Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1997, 2018, 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/classLoader.hpp"

 #include "classfile/javaAssertions.hpp"

 #include "classfile/symbolTable.hpp"

 #include "compiler/compilerOracle.hpp"

 #include "memory/allocation.inline.hpp"

 #include "memory/cardTableRS.hpp"

 #include "memory/genCollectedHeap.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/arguments_ext.hpp"

 #include "runtime/globals_extension.hpp"

 #include "runtime/java.hpp"

 #include "services/management.hpp"

 #include "services/memTracker.hpp"

 #include "utilities/defaultStream.hpp"

 #include "utilities/macros.hpp"

 #include "utilities/stringUtils.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_aix

 # include "os_aix.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_bsd

 # include "os_bsd.inline.hpp"

 #endif

 #if INCLUDE_ALL_GCS

 #include "gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp"

 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"

 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"

 #endif // INCLUDE_ALL_GCS

 // Note: This is a special bug reporting site for the JVM

 #define DEFAULT_VENDOR_URL_BUG "http://bugreport.java.com/bugreport/crash.jsp"

 #define DEFAULT_JAVA_LAUNCHER  "generic"

 // Disable options not supported in this release, with a warning if they

 // were explicitly requested on the command-line

 #define UNSUPPORTED_OPTION(opt, description)                    \

 do {                                                            \

   if (opt) {                                                    \

     if (FLAG_IS_CMDLINE(opt)) {                                 \

       warning(description " is disabled in this release.");     \

     }                                                           \

     FLAG_SET_DEFAULT(opt, false);                               \

   }                                                             \

 } while(0)

 #define UNSUPPORTED_GC_OPTION(gc)                                     \

 do {                                                                  \

   if (gc) {                                                           \

     if (FLAG_IS_CMDLINE(gc)) {                                        \

       warning(#gc " is not supported in this VM.  Using Serial GC."); \

     }                                                                 \

     FLAG_SET_DEFAULT(gc, false);                                      \

   }                                                                   \

 } while(0)

 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;

 size_t Arguments::_conservative_max_heap_alignment = 0;

 uintx  Arguments::_min_heap_size                = 0;

 uintx  Arguments::_min_heap_free_ratio          = 0;

 uintx  Arguments::_max_heap_free_ratio          = 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) },

   { "CMSPermGenPrecleaningEnabled", JDK_Version::jdk(8),  JDK_Version::jdk(9) },

   { "CMSTriggerPermRatio", JDK_Version::jdk(8),  JDK_Version::jdk(9) },

   { "CMSInitiatingPermOccupancyFraction", JDK_Version::jdk(8),  JDK_Version::jdk(9) },

   { "AdaptivePermSizeWeight", JDK_Version::jdk(8),  JDK_Version::jdk(9) },

   { "PermGenPadding", JDK_Version::jdk(8),  JDK_Version::jdk(9) },

   { "PermMarkSweepDeadRatio", JDK_Version::jdk(8),  JDK_Version::jdk(9) },

   { "PermSize", JDK_Version::jdk(8),  JDK_Version::jdk(9) },

   { "MaxPermSize", JDK_Version::jdk(8),  JDK_Version::jdk(9) },

   { "MinPermHeapExpansion", JDK_Version::jdk(8),  JDK_Version::jdk(9) },

   { "MaxPermHeapExpansion", JDK_Version::jdk(8),  JDK_Version::jdk(9) },

   { "CMSRevisitStackSize",           JDK_Version::jdk(8), JDK_Version::jdk(9) },

   { "PrintRevisitStats",             JDK_Version::jdk(8), JDK_Version::jdk(9) },

   { "UseVectoredExceptions",         JDK_Version::jdk(8), JDK_Version::jdk(9) },

   { "UseSplitVerifier",              JDK_Version::jdk(8), JDK_Version::jdk(9) },

   { "UseISM",                        JDK_Version::jdk(8), JDK_Version::jdk(9) },

   { "UsePermISM",                    JDK_Version::jdk(8), JDK_Version::jdk(9) },

   { "UseMPSS",                       JDK_Version::jdk(8), JDK_Version::jdk(9) },

   { "UseStringCache",                JDK_Version::jdk(8), JDK_Version::jdk(9) },

   { "UseOldInlining",                JDK_Version::jdk(9), JDK_Version::jdk(10) },

   { "AutoShutdownNMT",               JDK_Version::jdk(9), JDK_Version::jdk(10) },

   { "CompilationRepeat",             JDK_Version::jdk(8), JDK_Version::jdk(9) },

 #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], mtInternal);

     _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, mtInternal);

       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, mtInternal);

       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, mtInternal);

   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, mtInternal);

     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, mtInternal);

       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, mtInternal);

     } else {

       cp = REALLOC_C_HEAP_ARRAY(char, path, len, mtInternal);

       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), mtInternal);

