/*
 * libev event processing core, watcher management
 *
 * Copyright (c) 2007,2008,2009,2010,2011 Marc Alexander Lehmann <libev@schmorp.de>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, are permitted provided that the following conditions are met:
 * 
 *   1.  Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 * 
 *   2.  Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License ("GPL") version 2 or any later version,
 * in which case the provisions of the GPL are applicable instead of
 * the above. If you wish to allow the use of your version of this file
 * only under the terms of the GPL and not to allow others to use your
 * version of this file under the BSD license, indicate your decision
 * by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL. If you do not delete the
 * provisions above, a recipient may use your version of this file under
 * either the BSD or the GPL.
 */

/* this big block deduces configuration from config.h */
#ifndef EV_STANDALONE
# ifdef EV_CONFIG_H
#  include EV_CONFIG_H
# else
#  include "config.h"
# endif

# if HAVE_CLOCK_SYSCALL
#  ifndef EV_USE_CLOCK_SYSCALL
#   define EV_USE_CLOCK_SYSCALL 1
#   ifndef EV_USE_REALTIME
#    define EV_USE_REALTIME  0
#   endif
#   ifndef EV_USE_MONOTONIC
#    define EV_USE_MONOTONIC 1
#   endif
#  endif
# elif !defined(EV_USE_CLOCK_SYSCALL)
#  define EV_USE_CLOCK_SYSCALL 0
# endif

# if HAVE_CLOCK_GETTIME
#  ifndef EV_USE_MONOTONIC
#   define EV_USE_MONOTONIC 1
#  endif
#  ifndef EV_USE_REALTIME
#   define EV_USE_REALTIME  0
#  endif
# else
#  ifndef EV_USE_MONOTONIC
#   define EV_USE_MONOTONIC 0
#  endif
#  ifndef EV_USE_REALTIME
#   define EV_USE_REALTIME  0
#  endif
# endif

# if HAVE_NANOSLEEP
#  ifndef EV_USE_NANOSLEEP
#    define EV_USE_NANOSLEEP EV_FEATURE_OS
#  endif
# else
#   undef EV_USE_NANOSLEEP
#   define EV_USE_NANOSLEEP 0
# endif

# if HAVE_SELECT && HAVE_SYS_SELECT_H
#  ifndef EV_USE_SELECT
#   define EV_USE_SELECT EV_FEATURE_BACKENDS
#  endif
# else
#  undef EV_USE_SELECT
#  define EV_USE_SELECT 0
# endif

# if HAVE_POLL && HAVE_POLL_H
#  ifndef EV_USE_POLL
#   define EV_USE_POLL EV_FEATURE_BACKENDS
#  endif
# else
#  undef EV_USE_POLL
#  define EV_USE_POLL 0
# endif
   
# if HAVE_EPOLL_CTL && HAVE_SYS_EPOLL_H
#  ifndef EV_USE_EPOLL
#   define EV_USE_EPOLL EV_FEATURE_BACKENDS
#  endif
# else
#  undef EV_USE_EPOLL
#  define EV_USE_EPOLL 0
# endif
   
# if HAVE_KQUEUE && HAVE_SYS_EVENT_H
#  ifndef EV_USE_KQUEUE
#   define EV_USE_KQUEUE EV_FEATURE_BACKENDS
#  endif
# else
#  undef EV_USE_KQUEUE
#  define EV_USE_KQUEUE 0
# endif
   
# if HAVE_PORT_H && HAVE_PORT_CREATE
#  ifndef EV_USE_PORT
#   define EV_USE_PORT EV_FEATURE_BACKENDS
#  endif
# else
#  undef EV_USE_PORT
#  define EV_USE_PORT 0
# endif

# if HAVE_INOTIFY_INIT && HAVE_SYS_INOTIFY_H
#  ifndef EV_USE_INOTIFY
#   define EV_USE_INOTIFY EV_FEATURE_OS
#  endif
# else
#  undef EV_USE_INOTIFY
#  define EV_USE_INOTIFY 0
# endif

# if HAVE_SIGNALFD && HAVE_SYS_SIGNALFD_H
#  ifndef EV_USE_SIGNALFD
#   define EV_USE_SIGNALFD EV_FEATURE_OS
#  endif
# else
#  undef EV_USE_SIGNALFD
#  define EV_USE_SIGNALFD 0
# endif

# if HAVE_EVENTFD
#  ifndef EV_USE_EVENTFD
#   define EV_USE_EVENTFD EV_FEATURE_OS
#  endif
# else
#  undef EV_USE_EVENTFD
#  define EV_USE_EVENTFD 0
# endif
 
#endif

#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <stddef.h>

#include <stdio.h>

#include <assert.h>
#include <errno.h>
#include <sys/types.h>
#include <time.h>
#include <limits.h>

#include <signal.h>

#ifdef EV_H
# include EV_H
#else
# include "ev.h"
#endif

EV_CPP(extern "C" {)

#ifndef _WIN32
# include <sys/time.h>
# include <sys/wait.h>
# include <unistd.h>
#else
# include <io.h>
# define WIN32_LEAN_AND_MEAN
# include <windows.h>
# ifndef EV_SELECT_IS_WINSOCKET
#  define EV_SELECT_IS_WINSOCKET 1
# endif
# undef EV_AVOID_STDIO
#endif

/* OS X, in its infinite idiocy, actually HARDCODES
 * a limit of 1024 into their select. Where people have brains,
 * OS X engineers apparently have a vacuum. Or maybe they were
 * ordered to have a vacuum, or they do anything for money.
 * This might help. Or not.
 */
#define _DARWIN_UNLIMITED_SELECT 1

/* this block tries to deduce configuration from header-defined symbols and defaults */

/* try to deduce the maximum number of signals on this platform */
#if defined (EV_NSIG)
/* use what's provided */
#elif defined (NSIG)
# define EV_NSIG (NSIG)
#elif defined(_NSIG)
# define EV_NSIG (_NSIG)
#elif defined (SIGMAX)
# define EV_NSIG (SIGMAX+1)
#elif defined (SIG_MAX)
# define EV_NSIG (SIG_MAX+1)
#elif defined (_SIG_MAX)
# define EV_NSIG (_SIG_MAX+1)
#elif defined (MAXSIG)
# define EV_NSIG (MAXSIG+1)
#elif defined (MAX_SIG)
# define EV_NSIG (MAX_SIG+1)
#elif defined (SIGARRAYSIZE)
# define EV_NSIG (SIGARRAYSIZE) /* Assume ary[SIGARRAYSIZE] */
#elif defined (_sys_nsig)
# define EV_NSIG (_sys_nsig) /* Solaris 2.5 */
#else
# error "unable to find value for NSIG, please report"
/* to make it compile regardless, just remove the above line, */
/* but consider reporting it, too! :) */
# define EV_NSIG 65
#endif

#ifndef EV_USE_CLOCK_SYSCALL
# if __linux && __GLIBC__ >= 2
#  define EV_USE_CLOCK_SYSCALL EV_FEATURE_OS
# else
#  define EV_USE_CLOCK_SYSCALL 0
# endif
#endif

#ifndef EV_USE_MONOTONIC
# if defined (_POSIX_MONOTONIC_CLOCK) && _POSIX_MONOTONIC_CLOCK >= 0
#  define EV_USE_MONOTONIC EV_FEATURE_OS
# else
#  define EV_USE_MONOTONIC 0
# endif
#endif

#ifndef EV_USE_REALTIME
# define EV_USE_REALTIME !EV_USE_CLOCK_SYSCALL
#endif

#ifndef EV_USE_NANOSLEEP
# if _POSIX_C_SOURCE >= 199309L
#  define EV_USE_NANOSLEEP EV_FEATURE_OS
# else
#  define EV_USE_NANOSLEEP 0
# endif
#endif

