/java-1.7.0-openjdk/openjdk/hotspot/src/share/vm/runtime/arguments.cpp

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/*
 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "classfile/javaAssertions.hpp"
#include "compiler/compilerOracle.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/cardTableRS.hpp"
#include "memory/referenceProcessor.hpp"
#include "memory/universe.inline.hpp"
#include "oops/oop.inline.hpp"
#include "prims/jvmtiExport.hpp"
#include "runtime/arguments.hpp"
#include "runtime/globals_extension.hpp"
#include "runtime/java.hpp"
#include "services/management.hpp"
#include "utilities/defaultStream.hpp"
#include "utilities/taskqueue.hpp"
#ifdef TARGET_OS_FAMILY_linux
# include "os_linux.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_solaris
# include "os_solaris.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_windows
# include "os_windows.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_bsd
# include "os_bsd.inline.hpp"
#endif
#ifndef SERIALGC
#include "gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp"
#endif

#define DEFAULT_VENDOR_URL_BUG "http://icedtea.classpath.org/bugzilla"
#define DEFAULT_JAVA_LAUNCHER  "generic"

char**  Arguments::_jvm_flags_array             = NULL;
int     Arguments::_num_jvm_flags               = 0;
char**  Arguments::_jvm_args_array              = NULL;
int     Arguments::_num_jvm_args                = 0;
char*  Arguments::_java_command                 = NULL;
SystemProperty* Arguments::_system_properties   = NULL;
const char*  Arguments::_gc_log_filename        = NULL;
bool   Arguments::_has_profile                  = false;
bool   Arguments::_has_alloc_profile            = false;
uintx  Arguments::_min_heap_size                = 0;
Arguments::Mode Arguments::_mode                = _mixed;
bool   Arguments::_java_compiler                = false;
bool   Arguments::_xdebug_mode                  = false;
const char*  Arguments::_java_vendor_url_bug    = DEFAULT_VENDOR_URL_BUG;
const char*  Arguments::_sun_java_launcher      = DEFAULT_JAVA_LAUNCHER;
int    Arguments::_sun_java_launcher_pid        = -1;
bool   Arguments::_created_by_gamma_launcher    = false;

// These parameters are reset in method parse_vm_init_args(JavaVMInitArgs*)
bool   Arguments::_AlwaysCompileLoopMethods     = AlwaysCompileLoopMethods;
bool   Arguments::_UseOnStackReplacement        = UseOnStackReplacement;
bool   Arguments::_BackgroundCompilation        = BackgroundCompilation;
bool   Arguments::_ClipInlining                 = ClipInlining;

char*  Arguments::SharedArchivePath             = NULL;

AgentLibraryList Arguments::_libraryList;
AgentLibraryList Arguments::_agentList;

abort_hook_t     Arguments::_abort_hook         = NULL;
exit_hook_t      Arguments::_exit_hook          = NULL;
vfprintf_hook_t  Arguments::_vfprintf_hook      = NULL;


SystemProperty *Arguments::_java_ext_dirs = NULL;
SystemProperty *Arguments::_java_endorsed_dirs = NULL;
SystemProperty *Arguments::_sun_boot_library_path = NULL;
SystemProperty *Arguments::_java_library_path = NULL;
SystemProperty *Arguments::_java_home = NULL;
SystemProperty *Arguments::_java_class_path = NULL;
SystemProperty *Arguments::_sun_boot_class_path = NULL;

char* Arguments::_meta_index_path = NULL;
char* Arguments::_meta_index_dir = NULL;

// Check if head of 'option' matches 'name', and sets 'tail' remaining part of option string

static bool match_option(const JavaVMOption *option, const char* name,
                         const char** tail) {
  int len = (int)strlen(name);
  if (strncmp(option->optionString, name, len) == 0) {
    *tail = option->optionString + len;
    return true;
  } else {
    return false;
  }
}

static void logOption(const char* opt) {
  if (PrintVMOptions) {
    jio_fprintf(defaultStream::output_stream(), "VM option '%s'\n", opt);
  }
}

// Process java launcher properties.
void Arguments::process_sun_java_launcher_properties(JavaVMInitArgs* args) {
  // See if sun.java.launcher or sun.java.launcher.pid is defined.
  // Must do this before setting up other system properties,
  // as some of them may depend on launcher type.
  for (int index = 0; index < args->nOptions; index++) {
    const JavaVMOption* option = args->options + index;
    const char* tail;

    if (match_option(option, "-Dsun.java.launcher=", &tail)) {
      process_java_launcher_argument(tail, option->extraInfo);
      continue;
    }
    if (match_option(option, "-Dsun.java.launcher.pid=", &tail)) {
      _sun_java_launcher_pid = atoi(tail);
      continue;
    }
  }
}

// Initialize system properties key and value.
void Arguments::init_system_properties() {

  PropertyList_add(&_system_properties, new SystemProperty("java.vm.specification.name",
                                                                 "Java Virtual Machine Specification",  false));
  PropertyList_add(&_system_properties, new SystemProperty("java.vm.version", VM_Version::vm_release(),  false));
  PropertyList_add(&_system_properties, new SystemProperty("java.vm.name", VM_Version::vm_name(),  false));
  PropertyList_add(&_system_properties, new SystemProperty("java.vm.info", VM_Version::vm_info_string(),  true));

  // following are JVMTI agent writeable properties.
  // Properties values are set to NULL and they are
  // os specific they are initialized in os::init_system_properties_values().
  _java_ext_dirs = new SystemProperty("java.ext.dirs", NULL,  true);
  _java_endorsed_dirs = new SystemProperty("java.endorsed.dirs", NULL,  true);
  _sun_boot_library_path = new SystemProperty("sun.boot.library.path", NULL,  true);
  _java_library_path = new SystemProperty("java.library.path", NULL,  true);
  _java_home =  new SystemProperty("java.home", NULL,  true);
  _sun_boot_class_path = new SystemProperty("sun.boot.class.path", NULL,  true);

  _java_class_path = new SystemProperty("java.class.path", "",  true);

  // Add to System Property list.
  PropertyList_add(&_system_properties, _java_ext_dirs);
  PropertyList_add(&_system_properties, _java_endorsed_dirs);
  PropertyList_add(&_system_properties, _sun_boot_library_path);
  PropertyList_add(&_system_properties, _java_library_path);
  PropertyList_add(&_system_properties, _java_home);
  PropertyList_add(&_system_properties, _java_class_path);
  PropertyList_add(&_system_properties, _sun_boot_class_path);

  // Set OS specific system properties values
  os::init_system_properties_values();
}