   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) {

       size_t length = directory_len + 2 + strlen(name);

       char* jarpath = NEW_C_HEAP_ARRAY(char, length, mtInternal);

       jio_snprintf(jarpath, length, "%s%s%s", directory, dir_sep, name);

       path = add_to_path(path, jarpath, false);

       FREE_C_HEAP_ARRAY(char, jarpath, mtInternal);

     }

   }

   FREE_C_HEAP_ARRAY(char, dbuf, mtInternal);

   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, JULONG_FORMAT, &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, Flag::Flags origin) {

   return CommandLineFlags::boolAtPut(name, &value, origin);

 }

 static bool set_fp_numeric_flag(char* name, char* value, Flag::Flags 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, Flag::Flags 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, Flag::Flags origin) {

   if (!CommandLineFlags::ccstrAtPut(name, &value, origin))  return false;

   // Contract:  CommandLineFlags always returns a pointer that needs freeing.

   FREE_C_HEAP_ARRAY(char, value, mtInternal);

   return true;

 }

 static bool append_to_string_flag(char* name, const char* new_value, Flag::Flags 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 {

     size_t length = old_len + 1 + new_len + 1;

     char* buf = NEW_C_HEAP_ARRAY(char, length, mtInternal);

     // each new setting adds another LINE to the switch:

     jio_snprintf(buf, length, "%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, mtInternal);

   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, mtInternal);

   }

   return true;

 }

 bool Arguments::parse_argument(const char* arg, Flag::Flags 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 new_count = *count + 1;

   // expand the array and add arg to the last element

   if (*bldarray == NULL) {

     *bldarray = NEW_C_HEAP_ARRAY(char*, new_count, mtInternal);

   } else {

     *bldarray = REALLOC_C_HEAP_ARRAY(char*, *bldarray, new_count, mtInternal);

   }

   (*bldarray)[*count] = strdup(arg);

   *count = new_count;

 }

 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 = 0;

   for (int i = 0; i < count; i++) {

     length += strlen(args[i]) + 1; // add 1 for a space or NULL terminating character

   }

   char* s = NEW_RESOURCE_ARRAY(char, length);

   char* dst = s;

   for (int j = 0; j < count; j++) {

     size_t offset = strlen(args[j]) + 1; // add 1 for a space or NULL terminating character

     jio_snprintf(dst, length, "%s ", args[j]); // jio_snprintf will replace the last space character with NULL character

     dst += offset;

     length -= offset;

   }

   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>");

   if (_java_class_path != NULL) {

     char* path = _java_class_path->value();

     st->print_cr("java_class_path (initial): %s", strlen(path) == 0 ? "<not set>" : path );

   }

   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->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->cr();

   }

 }

 bool Arguments::process_argument(const char* arg,

     jboolean ignore_unrecognized, Flag::Flags origin) {

   JDK_Version since = JDK_Version();

   if (parse_argument(arg, origin) || ignore_unrecognized) {

     return true;

   }

   bool has_plus_minus = (*arg == '+' || *arg == '-');

   const char* const argname = has_plus_minus ? 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.

   size_t arg_len;

   const char* equal_sign = strchr(argname, '=');

   if (equal_sign == NULL) {

     arg_len = strlen(argname);

   } else {

     arg_len = equal_sign - argname;

   }

   Flag* found_flag = Flag::find_flag((const char*)argname, arg_len, true, true);

   if (found_flag != NULL) {

     char locked_message_buf[BUFLEN];

     found_flag->get_locked_message(locked_message_buf, BUFLEN);

     if (strlen(locked_message_buf) == 0) {

       if (found_flag->is_bool() && !has_plus_minus) {

         jio_fprintf(defaultStream::error_stream(),

           "Missing +/- setting for VM option '%s'\n", argname);

       } else if (!found_flag->is_bool() && has_plus_minus) {

         jio_fprintf(defaultStream::error_stream(),

           "Unexpected +/- setting in VM option '%s'\n", argname);

       } else {

         jio_fprintf(defaultStream::error_stream(),

           "Improperly specified VM option '%s'\n", argname);

       }

     } else {

       jio_fprintf(defaultStream::error_stream(), "%s", locked_message_buf);

     }

   } else {

     jio_fprintf(defaultStream::error_stream(),

                 "Unrecognized VM option '%s'\n", argname);

     Flag* fuzzy_matched = Flag::fuzzy_match((const char*)argname, arg_len, true);

     if (fuzzy_matched != NULL) {

       jio_fprintf(defaultStream::error_stream(),

                   "Did you mean '%s%s%s'?\n",

                   (fuzzy_matched->is_bool()) ? "(+/-)" : "",

                   fuzzy_matched->_name,

                   (fuzzy_matched->is_bool()) ? "" : "=<value>");

     }

   }

   // 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 && pos < (int)(sizeof(token)-1)) {