#ifndef EV_USE_SELECT
# define EV_USE_SELECT EV_FEATURE_BACKENDS
#endif

#ifndef EV_USE_POLL
# ifdef _WIN32
#  define EV_USE_POLL 0
# else
#  define EV_USE_POLL EV_FEATURE_BACKENDS
# endif
#endif

#ifndef EV_USE_EPOLL
# if __linux && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 4))
#  define EV_USE_EPOLL EV_FEATURE_BACKENDS
# else
#  define EV_USE_EPOLL 0
# endif
#endif

#ifndef EV_USE_KQUEUE
# define EV_USE_KQUEUE 0
#endif

#ifndef EV_USE_PORT
# define EV_USE_PORT 0
#endif

#ifndef EV_USE_INOTIFY
# if __linux && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 4))
#  define EV_USE_INOTIFY EV_FEATURE_OS
# else
#  define EV_USE_INOTIFY 0
# endif
#endif

#ifndef EV_PID_HASHSIZE
# define EV_PID_HASHSIZE EV_FEATURE_DATA ? 16 : 1
#endif

#ifndef EV_INOTIFY_HASHSIZE
# define EV_INOTIFY_HASHSIZE EV_FEATURE_DATA ? 16 : 1
#endif

#ifndef EV_USE_EVENTFD
# if __linux && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 7))
#  define EV_USE_EVENTFD EV_FEATURE_OS
# else
#  define EV_USE_EVENTFD 0
# endif
#endif

#ifndef EV_USE_SIGNALFD
# if __linux && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 7))
#  define EV_USE_SIGNALFD EV_FEATURE_OS
# else
#  define EV_USE_SIGNALFD 0
# endif
#endif

#if 0 /* debugging */
# define EV_VERIFY 3
# define EV_USE_4HEAP 1
# define EV_HEAP_CACHE_AT 1
#endif

#ifndef EV_VERIFY
# define EV_VERIFY (EV_FEATURE_API ? 1 : 0)
#endif

#ifndef EV_USE_4HEAP
# define EV_USE_4HEAP EV_FEATURE_DATA
#endif

#ifndef EV_HEAP_CACHE_AT
# define EV_HEAP_CACHE_AT EV_FEATURE_DATA
#endif

/* on linux, we can use a (slow) syscall to avoid a dependency on pthread, */
/* which makes programs even slower. might work on other unices, too. */
#if EV_USE_CLOCK_SYSCALL
# include <syscall.h>
# ifdef SYS_clock_gettime
#  define clock_gettime(id, ts) syscall (SYS_clock_gettime, (id), (ts))
#  undef EV_USE_MONOTONIC
#  define EV_USE_MONOTONIC 1
# else
#  undef EV_USE_CLOCK_SYSCALL
#  define EV_USE_CLOCK_SYSCALL 0
# endif
#endif

/* this block fixes any misconfiguration where we know we run into trouble otherwise */

#ifdef _AIX
/* AIX has a completely broken poll.h header */
# undef EV_USE_POLL
# define EV_USE_POLL 0
#endif

#ifndef CLOCK_MONOTONIC
# undef EV_USE_MONOTONIC
# define EV_USE_MONOTONIC 0
#endif

#ifndef CLOCK_REALTIME
# undef EV_USE_REALTIME
# define EV_USE_REALTIME 0
#endif

#if !EV_STAT_ENABLE
# undef EV_USE_INOTIFY
# define EV_USE_INOTIFY 0
#endif

#if !EV_USE_NANOSLEEP
# ifndef _WIN32
#  include <sys/select.h>
# endif
#endif

#if EV_USE_INOTIFY
# include <sys/statfs.h>
# include <sys/inotify.h>
/* some very old inotify.h headers don't have IN_DONT_FOLLOW */
# ifndef IN_DONT_FOLLOW
#  undef EV_USE_INOTIFY
#  define EV_USE_INOTIFY 0
# endif
#endif

#if EV_SELECT_IS_WINSOCKET
# include <winsock.h>
#endif

#if EV_USE_EVENTFD
/* our minimum requirement is glibc 2.7 which has the stub, but not the header */
# include <stdint.h>
# ifndef EFD_NONBLOCK
#  define EFD_NONBLOCK O_NONBLOCK
# endif
# ifndef EFD_CLOEXEC
#  ifdef O_CLOEXEC
#   define EFD_CLOEXEC O_CLOEXEC
#  else
#   define EFD_CLOEXEC 02000000
#  endif
# endif
EV_CPP(extern "C") int (eventfd) (unsigned int initval, int flags);
#endif

#if EV_USE_SIGNALFD
/* our minimum requirement is glibc 2.7 which has the stub, but not the header */
# include <stdint.h>
# ifndef SFD_NONBLOCK
#  define SFD_NONBLOCK O_NONBLOCK
# endif
# ifndef SFD_CLOEXEC
#  ifdef O_CLOEXEC
#   define SFD_CLOEXEC O_CLOEXEC
#  else
#   define SFD_CLOEXEC 02000000
#  endif
# endif
EV_CPP (extern "C") int signalfd (int fd, const sigset_t *mask, int flags);

struct signalfd_siginfo
{
  uint32_t ssi_signo;
  char pad[128 - sizeof (uint32_t)];
};
#endif

/**/

#if EV_VERIFY >= 3
# define EV_FREQUENT_CHECK ev_verify (EV_A)
#else
# define EV_FREQUENT_CHECK do { } while (0)
#endif

/*
 * This is used to avoid floating point rounding problems.
 * It is added to ev_rt_now when scheduling periodics
 * to ensure progress, time-wise, even when rounding
 * errors are against us.
 * This value is good at least till the year 4000.
 * Better solutions welcome.
 */
#define TIME_EPSILON  0.0001220703125 /* 1/8192 */

#define MIN_TIMEJUMP  1. /* minimum timejump that gets detected (if monotonic clock available) */
#define MAX_BLOCKTIME 59.743 /* never wait longer than this time (to detect time jumps) */

#define EV_TV_SET(tv,t) do { tv.tv_sec = (long)t; tv.tv_usec = (long)((t - tv.tv_sec) * 1e6); } while (0)
#define EV_TS_SET(ts,t) do { ts.tv_sec = (long)t; ts.tv_nsec = (long)((t - ts.tv_sec) * 1e9); } while (0)

#if __GNUC__ >= 4
# define expect(expr,value)         __builtin_expect ((expr),(value))
# define noinline                   __attribute__ ((noinline))
#else
# define expect(expr,value)         (expr)
# define noinline
# if __STDC_VERSION__ < 199901L && __GNUC__ < 2
#  define inline
# endif
#endif

#define expect_false(expr) expect ((expr) != 0, 0)
#define expect_true(expr)  expect ((expr) != 0, 1)
#define inline_size        static inline

#if EV_FEATURE_CODE
# define inline_speed      static inline
#else
# define inline_speed      static noinline
#endif

#define NUMPRI (EV_MAXPRI - EV_MINPRI + 1)

#if EV_MINPRI == EV_MAXPRI
# define ABSPRI(w) (((W)w), 0)
#else
# define ABSPRI(w) (((W)w)->priority - EV_MINPRI)
#endif

#define EMPTY       /* required for microsofts broken pseudo-c compiler */
#define EMPTY2(a,b) /* used to suppress some warnings */

typedef ev_watcher *W;
typedef ev_watcher_list *WL;
typedef ev_watcher_time *WT;

#define ev_active(w) ((W)(w))->active
#define ev_at(w) ((WT)(w))->at

#if EV_USE_REALTIME
/* sig_atomic_t is used to avoid per-thread variables or locking but still */
/* giving it a reasonably high chance of working on typical architectures */
static EV_ATOMIC_T have_realtime; /* did clock_gettime (CLOCK_REALTIME) work? */
#endif