  // Update/Initialize System properties after JDK version number is known
void Arguments::init_version_specific_system_properties() {
  enum { bufsz = 16 };
  char buffer[bufsz];
  const char* spec_vendor = "Sun Microsystems Inc.";
  uint32_t spec_version = 0;

  if (JDK_Version::is_gte_jdk17x_version()) {
    spec_vendor = "Oracle Corporation";
    spec_version = JDK_Version::current().major_version();
  }
  jio_snprintf(buffer, bufsz, "1." UINT32_FORMAT, spec_version);

  PropertyList_add(&_system_properties,
      new SystemProperty("java.vm.specification.vendor",  spec_vendor, false));
  PropertyList_add(&_system_properties,
      new SystemProperty("java.vm.specification.version", buffer, false));
  PropertyList_add(&_system_properties,
      new SystemProperty("java.vm.vendor", VM_Version::vm_vendor(),  false));
}

/**
 * Provide a slightly more user-friendly way of eliminating -XX flags.
 * When a flag is eliminated, it can be added to this list in order to
 * continue accepting this flag on the command-line, while issuing a warning
 * and ignoring the value.  Once the JDK version reaches the 'accept_until'
 * limit, we flatly refuse to admit the existence of the flag.  This allows
 * a flag to die correctly over JDK releases using HSX.
 */
typedef struct {
  const char* name;
  JDK_Version obsoleted_in; // when the flag went away
  JDK_Version accept_until; // which version to start denying the existence
} ObsoleteFlag;

static ObsoleteFlag obsolete_jvm_flags[] = {
  { "UseTrainGC",                    JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "UseSpecialLargeObjectHandling", JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "UseOversizedCarHandling",       JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "TraceCarAllocation",            JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "PrintTrainGCProcessingStats",   JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "LogOfCarSpaceSize",             JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "OversizedCarThreshold",         JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "MinTickInterval",               JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "DefaultTickInterval",           JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "MaxTickInterval",               JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "DelayTickAdjustment",           JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "ProcessingToTenuringRatio",     JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "MinTrainLength",                JDK_Version::jdk(5), JDK_Version::jdk(7) },
  { "AppendRatio",         JDK_Version::jdk_update(6,10), JDK_Version::jdk(7) },
  { "DefaultMaxRAM",       JDK_Version::jdk_update(6,18), JDK_Version::jdk(7) },
  { "DefaultInitialRAMFraction",
                           JDK_Version::jdk_update(6,18), JDK_Version::jdk(7) },
  { "UseDepthFirstScavengeOrder",
                           JDK_Version::jdk_update(6,22), JDK_Version::jdk(7) },
  { "HandlePromotionFailure",
                           JDK_Version::jdk_update(6,24), JDK_Version::jdk(8) },
  { "MaxLiveObjectEvacuationRatio",
                           JDK_Version::jdk_update(6,24), JDK_Version::jdk(8) },
  { "ForceSharedSpaces",   JDK_Version::jdk_update(6,25), JDK_Version::jdk(8) },
  { "UseParallelOldGCCompacting",
                           JDK_Version::jdk_update(6,27), JDK_Version::jdk(8) },
  { "UseParallelDensePrefixUpdate",
                           JDK_Version::jdk_update(6,27), JDK_Version::jdk(8) },
  { "UseParallelOldGCDensePrefix",
                           JDK_Version::jdk_update(6,27), JDK_Version::jdk(8) },
  { "AllowTransitionalJSR292",       JDK_Version::jdk(7), JDK_Version::jdk(8) },
  { "UseCompressedStrings",          JDK_Version::jdk(7), JDK_Version::jdk(8) },
#ifdef PRODUCT
  { "DesiredMethodLimit",
                           JDK_Version::jdk_update(7, 2), JDK_Version::jdk(8) },
#endif // PRODUCT
  { NULL, JDK_Version(0), JDK_Version(0) }
};

// Returns true if the flag is obsolete and fits into the range specified
// for being ignored.  In the case that the flag is ignored, the 'version'
// value is filled in with the version number when the flag became
// obsolete so that that value can be displayed to the user.
bool Arguments::is_newly_obsolete(const char *s, JDK_Version* version) {
  int i = 0;
  assert(version != NULL, "Must provide a version buffer");
  while (obsolete_jvm_flags[i].name != NULL) {
    const ObsoleteFlag& flag_status = obsolete_jvm_flags[i];
    // <flag>=xxx form
    // [-|+]<flag> form
    if ((strncmp(flag_status.name, s, strlen(flag_status.name)) == 0) ||
        ((s[0] == '+' || s[0] == '-') &&
        (strncmp(flag_status.name, &s[1], strlen(flag_status.name)) == 0))) {
      if (JDK_Version::current().compare(flag_status.accept_until) == -1) {
          *version = flag_status.obsoleted_in;
          return true;
      }
    }
    i++;
  }
  return false;
}

// Constructs the system class path (aka boot class path) from the following
// components, in order:
//
//     prefix           // from -Xbootclasspath/p:...
//     endorsed         // the expansion of -Djava.endorsed.dirs=...
//     base             // from os::get_system_properties() or -Xbootclasspath=
//     suffix           // from -Xbootclasspath/a:...
//
// java.endorsed.dirs is a list of directories; any jar or zip files in the
// directories are added to the sysclasspath just before the base.
//
// This could be AllStatic, but it isn't needed after argument processing is
// complete.
class SysClassPath: public StackObj {
public:
  SysClassPath(const char* base);
  ~SysClassPath();

  inline void set_base(const char* base);
  inline void add_prefix(const char* prefix);
  inline void add_suffix_to_prefix(const char* suffix);
  inline void add_suffix(const char* suffix);
  inline void reset_path(const char* base);

  // Expand the jar/zip files in each directory listed by the java.endorsed.dirs
  // property.  Must be called after all command-line arguments have been
  // processed (in particular, -Djava.endorsed.dirs=...) and before calling
  // combined_path().
  void expand_endorsed();

  inline const char* get_base()     const { return _items[_scp_base]; }
  inline const char* get_prefix()   const { return _items[_scp_prefix]; }
  inline const char* get_suffix()   const { return _items[_scp_suffix]; }
  inline const char* get_endorsed() const { return _items[_scp_endorsed]; }

  // Combine all the components into a single c-heap-allocated string; caller
  // must free the string if/when no longer needed.
  char* combined_path();

private:
  // Utility routines.
  static char* add_to_path(const char* path, const char* str, bool prepend);
  static char* add_jars_to_path(char* path, const char* directory);

  inline void reset_item_at(int index);

  // Array indices for the items that make up the sysclasspath.  All except the
  // base are allocated in the C heap and freed by this class.
  enum {
    _scp_prefix,        // from -Xbootclasspath/p:...
    _scp_endorsed,      // the expansion of -Djava.endorsed.dirs=...
    _scp_base,          // the default sysclasspath
    _scp_suffix,        // from -Xbootclasspath/a:...
    _scp_nitems         // the number of items, must be last.
  };

  const char* _items[_scp_nitems];
  DEBUG_ONLY(bool _expansion_done;)
};