     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, Flag::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, Flag::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, mtInternal);

   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, mtInternal);

     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;

   }

 }

 #if defined(COMPILER2) || defined(_LP64) || !INCLUDE_CDS

 // Conflict: required to use shared spaces (-Xshare:on), but

 // incompatible command line options were chosen.

 static void no_shared_spaces(const char* message) {

   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.", message);

   } else {

     FLAG_SET_DEFAULT(UseSharedSpaces, false);

   }

 }

 #endif

 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 * 5);

   }

   if (!UseInterpreter) { // -Xcomp

     Tier3InvokeNotifyFreqLog = 0;

     Tier4InvocationThreshold = 0;

   }

 }

 /**

  * Returns the minimum number of compiler threads needed to run the JVM. The following

  * configurations are possible.

  *

  * 1) The JVM is build using an interpreter only. As a result, the minimum number of

  *    compiler threads is 0.

  * 2) The JVM is build using the compiler(s) and tiered compilation is disabled. As

  *    a result, either C1 or C2 is used, so the minimum number of compiler threads is 1.

  * 3) The JVM is build using the compiler(s) and tiered compilation is enabled. However,

  *    the option "TieredStopAtLevel < CompLevel_full_optimization". As a result, only

  *    C1 can be used, so the minimum number of compiler threads is 1.

  * 4) The JVM is build using the compilers and tiered compilation is enabled. The option

  *    'TieredStopAtLevel = CompLevel_full_optimization' (the default value). As a result,

  *    the minimum number of compiler threads is 2.

  */

 int Arguments::get_min_number_of_compiler_threads() {

 #if !defined(COMPILER1) && !defined(COMPILER2) && !defined(SHARK)

   return 0;   // case 1

 #else

   if (!TieredCompilation || (TieredStopAtLevel < CompLevel_full_optimization)) {

     return 1; // case 2 or case 3

   }

   return 2;   // case 4 (tiered)

 #endif

 }

 #if INCLUDE_ALL_GCS

 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);

   }

 }

 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 (FLAG_IS_DEFAULT(ParallelGCThreads)) {

     FLAG_SET_DEFAULT(ParallelGCThreads, Abstract_VM_Version::parallel_worker_threads());

     assert(ParallelGCThreads > 0, "We should always have at least one thread by default");

   } else if (ParallelGCThreads == 0) {

     jio_fprintf(defaultStream::error_stream(),

         "The ParNew GC can not be combined with -XX:ParallelGCThreads=0\n");

     vm_exit(1);

   }

   // 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(uintx, 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 by default 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();

   }

   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(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

     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(NewSize, min_new));

         FLAG_SET_ERGO(uintx, NewSize, MIN2(preferred_max_new_size, 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(uintx, 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(uintx, SurvivorRatio, MAX2((uintx)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",

       (unsigned int) (MarkStackSize / K), (uint) (MarkStackSizeMax / K));

     tty->print_cr("ConcGCThreads: %u", (uint) ConcGCThreads);

   }

 }

 #endif // INCLUDE_ALL_GCS

 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;

 #if INCLUDE_ALL_GCS

   // Set CMS global values

   CompactibleFreeListSpace::set_cms_values();

 #endif // INCLUDE_ALL_GCS

 }

 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 than 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 than page size %d\n",

                 (int)ObjectAlignmentInBytes, os::vm_page_size());

     return false;

   }

   if(SurvivorAlignmentInBytes == 0) {

     SurvivorAlignmentInBytes = ObjectAlignmentInBytes;

   } else {

     if (!is_power_of_2(SurvivorAlignmentInBytes)) {

       jio_fprintf(defaultStream::error_stream(),

             "error: SurvivorAlignmentInBytes=%d must be power of 2\n",

             (int)SurvivorAlignmentInBytes);

       return false;

     }

     if (SurvivorAlignmentInBytes < ObjectAlignmentInBytes) {

       jio_fprintf(defaultStream::error_stream(),

           "error: SurvivorAlignmentInBytes=%d must be greater than ObjectAlignmentInBytes=%d \n",

           (int)SurvivorAlignmentInBytes, (int)ObjectAlignmentInBytes);

       return false;

     }

   }

   return true;

 }

 size_t Arguments::max_heap_for_compressed_oops() {

   // Avoid sign flip.

   assert(OopEncodingHeapMax > (uint64_t)os::vm_page_size(), "Unusual page size");

   // We need to fit both the NULL page and the heap into the memory budget, while

   // keeping alignment constraints of the heap. To guarantee the latter, as the

   // NULL page is located before the heap, we pad the NULL page to the conservative

   // maximum alignment that the GC may ever impose upon the heap.

   size_t displacement_due_to_null_page = align_size_up_(os::vm_page_size(),

                                                         _conservative_max_heap_alignment);

   LP64_ONLY(return OopEncodingHeapMax - displacement_due_to_null_page);

