- switch ((worker_pid = bgworker_forkexec(rw->rw_shmem_slot)))
- #else
- switch ((worker_pid = fork_process()))
- #endif
- {
- case -1:
- ereport(LOG,
- (errmsg("could not fork worker process: %m")));
- return;
- #ifndef EXEC_BACKEND
- case 0:
- /* in postmaster child ... */
- /* Close the postmaster's sockets */
- ClosePostmasterPorts(false);
- /* Lose the postmaster's on-exit routines */
- on_exit_reset();
- /* Do NOT release postmaster's working memory context */
- MyBgworkerEntry = &rw->rw_worker;
- StartBackgroundWorker();
- break;
- #endif
- default:
- rw->rw_pid = worker_pid;
- if (rw->rw_backend)
- rw->rw_backend->pid = rw->rw_pid;
- ReportBackgroundWorkerPID(rw);
- }
- }
- /*
- * Does the current postmaster state require starting a worker with the
- * specified start_time?
- */
- static bool
- bgworker_should_start_now(BgWorkerStartTime start_time)
- {
- switch (pmState)
- {
- case PM_NO_CHILDREN:
- case PM_WAIT_DEAD_END:
- case PM_SHUTDOWN_2:
- case PM_SHUTDOWN:
- case PM_WAIT_BACKENDS:
- case PM_WAIT_READONLY:
- case PM_WAIT_BACKUP:
- break;
- case PM_RUN:
- if (start_time == BgWorkerStart_RecoveryFinished)
- return true;
- /* fall through */
- case PM_HOT_STANDBY:
- if (start_time == BgWorkerStart_ConsistentState)
- return true;
- /* fall through */
- case PM_RECOVERY:
- case PM_STARTUP:
- case PM_INIT:
- if (start_time == BgWorkerStart_PostmasterStart)
- return true;
- /* fall through */
- }
- return false;
- }
- /*
- * Allocate the Backend struct for a connected background worker, but don't
- * add it to the list of backends just yet.
- *
- * Some info from the Backend is copied into the passed rw.
- */
- static bool
- assign_backendlist_entry(RegisteredBgWorker *rw)
- {
- Backend *bn = malloc(sizeof(Backend));
- if (bn == NULL)
- {
- ereport(LOG,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("out of memory")));
- /*
- * The worker didn't really crash, but setting this nonzero makes
- * postmaster wait a bit before attempting to start it again; if it
- * tried again right away, most likely it'd find itself under the same
- * memory pressure.
- */
- rw->rw_crashed_at = GetCurrentTimestamp();
- return false;
- }
- /*
- * Compute the cancel key that will be assigned to this session. We
- * probably don't need cancel keys for background workers, but we'd better
- * have something random in the field to prevent unfriendly people from
- * sending cancels to them.
- */
- MyCancelKey = PostmasterRandom();
- bn->cancel_key = MyCancelKey;
- bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
- bn->bkend_type = BACKEND_TYPE_BGWORKER;
- bn->dead_end = false;
- bn->bgworker_notify = false;
- rw->rw_backend = bn;
- rw->rw_child_slot = bn->child_slot;
- return true;
- }
- /*
- * If the time is right, start one background worker.
- *
- * As a side effect, the bgworker control variables are set or reset whenever
- * there are more workers to start after this one, and whenever the overall
- * system state requires it.
- */
- static void
- maybe_start_bgworker(void)
- {
- slist_mutable_iter iter;
- TimestampTz now = 0;
- if (FatalError)
- {
- StartWorkerNeeded = false;
- HaveCrashedWorker = false;
- return; /* not yet */
- }
- HaveCrashedWorker = false;
- slist_foreach_modify(iter, &BackgroundWorkerList)
- {
- RegisteredBgWorker *rw;
- rw = slist_container(RegisteredBgWorker, rw_lnode, iter.cur);
- /* already running? */
- if (rw->rw_pid != 0)
- continue;
- /* marked for death? */
- if (rw->rw_terminate)
- {
- ForgetBackgroundWorker(&iter);
- continue;
- }
- /*
- * If this worker has crashed previously, maybe it needs to be
- * restarted (unless on registration it specified it doesn't want to
- * be restarted at all). Check how long ago did a crash last happen.
- * If the last crash is too recent, don't start it right away; let it
- * be restarted once enough time has passed.