SysClassPath::SysClassPath(const char* base) {
  memset(_items, 0, sizeof(_items));
  _items[_scp_base] = base;
  DEBUG_ONLY(_expansion_done = false;)
}

SysClassPath::~SysClassPath() {
  // Free everything except the base.
  for (int i = 0; i < _scp_nitems; ++i) {
    if (i != _scp_base) reset_item_at(i);
  }
  DEBUG_ONLY(_expansion_done = false;)
}

inline void SysClassPath::set_base(const char* base) {
  _items[_scp_base] = base;
}

inline void SysClassPath::add_prefix(const char* prefix) {
  _items[_scp_prefix] = add_to_path(_items[_scp_prefix], prefix, true);
}

inline void SysClassPath::add_suffix_to_prefix(const char* suffix) {
  _items[_scp_prefix] = add_to_path(_items[_scp_prefix], suffix, false);
}

inline void SysClassPath::add_suffix(const char* suffix) {
  _items[_scp_suffix] = add_to_path(_items[_scp_suffix], suffix, false);
}

inline void SysClassPath::reset_item_at(int index) {
  assert(index < _scp_nitems && index != _scp_base, "just checking");
  if (_items[index] != NULL) {
    FREE_C_HEAP_ARRAY(char, _items[index]);
    _items[index] = NULL;
  }
}

inline void SysClassPath::reset_path(const char* base) {
  // Clear the prefix and suffix.
  reset_item_at(_scp_prefix);
  reset_item_at(_scp_suffix);
  set_base(base);
}

//------------------------------------------------------------------------------

void SysClassPath::expand_endorsed() {
  assert(_items[_scp_endorsed] == NULL, "can only be called once.");

  const char* path = Arguments::get_property("java.endorsed.dirs");
  if (path == NULL) {
    path = Arguments::get_endorsed_dir();
    assert(path != NULL, "no default for java.endorsed.dirs");
  }

  char* expanded_path = NULL;
  const char separator = *os::path_separator();
  const char* const end = path + strlen(path);
  while (path < end) {
    const char* tmp_end = strchr(path, separator);
    if (tmp_end == NULL) {
      expanded_path = add_jars_to_path(expanded_path, path);
      path = end;
    } else {
      char* dirpath = NEW_C_HEAP_ARRAY(char, tmp_end - path + 1);
      memcpy(dirpath, path, tmp_end - path);
      dirpath[tmp_end - path] = '\0';
      expanded_path = add_jars_to_path(expanded_path, dirpath);
      FREE_C_HEAP_ARRAY(char, dirpath);
      path = tmp_end + 1;
    }
  }
  _items[_scp_endorsed] = expanded_path;
  DEBUG_ONLY(_expansion_done = true;)
}

// Combine the bootclasspath elements, some of which may be null, into a single
// c-heap-allocated string.
char* SysClassPath::combined_path() {
  assert(_items[_scp_base] != NULL, "empty default sysclasspath");
  assert(_expansion_done, "must call expand_endorsed() first.");

  size_t lengths[_scp_nitems];
  size_t total_len = 0;

  const char separator = *os::path_separator();

  // Get the lengths.
  int i;
  for (i = 0; i < _scp_nitems; ++i) {
    if (_items[i] != NULL) {
      lengths[i] = strlen(_items[i]);
      // Include space for the separator char (or a NULL for the last item).
      total_len += lengths[i] + 1;
    }
  }
  assert(total_len > 0, "empty sysclasspath not allowed");

  // Copy the _items to a single string.
  char* cp = NEW_C_HEAP_ARRAY(char, total_len);
  char* cp_tmp = cp;
  for (i = 0; i < _scp_nitems; ++i) {
    if (_items[i] != NULL) {
      memcpy(cp_tmp, _items[i], lengths[i]);
      cp_tmp += lengths[i];
      *cp_tmp++ = separator;
    }
  }
  *--cp_tmp = '\0';     // Replace the extra separator.
  return cp;
}

// Note:  path must be c-heap-allocated (or NULL); it is freed if non-null.
char*
SysClassPath::add_to_path(const char* path, const char* str, bool prepend) {
  char *cp;

  assert(str != NULL, "just checking");
  if (path == NULL) {
    size_t len = strlen(str) + 1;
    cp = NEW_C_HEAP_ARRAY(char, len);
    memcpy(cp, str, len);                       // copy the trailing null
  } else {
    const char separator = *os::path_separator();
    size_t old_len = strlen(path);
    size_t str_len = strlen(str);
    size_t len = old_len + str_len + 2;

    if (prepend) {
      cp = NEW_C_HEAP_ARRAY(char, len);
      char* cp_tmp = cp;
      memcpy(cp_tmp, str, str_len);
      cp_tmp += str_len;
      *cp_tmp = separator;
      memcpy(++cp_tmp, path, old_len + 1);      // copy the trailing null
      FREE_C_HEAP_ARRAY(char, path);
    } else {
      cp = REALLOC_C_HEAP_ARRAY(char, path, len);
      char* cp_tmp = cp + old_len;
      *cp_tmp = separator;
      memcpy(++cp_tmp, str, str_len + 1);       // copy the trailing null
    }
  }
  return cp;
}

// Scan the directory and append any jar or zip files found to path.
// Note:  path must be c-heap-allocated (or NULL); it is freed if non-null.
char* SysClassPath::add_jars_to_path(char* path, const char* directory) {
  DIR* dir = os::opendir(directory);
  if (dir == NULL) return path;

  char dir_sep[2] = { '\0', '\0' };
  size_t directory_len = strlen(directory);
  const char fileSep = *os::file_separator();
  if (directory[directory_len - 1] != fileSep) dir_sep[0] = fileSep;

  /* Scan the directory for jars/zips, appending them to path. */
  struct dirent *entry;
  char *dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(directory));
  while ((entry = os::readdir(dir, (dirent *) dbuf)) != NULL) {
    const char* name = entry->d_name;
    const char* ext = name + strlen(name) - 4;
    bool isJarOrZip = ext > name &&
      (os::file_name_strcmp(ext, ".jar") == 0 ||
       os::file_name_strcmp(ext, ".zip") == 0);
    if (isJarOrZip) {
      char* jarpath = NEW_C_HEAP_ARRAY(char, directory_len + 2 + strlen(name));
      sprintf(jarpath, "%s%s%s", directory, dir_sep, name);
      path = add_to_path(path, jarpath, false);
      FREE_C_HEAP_ARRAY(char, jarpath);
    }
  }
  FREE_C_HEAP_ARRAY(char, dbuf);
  os::closedir(dir);
  return path;
}