   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)", (int) MaxGCPauseMillis);

     }

     return true;

   }

   return false;

 }

 void Arguments::set_use_compressed_oops() {

 #ifndef ZERO

 #ifdef _LP64

   // MaxHeapSize is not set up properly at this point, but

   // the only value that can override MaxHeapSize if we are

   // to use UseCompressedOops is InitialHeapSize.

   size_t max_heap_size = MAX2(MaxHeapSize, InitialHeapSize);

   if (max_heap_size <= max_heap_for_compressed_oops()) {

 #if !defined(COMPILER1) || defined(TIERED)

     if (FLAG_IS_DEFAULT(UseCompressedOops)) {

       FLAG_SET_ERGO(bool, UseCompressedOops, true);

     }

 #endif

 #ifdef _WIN64

     if (UseLargePages && UseCompressedOops) {

       // Cannot allocate guard pages for implicit checks in indexed addressing

       // mode, when large pages are specified on windows.

       // This flag could be switched ON if narrow oop base address is set to 0,

       // see code in Universe::initialize_heap().

       Universe::set_narrow_oop_use_implicit_null_checks(false);

     }

 #endif //  _WIN64

   } else {

     if (UseCompressedOops && !FLAG_IS_DEFAULT(UseCompressedOops)) {

       warning("Max heap size too large for Compressed Oops");

       FLAG_SET_DEFAULT(UseCompressedOops, false);

       FLAG_SET_DEFAULT(UseCompressedClassPointers, false);

     }

   }

 #endif // _LP64

 #endif // ZERO

 }

 // NOTE: set_use_compressed_klass_ptrs() must be called after calling

 // set_use_compressed_oops().

 void Arguments::set_use_compressed_klass_ptrs() {

 #ifndef ZERO

 #ifdef _LP64

   // UseCompressedOops must be on for UseCompressedClassPointers to be on.

   if (!UseCompressedOops) {

     if (UseCompressedClassPointers) {

       warning("UseCompressedClassPointers requires UseCompressedOops");

     }

     FLAG_SET_DEFAULT(UseCompressedClassPointers, false);

   } else {

     // Turn on UseCompressedClassPointers too

     if (FLAG_IS_DEFAULT(UseCompressedClassPointers)) {

       FLAG_SET_ERGO(bool, UseCompressedClassPointers, true);

     }

     // Check the CompressedClassSpaceSize to make sure we use compressed klass ptrs.

     if (UseCompressedClassPointers) {

       if (CompressedClassSpaceSize > KlassEncodingMetaspaceMax) {

         warning("CompressedClassSpaceSize is too large for UseCompressedClassPointers");

         FLAG_SET_DEFAULT(UseCompressedClassPointers, false);

       }

     }

   }

 #endif // _LP64

 #endif // !ZERO

 }

 void Arguments::set_conservative_max_heap_alignment() {

   // The conservative maximum required alignment for the heap is the maximum of

   // the alignments imposed by several sources: any requirements from the heap

   // itself, the collector policy and the maximum page size we may run the VM

   // with.

   size_t heap_alignment = GenCollectedHeap::conservative_max_heap_alignment();

 #if INCLUDE_ALL_GCS

   if (UseParallelGC) {

     heap_alignment = ParallelScavengeHeap::conservative_max_heap_alignment();

   } else if (UseG1GC) {

     heap_alignment = G1CollectedHeap::conservative_max_heap_alignment();

   }

 #endif // INCLUDE_ALL_GCS

   _conservative_max_heap_alignment = MAX4(heap_alignment,

                                           (size_t)os::vm_allocation_granularity(),

                                           os::max_page_size(),

                                           CollectorPolicy::compute_heap_alignment());

 }

 void Arguments::select_gc_ergonomically() {

   if (os::is_server_class_machine()) {

     if (should_auto_select_low_pause_collector()) {

       FLAG_SET_ERGO(bool, UseConcMarkSweepGC, true);

     } else {

       FLAG_SET_ERGO(bool, UseParallelGC, true);

     }

   }

 }

 void Arguments::select_gc() {

   if (!gc_selected()) {

     select_gc_ergonomically();

   }

 }

 void Arguments::set_ergonomics_flags() {

   select_gc();

 #ifdef COMPILER2

   // Shared spaces work fine with other GCs but causes bytecode rewriting

   // to be disabled, which hurts interpreter performance and decreases

   // server performance.  When -server is specified, keep the default off

   // unless it is asked for.  Future work: either add bytecode rewriting

   // at link time, or rewrite bytecodes in non-shared methods.

   if (!DumpSharedSpaces && !RequireSharedSpaces &&

       (FLAG_IS_DEFAULT(UseSharedSpaces) || !UseSharedSpaces)) {

     no_shared_spaces("COMPILER2 default: -Xshare:auto | off, have to manually setup to on.");

   }

 #endif

   set_conservative_max_heap_alignment();

 #ifndef ZERO

 #ifdef _LP64

   set_use_compressed_oops();

   // set_use_compressed_klass_ptrs() must be called after calling

   // set_use_compressed_oops().

   set_use_compressed_klass_ptrs();

   // Also checks that certain machines are slower with compressed oops

   // in vm_version initialization code.