#if EV_USE_MONOTONIC
static EV_ATOMIC_T have_monotonic; /* did clock_gettime (CLOCK_MONOTONIC) work? */
#endif

#ifndef EV_FD_TO_WIN32_HANDLE
# define EV_FD_TO_WIN32_HANDLE(fd) _get_osfhandle (fd)
#endif
#ifndef EV_WIN32_HANDLE_TO_FD
# define EV_WIN32_HANDLE_TO_FD(handle) _open_osfhandle (handle, 0)
#endif
#ifndef EV_WIN32_CLOSE_FD
# define EV_WIN32_CLOSE_FD(fd) close (fd)
#endif

#ifdef _WIN32
# include "ev_win32.c"
#endif

/*****************************************************************************/

#ifdef __linux
# include <sys/utsname.h>
#endif

static unsigned int noinline
ev_linux_version (void)
{
#ifdef __linux
  unsigned int v = 0;
  struct utsname buf;
  int i;
  char *p = buf.release;

  if (uname (&buf))
    return 0;

  for (i = 3+1; --i; )
    {
      unsigned int c = 0;

      for (;;)
        {
          if (*p >= '0' && *p <= '9')
            c = c * 10 + *p++ - '0';
          else
            {
              p += *p == '.';
              break;
            }
        }

      v = (v << 8) | c;
    }

  return v;
#else
  return 0;
#endif
}

/*****************************************************************************/

#if EV_AVOID_STDIO
static void noinline
ev_printerr (const char *msg)
{
  write (STDERR_FILENO, msg, strlen (msg));
}
#endif

static void (*syserr_cb)(const char *msg);

void
ev_set_syserr_cb (void (*cb)(const char *msg))
{
  syserr_cb = cb;
}

static void noinline
ev_syserr (const char *msg)
{
  if (!msg)
    msg = "(libev) system error";

  if (syserr_cb)
    syserr_cb (msg);
  else
    {
#if EV_AVOID_STDIO
      ev_printerr (msg);
      ev_printerr (": ");
      ev_printerr (strerror (errno));
      ev_printerr ("\n");
#else
      perror (msg);
#endif
      abort ();
    }
}

static void *
ev_realloc_emul (void *ptr, long size)
{
#if __GLIBC__
  return realloc (ptr, size);
#else
  /* some systems, notably openbsd and darwin, fail to properly
   * implement realloc (x, 0) (as required by both ansi c-89 and
   * the single unix specification, so work around them here.
   */

  if (size)
    return realloc (ptr, size);

  free (ptr);
  return 0;
#endif
}

static void *(*alloc)(void *ptr, long size) = ev_realloc_emul;

void
ev_set_allocator (void *(*cb)(void *ptr, long size))
{
  alloc = cb;
}

inline_speed void *
ev_realloc (void *ptr, long size)
{
  ptr = alloc (ptr, size);

  if (!ptr && size)
    {
#if EV_AVOID_STDIO
      ev_printerr ("(libev) memory allocation failed, aborting.\n");
#else
      fprintf (stderr, "(libev) cannot allocate %ld bytes, aborting.", size);
#endif
      abort ();
    }

  return ptr;
}

#define ev_malloc(size) ev_realloc (0, (size))
#define ev_free(ptr)    ev_realloc ((ptr), 0)

/*****************************************************************************/

/* set in reify when reification needed */
#define EV_ANFD_REIFY 1

/* file descriptor info structure */
typedef struct
{
  WL head;
  unsigned char events; /* the events watched for */
  unsigned char reify;  /* flag set when this ANFD needs reification (EV_ANFD_REIFY, EV__IOFDSET) */
  unsigned char emask;  /* the epoll backend stores the actual kernel mask in here */
  unsigned char unused;
#if EV_USE_EPOLL
  unsigned int egen;    /* generation counter to counter epoll bugs */
#endif
#if EV_SELECT_IS_WINSOCKET || EV_USE_IOCP
  SOCKET handle;
#endif
#if EV_USE_IOCP
  OVERLAPPED or, ow;
#endif
} ANFD;

/* stores the pending event set for a given watcher */
typedef struct
{
  W w;
  int events; /* the pending event set for the given watcher */
} ANPENDING;

#if EV_USE_INOTIFY
/* hash table entry per inotify-id */
typedef struct
{
  WL head;
} ANFS;
#endif

/* Heap Entry */
#if EV_HEAP_CACHE_AT
  /* a heap element */
  typedef struct {
    ev_tstamp at;
    WT w;
  } ANHE;

  #define ANHE_w(he)        (he).w     /* access watcher, read-write */
  #define ANHE_at(he)       (he).at    /* access cached at, read-only */
  #define ANHE_at_cache(he) (he).at = (he).w->at /* update at from watcher */
#else
  /* a heap element */
  typedef WT ANHE;

  #define ANHE_w(he)        (he)
  #define ANHE_at(he)       (he)->at
  #define ANHE_at_cache(he)
#endif

#if EV_MULTIPLICITY

  struct ev_loop
  {
    ev_tstamp ev_rt_now;
    #define ev_rt_now ((loop)->ev_rt_now)
    #define VAR(name,decl) decl;
      #include "ev_vars.h"
    #undef VAR
  };
  #include "ev_wrap.h"

  static struct ev_loop default_loop_struct;
  struct ev_loop *ev_default_loop_ptr;

#else

  ev_tstamp ev_rt_now;
  #define VAR(name,decl) static decl;
    #include "ev_vars.h"
  #undef VAR

  static int ev_default_loop_ptr;

#endif

#if EV_FEATURE_API
# define EV_RELEASE_CB if (expect_false (release_cb)) release_cb (EV_A)
# define EV_ACQUIRE_CB if (expect_false (acquire_cb)) acquire_cb (EV_A)
# define EV_INVOKE_PENDING invoke_cb (EV_A)
#else
# define EV_RELEASE_CB (void)0
# define EV_ACQUIRE_CB (void)0
# define EV_INVOKE_PENDING ev_invoke_pending (EV_A)
#endif

#define EVBREAK_RECURSE 0x80

/*****************************************************************************/

#ifndef EV_HAVE_EV_TIME
ev_tstamp
ev_time (void)
{
#if EV_USE_REALTIME
  if (expect_true (have_realtime))
    {
      struct timespec ts;
      clock_gettime (CLOCK_REALTIME, &ts);
      return ts.tv_sec + ts.tv_nsec * 1e-9;
    }
#endif

  struct timeval tv;
  gettimeofday (&tv, 0);
  return tv.tv_sec + tv.tv_usec * 1e-6;
}
#endif

inline_size ev_tstamp
get_clock (void)
{
#if EV_USE_MONOTONIC
  if (expect_true (have_monotonic))
    {
      struct timespec ts;
      clock_gettime (CLOCK_MONOTONIC, &ts);
      return ts.tv_sec + ts.tv_nsec * 1e-9;
    }
#endif

  return ev_time ();
}

#if EV_MULTIPLICITY
ev_tstamp
ev_now (EV_P)
{
  return ev_rt_now;
}
#endif

void
ev_sleep (ev_tstamp delay)
{
  if (delay > 0.)
    {
#if EV_USE_NANOSLEEP
      struct timespec ts;

      EV_TS_SET (ts, delay);
      nanosleep (&ts, 0);
#elif defined(_WIN32)
      Sleep ((unsigned long)(delay * 1e3));
#else
      struct timeval tv;

      /* here we rely on sys/time.h + sys/types.h + unistd.h providing select */
      /* something not guaranteed by newer posix versions, but guaranteed */
      /* by older ones */
      EV_TV_SET (tv, delay);
      select (0, 0, 0, 0, &tv);
#endif
    }
}