// Parses a memory size specification string.
static bool atomull(const char *s, julong* result) {
  julong n = 0;
  int args_read = sscanf(s, os::julong_format_specifier(), &n);
  if (args_read != 1) {
    return false;
  }
  while (*s != '\0' && isdigit(*s)) {
    s++;
  }
  // 4705540: illegal if more characters are found after the first non-digit
  if (strlen(s) > 1) {
    return false;
  }
  switch (*s) {
    case 'T': case 't':
      *result = n * G * K;
      // Check for overflow.
      if (*result/((julong)G * K) != n) return false;
      return true;
    case 'G': case 'g':
      *result = n * G;
      if (*result/G != n) return false;
      return true;
    case 'M': case 'm':
      *result = n * M;
      if (*result/M != n) return false;
      return true;
    case 'K': case 'k':
      *result = n * K;
      if (*result/K != n) return false;
      return true;
    case '\0':
      *result = n;
      return true;
    default:
      return false;
  }
}

Arguments::ArgsRange Arguments::check_memory_size(julong size, julong min_size) {
  if (size < min_size) return arg_too_small;
  // Check that size will fit in a size_t (only relevant on 32-bit)
  if (size > max_uintx) return arg_too_big;
  return arg_in_range;
}

// Describe an argument out of range error
void Arguments::describe_range_error(ArgsRange errcode) {
  switch(errcode) {
  case arg_too_big:
    jio_fprintf(defaultStream::error_stream(),
                "The specified size exceeds the maximum "
                "representable size.\n");
    break;
  case arg_too_small:
  case arg_unreadable:
  case arg_in_range:
    // do nothing for now
    break;
  default:
    ShouldNotReachHere();
  }
}

static bool set_bool_flag(char* name, bool value, FlagValueOrigin origin) {
  return CommandLineFlags::boolAtPut(name, &value, origin);
}

static bool set_fp_numeric_flag(char* name, char* value, FlagValueOrigin origin) {
  double v;
  if (sscanf(value, "%lf", &v) != 1) {
    return false;
  }

  if (CommandLineFlags::doubleAtPut(name, &v, origin)) {
    return true;
  }
  return false;
}

static bool set_numeric_flag(char* name, char* value, FlagValueOrigin origin) {
  julong v;
  intx intx_v;
  bool is_neg = false;
  // Check the sign first since atomull() parses only unsigned values.
  if (*value == '-') {
    if (!CommandLineFlags::intxAt(name, &intx_v)) {
      return false;
    }
    value++;
    is_neg = true;
  }
  if (!atomull(value, &v)) {
    return false;
  }
  intx_v = (intx) v;
  if (is_neg) {
    intx_v = -intx_v;
  }
  if (CommandLineFlags::intxAtPut(name, &intx_v, origin)) {
    return true;
  }
  uintx uintx_v = (uintx) v;
  if (!is_neg && CommandLineFlags::uintxAtPut(name, &uintx_v, origin)) {
    return true;
  }
  uint64_t uint64_t_v = (uint64_t) v;
  if (!is_neg && CommandLineFlags::uint64_tAtPut(name, &uint64_t_v, origin)) {
    return true;
  }
  return false;
}

static bool set_string_flag(char* name, const char* value, FlagValueOrigin origin) {
  if (!CommandLineFlags::ccstrAtPut(name, &value, origin))  return false;
  // Contract:  CommandLineFlags always returns a pointer that needs freeing.
  FREE_C_HEAP_ARRAY(char, value);
  return true;
}

static bool append_to_string_flag(char* name, const char* new_value, FlagValueOrigin origin) {
  const char* old_value = "";
  if (!CommandLineFlags::ccstrAt(name, &old_value))  return false;
  size_t old_len = old_value != NULL ? strlen(old_value) : 0;
  size_t new_len = strlen(new_value);
  const char* value;
  char* free_this_too = NULL;
  if (old_len == 0) {
    value = new_value;
  } else if (new_len == 0) {
    value = old_value;
  } else {
    char* buf = NEW_C_HEAP_ARRAY(char, old_len + 1 + new_len + 1);
    // each new setting adds another LINE to the switch:
    sprintf(buf, "%s\n%s", old_value, new_value);
    value = buf;
    free_this_too = buf;
  }
  (void) CommandLineFlags::ccstrAtPut(name, &value, origin);
  // CommandLineFlags always returns a pointer that needs freeing.
  FREE_C_HEAP_ARRAY(char, value);
  if (free_this_too != NULL) {
    // CommandLineFlags made its own copy, so I must delete my own temp. buffer.
    FREE_C_HEAP_ARRAY(char, free_this_too);
  }
  return true;
}

bool Arguments::parse_argument(const char* arg, FlagValueOrigin origin) {

  // range of acceptable characters spelled out for portability reasons
#define NAME_RANGE  "[abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_]"
#define BUFLEN 255
  char name[BUFLEN+1];
  char dummy;

  if (sscanf(arg, "-%" XSTR(BUFLEN) NAME_RANGE "%c", name, &dummy) == 1) {
    return set_bool_flag(name, false, origin);
  }
  if (sscanf(arg, "+%" XSTR(BUFLEN) NAME_RANGE "%c", name, &dummy) == 1) {
    return set_bool_flag(name, true, origin);
  }

  char punct;
  if (sscanf(arg, "%" XSTR(BUFLEN) NAME_RANGE "%c", name, &punct) == 2 && punct == '=') {
    const char* value = strchr(arg, '=') + 1;
    Flag* flag = Flag::find_flag(name, strlen(name));
    if (flag != NULL && flag->is_ccstr()) {
      if (flag->ccstr_accumulates()) {
        return append_to_string_flag(name, value, origin);
      } else {
        if (value[0] == '\0') {
          value = NULL;
        }
        return set_string_flag(name, value, origin);
      }
    }
  }

  if (sscanf(arg, "%" XSTR(BUFLEN) NAME_RANGE ":%c", name, &punct) == 2 && punct == '=') {
    const char* value = strchr(arg, '=') + 1;
    // -XX:Foo:=xxx will reset the string flag to the given value.
    if (value[0] == '\0') {
      value = NULL;
    }
    return set_string_flag(name, value, origin);
  }

#define SIGNED_FP_NUMBER_RANGE "[-0123456789.]"
#define SIGNED_NUMBER_RANGE    "[-0123456789]"
#define        NUMBER_RANGE    "[0123456789]"
  char value[BUFLEN + 1];
  char value2[BUFLEN + 1];
  if (sscanf(arg, "%" XSTR(BUFLEN) NAME_RANGE "=" "%" XSTR(BUFLEN) SIGNED_NUMBER_RANGE "." "%" XSTR(BUFLEN) NUMBER_RANGE "%c", name, value, value2, &dummy) == 3) {
    // Looks like a floating-point number -- try again with more lenient format string
    if (sscanf(arg, "%" XSTR(BUFLEN) NAME_RANGE "=" "%" XSTR(BUFLEN) SIGNED_FP_NUMBER_RANGE "%c", name, value, &dummy) == 2) {
      return set_fp_numeric_flag(name, value, origin);
    }
  }