 #endif // _LP64

 #endif // !ZERO

 }

 void Arguments::set_parallel_gc_flags() {

   assert(UseParallelGC || UseParallelOldGC, "Error");

   // Enable ParallelOld unless it was explicitly disabled (cmd line or rc file).

   if (FLAG_IS_DEFAULT(UseParallelOldGC)) {

     FLAG_SET_DEFAULT(UseParallelOldGC, true);

   }

   FLAG_SET_DEFAULT(UseParallelGC, true);

   // If no heap maximum was requested explicitly, use some reasonable fraction

   // of the physical memory, up to a maximum of 1GB.

   FLAG_SET_DEFAULT(ParallelGCThreads,

                    Abstract_VM_Version::parallel_worker_threads());

   if (ParallelGCThreads == 0) {

     jio_fprintf(defaultStream::error_stream(),

         "The Parallel GC can not be combined with -XX:ParallelGCThreads=0\n");

     vm_exit(1);

   }

   if (UseAdaptiveSizePolicy) {

     // We don't want to limit adaptive heap sizing's freedom to adjust the heap

     // unless the user actually sets these flags.

     if (FLAG_IS_DEFAULT(MinHeapFreeRatio)) {

       FLAG_SET_DEFAULT(MinHeapFreeRatio, 0);

       _min_heap_free_ratio = MinHeapFreeRatio;

     }

     if (FLAG_IS_DEFAULT(MaxHeapFreeRatio)) {

       FLAG_SET_DEFAULT(MaxHeapFreeRatio, 100);

       _max_heap_free_ratio = MaxHeapFreeRatio;

     }

   }

   // If InitialSurvivorRatio or MinSurvivorRatio were not specified, but the

   // SurvivorRatio has been set, reset their default values to SurvivorRatio +

   // 2.  By doing this we make SurvivorRatio also work for Parallel Scavenger.

   // See CR 6362902 for details.

   if (!FLAG_IS_DEFAULT(SurvivorRatio)) {

     if (FLAG_IS_DEFAULT(InitialSurvivorRatio)) {

        FLAG_SET_DEFAULT(InitialSurvivorRatio, SurvivorRatio + 2);

     }

     if (FLAG_IS_DEFAULT(MinSurvivorRatio)) {

       FLAG_SET_DEFAULT(MinSurvivorRatio, SurvivorRatio + 2);

     }

   }

   if (UseParallelOldGC) {

     // Par compact uses lower default values since they are treated as

     // minimums.  These are different defaults because of the different

     // interpretation and are not ergonomically set.

     if (FLAG_IS_DEFAULT(MarkSweepDeadRatio)) {

       FLAG_SET_DEFAULT(MarkSweepDeadRatio, 1);

     }

   }

 }

 void Arguments::set_g1_gc_flags() {

   assert(UseG1GC, "Error");

 #ifdef COMPILER1

   FastTLABRefill = false;

 #endif

   FLAG_SET_DEFAULT(ParallelGCThreads,

                      Abstract_VM_Version::parallel_worker_threads());

   if (ParallelGCThreads == 0) {

     vm_exit_during_initialization("The flag -XX:+UseG1GC can not be combined with -XX:ParallelGCThreads=0", NULL);

     }

 #if INCLUDE_ALL_GCS

   if (G1ConcRefinementThreads == 0) {

     FLAG_SET_DEFAULT(G1ConcRefinementThreads, ParallelGCThreads);

   }

 #endif

   // MarkStackSize will be set (if it hasn't been set by the user)

   // when concurrent marking is initialized.

   // Its value will be based upon the number of parallel marking threads.

   // But we do set the maximum mark stack size here.

   if (FLAG_IS_DEFAULT(MarkStackSizeMax)) {

     FLAG_SET_DEFAULT(MarkStackSizeMax, 128 * TASKQUEUE_SIZE);

   }

   if (FLAG_IS_DEFAULT(GCTimeRatio) || GCTimeRatio == 0) {

     // In G1, we want the default GC overhead goal to be higher than

     // say in PS. So we set it here to 10%. Otherwise the heap might

     // be expanded more aggressively than we would like it to. In

     // fact, even 10% seems to not be high enough in some cases

     // (especially small GC stress tests that the main thing they do

     // is allocation). We might consider increase it further.