/*****************************************************************************/

#define MALLOC_ROUND 4096 /* prefer to allocate in chunks of this size, must be 2**n and >> 4 longs */

/* find a suitable new size for the given array, */
/* hopefully by rounding to a nice-to-malloc size */
inline_size int
array_nextsize (int elem, int cur, int cnt)
{
  int ncur = cur + 1;

  do
    ncur <<= 1;
  while (cnt > ncur);

  /* if size is large, round to MALLOC_ROUND - 4 * longs to accomodate malloc overhead */
  if (elem * ncur > MALLOC_ROUND - sizeof (void *) * 4)
    {
      ncur *= elem;
      ncur = (ncur + elem + (MALLOC_ROUND - 1) + sizeof (void *) * 4) & ~(MALLOC_ROUND - 1);
      ncur = ncur - sizeof (void *) * 4;
      ncur /= elem;
    }

  return ncur;
}

static noinline void *
array_realloc (int elem, void *base, int *cur, int cnt)
{
  *cur = array_nextsize (elem, *cur, cnt);
  return ev_realloc (base, elem * *cur);
}

#define array_init_zero(base,count)	\
  memset ((void *)(base), 0, sizeof (*(base)) * (count))

#define array_needsize(type,base,cur,cnt,init)			\
  if (expect_false ((cnt) > (cur)))				\
    {								\
      int ocur_ = (cur);					\
      (base) = (type *)array_realloc				\
         (sizeof (type), (base), &(cur), (cnt));		\
      init ((base) + (ocur_), (cur) - ocur_);			\
    }

#if 0
#define array_slim(type,stem)					\
  if (stem ## max < array_roundsize (stem ## cnt >> 2))		\
    {								\
      stem ## max = array_roundsize (stem ## cnt >> 1);		\
      base = (type *)ev_realloc (base, sizeof (type) * (stem ## max));\
      fprintf (stderr, "slimmed down " # stem " to %d\n", stem ## max);/*D*/\
    }
#endif

#define array_free(stem, idx) \
  ev_free (stem ## s idx); stem ## cnt idx = stem ## max idx = 0; stem ## s idx = 0

/*****************************************************************************/

/* dummy callback for pending events */
static void noinline
pendingcb (EV_P_ ev_prepare *w, int revents)
{
}

void noinline
ev_feed_event (EV_P_ void *w, int revents)
{
  W w_ = (W)w;
  int pri = ABSPRI (w_);

  if (expect_false (w_->pending))
    pendings [pri][w_->pending - 1].events |= revents;
  else
    {
      w_->pending = ++pendingcnt [pri];
      array_needsize (ANPENDING, pendings [pri], pendingmax [pri], w_->pending, EMPTY2);
      pendings [pri][w_->pending - 1].w      = w_;
      pendings [pri][w_->pending - 1].events = revents;
    }
}

inline_speed void
feed_reverse (EV_P_ W w)
{
  array_needsize (W, rfeeds, rfeedmax, rfeedcnt + 1, EMPTY2);
  rfeeds [rfeedcnt++] = w;
}

inline_size void
feed_reverse_done (EV_P_ int revents)
{
  do
    ev_feed_event (EV_A_ rfeeds [--rfeedcnt], revents);
  while (rfeedcnt);
}

inline_speed void
queue_events (EV_P_ W *events, int eventcnt, int type)
{
  int i;

  for (i = 0; i < eventcnt; ++i)
    ev_feed_event (EV_A_ events [i], type);
}

/*****************************************************************************/

inline_speed void
fd_event_nocheck (EV_P_ int fd, int revents)
{
  ANFD *anfd = anfds + fd;
  ev_io *w;

  for (w = (ev_io *)anfd->head; w; w = (ev_io *)((WL)w)->next)
    {
      int ev = w->events & revents;

      if (ev)
        ev_feed_event (EV_A_ (W)w, ev);
    }
}

/* do not submit kernel events for fds that have reify set */
/* because that means they changed while we were polling for new events */
inline_speed void
fd_event (EV_P_ int fd, int revents)
{
  ANFD *anfd = anfds + fd;

  if (expect_true (!anfd->reify))
    fd_event_nocheck (EV_A_ fd, revents);
}

void
ev_feed_fd_event (EV_P_ int fd, int revents)
{
  if (fd >= 0 && fd < anfdmax)
    fd_event_nocheck (EV_A_ fd, revents);
}

/* make sure the external fd watch events are in-sync */
/* with the kernel/libev internal state */
inline_size void
fd_reify (EV_P)
{
  int i;

  for (i = 0; i < fdchangecnt; ++i)
    {
      int fd = fdchanges [i];
      ANFD *anfd = anfds + fd;
      ev_io *w;

      unsigned char o_events = anfd->events;
      unsigned char o_reify  = anfd->reify;

      anfd->reify  = 0;

#if EV_SELECT_IS_WINSOCKET || EV_USE_IOCP
      if (o_reify & EV__IOFDSET)
        {
          unsigned long arg;
          anfd->handle = EV_FD_TO_WIN32_HANDLE (fd);
          assert (("libev: only socket fds supported in this configuration", ioctlsocket (anfd->handle, FIONREAD, &arg) == 0));
          printf ("oi %d %x\n", fd, anfd->handle);//D
        }
#endif

      /*if (expect_true (o_reify & EV_ANFD_REIFY)) probably a deoptimisation */
        {
          anfd->events = 0;

          for (w = (ev_io *)anfd->head; w; w = (ev_io *)((WL)w)->next)
            anfd->events |= (unsigned char)w->events;

          if (o_events != anfd->events)
            o_reify = EV__IOFDSET; /* actually |= */
        }

      if (o_reify & EV__IOFDSET)
        backend_modify (EV_A_ fd, o_events, anfd->events);
    }

  fdchangecnt = 0;
}

/* something about the given fd changed */
inline_size void
fd_change (EV_P_ int fd, int flags)
{
  unsigned char reify = anfds [fd].reify;
  anfds [fd].reify |= flags;

  if (expect_true (!reify))
    {
      ++fdchangecnt;
      array_needsize (int, fdchanges, fdchangemax, fdchangecnt, EMPTY2);
      fdchanges [fdchangecnt - 1] = fd;
    }
}

/* the given fd is invalid/unusable, so make sure it doesn't hurt us anymore */
inline_speed void
fd_kill (EV_P_ int fd)
{
  ev_io *w;

  while ((w = (ev_io *)anfds [fd].head))
    {
      ev_io_stop (EV_A_ w);
      ev_feed_event (EV_A_ (W)w, EV_ERROR | EV_READ | EV_WRITE);
    }
}

/* check whether the given fd is actually valid, for error recovery */
inline_size int
fd_valid (int fd)
{
#ifdef _WIN32
  return EV_FD_TO_WIN32_HANDLE (fd) != -1;
#else
  return fcntl (fd, F_GETFD) != -1;
#endif
}

/* called on EBADF to verify fds */
static void noinline
fd_ebadf (EV_P)
{
  int fd;

  for (fd = 0; fd < anfdmax; ++fd)
    if (anfds [fd].events)
      if (!fd_valid (fd) && errno == EBADF)
        fd_kill (EV_A_ fd);
}

/* called on ENOMEM in select/poll to kill some fds and retry */
static void noinline
fd_enomem (EV_P)
{
  int fd;

  for (fd = anfdmax; fd--; )
    if (anfds [fd].events)
      {
        fd_kill (EV_A_ fd);
        break;
      }
}

/* usually called after fork if backend needs to re-arm all fds from scratch */
static void noinline
fd_rearm_all (EV_P)
{
  int fd;

  for (fd = 0; fd < anfdmax; ++fd)
    if (anfds [fd].events)
      {
        anfds [fd].events = 0;
        anfds [fd].emask  = 0;
        fd_change (EV_A_ fd, EV__IOFDSET | EV_ANFD_REIFY);
      }
}