#define VALUE_RANGE "[-kmgtKMGT0123456789]"
  if (sscanf(arg, "%" XSTR(BUFLEN) NAME_RANGE "=" "%" XSTR(BUFLEN) VALUE_RANGE "%c", name, value, &dummy) == 2) {
    return set_numeric_flag(name, value, origin);
  }

  return false;
}

void Arguments::add_string(char*** bldarray, int* count, const char* arg) {
  assert(bldarray != NULL, "illegal argument");

  if (arg == NULL) {
    return;
  }

  int index = *count;

  // expand the array and add arg to the last element
  (*count)++;
  if (*bldarray == NULL) {
    *bldarray = NEW_C_HEAP_ARRAY(char*, *count);
  } else {
    *bldarray = REALLOC_C_HEAP_ARRAY(char*, *bldarray, *count);
  }
  (*bldarray)[index] = strdup(arg);
}

void Arguments::build_jvm_args(const char* arg) {
  add_string(&_jvm_args_array, &_num_jvm_args, arg);
}

void Arguments::build_jvm_flags(const char* arg) {
  add_string(&_jvm_flags_array, &_num_jvm_flags, arg);
}

// utility function to return a string that concatenates all
// strings in a given char** array
const char* Arguments::build_resource_string(char** args, int count) {
  if (args == NULL || count == 0) {
    return NULL;
  }
  size_t length = strlen(args[0]) + 1; // add 1 for the null terminator
  for (int i = 1; i < count; i++) {
    length += strlen(args[i]) + 1; // add 1 for a space
  }
  char* s = NEW_RESOURCE_ARRAY(char, length);
  strcpy(s, args[0]);
  for (int j = 1; j < count; j++) {
    strcat(s, " ");
    strcat(s, args[j]);
  }
  return (const char*) s;
}

void Arguments::print_on(outputStream* st) {
  st->print_cr("VM Arguments:");
  if (num_jvm_flags() > 0) {
    st->print("jvm_flags: "); print_jvm_flags_on(st);
  }
  if (num_jvm_args() > 0) {
    st->print("jvm_args: "); print_jvm_args_on(st);
  }
  st->print_cr("java_command: %s", java_command() ? java_command() : "<unknown>");
  st->print_cr("Launcher Type: %s", _sun_java_launcher);
}

void Arguments::print_jvm_flags_on(outputStream* st) {
  if (_num_jvm_flags > 0) {
    for (int i=0; i < _num_jvm_flags; i++) {
      st->print("%s ", _jvm_flags_array[i]);
    }
    st->print_cr("");
  }
}

void Arguments::print_jvm_args_on(outputStream* st) {
  if (_num_jvm_args > 0) {
    for (int i=0; i < _num_jvm_args; i++) {
      st->print("%s ", _jvm_args_array[i]);
    }
    st->print_cr("");
  }
}

bool Arguments::process_argument(const char* arg,
    jboolean ignore_unrecognized, FlagValueOrigin origin) {

  JDK_Version since = JDK_Version();

  if (parse_argument(arg, origin) || ignore_unrecognized) {
    return true;
  }

  const char * const argname = *arg == '+' || *arg == '-' ? arg + 1 : arg;
  if (is_newly_obsolete(arg, &since)) {
    char version[256];
    since.to_string(version, sizeof(version));
    warning("ignoring option %s; support was removed in %s", argname, version);
    return true;
  }

  // For locked flags, report a custom error message if available.
  // Otherwise, report the standard unrecognized VM option.

  Flag* locked_flag = Flag::find_flag((char*)argname, strlen(argname), true);
  if (locked_flag != NULL) {
    char locked_message_buf[BUFLEN];
    locked_flag->get_locked_message(locked_message_buf, BUFLEN);
    if (strlen(locked_message_buf) == 0) {
      jio_fprintf(defaultStream::error_stream(),
        "Unrecognized VM option '%s'\n", argname);
    } else {
      jio_fprintf(defaultStream::error_stream(), "%s", locked_message_buf);
    }
  }

  // allow for commandline "commenting out" options like -XX:#+Verbose
  return arg[0] == '#';
}

bool Arguments::process_settings_file(const char* file_name, bool should_exist, jboolean ignore_unrecognized) {
  FILE* stream = fopen(file_name, "rb");
  if (stream == NULL) {
    if (should_exist) {
      jio_fprintf(defaultStream::error_stream(),
                  "Could not open settings file %s\n", file_name);
      return false;
    } else {
      return true;
    }
  }

  char token[1024];
  int  pos = 0;

  bool in_white_space = true;
  bool in_comment     = false;
  bool in_quote       = false;
  char quote_c        = 0;
  bool result         = true;

  int c = getc(stream);
  while(c != EOF) {
    if (in_white_space) {
      if (in_comment) {
        if (c == '\n') in_comment = false;
      } else {
        if (c == '#') in_comment = true;
        else if (!isspace(c)) {
          in_white_space = false;
          token[pos++] = c;
        }
      }
    } else {
      if (c == '\n' || (!in_quote && isspace(c))) {
        // token ends at newline, or at unquoted whitespace
        // this allows a way to include spaces in string-valued options
        token[pos] = '\0';
        logOption(token);
        result &= process_argument(token, ignore_unrecognized, CONFIG_FILE);
        build_jvm_flags(token);
        pos = 0;
        in_white_space = true;
        in_quote = false;
      } else if (!in_quote && (c == '\'' || c == '"')) {
        in_quote = true;
        quote_c = c;
      } else if (in_quote && (c == quote_c)) {
        in_quote = false;
      } else {
        token[pos++] = c;
      }
    }
    c = getc(stream);
  }
  if (pos > 0) {
    token[pos] = '\0';
    result &= process_argument(token, ignore_unrecognized, CONFIG_FILE);
    build_jvm_flags(token);
  }
  fclose(stream);
  return result;
}