- */
- if (rw->rw_crashed_at != 0)
- {
- if (rw->rw_worker.bgw_restart_time == BGW_NEVER_RESTART)
- {
- ForgetBackgroundWorker(&iter);
- continue;
- }
- if (now == 0)
- now = GetCurrentTimestamp();
- if (!TimestampDifferenceExceeds(rw->rw_crashed_at, now,
- rw->rw_worker.bgw_restart_time * 1000))
- {
- HaveCrashedWorker = true;
- continue;
- }
- }
- if (bgworker_should_start_now(rw->rw_worker.bgw_start_time))
- {
- /* reset crash time before calling assign_backendlist_entry */
- rw->rw_crashed_at = 0;
- /*
- * If necessary, allocate and assign the Backend element. Note we
- * must do this before forking, so that we can handle out of
- * memory properly.
- *
- * If not connected, we don't need a Backend element, but we still
- * need a PMChildSlot.
- */
- if (rw->rw_worker.bgw_flags & BGWORKER_BACKEND_DATABASE_CONNECTION)
- {
- if (!assign_backendlist_entry(rw))
- return;
- }
- else
- rw->rw_child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
- do_start_bgworker(rw); /* sets rw->rw_pid */
- if (rw->rw_backend)
- {
- dlist_push_head(&BackendList, &rw->rw_backend->elem);
- #ifdef EXEC_BACKEND
- ShmemBackendArrayAdd(rw->rw_backend);
- #endif
- }
- /*
- * Have ServerLoop call us again. Note that there might not
- * actually *be* another runnable worker, but we don't care all
- * that much; we will find out the next time we run.
- */
- StartWorkerNeeded = true;
- return;
- }
- }
- /* no runnable worker found */
- StartWorkerNeeded = false;
- }
- /*
- * When a backend asks to be notified about worker state changes, we
- * set a flag in its backend entry. The background worker machinery needs
- * to know when such backends exit.
- */
- bool
- PostmasterMarkPIDForWorkerNotify(int pid)
- {
- dlist_iter iter;
- Backend *bp;
- dlist_foreach(iter, &BackendList)
- {
- bp = dlist_container(Backend, elem, iter.cur);
- if (bp->pid == pid)
- {
- bp->bgworker_notify = true;
- return true;
- }
- }
- return false;
- }
- #ifdef EXEC_BACKEND
- /*
- * The following need to be available to the save/restore_backend_variables
- * functions. They are marked NON_EXEC_STATIC in their home modules.
- */
- extern slock_t *ShmemLock;
- extern slock_t *ProcStructLock;
- extern PGPROC *AuxiliaryProcs;
- extern PMSignalData *PMSignalState;
- extern pgsocket pgStatSock;
- extern pg_time_t first_syslogger_file_time;
- #ifndef WIN32
- #define write_inheritable_socket(dest, src, childpid) ((*(dest) = (src)), true)
- #define read_inheritable_socket(dest, src) (*(dest) = *(src))
- #else
- static bool write_duplicated_handle(HANDLE *dest, HANDLE src, HANDLE child);
- static bool write_inheritable_socket(InheritableSocket *dest, SOCKET src,
- pid_t childPid);
- static void read_inheritable_socket(SOCKET *dest, InheritableSocket *src);
- #endif
- /* Save critical backend variables into the BackendParameters struct */
- #ifndef WIN32
- static bool
- save_backend_variables(BackendParameters *param, Port *port)
- #else
- static bool
- save_backend_variables(BackendParameters *param, Port *port,
- HANDLE childProcess, pid_t childPid)
- #endif
- {
- memcpy(¶m->port, port, sizeof(Port));
- if (!write_inheritable_socket(¶m->portsocket, port->sock, childPid))
- return false;
- strlcpy(param->DataDir, DataDir, MAXPGPATH);
- memcpy(¶m->ListenSocket, &ListenSocket, sizeof(ListenSocket));
- param->MyCancelKey = MyCancelKey;
- param->MyPMChildSlot = MyPMChildSlot;
- param->UsedShmemSegID = UsedShmemSegID;
- param->UsedShmemSegAddr = UsedShmemSegAddr;
- param->ShmemLock = ShmemLock;
- param->ShmemVariableCache = ShmemVariableCache;