/* used to prepare libev internal fd's */
/* this is not fork-safe */
inline_speed void
fd_intern (int fd)
{
#ifdef _WIN32
  unsigned long arg = 1;
  ioctlsocket (EV_FD_TO_WIN32_HANDLE (fd), FIONBIO, &arg);
#else
  fcntl (fd, F_SETFD, FD_CLOEXEC);
  fcntl (fd, F_SETFL, O_NONBLOCK);
#endif
}

/*****************************************************************************/

/*
 * the heap functions want a real array index. array index 0 is guaranteed to not
 * be in-use at any time. the first heap entry is at array [HEAP0]. DHEAP gives
 * the branching factor of the d-tree.
 */

/*
 * at the moment we allow libev the luxury of two heaps,
 * a small-code-size 2-heap one and a ~1.5kb larger 4-heap
 * which is more cache-efficient.
 * the difference is about 5% with 50000+ watchers.
 */
#if EV_USE_4HEAP

#define DHEAP 4
#define HEAP0 (DHEAP - 1) /* index of first element in heap */
#define HPARENT(k) ((((k) - HEAP0 - 1) / DHEAP) + HEAP0)
#define UPHEAP_DONE(p,k) ((p) == (k))

/* away from the root */
inline_speed void
downheap (ANHE *heap, int N, int k)
{
  ANHE he = heap [k];
  ANHE *E = heap + N + HEAP0;

  for (;;)
    {
      ev_tstamp minat;
      ANHE *minpos;
      ANHE *pos = heap + DHEAP * (k - HEAP0) + HEAP0 + 1;

      /* find minimum child */
      if (expect_true (pos + DHEAP - 1 < E))
        {
          /* fast path */                               (minpos = pos + 0), (minat = ANHE_at (*minpos));
          if (               ANHE_at (pos [1]) < minat) (minpos = pos + 1), (minat = ANHE_at (*minpos));
          if (               ANHE_at (pos [2]) < minat) (minpos = pos + 2), (minat = ANHE_at (*minpos));
          if (               ANHE_at (pos [3]) < minat) (minpos = pos + 3), (minat = ANHE_at (*minpos));
        }
      else if (pos < E)
        {
          /* slow path */                               (minpos = pos + 0), (minat = ANHE_at (*minpos));
          if (pos + 1 < E && ANHE_at (pos [1]) < minat) (minpos = pos + 1), (minat = ANHE_at (*minpos));
          if (pos + 2 < E && ANHE_at (pos [2]) < minat) (minpos = pos + 2), (minat = ANHE_at (*minpos));
          if (pos + 3 < E && ANHE_at (pos [3]) < minat) (minpos = pos + 3), (minat = ANHE_at (*minpos));
        }
      else
        break;

      if (ANHE_at (he) <= minat)
        break;

      heap [k] = *minpos;
      ev_active (ANHE_w (*minpos)) = k;

      k = minpos - heap;
    }

  heap [k] = he;
  ev_active (ANHE_w (he)) = k;
}

#else /* 4HEAP */

#define HEAP0 1
#define HPARENT(k) ((k) >> 1)
#define UPHEAP_DONE(p,k) (!(p))

/* away from the root */
inline_speed void
downheap (ANHE *heap, int N, int k)
{
  ANHE he = heap [k];

  for (;;)
    {
      int c = k << 1;

      if (c >= N + HEAP0)
        break;

      c += c + 1 < N + HEAP0 && ANHE_at (heap [c]) > ANHE_at (heap [c + 1])
           ? 1 : 0;

      if (ANHE_at (he) <= ANHE_at (heap [c]))
        break;

      heap [k] = heap [c];
      ev_active (ANHE_w (heap [k])) = k;
      
      k = c;
    }

  heap [k] = he;
  ev_active (ANHE_w (he)) = k;
}
#endif

/* towards the root */
inline_speed void
upheap (ANHE *heap, int k)
{
  ANHE he = heap [k];

  for (;;)
    {
      int p = HPARENT (k);

      if (UPHEAP_DONE (p, k) || ANHE_at (heap [p]) <= ANHE_at (he))
        break;

      heap [k] = heap [p];
      ev_active (ANHE_w (heap [k])) = k;
      k = p;
    }

  heap [k] = he;
  ev_active (ANHE_w (he)) = k;
}

/* move an element suitably so it is in a correct place */
inline_size void
adjustheap (ANHE *heap, int N, int k)
{
  if (k > HEAP0 && ANHE_at (heap [k]) <= ANHE_at (heap [HPARENT (k)]))
    upheap (heap, k);
  else
    downheap (heap, N, k);
}

/* rebuild the heap: this function is used only once and executed rarely */
inline_size void
reheap (ANHE *heap, int N)
{
  int i;

  /* we don't use floyds algorithm, upheap is simpler and is more cache-efficient */
  /* also, this is easy to implement and correct for both 2-heaps and 4-heaps */
  for (i = 0; i < N; ++i)
    upheap (heap, i + HEAP0);
}

/*****************************************************************************/

/* associate signal watchers to a signal signal */
typedef struct
{
  EV_ATOMIC_T pending;
#if EV_MULTIPLICITY
  EV_P;
#endif
  WL head;
} ANSIG;

static ANSIG signals [EV_NSIG - 1];

/*****************************************************************************/

#if EV_SIGNAL_ENABLE || EV_ASYNC_ENABLE

static void noinline
evpipe_init (EV_P)
{
  if (!ev_is_active (&pipe_w))
    {
# if EV_USE_EVENTFD
      evfd = eventfd (0, EFD_NONBLOCK | EFD_CLOEXEC);
      if (evfd < 0 && errno == EINVAL)
        evfd = eventfd (0, 0);

      if (evfd >= 0)
        {
          evpipe [0] = -1;
          fd_intern (evfd); /* doing it twice doesn't hurt */
          ev_io_set (&pipe_w, evfd, EV_READ);
        }
      else
# endif
        {
          while (pipe (evpipe))
            ev_syserr ("(libev) error creating signal/async pipe");

          fd_intern (evpipe [0]);
          fd_intern (evpipe [1]);
          ev_io_set (&pipe_w, evpipe [0], EV_READ);
        }

      ev_io_start (EV_A_ &pipe_w);
      ev_unref (EV_A); /* watcher should not keep loop alive */
    }
}

inline_size void
evpipe_write (EV_P_ EV_ATOMIC_T *flag)
{
  if (!*flag)
    {
      int old_errno = errno; /* save errno because write might clobber it */
      char dummy;

      *flag = 1;

#if EV_USE_EVENTFD
      if (evfd >= 0)
        {
          uint64_t counter = 1;
          write (evfd, &counter, sizeof (uint64_t));
        }
      else
#endif
        /* win32 people keep sending patches that change this write() to send() */
        /* and then run away. but send() is wrong, it wants a socket handle on win32 */
        /* so when you think this write should be a send instead, please find out */
        /* where your send() is from - it's definitely not the microsoft send, and */
        /* tell me. thank you. */
        write (evpipe [1], &dummy, 1);

      errno = old_errno;
    }
}

/* called whenever the libev signal pipe */
/* got some events (signal, async) */
static void
pipecb (EV_P_ ev_io *iow, int revents)
{
  int i;

#if EV_USE_EVENTFD
  if (evfd >= 0)
    {
      uint64_t counter;
      read (evfd, &counter, sizeof (uint64_t));
    }
  else
#endif
    {
      char dummy;
      /* see discussion in evpipe_write when you think this read should be recv in win32 */
      read (evpipe [0], &dummy, 1);
    }

  if (sig_pending)
    {    
      sig_pending = 0;

      for (i = EV_NSIG - 1; i--; )
        if (expect_false (signals [i].pending))
          ev_feed_signal_event (EV_A_ i + 1);
    }