//=============================================================================================================
// Parsing of properties (-D)

const char* Arguments::get_property(const char* key) {
  return PropertyList_get_value(system_properties(), key);
}

bool Arguments::add_property(const char* prop) {
  const char* eq = strchr(prop, '=');
  char* key;
  // ns must be static--its address may be stored in a SystemProperty object.
  const static char ns[1] = {0};
  char* value = (char *)ns;

  size_t key_len = (eq == NULL) ? strlen(prop) : (eq - prop);
  key = AllocateHeap(key_len + 1, "add_property");
  strncpy(key, prop, key_len);
  key[key_len] = '\0';

  if (eq != NULL) {
    size_t value_len = strlen(prop) - key_len - 1;
    value = AllocateHeap(value_len + 1, "add_property");
    strncpy(value, &prop[key_len + 1], value_len + 1);
  }

  if (strcmp(key, "java.compiler") == 0) {
    process_java_compiler_argument(value);
    FreeHeap(key);
    if (eq != NULL) {
      FreeHeap(value);
    }
    return true;
  } else if (strcmp(key, "sun.java.command") == 0) {
    _java_command = value;

    // Record value in Arguments, but let it get passed to Java.
  } else if (strcmp(key, "sun.java.launcher.pid") == 0) {
    // launcher.pid property is private and is processed
    // in process_sun_java_launcher_properties();
    // the sun.java.launcher property is passed on to the java application
    FreeHeap(key);
    if (eq != NULL) {
      FreeHeap(value);
    }
    return true;
  } else if (strcmp(key, "java.vendor.url.bug") == 0) {
    // save it in _java_vendor_url_bug, so JVM fatal error handler can access
    // its value without going through the property list or making a Java call.
    _java_vendor_url_bug = value;
  } else if (strcmp(key, "sun.boot.library.path") == 0) {
    PropertyList_unique_add(&_system_properties, key, value, true);
    return true;
  }
  // Create new property and add at the end of the list
  PropertyList_unique_add(&_system_properties, key, value);
  return true;
}

//===========================================================================================================
// Setting int/mixed/comp mode flags

void Arguments::set_mode_flags(Mode mode) {
  // Set up default values for all flags.
  // If you add a flag to any of the branches below,
  // add a default value for it here.
  set_java_compiler(false);
  _mode                      = mode;

  // Ensure Agent_OnLoad has the correct initial values.
  // This may not be the final mode; mode may change later in onload phase.
  PropertyList_unique_add(&_system_properties, "java.vm.info",
                          (char*)VM_Version::vm_info_string(), false);

  UseInterpreter             = true;
  UseCompiler                = true;
  UseLoopCounter             = true;

#ifndef ZERO
  // Turn these off for mixed and comp.  Leave them on for Zero.
  if (FLAG_IS_DEFAULT(UseFastAccessorMethods)) {
    UseFastAccessorMethods = (mode == _int);
  }
  if (FLAG_IS_DEFAULT(UseFastEmptyMethods)) {
    UseFastEmptyMethods = (mode == _int);
  }
#endif

  // Default values may be platform/compiler dependent -
  // use the saved values
  ClipInlining               = Arguments::_ClipInlining;
  AlwaysCompileLoopMethods   = Arguments::_AlwaysCompileLoopMethods;
  UseOnStackReplacement      = Arguments::_UseOnStackReplacement;
  BackgroundCompilation      = Arguments::_BackgroundCompilation;

  // Change from defaults based on mode
  switch (mode) {
  default:
    ShouldNotReachHere();
    break;
  case _int:
    UseCompiler              = false;
    UseLoopCounter           = false;
    AlwaysCompileLoopMethods = false;
    UseOnStackReplacement    = false;
    break;
  case _mixed:
    // same as default
    break;
  case _comp:
    UseInterpreter           = false;
    BackgroundCompilation    = false;
    ClipInlining             = false;
    // Be much more aggressive in tiered mode with -Xcomp and exercise C2 more.
    // We will first compile a level 3 version (C1 with full profiling), then do one invocation of it and
    // compile a level 4 (C2) and then continue executing it.
    if (TieredCompilation) {
      Tier3InvokeNotifyFreqLog = 0;
      Tier4InvocationThreshold = 0;
    }
    break;
  }
}

// Conflict: required to use shared spaces (-Xshare:on), but
// incompatible command line options were chosen.

static void no_shared_spaces() {
  if (RequireSharedSpaces) {
    jio_fprintf(defaultStream::error_stream(),
      "Class data sharing is inconsistent with other specified options.\n");
    vm_exit_during_initialization("Unable to use shared archive.", NULL);
  } else {
    FLAG_SET_DEFAULT(UseSharedSpaces, false);
  }
}

void Arguments::set_tiered_flags() {
  // With tiered, set default policy to AdvancedThresholdPolicy, which is 3.
  if (FLAG_IS_DEFAULT(CompilationPolicyChoice)) {
    FLAG_SET_DEFAULT(CompilationPolicyChoice, 3);
  }
  if (CompilationPolicyChoice < 2) {
    vm_exit_during_initialization(
      "Incompatible compilation policy selected", NULL);
  }
  // Increase the code cache size - tiered compiles a lot more.
  if (FLAG_IS_DEFAULT(ReservedCodeCacheSize)) {
    FLAG_SET_DEFAULT(ReservedCodeCacheSize, ReservedCodeCacheSize * 2);
  }
}

#ifndef KERNEL
static void disable_adaptive_size_policy(const char* collector_name) {
  if (UseAdaptiveSizePolicy) {
    if (FLAG_IS_CMDLINE(UseAdaptiveSizePolicy)) {
      warning("disabling UseAdaptiveSizePolicy; it is incompatible with %s.",
              collector_name);
    }
    FLAG_SET_DEFAULT(UseAdaptiveSizePolicy, false);
  }
}

// If the user has chosen ParallelGCThreads > 0, we set UseParNewGC
// if it's not explictly set or unset. If the user has chosen
// UseParNewGC and not explicitly set ParallelGCThreads we
// set it, unless this is a single cpu machine.
void Arguments::set_parnew_gc_flags() {
  assert(!UseSerialGC && !UseParallelOldGC && !UseParallelGC && !UseG1GC,
         "control point invariant");
  assert(UseParNewGC, "Error");

  // Turn off AdaptiveSizePolicy for parnew until it is complete.
  disable_adaptive_size_policy("UseParNewGC");

  if (ParallelGCThreads == 0) {
    FLAG_SET_DEFAULT(ParallelGCThreads,
                     Abstract_VM_Version::parallel_worker_threads());
    if (ParallelGCThreads == 1) {
      FLAG_SET_DEFAULT(UseParNewGC, false);
      FLAG_SET_DEFAULT(ParallelGCThreads, 0);
    }
  }
  if (UseParNewGC) {
    // CDS doesn't work with ParNew yet
    no_shared_spaces();

    // By default YoungPLABSize and OldPLABSize are set to 4096 and 1024 respectively,
    // these settings are default for Parallel Scavenger. For ParNew+Tenured configuration
    // we set them to 1024 and 1024.
    // See CR 6362902.
    if (FLAG_IS_DEFAULT(YoungPLABSize)) {
      FLAG_SET_DEFAULT(YoungPLABSize, (intx)1024);
    }
    if (FLAG_IS_DEFAULT(OldPLABSize)) {
      FLAG_SET_DEFAULT(OldPLABSize, (intx)1024);
    }