- param->ShmemBackendArray = ShmemBackendArray;
- #ifndef HAVE_SPINLOCKS
- param->SpinlockSemaArray = SpinlockSemaArray;
- #endif
- param->MainLWLockArray = MainLWLockArray;
- param->ProcStructLock = ProcStructLock;
- param->ProcGlobal = ProcGlobal;
- param->AuxiliaryProcs = AuxiliaryProcs;
- param->PreparedXactProcs = PreparedXactProcs;
- param->PMSignalState = PMSignalState;
- if (!write_inheritable_socket(¶m->pgStatSock, pgStatSock, childPid))
- return false;
- param->PostmasterPid = PostmasterPid;
- param->PgStartTime = PgStartTime;
- param->PgReloadTime = PgReloadTime;
- param->first_syslogger_file_time = first_syslogger_file_time;
- param->redirection_done = redirection_done;
- param->IsBinaryUpgrade = IsBinaryUpgrade;
- param->max_safe_fds = max_safe_fds;
- param->MaxBackends = MaxBackends;
- #ifdef WIN32
- param->PostmasterHandle = PostmasterHandle;
- if (!write_duplicated_handle(¶m->initial_signal_pipe,
- pgwin32_create_signal_listener(childPid),
- childProcess))
- return false;
- #else
- memcpy(¶m->postmaster_alive_fds, &postmaster_alive_fds,
- sizeof(postmaster_alive_fds));
- #endif
- memcpy(¶m->syslogPipe, &syslogPipe, sizeof(syslogPipe));
- strlcpy(param->my_exec_path, my_exec_path, MAXPGPATH);
- strlcpy(param->pkglib_path, pkglib_path, MAXPGPATH);
- strlcpy(param->ExtraOptions, ExtraOptions, MAXPGPATH);
- return true;
- }
- #ifdef WIN32
- /*
- * Duplicate a handle for usage in a child process, and write the child
- * process instance of the handle to the parameter file.
- */
- static bool
- write_duplicated_handle(HANDLE *dest, HANDLE src, HANDLE childProcess)
- {
- HANDLE hChild = INVALID_HANDLE_VALUE;
- if (!DuplicateHandle(GetCurrentProcess(),
- src,
- childProcess,
- &hChild,
- 0,
- TRUE,
- DUPLICATE_CLOSE_SOURCE | DUPLICATE_SAME_ACCESS))
- {
- ereport(LOG,
- (errmsg_internal("could not duplicate handle to be written to backend parameter file: error code %lu",
- GetLastError())));
- return false;
- }
- *dest = hChild;
- return true;
- }
- /*
- * Duplicate a socket for usage in a child process, and write the resulting
- * structure to the parameter file.
- * This is required because a number of LSPs (Layered Service Providers) very
- * common on Windows (antivirus, firewalls, download managers etc) break
- * straight socket inheritance.
- */
- static bool
- write_inheritable_socket(InheritableSocket *dest, SOCKET src, pid_t childpid)
- {
- dest->origsocket = src;
- if (src != 0 && src != PGINVALID_SOCKET)
- {
- /* Actual socket */
- if (WSADuplicateSocket(src, childpid, &dest->wsainfo) != 0)
- {
- ereport(LOG,
- (errmsg("could not duplicate socket %d for use in backend: error code %d",
- (int) src, WSAGetLastError())));
- return false;
- }
- }
- return true;
- }
- /*
- * Read a duplicate socket structure back, and get the socket descriptor.
- */
- static void
- read_inheritable_socket(SOCKET *dest, InheritableSocket *src)
- {
- SOCKET s;
- if (src->origsocket == PGINVALID_SOCKET || src->origsocket == 0)
- {
- /* Not a real socket! */
- *dest = src->origsocket;
- }
- else
- {
- /* Actual socket, so create from structure */
- s = WSASocket(FROM_PROTOCOL_INFO,
- FROM_PROTOCOL_INFO,
- FROM_PROTOCOL_INFO,
- &src->wsainfo,
- 0,
- 0);
- if (s == INVALID_SOCKET)
- {
- write_stderr("could not create inherited socket: error code %d\n",
- WSAGetLastError());
- exit(1);
- }
- *dest = s;
- /*
- * To make sure we don't get two references to the same socket, close
- * the original one. (This would happen when inheritance actually
- * works..