#if EV_ASYNC_ENABLE
  if (async_pending)
    {
      async_pending = 0;

      for (i = asynccnt; i--; )
        if (asyncs [i]->sent)
          {
            asyncs [i]->sent = 0;
            ev_feed_event (EV_A_ asyncs [i], EV_ASYNC);
          }
    }
#endif
}

/*****************************************************************************/

void
ev_feed_signal (int signum)
{
#if EV_MULTIPLICITY
  EV_P = signals [signum - 1].loop;

  if (!EV_A)
    return;
#endif

  signals [signum - 1].pending = 1;
  evpipe_write (EV_A_ &sig_pending);
}

static void
ev_sighandler (int signum)
{
#ifdef _WIN32
  signal (signum, ev_sighandler);
#endif

  ev_feed_signal (signum);
}

void noinline
ev_feed_signal_event (EV_P_ int signum)
{
  WL w;

  if (expect_false (signum <= 0 || signum > EV_NSIG))
    return;

  --signum;

#if EV_MULTIPLICITY
  /* it is permissible to try to feed a signal to the wrong loop */
  /* or, likely more useful, feeding a signal nobody is waiting for */

  if (expect_false (signals [signum].loop != EV_A))
    return;
#endif

  signals [signum].pending = 0;

  for (w = signals [signum].head; w; w = w->next)
    ev_feed_event (EV_A_ (W)w, EV_SIGNAL);
}

#if EV_USE_SIGNALFD
static void
sigfdcb (EV_P_ ev_io *iow, int revents)
{
  struct signalfd_siginfo si[2], *sip; /* these structs are big */

  for (;;)
    {
      ssize_t res = read (sigfd, si, sizeof (si));

      /* not ISO-C, as res might be -1, but works with SuS */
      for (sip = si; (char *)sip < (char *)si + res; ++sip)
        ev_feed_signal_event (EV_A_ sip->ssi_signo);

      if (res < (ssize_t)sizeof (si))
        break;
    }
}
#endif

#endif

/*****************************************************************************/

#if EV_CHILD_ENABLE
static WL childs [EV_PID_HASHSIZE];

static ev_signal childev;

#ifndef WIFCONTINUED
# define WIFCONTINUED(status) 0
#endif

/* handle a single child status event */
inline_speed void
child_reap (EV_P_ int chain, int pid, int status)
{
  ev_child *w;
  int traced = WIFSTOPPED (status) || WIFCONTINUED (status);

  for (w = (ev_child *)childs [chain & ((EV_PID_HASHSIZE) - 1)]; w; w = (ev_child *)((WL)w)->next)
    {
      if ((w->pid == pid || !w->pid)
          && (!traced || (w->flags & 1)))
        {
          ev_set_priority (w, EV_MAXPRI); /* need to do it *now*, this *must* be the same prio as the signal watcher itself */
          w->rpid    = pid;
          w->rstatus = status;
          ev_feed_event (EV_A_ (W)w, EV_CHILD);
        }
    }
}

#ifndef WCONTINUED
# define WCONTINUED 0
#endif

/* called on sigchld etc., calls waitpid */
static void
childcb (EV_P_ ev_signal *sw, int revents)
{
  int pid, status;

  /* some systems define WCONTINUED but then fail to support it (linux 2.4) */
  if (0 >= (pid = waitpid (-1, &status, WNOHANG | WUNTRACED | WCONTINUED)))
    if (!WCONTINUED
        || errno != EINVAL
        || 0 >= (pid = waitpid (-1, &status, WNOHANG | WUNTRACED)))
      return;

  /* make sure we are called again until all children have been reaped */
  /* we need to do it this way so that the callback gets called before we continue */
  ev_feed_event (EV_A_ (W)sw, EV_SIGNAL);

  child_reap (EV_A_ pid, pid, status);
  if ((EV_PID_HASHSIZE) > 1)
    child_reap (EV_A_ 0, pid, status); /* this might trigger a watcher twice, but feed_event catches that */
}

#endif

/*****************************************************************************/

#if EV_USE_IOCP
# include "ev_iocp.c"
#endif
#if EV_USE_PORT
# include "ev_port.c"
#endif
#if EV_USE_KQUEUE
# include "ev_kqueue.c"
#endif
#if EV_USE_EPOLL
# include "ev_epoll.c"
#endif
#if EV_USE_POLL
# include "ev_poll.c"
#endif
#if EV_USE_SELECT
# include "ev_select.c"
#endif

int
ev_version_major (void)
{
  return EV_VERSION_MAJOR;
}

int
ev_version_minor (void)
{
  return EV_VERSION_MINOR;
}

/* return true if we are running with elevated privileges and should ignore env variables */
int inline_size
enable_secure (void)
{
#ifdef _WIN32
  return 0;
#else
  return getuid () != geteuid ()
      || getgid () != getegid ();
#endif
}

unsigned int
ev_supported_backends (void)
{
  unsigned int flags = 0;

  if (EV_USE_PORT  ) flags |= EVBACKEND_PORT;
  if (EV_USE_KQUEUE) flags |= EVBACKEND_KQUEUE;
  if (EV_USE_EPOLL ) flags |= EVBACKEND_EPOLL;
  if (EV_USE_POLL  ) flags |= EVBACKEND_POLL;
  if (EV_USE_SELECT) flags |= EVBACKEND_SELECT;
  
  return flags;
}

unsigned int
ev_recommended_backends (void)
{
  unsigned int flags = ev_supported_backends ();

#ifndef __NetBSD__
  /* kqueue is borked on everything but netbsd apparently */
  /* it usually doesn't work correctly on anything but sockets and pipes */
  flags &= ~EVBACKEND_KQUEUE;
#endif
#ifdef __APPLE__
  /* only select works correctly on that "unix-certified" platform */
  flags &= ~EVBACKEND_KQUEUE; /* horribly broken, even for sockets */
  flags &= ~EVBACKEND_POLL;   /* poll is based on kqueue from 10.5 onwards */
#endif
#ifdef __FreeBSD__
  flags &= ~EVBACKEND_POLL;   /* poll return value is unusable (http://forums.freebsd.org/archive/index.php/t-10270.html) */
#endif

  return flags;
}

unsigned int
ev_embeddable_backends (void)
{
  int flags = EVBACKEND_EPOLL | EVBACKEND_KQUEUE | EVBACKEND_PORT;

  /* epoll embeddability broken on all linux versions up to at least 2.6.23 */
  if (ev_linux_version () < 0x020620) /* disable it on linux < 2.6.32 */
    flags &= ~EVBACKEND_EPOLL;

  return flags;
}

unsigned int
ev_backend (EV_P)
{
  return backend;
}

#if EV_FEATURE_API
unsigned int
ev_iteration (EV_P)
{
  return loop_count;
}

unsigned int
ev_depth (EV_P)
{
  return loop_depth;
}

void
ev_set_io_collect_interval (EV_P_ ev_tstamp interval)
{
  io_blocktime = interval;
}

void
ev_set_timeout_collect_interval (EV_P_ ev_tstamp interval)
{
  timeout_blocktime = interval;
}

void
ev_set_userdata (EV_P_ void *data)
{
  userdata = data;
}

void *
ev_userdata (EV_P)
{
  return userdata;
}

void ev_set_invoke_pending_cb (EV_P_ void (*invoke_pending_cb)(EV_P))
{
  invoke_cb = invoke_pending_cb;
}

void ev_set_loop_release_cb (EV_P_ void (*release)(EV_P), void (*acquire)(EV_P))
{
  release_cb = release;
  acquire_cb = acquire;
}
#endif