    // AlwaysTenure flag should make ParNew promote all at first collection.
    // See CR 6362902.
    if (AlwaysTenure) {
      FLAG_SET_CMDLINE(intx, MaxTenuringThreshold, 0);
    }
    // When using compressed oops, we use local overflow stacks,
    // rather than using a global overflow list chained through
    // the klass word of the object's pre-image.
    if (UseCompressedOops && !ParGCUseLocalOverflow) {
      if (!FLAG_IS_DEFAULT(ParGCUseLocalOverflow)) {
        warning("Forcing +ParGCUseLocalOverflow: needed if using compressed references");
      }
      FLAG_SET_DEFAULT(ParGCUseLocalOverflow, true);
    }
    assert(ParGCUseLocalOverflow || !UseCompressedOops, "Error");
  }
}

// Adjust some sizes to suit CMS and/or ParNew needs; these work well on
// sparc/solaris for certain applications, but would gain from
// further optimization and tuning efforts, and would almost
// certainly gain from analysis of platform and environment.
void Arguments::set_cms_and_parnew_gc_flags() {
  assert(!UseSerialGC && !UseParallelOldGC && !UseParallelGC, "Error");
  assert(UseConcMarkSweepGC, "CMS is expected to be on here");

  // If we are using CMS, we prefer to UseParNewGC,
  // unless explicitly forbidden.
  if (FLAG_IS_DEFAULT(UseParNewGC)) {
    FLAG_SET_ERGO(bool, UseParNewGC, true);
  }

  // Turn off AdaptiveSizePolicy for CMS until it is complete.
  disable_adaptive_size_policy("UseConcMarkSweepGC");

  // In either case, adjust ParallelGCThreads and/or UseParNewGC
  // as needed.
  if (UseParNewGC) {
    set_parnew_gc_flags();
  }

  // MaxHeapSize is aligned down in collectorPolicy
  size_t max_heap = align_size_down(MaxHeapSize,
                                    CardTableRS::ct_max_alignment_constraint());

  // Now make adjustments for CMS
  intx   tenuring_default = (intx)6;
  size_t young_gen_per_worker = CMSYoungGenPerWorker;

  // Preferred young gen size for "short" pauses:
  // upper bound depends on # of threads and NewRatio.
  const uintx parallel_gc_threads =
    (ParallelGCThreads == 0 ? 1 : ParallelGCThreads);
  const size_t preferred_max_new_size_unaligned =
    MIN2(max_heap/(NewRatio+1), ScaleForWordSize(young_gen_per_worker * parallel_gc_threads));
  size_t preferred_max_new_size =
    align_size_up(preferred_max_new_size_unaligned, os::vm_page_size());

  // Unless explicitly requested otherwise, size young gen
  // for "short" pauses ~ CMSYoungGenPerWorker*ParallelGCThreads

  // If either MaxNewSize or NewRatio is set on the command line,
  // assume the user is trying to set the size of the young gen.
  if (FLAG_IS_DEFAULT(MaxNewSize) && FLAG_IS_DEFAULT(NewRatio)) {

    // Set MaxNewSize to our calculated preferred_max_new_size unless
    // NewSize was set on the command line and it is larger than
    // preferred_max_new_size.
    if (!FLAG_IS_DEFAULT(NewSize)) {   // NewSize explicitly set at command-line
      FLAG_SET_ERGO(uintx, MaxNewSize, MAX2((size_t) NewSize, preferred_max_new_size));
    } else {
      FLAG_SET_ERGO(uintx, MaxNewSize, preferred_max_new_size);
    }
    if (PrintGCDetails && Verbose) {
      // Too early to use gclog_or_tty
      tty->print_cr("CMS ergo set MaxNewSize: " SIZE_FORMAT, MaxNewSize);
    }

    // Code along this path potentially sets NewSize and OldSize

    assert(max_heap >= InitialHeapSize, "Error");
    assert(max_heap >= NewSize, "Error");

    if (PrintGCDetails && Verbose) {
      // Too early to use gclog_or_tty
      tty->print_cr("CMS set min_heap_size: " SIZE_FORMAT
           " initial_heap_size:  " SIZE_FORMAT
           " max_heap: " SIZE_FORMAT,
           min_heap_size(), InitialHeapSize, max_heap);
    }
    size_t min_new = preferred_max_new_size;
    if (FLAG_IS_CMDLINE(NewSize)) {
      min_new = NewSize;
    }
    if (max_heap > min_new && min_heap_size() > min_new) {
      // Unless explicitly requested otherwise, make young gen
      // at least min_new, and at most preferred_max_new_size.
      if (FLAG_IS_DEFAULT(NewSize)) {
        FLAG_SET_ERGO(uintx, NewSize, MAX2((size_t) NewSize, min_new));
        FLAG_SET_ERGO(uintx, NewSize, MIN2(preferred_max_new_size, (size_t) NewSize));
        if (PrintGCDetails && Verbose) {
          // Too early to use gclog_or_tty
          tty->print_cr("CMS ergo set NewSize: " SIZE_FORMAT, NewSize);
        }
      }
      // Unless explicitly requested otherwise, size old gen
      // so it's NewRatio x of NewSize.
      if (FLAG_IS_DEFAULT(OldSize)) {
        if (max_heap > NewSize) {
          FLAG_SET_ERGO(uintx, OldSize, MIN2(NewRatio*NewSize, max_heap - NewSize));
          if (PrintGCDetails && Verbose) {
            // Too early to use gclog_or_tty
            tty->print_cr("CMS ergo set OldSize: " SIZE_FORMAT, OldSize);
          }
        }
      }
    }
  }
  // Unless explicitly requested otherwise, definitely
  // promote all objects surviving "tenuring_default" scavenges.
  if (FLAG_IS_DEFAULT(MaxTenuringThreshold) &&
      FLAG_IS_DEFAULT(SurvivorRatio)) {
    FLAG_SET_ERGO(intx, MaxTenuringThreshold, tenuring_default);
  }
  // If we decided above (or user explicitly requested)
  // `promote all' (via MaxTenuringThreshold := 0),
  // prefer minuscule survivor spaces so as not to waste
  // space for (non-existent) survivors
  if (FLAG_IS_DEFAULT(SurvivorRatio) && MaxTenuringThreshold == 0) {
    FLAG_SET_ERGO(intx, SurvivorRatio, MAX2((intx)1024, SurvivorRatio));
  }
  // If OldPLABSize is set and CMSParPromoteBlocksToClaim is not,
  // set CMSParPromoteBlocksToClaim equal to OldPLABSize.
  // This is done in order to make ParNew+CMS configuration to work
  // with YoungPLABSize and OldPLABSize options.
  // See CR 6362902.
  if (!FLAG_IS_DEFAULT(OldPLABSize)) {
    if (FLAG_IS_DEFAULT(CMSParPromoteBlocksToClaim)) {
      // OldPLABSize is not the default value but CMSParPromoteBlocksToClaim
      // is.  In this situtation let CMSParPromoteBlocksToClaim follow
      // the value (either from the command line or ergonomics) of
      // OldPLABSize.  Following OldPLABSize is an ergonomics decision.
      FLAG_SET_ERGO(uintx, CMSParPromoteBlocksToClaim, OldPLABSize);
    } else {
      // OldPLABSize and CMSParPromoteBlocksToClaim are both set.
      // CMSParPromoteBlocksToClaim is a collector-specific flag, so
      // we'll let it to take precedence.
      jio_fprintf(defaultStream::error_stream(),
                  "Both OldPLABSize and CMSParPromoteBlocksToClaim"
                  " options are specified for the CMS collector."
                  " CMSParPromoteBlocksToClaim will take precedence.\n");
    }
  }
  if (!FLAG_IS_DEFAULT(ResizeOldPLAB) && !ResizeOldPLAB) {
    // OldPLAB sizing manually turned off: Use a larger default setting,
    // unless it was manually specified. This is because a too-low value
    // will slow down scavenges.
    if (FLAG_IS_DEFAULT(CMSParPromoteBlocksToClaim)) {
      FLAG_SET_ERGO(uintx, CMSParPromoteBlocksToClaim, 50); // default value before 6631166
    }
  }
  // Overwrite OldPLABSize which is the variable we will internally use everywhere.
  FLAG_SET_ERGO(uintx, OldPLABSize, CMSParPromoteBlocksToClaim);
  // If either of the static initialization defaults have changed, note this
  // modification.
  if (!FLAG_IS_DEFAULT(CMSParPromoteBlocksToClaim) || !FLAG_IS_DEFAULT(OldPLABWeight)) {
    CFLS_LAB::modify_initialization(OldPLABSize, OldPLABWeight);
  }
  if (PrintGCDetails && Verbose) {
    tty->print_cr("MarkStackSize: %uk  MarkStackSizeMax: %uk",
      MarkStackSize / K, MarkStackSizeMax / K);
    tty->print_cr("ConcGCThreads: %u", ConcGCThreads);
  }
}
#endif // KERNEL