     FLAG_SET_DEFAULT(GCTimeRatio, 9);

   }

   if (PrintGCDetails && Verbose) {

     tty->print_cr("MarkStackSize: %uk  MarkStackSizeMax: %uk",

       (unsigned int) (MarkStackSize / K), (uint) (MarkStackSizeMax / K));

     tty->print_cr("ConcGCThreads: %u", (uint) ConcGCThreads);

   }

 }

 #if !INCLUDE_ALL_GCS

 #ifdef ASSERT

 static bool verify_serial_gc_flags() {

   return (UseSerialGC &&

         !(UseParNewGC || (UseConcMarkSweepGC || CMSIncrementalMode) || UseG1GC ||

           UseParallelGC || UseParallelOldGC));

 }

 #endif // ASSERT

 #endif // INCLUDE_ALL_GCS

 void Arguments::set_gc_specific_flags() {

 #if INCLUDE_ALL_GCS

   // Set per-collector flags

   if (UseParallelGC || UseParallelOldGC) {

     set_parallel_gc_flags();

   } else if (UseConcMarkSweepGC) { // Should be done before ParNew check below

     set_cms_and_parnew_gc_flags();

   } else if (UseParNewGC) {  // Skipped if CMS is set above

     set_parnew_gc_flags();

   } else if (UseG1GC) {

     set_g1_gc_flags();

   }

   check_deprecated_gcs();

   check_deprecated_gc_flags();

   if (AssumeMP && !UseSerialGC) {

     if (FLAG_IS_DEFAULT(ParallelGCThreads) && ParallelGCThreads == 1) {

       warning("If the number of processors is expected to increase from one, then"

               " you should configure the number of parallel GC threads appropriately"

               " using -XX:ParallelGCThreads=N");

     }

   }

   if (MinHeapFreeRatio == 100) {

     // Keeping the heap 100% free is hard ;-) so limit it to 99%.

     FLAG_SET_ERGO(uintx, MinHeapFreeRatio, 99);

   }

   // If class unloading is disabled, also disable concurrent class unloading.

   if (!ClassUnloading) {

     FLAG_SET_CMDLINE(bool, CMSClassUnloadingEnabled, false);

     FLAG_SET_CMDLINE(bool, ClassUnloadingWithConcurrentMark, false);

     FLAG_SET_CMDLINE(bool, ExplicitGCInvokesConcurrentAndUnloadsClasses, false);

   }

 #else // INCLUDE_ALL_GCS

   assert(verify_serial_gc_flags(), "SerialGC unset");

 #endif // INCLUDE_ALL_GCS

 }

 julong Arguments::limit_by_allocatable_memory(julong limit) {

   julong max_allocatable;

   julong result = limit;

   if (os::has_allocatable_memory_limit(&max_allocatable)) {

     result = MIN2(result, max_allocatable / MaxVirtMemFraction);

   }

   return result;

 }

 void Arguments::set_heap_size() {

   if (!FLAG_IS_DEFAULT(DefaultMaxRAMFraction)) {

     // Deprecated flag

     FLAG_SET_CMDLINE(uintx, MaxRAMFraction, DefaultMaxRAMFraction);

   }

   julong phys_mem =

     FLAG_IS_DEFAULT(MaxRAM) ? MIN2(os::physical_memory(), (julong)MaxRAM)

                             : (julong)MaxRAM;

   // Experimental support for CGroup memory limits

   if (UseCGroupMemoryLimitForHeap) {

     // This is a rough indicator that a CGroup limit may be in force

     // for this process

     const char* lim_file = "/sys/fs/cgroup/memory/memory.limit_in_bytes";

     FILE *fp = fopen(lim_file, "r");

     if (fp != NULL) {

       julong cgroup_max = 0;

       int ret = fscanf(fp, JULONG_FORMAT, &cgroup_max);

       if (ret == 1 && cgroup_max > 0) {

         // If unlimited, cgroup_max will be a very large, but unspecified

         // value, so use initial phys_mem as a limit

         if (PrintGCDetails && Verbose) {

           // Cannot use gclog_or_tty yet.

           tty->print_cr("Setting phys_mem to the min of cgroup limit ("

                         JULONG_FORMAT "MB) and initial phys_mem ("

                         JULONG_FORMAT "MB)", cgroup_max/M, phys_mem/M);

         }

         phys_mem = MIN2(cgroup_max, phys_mem);

       } else {

         warning("Unable to read/parse cgroup memory limit from %s: %s",

                 lim_file, errno != 0 ? strerror(errno) : "unknown error");

       }

       fclose(fp);

     } else {

       warning("Unable to open cgroup memory limit file %s (%s)", lim_file, strerror(errno));

     }

   }

   // Convert Fraction to Precentage values

   if (FLAG_IS_DEFAULT(MaxRAMPercentage) &&

       !FLAG_IS_DEFAULT(MaxRAMFraction))

     MaxRAMPercentage = 100.0 / MaxRAMFraction;

    if (FLAG_IS_DEFAULT(MinRAMPercentage) &&

        !FLAG_IS_DEFAULT(MinRAMFraction))