/* initialise a loop structure, must be zero-initialised */
static void noinline
loop_init (EV_P_ unsigned int flags)
{
  if (!backend)
    {
      origflags = flags;

#if EV_USE_REALTIME
      if (!have_realtime)
        {
          struct timespec ts;

          if (!clock_gettime (CLOCK_REALTIME, &ts))
            have_realtime = 1;
        }
#endif

#if EV_USE_MONOTONIC
      if (!have_monotonic)
        {
          struct timespec ts;

          if (!clock_gettime (CLOCK_MONOTONIC, &ts))
            have_monotonic = 1;
        }
#endif

      /* pid check not overridable via env */
#ifndef _WIN32
      if (flags & EVFLAG_FORKCHECK)
        curpid = getpid ();
#endif

      if (!(flags & EVFLAG_NOENV)
          && !enable_secure ()
          && getenv ("LIBEV_FLAGS"))
        flags = atoi (getenv ("LIBEV_FLAGS"));

      ev_rt_now         = ev_time ();
      mn_now            = get_clock ();
      now_floor         = mn_now;
      rtmn_diff         = ev_rt_now - mn_now;
#if EV_FEATURE_API
      invoke_cb         = ev_invoke_pending;
#endif

      io_blocktime      = 0.;
      timeout_blocktime = 0.;
      backend           = 0;
      backend_fd        = -1;
      sig_pending       = 0;
#if EV_ASYNC_ENABLE
      async_pending     = 0;
#endif
#if EV_USE_INOTIFY
      fs_fd             = flags & EVFLAG_NOINOTIFY ? -1 : -2;
#endif
#if EV_USE_SIGNALFD
      sigfd             = flags & EVFLAG_SIGNALFD  ? -2 : -1;
#endif

      if (!(flags & EVBACKEND_MASK))
        flags |= ev_recommended_backends ();

#if EV_USE_IOCP
      if (!backend && (flags & EVBACKEND_IOCP  )) backend = iocp_init   (EV_A_ flags);
#endif
#if EV_USE_PORT
      if (!backend && (flags & EVBACKEND_PORT  )) backend = port_init   (EV_A_ flags);
#endif
#if EV_USE_KQUEUE
      if (!backend && (flags & EVBACKEND_KQUEUE)) backend = kqueue_init (EV_A_ flags);
#endif
#if EV_USE_EPOLL
      if (!backend && (flags & EVBACKEND_EPOLL )) backend = epoll_init  (EV_A_ flags);
#endif
#if EV_USE_POLL
      if (!backend && (flags & EVBACKEND_POLL  )) backend = poll_init   (EV_A_ flags);
#endif
#if EV_USE_SELECT
      if (!backend && (flags & EVBACKEND_SELECT)) backend = select_init (EV_A_ flags);
#endif

      ev_prepare_init (&pending_w, pendingcb);

#if EV_SIGNAL_ENABLE || EV_ASYNC_ENABLE
      ev_init (&pipe_w, pipecb);
      ev_set_priority (&pipe_w, EV_MAXPRI);
#endif
    }
}

/* free up a loop structure */
void
ev_loop_destroy (EV_P)
{
  int i;

#if EV_MULTIPLICITY
  /* mimic free (0) */
  if (!EV_A)
    return;
#endif

#if EV_CLEANUP_ENABLE
  /* queue cleanup watchers (and execute them) */
  if (expect_false (cleanupcnt))
    {
      queue_events (EV_A_ (W *)cleanups, cleanupcnt, EV_CLEANUP);
      EV_INVOKE_PENDING;
    }
#endif

#if EV_CHILD_ENABLE
  if (ev_is_active (&childev))
    {
      ev_ref (EV_A); /* child watcher */
      ev_signal_stop (EV_A_ &childev);
    }
#endif

  if (ev_is_active (&pipe_w))
    {
      /*ev_ref (EV_A);*/
      /*ev_io_stop (EV_A_ &pipe_w);*/

#if EV_USE_EVENTFD
      if (evfd >= 0)
        close (evfd);
#endif

      if (evpipe [0] >= 0)
        {
          EV_WIN32_CLOSE_FD (evpipe [0]);
          EV_WIN32_CLOSE_FD (evpipe [1]);
        }
    }

#if EV_USE_SIGNALFD
  if (ev_is_active (&sigfd_w))
    close (sigfd);
#endif

#if EV_USE_INOTIFY
  if (fs_fd >= 0)
    close (fs_fd);
#endif

  if (backend_fd >= 0)
    close (backend_fd);

#if EV_USE_IOCP
  if (backend == EVBACKEND_IOCP  ) iocp_destroy   (EV_A);
#endif
#if EV_USE_PORT
  if (backend == EVBACKEND_PORT  ) port_destroy   (EV_A);
#endif
#if EV_USE_KQUEUE
  if (backend == EVBACKEND_KQUEUE) kqueue_destroy (EV_A);
#endif
#if EV_USE_EPOLL
  if (backend == EVBACKEND_EPOLL ) epoll_destroy  (EV_A);
#endif
#if EV_USE_POLL
  if (backend == EVBACKEND_POLL  ) poll_destroy   (EV_A);
#endif
#if EV_USE_SELECT
  if (backend == EVBACKEND_SELECT) select_destroy (EV_A);
#endif

  for (i = NUMPRI; i--; )
    {
      array_free (pending, [i]);
#if EV_IDLE_ENABLE
      array_free (idle, [i]);
#endif
    }

  ev_free (anfds); anfds = 0; anfdmax = 0;

  /* have to use the microsoft-never-gets-it-right macro */
  array_free (rfeed, EMPTY);
  array_free (fdchange, EMPTY);
  array_free (timer, EMPTY);
#if EV_PERIODIC_ENABLE
  array_free (periodic, EMPTY);
#endif
#if EV_FORK_ENABLE
  array_free (fork, EMPTY);
#endif
#if EV_CLEANUP_ENABLE
  array_free (cleanup, EMPTY);
#endif
  array_free (prepare, EMPTY);
  array_free (check, EMPTY);
#if EV_ASYNC_ENABLE
  array_free (async, EMPTY);
#endif

  backend = 0;

#if EV_MULTIPLICITY
  if (ev_is_default_loop (EV_A))
#endif
    ev_default_loop_ptr = 0;
#if EV_MULTIPLICITY
  else
    ev_free (EV_A);
#endif
}

#if EV_USE_INOTIFY
inline_size void infy_fork (EV_P);
#endif

inline_size void
loop_fork (EV_P)
{
#if EV_USE_PORT
  if (backend == EVBACKEND_PORT  ) port_fork   (EV_A);
#endif
#if EV_USE_KQUEUE
  if (backend == EVBACKEND_KQUEUE) kqueue_fork (EV_A);
#endif
#if EV_USE_EPOLL
  if (backend == EVBACKEND_EPOLL ) epoll_fork  (EV_A);
#endif
#if EV_USE_INOTIFY
  infy_fork (EV_A);
#endif

  if (ev_is_active (&pipe_w))
    {
      /* this "locks" the handlers against writing to the pipe */
      /* while we modify the fd vars */
      sig_pending   = 1;
#if EV_ASYNC_ENABLE
      async_pending = 1;
#endif

      ev_ref (EV_A);
      ev_io_stop (EV_A_ &pipe_w);

#if EV_USE_EVENTFD
      if (evfd >= 0)
        close (evfd);
#endif

      if (evpipe [0] >= 0)
        {
          EV_WIN32_CLOSE_FD (evpipe [0]);
          EV_WIN32_CLOSE_FD (evpipe [1]);
        }