- */
- closesocket(src->origsocket);
- }
- }
- #endif
- static void
- read_backend_variables(char *id, Port *port)
- {
- BackendParameters param;
- #ifndef WIN32
- /* Non-win32 implementation reads from file */
- FILE *fp;
- /* Open file */
- fp = AllocateFile(id, PG_BINARY_R);
- if (!fp)
- {
- write_stderr("could not read from backend variables file \"%s\": %s\n",
- id, strerror(errno));
- exit(1);
- }
- if (fread(¶m, sizeof(param), 1, fp) != 1)
- {
- write_stderr("could not read from backend variables file \"%s\": %s\n",
- id, strerror(errno));
- exit(1);
- }
- /* Release file */
- FreeFile(fp);
- if (unlink(id) != 0)
- {
- write_stderr("could not remove file \"%s\": %s\n",
- id, strerror(errno));
- exit(1);
- }
- #else
- /* Win32 version uses mapped file */
- HANDLE paramHandle;
- BackendParameters *paramp;
- #ifdef _WIN64
- paramHandle = (HANDLE) _atoi64(id);
- #else
- paramHandle = (HANDLE) atol(id);
- #endif
- paramp = MapViewOfFile(paramHandle, FILE_MAP_READ, 0, 0, 0);
- if (!paramp)
- {
- write_stderr("could not map view of backend variables: error code %lu\n",
- GetLastError());
- exit(1);
- }
- memcpy(¶m, paramp, sizeof(BackendParameters));
- if (!UnmapViewOfFile(paramp))
- {
- write_stderr("could not unmap view of backend variables: error code %lu\n",
- GetLastError());
- exit(1);
- }
- if (!CloseHandle(paramHandle))
- {
- write_stderr("could not close handle to backend parameter variables: error code %lu\n",
- GetLastError());
- exit(1);
- }
- #endif
- restore_backend_variables(¶m, port);
- }
- /* Restore critical backend variables from the BackendParameters struct */
- static void
- restore_backend_variables(BackendParameters *param, Port *port)
- {
- memcpy(port, ¶m->port, sizeof(Port));
- read_inheritable_socket(&port->sock, ¶m->portsocket);
- SetDataDir(param->DataDir);
- memcpy(&ListenSocket, ¶m->ListenSocket, sizeof(ListenSocket));
- MyCancelKey = param->MyCancelKey;
- MyPMChildSlot = param->MyPMChildSlot;
- UsedShmemSegID = param->UsedShmemSegID;
- UsedShmemSegAddr = param->UsedShmemSegAddr;
- ShmemLock = param->ShmemLock;
- ShmemVariableCache = param->ShmemVariableCache;
- ShmemBackendArray = param->ShmemBackendArray;
- #ifndef HAVE_SPINLOCKS
- SpinlockSemaArray = param->SpinlockSemaArray;
- #endif
- MainLWLockArray = param->MainLWLockArray;
- ProcStructLock = param->ProcStructLock;
- ProcGlobal = param->ProcGlobal;
- AuxiliaryProcs = param->AuxiliaryProcs;
- PreparedXactProcs = param->PreparedXactProcs;
- PMSignalState = param->PMSignalState;
- read_inheritable_socket(&pgStatSock, ¶m->pgStatSock);
- PostmasterPid = param->PostmasterPid;
- PgStartTime = param->PgStartTime;
- PgReloadTime = param->PgReloadTime;
- first_syslogger_file_time = param->first_syslogger_file_time;
- redirection_done = param->redirection_done;
- IsBinaryUpgrade = param->IsBinaryUpgrade;
- max_safe_fds = param->max_safe_fds;
- MaxBackends = param->MaxBackends;
- #ifdef WIN32
- PostmasterHandle = param->PostmasterHandle;
- pgwin32_initial_signal_pipe = param->initial_signal_pipe;
- #else
- memcpy(&postmaster_alive_fds, ¶m->postmaster_alive_fds,
- sizeof(postmaster_alive_fds));
- #endif
- memcpy(&syslogPipe, ¶m->syslogPipe, sizeof(syslogPipe));
- strlcpy(my_exec_path, param->my_exec_path, MAXPGPATH);
- strlcpy(pkglib_path, param->pkglib_path, MAXPGPATH);
- strlcpy(ExtraOptions, param->ExtraOptions, MAXPGPATH);
- }
- Size
- ShmemBackendArraySize(void)
- {
- return mul_size(MaxLivePostmasterChildren(), sizeof(Backend));
- }
- void
- ShmemBackendArrayAllocation(void)
- {
- Size size = ShmemBackendArraySize();
- ShmemBackendArray = (Backend *) ShmemAlloc(size);
- /* Mark all slots as empty */
- memset(ShmemBackendArray, 0, size);
- }
- static void
- ShmemBackendArrayAdd(Backend *bn)
- {
- /* The array slot corresponding to my PMChildSlot should be free */
- int i = bn->child_slot - 1;
- Assert(ShmemBackendArray[i].pid == 0);
- ShmemBackendArray[i] = *bn;
- }
- static void
- ShmemBackendArrayRemove(Backend *bn)
- {
- int i = bn->child_slot - 1;
- Assert(ShmemBackendArray[i].pid == bn->pid);
- /* Mark the slot as empty */
- ShmemBackendArray[i].pid = 0;
- }
- #endif /* EXEC_BACKEND */
- #ifdef WIN32
- /*
- * Subset implementation of waitpid() for Windows. We assume pid is -1
- * (that is, check all child processes) and options is WNOHANG (don't wait).