      MinRAMPercentage = 100.0 / MinRAMFraction;

    if (FLAG_IS_DEFAULT(InitialRAMPercentage) &&

        !FLAG_IS_DEFAULT(InitialRAMFraction))

      InitialRAMPercentage = 100.0 / InitialRAMFraction;

   // If the maximum heap size has not been set with -Xmx,

   // then set it as fraction of the size of physical memory,

   // respecting the maximum and minimum sizes of the heap.

   if (FLAG_IS_DEFAULT(MaxHeapSize)) {

     julong reasonable_max = (julong)((phys_mem * MaxRAMPercentage) / 100);

     const julong reasonable_min = (julong)((phys_mem * MinRAMPercentage) / 100);

     if (reasonable_min < MaxHeapSize) {

       // Small physical memory, so use a minimum fraction of it for the heap

       reasonable_max = reasonable_min;

     } else {

       // Not-small physical memory, so require a heap at least

       // as large as MaxHeapSize

       reasonable_max = MAX2(reasonable_max, (julong)MaxHeapSize);

     }

     if (!FLAG_IS_DEFAULT(ErgoHeapSizeLimit) && ErgoHeapSizeLimit != 0) {

       // Limit the heap size to ErgoHeapSizeLimit

       reasonable_max = MIN2(reasonable_max, (julong)ErgoHeapSizeLimit);

     }

     if (UseCompressedOops) {

       // Limit the heap size to the maximum possible when using compressed oops

       julong max_coop_heap = (julong)max_heap_for_compressed_oops();

       if (HeapBaseMinAddress + MaxHeapSize < max_coop_heap) {

         // Heap should be above HeapBaseMinAddress to get zero based compressed oops

         // but it should be not less than default MaxHeapSize.

         max_coop_heap -= HeapBaseMinAddress;

       }

       reasonable_max = MIN2(reasonable_max, max_coop_heap);

     }

     reasonable_max = limit_by_allocatable_memory(reasonable_max);

     if (!FLAG_IS_DEFAULT(InitialHeapSize)) {

       // An initial heap size was specified on the command line,

       // so be sure that the maximum size is consistent.  Done

       // after call to limit_by_allocatable_memory because that

       // method might reduce the allocation size.

       reasonable_max = MAX2(reasonable_max, (julong)InitialHeapSize);

     }

     if (PrintGCDetails && Verbose) {

       // Cannot use gclog_or_tty yet.

       tty->print_cr("  Maximum heap size " SIZE_FORMAT, (size_t) reasonable_max);

     }

     FLAG_SET_ERGO(uintx, MaxHeapSize, (uintx)reasonable_max);

   }

   // If the minimum or initial heap_size have not been set or requested to be set

   // ergonomically, set them accordingly.

   if (InitialHeapSize == 0 || min_heap_size() == 0) {

     julong reasonable_minimum = (julong)(OldSize + NewSize);

     reasonable_minimum = MIN2(reasonable_minimum, (julong)MaxHeapSize);

     reasonable_minimum = limit_by_allocatable_memory(reasonable_minimum);

     if (InitialHeapSize == 0) {

       julong reasonable_initial = (julong)((phys_mem * InitialRAMPercentage) / 100);

       reasonable_initial = MAX3(reasonable_initial, reasonable_minimum, (julong)min_heap_size());

       reasonable_initial = MIN2(reasonable_initial, (julong)MaxHeapSize);

       reasonable_initial = limit_by_allocatable_memory(reasonable_initial);

       if (PrintGCDetails && Verbose) {

         // Cannot use gclog_or_tty yet.

         tty->print_cr("  Initial heap size " SIZE_FORMAT, (uintx)reasonable_initial);

       }

       FLAG_SET_ERGO(uintx, InitialHeapSize, (uintx)reasonable_initial);

     }

     // If the minimum heap size has not been set (via -Xms),

     // synchronize with InitialHeapSize to avoid errors with the default value.

     if (min_heap_size() == 0) {

       set_min_heap_size(MIN2((uintx)reasonable_minimum, InitialHeapSize));

       if (PrintGCDetails && Verbose) {

         // Cannot use gclog_or_tty yet.

         tty->print_cr("  Minimum heap size " SIZE_FORMAT, min_heap_size());

       }

     }

   }

 }

 // This option inspects the machine and attempts to set various

 // parameters to be optimal for long-running, memory allocation

 // intensive jobs.  It is intended for machines with large

 // amounts of cpu and memory.

 jint Arguments::set_aggressive_heap_flags() {

   // initHeapSize is needed since _initial_heap_size is 4 bytes on a 32 bit

   // VM, but we may not be able to represent the total physical memory

   // available (like having 8gb of memory on a box but using a 32bit VM).