void set_object_alignment() {
  // Object alignment.
  assert(is_power_of_2(ObjectAlignmentInBytes), "ObjectAlignmentInBytes must be power of 2");
  MinObjAlignmentInBytes     = ObjectAlignmentInBytes;
  assert(MinObjAlignmentInBytes >= HeapWordsPerLong * HeapWordSize, "ObjectAlignmentInBytes value is too small");
  MinObjAlignment            = MinObjAlignmentInBytes / HeapWordSize;
  assert(MinObjAlignmentInBytes == MinObjAlignment * HeapWordSize, "ObjectAlignmentInBytes value is incorrect");
  MinObjAlignmentInBytesMask = MinObjAlignmentInBytes - 1;

  LogMinObjAlignmentInBytes  = exact_log2(ObjectAlignmentInBytes);
  LogMinObjAlignment         = LogMinObjAlignmentInBytes - LogHeapWordSize;

  // Oop encoding heap max
  OopEncodingHeapMax = (uint64_t(max_juint) + 1) << LogMinObjAlignmentInBytes;

#ifndef KERNEL
  // Set CMS global values
  CompactibleFreeListSpace::set_cms_values();
#endif // KERNEL
}

bool verify_object_alignment() {
  // Object alignment.
  if (!is_power_of_2(ObjectAlignmentInBytes)) {
    jio_fprintf(defaultStream::error_stream(),
                "error: ObjectAlignmentInBytes=%d must be power of 2\n",
                (int)ObjectAlignmentInBytes);
    return false;
  }
  if ((int)ObjectAlignmentInBytes < BytesPerLong) {
    jio_fprintf(defaultStream::error_stream(),
                "error: ObjectAlignmentInBytes=%d must be greater or equal %d\n",
                (int)ObjectAlignmentInBytes, BytesPerLong);
    return false;
  }
  // It does not make sense to have big object alignment
  // since a space lost due to alignment will be greater
  // then a saved space from compressed oops.
  if ((int)ObjectAlignmentInBytes > 256) {
    jio_fprintf(defaultStream::error_stream(),
                "error: ObjectAlignmentInBytes=%d must not be greater then 256\n",
                (int)ObjectAlignmentInBytes);
    return false;
  }
  // In case page size is very small.
  if ((int)ObjectAlignmentInBytes >= os::vm_page_size()) {
    jio_fprintf(defaultStream::error_stream(),
                "error: ObjectAlignmentInBytes=%d must be less then page size %d\n",
                (int)ObjectAlignmentInBytes, os::vm_page_size());
    return false;
  }
  return true;
}

inline uintx max_heap_for_compressed_oops() {
  // Avoid sign flip.
  if (OopEncodingHeapMax < MaxPermSize + os::vm_page_size()) {
    return 0;
  }
  LP64_ONLY(return OopEncodingHeapMax - MaxPermSize - os::vm_page_size());
  NOT_LP64(ShouldNotReachHere(); return 0);
}

bool Arguments::should_auto_select_low_pause_collector() {
  if (UseAutoGCSelectPolicy &&
      !FLAG_IS_DEFAULT(MaxGCPauseMillis) &&
      (MaxGCPauseMillis <= AutoGCSelectPauseMillis)) {
    if (PrintGCDetails) {
      // Cannot use gclog_or_tty yet.
      tty->print_cr("Automatic selection of the low pause collector"
       " based on pause goal of %d (ms)", MaxGCPauseMillis);
    }
    return true;
  }
  return false;
}

void Arguments::set_ergonomics_flags() {
  // Parallel GC is not compatible with sharing. If one specifies
  // that they want sharing explicitly, do not set ergonomics flags.
  if (DumpSharedSpaces || RequireSharedSpaces) {
    return;
  }

  if (os::is_server_class_machine()) {
    // If no other collector is requested explicitly,
    // let the VM select the collector based on
    // machine class and automatic selection policy.
    if (!UseSerialGC &&
        !UseConcMarkSweepGC &&
        !UseG1GC &&
        !UseParNewGC &&
        !DumpSharedSpaces &&
        FLAG_IS_DEFAULT(UseParallelGC)) {
      if (should_auto_select_low_pause_collector()) {
        FLAG_SET_ERGO(bool, UseConcMarkSweepGC, true);
      } else {
        FLAG_SET_ERGO(bool, UseParallelGC, true);
      }
      no_s…