#if EV_SIGNAL_ENABLE || EV_ASYNC_ENABLE
      evpipe_init (EV_A);
      /* now iterate over everything, in case we missed something */
      pipecb (EV_A_ &pipe_w, EV_READ);
#endif
    }

  postfork = 0;
}

#if EV_MULTIPLICITY

struct ev_loop *
ev_loop_new (unsigned int flags)
{
  EV_P = (struct ev_loop *)ev_malloc (sizeof (struct ev_loop));

  memset (EV_A, 0, sizeof (struct ev_loop));
  loop_init (EV_A_ flags);

  if (ev_backend (EV_A))
    return EV_A;

  ev_free (EV_A);
  return 0;
}

#endif /* multiplicity */

#if EV_VERIFY
static void noinline
verify_watcher (EV_P_ W w)
{
  assert (("libev: watcher has invalid priority", ABSPRI (w) >= 0 && ABSPRI (w) < NUMPRI));

  if (w->pending)
    assert (("libev: pending watcher not on pending queue", pendings [ABSPRI (w)][w->pending - 1].w == w));
}

static void noinline
verify_heap (EV_P_ ANHE *heap, int N)
{
  int i;

  for (i = HEAP0; i < N + HEAP0; ++i)
    {
      assert (("libev: active index mismatch in heap", ev_active (ANHE_w (heap [i])) == i));
      assert (("libev: heap condition violated", i == HEAP0 || ANHE_at (heap [HPARENT (i)]) <= ANHE_at (heap [i])));
      assert (("libev: heap at cache mismatch", ANHE_at (heap [i]) == ev_at (ANHE_w (heap [i]))));

      verify_watcher (EV_A_ (W)ANHE_w (heap [i]));
    }
}

static void noinline
array_verify (EV_P_ W *ws, int cnt)
{
  while (cnt--)
    {
      assert (("libev: active index mismatch", ev_active (ws [cnt]) == cnt + 1));
      verify_watcher (EV_A_ ws [cnt]);
    }
}
#endif

#if EV_FEATURE_API
void
ev_verify (EV_P)
{
#if EV_VERIFY
  int i;
  WL w;

  assert (activecnt >= -1);

  assert (fdchangemax >= fdchangecnt);
  for (i = 0; i < fdchangecnt; ++i)
    assert (("libev: negative fd in fdchanges", fdchanges [i] >= 0));

  assert (anfdmax >= 0);
  for (i = 0; i < anfdmax; ++i)
    for (w = anfds [i].head; w; w = w->next)
      {
        verify_watcher (EV_A_ (W)w);
        assert (("libev: inactive fd watcher on anfd list", ev_active (w) == 1));
        assert (("libev: fd mismatch between watcher and anfd", ((ev_io *)w)->fd == i));
      }

  assert (timermax >= timercnt);
  verify_heap (EV_A_ timers, timercnt);

#if EV_PERIODIC_ENABLE
  assert (periodicmax >= periodiccnt);
  verify_heap (EV_A_ periodics, periodiccnt);
#endif

  for (i = NUMPRI; i--; )
    {
      assert (pendingmax [i] >= pendingcnt [i]);
#if EV_IDLE_ENABLE
      assert (idleall >= 0);
      assert (idlemax [i] >= idlecnt [i]);
      array_verify (EV_A_ (W *)idles [i], idlecnt [i]);
#endif
    }

#if EV_FORK_ENABLE
  assert (forkmax >= forkcnt);
  array_verify (EV_A_ (W *)forks, forkcnt);
#endif

#if EV_CLEANUP_ENABLE
  assert (cleanupmax >= cleanupcnt);
  array_verify (EV_A_ (W *)cleanups, cleanupcnt);
#endif

#if EV_ASYNC_ENABLE
  assert (asyncmax >= asynccnt);
  array_verify (EV_A_ (W *)asyncs, asynccnt);
#endif

#if EV_PREPARE_ENABLE
  assert (preparemax >= preparecnt);
  array_verify (EV_A_ (W *)prepares, preparecnt);
#endif

#if EV_CHECK_ENABLE
  assert (checkmax >= checkcnt);
  array_verify (EV_A_ (W *)checks, checkcnt);
#endif

# if 0
#if EV_CHILD_ENABLE
  for (w = (ev_child *)childs [chain & ((EV_PID_HASHSIZE) - 1)]; w; w = (ev_child *)((WL)w)->next)
  for (signum = EV_NSIG; signum--; ) if (signals [signum].pending)
#endif
# endif
#endif
}
#endif

#if EV_MULTIPLICITY
struct ev_loop *
#else
int
#endif
ev_default_loop (unsigned int flags)
{
  if (!ev_default_loop_ptr)
    {
#if EV_MULTIPLICITY
      EV_P = ev_default_loop_ptr = &default_loop_struct;
#else
      ev_default_loop_ptr = 1;
#endif

      loop_init (EV_A_ flags);

      if (ev_backend (EV_A))
        {
#if EV_CHILD_ENABLE
          ev_signal_init (&childev, childcb, SIGCHLD);
          ev_set_priority (&childev, EV_MAXPRI);
          ev_signal_start (EV_A_ &childev);
          ev_unref (EV_A); /* child watcher should not keep loop alive */
#endif
        }
      else
        ev_default_loop_ptr = 0;
    }

  return ev_default_loop_ptr;
}

void
ev_loop_fork (EV_P)
{
  postfork = 1; /* must be in line with ev_default_fork */
}

/*****************************************************************************/

void
ev_invoke (EV_P_ void *w, int revents)
{
  EV_CB_INVOKE ((W)w, revents);
}

unsigned int
ev_pending_count (EV_P)
{
  int pri;
  unsigned int count = 0;

  for (pri = NUMPRI; pri--; )
    count += pendingcnt [pri];

  return count;
}

void noinline
ev_invoke_pending (EV_P)
{
  int pri;

  for (pri = NUMPRI; pri--; )
    while (pendingcnt [pri])
      {
        ANPENDING *p = pendings [pri] + --pendingcnt [pri];

        p->w->pending = 0;
        EV_CB_INVOKE (p->w, p->events);
        EV_FREQUENT_CHECK;
      }
}

#if EV_IDLE_ENABLE
/* make idle watchers pending. this handles the "call-idle */
/* only when higher priorities are idle" logic */
inline_size void
idle_reify (EV_P)
{
  if (expect_false (idleall))
    {
      int pri;

      for (pri = NUMPRI; pri--; )
        {
          if (pendingcnt [pri])
            break;

          if (idlecnt [pri])
            {
              queue_events (EV_A_ (W *)idles [pri], idlecnt [pri], EV_IDLE);
              break;
            }
        }
    }
}
#endif

/* make timers pending */
inline_size void
timers_reify (EV_P)
{
  EV_FREQUENT_CHECK;

  if (timercnt && ANHE_at (timers [HEAP0]) < mn_now)
    {
      do
        {
          ev_timer *w = (ev_timer *)ANHE_w (timers [HEAP0]);

          /*assert (("libev: inactive timer on timer heap detected", ev_is_active (w)));*/

          /* first reschedule or stop timer */
          if (w->repeat)
            {
              ev_at (w) += w->repeat;
              if (ev_at (w) < mn_now)
                ev_at (w) = mn_now;

              assert (("libev: negative ev_timer repeat value found while processing timers", w->repeat > 0.));

              ANHE_at_cache (timers [HEAP0]);
              downheap (timers, timercnt, HEAP0);
            }
          else
            ev_timer_stop (EV_A_ w); /* nonrepeating: stop timer */

          EV_FREQUENT_CHECK;
          feed_reverse (EV_A_ (W)w);
        }
      while (timercnt && ANHE_at (timers [HEAP0]) < mn_now);

      feed_reverse_done (EV_A_ EV_TIMER);
    }
}

#if EV_PERIODIC_ENABLE
/* make periodics pending */
inline_size void
periodics_reify (EV_P)
{
  EV_FREQUENT_CHECK;

  while (periodiccnt && ANHE_at (period…