- */
- static pid_t
- waitpid(pid_t pid, int *exitstatus, int options)
- {
- DWORD dwd;
- ULONG_PTR key;
- OVERLAPPED *ovl;
- /*
- * Check if there are any dead children. If there are, return the pid of
- * the first one that died.
- */
- if (GetQueuedCompletionStatus(win32ChildQueue, &dwd, &key, &ovl, 0))
- {
- *exitstatus = (int) key;
- return dwd;
- }
- return -1;
- }
- /*
- * Note! Code below executes on a thread pool! All operations must
- * be thread safe! Note that elog() and friends must *not* be used.
- */
- static void WINAPI
- pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
- {
- win32_deadchild_waitinfo *childinfo = (win32_deadchild_waitinfo *) lpParameter;
- DWORD exitcode;
- if (TimerOrWaitFired)
- return; /* timeout. Should never happen, since we use
- * INFINITE as timeout value. */
- /*
- * Remove handle from wait - required even though it's set to wait only
- * once
- */
- UnregisterWaitEx(childinfo->waitHandle, NULL);
- if (!GetExitCodeProcess(childinfo->procHandle, &exitcode))
- {
- /*
- * Should never happen. Inform user and set a fixed exitcode.
- */
- write_stderr("could not read exit code for process\n");
- exitcode = 255;
- }
- if (!PostQueuedCompletionStatus(win32ChildQueue, childinfo->procId, (ULONG_PTR) exitcode, NULL))
- write_stderr("could not post child completion status\n");
- /*
- * Handle is per-process, so we close it here instead of in the
- * originating thread
- */
- CloseHandle(childinfo->procHandle);
- /*
- * Free struct that was allocated before the call to
- * RegisterWaitForSingleObject()
- */
- free(childinfo);
- /* Queue SIGCHLD signal */
- pg_queue_signal(SIGCHLD);
- }
- #endif /* WIN32 */
- /*
- * Initialize one and only handle for monitoring postmaster death.
- *
- * Called once in the postmaster, so that child processes can subsequently
- * monitor if their parent is dead.
- */
- static void
- InitPostmasterDeathWatchHandle(void)
- {
- #ifndef WIN32
- /*
- * Create a pipe. Postmaster holds the write end of the pipe open
- * (POSTMASTER_FD_OWN), and children hold the read end. Children can pass
- * the read file descriptor to select() to wake up in case postmaster
- * dies, or check for postmaster death with a (read() == 0). Children must
- * close the write end as soon as possible after forking, because EOF
- * won't be signaled in the read end until all processes have closed the
- * write fd. That is taken care of in ClosePostmasterPorts().
- */
- Assert(MyProcPid == PostmasterPid);
- if (pipe(postmaster_alive_fds))
- ereport(FATAL,
- (errcode_for_file_access(),
- errmsg_internal("could not create pipe to monitor postmaster death: %m")));
- /*
- * Set O_NONBLOCK to allow testing for the fd's presence with a read()
- * call.
- */
- if (fcntl(postmaster_alive_fds[POSTMASTER_FD_WATCH], F_SETFL, O_NONBLOCK))
- ereport(FATAL,
- (errcode_for_socket_access(),
- errmsg_internal("could not set postmaster death monitoring pipe to nonblocking mode: %m")));
- #else
- /*
- * On Windows, we use a process handle for the same purpose.
- */
- if (DuplicateHandle(GetCurrentProcess(),
- GetCurrentProcess(),
- GetCurrentProcess(),
- &PostmasterHandle,
- 0,
- TRUE,
- DUPLICATE_SAME_ACCESS) == 0)
- ereport(FATAL,
- (errmsg_internal("could not duplicate postmaster handle: error code %lu",
- GetLastError())));
- #endif /* WIN32 */
- }