   // Thus, we need to make sure we're using a julong for intermediate

   // calculations.

   julong initHeapSize;

   julong total_memory = os::physical_memory();

   if (total_memory < (julong) 256 * M) {

     jio_fprintf(defaultStream::error_stream(),

             "You need at least 256mb of memory to use -XX:+AggressiveHeap\n");

     vm_exit(1);

   }

   // The heap size is half of available memory, or (at most)

   // all of possible memory less 160mb (leaving room for the OS

   // when using ISM).  This is the maximum; because adaptive sizing

   // is turned on below, the actual space used may be smaller.

   initHeapSize = MIN2(total_memory / (julong) 2,

                       total_memory - (julong) 160 * M);

   initHeapSize = limit_by_allocatable_memory(initHeapSize);

   if (FLAG_IS_DEFAULT(MaxHeapSize)) {

     FLAG_SET_CMDLINE(uintx, MaxHeapSize, initHeapSize);

     FLAG_SET_CMDLINE(uintx, InitialHeapSize, initHeapSize);

     // Currently the minimum size and the initial heap sizes are the same.

     set_min_heap_size(initHeapSize);

   }

   if (FLAG_IS_DEFAULT(NewSize)) {

     // Make the young generation 3/8ths of the total heap.

     FLAG_SET_CMDLINE(uintx, NewSize,

             ((julong) MaxHeapSize / (julong) 8) * (julong) 3);

     FLAG_SET_CMDLINE(uintx, MaxNewSize, NewSize);

   }

 #ifndef _ALLBSD_SOURCE  // UseLargePages is not yet supported on BSD.

   FLAG_SET_DEFAULT(UseLargePages, true);

 #endif

   // Increase some data structure sizes for efficiency

   FLAG_SET_CMDLINE(uintx, BaseFootPrintEstimate, MaxHeapSize);

   FLAG_SET_CMDLINE(bool, ResizeTLAB, false);

   FLAG_SET_CMDLINE(uintx, TLABSize, 256 * K);

   // See the OldPLABSize comment below, but replace 'after promotion'

   // with 'after copying'.  YoungPLABSize is the size of the survivor

   // space per-gc-thread buffers.  The default is 4kw.

   FLAG_SET_CMDLINE(uintx, YoungPLABSize, 256 * K);     // Note: this is in words

   // OldPLABSize is the size of the buffers in the old gen that

   // UseParallelGC uses to promote live data that doesn't fit in the

   // survivor spaces.  At any given time, there's one for each gc thread.

   // The default size is 1kw. These buffers are rarely used, since the

   // survivor spaces are usually big enough.  For specjbb, however, there

   // are occasions when there's lots of live data in the young gen

   // and we end up promoting some of it.  We don't have a definite

   // explanation for why bumping OldPLABSize helps, but the theory

   // is that a bigger PLAB results in retaining something like the

   // original allocation order after promotion, which improves mutator

   // locality.  A minor effect may be that larger PLABs reduce the

   // number of PLAB allocation events during gc.  The value of 8kw

   // was arrived at by experimenting with specjbb.

   FLAG_SET_CMDLINE(uintx, OldPLABSize, 8 * K);      // Note: this is in words

   // Enable parallel GC and adaptive generation sizing

   FLAG_SET_CMDLINE(bool, UseParallelGC, true);

   // Encourage steady state memory management

   FLAG_SET_CMDLINE(uintx, ThresholdTolerance, 100);

   // This appears to improve mutator locality

   FLAG_SET_CMDLINE(bool, ScavengeBeforeFullGC, false);

   // Get around early Solaris scheduling bug

   // (affinity vs other jobs on system)

   // but disallow DR and offlining (5008695).

   FLAG_SET_CMDLINE(bool, BindGCTaskThreadsToCPUs, true);

   return JNI_OK;

 }

 // This must be called after ergonomics because we want bytecode rewriting

 // if the server compiler is used, or if UseSharedSpaces is disabled.

 void Arguments::set_bytecode_flags() {

   // Better not attempt to store into a read-only space.

   if (UseSharedSpaces) {

     FLAG_SET_DEFAULT(RewriteBytecodes, false);

     FLAG_SET_DEFAULT(RewriteFrequentPairs, false);

   }

   if (!RewriteBytecodes) {

     FLAG_SET_DEFAULT(RewriteFrequentPairs, false);

   }

 }

 // Aggressive optimization flags  -XX:+AggressiveOpts

 void Arguments::set_aggressive_opts_flags() {

 #ifdef COMPILER2

   if (AggressiveUnboxing) {

     if (FLAG_IS_DEFAULT(EliminateAutoBox)) {

       FLAG_SET_DEFAULT(EliminateAutoBox, true);

     } else if (!EliminateAutoBox) {

       // warning("AggressiveUnboxing is disabled because EliminateAutoBox is disabled");

       AggressiveUnboxing = false;

     }

     if (FLAG_IS_DEFAULT(DoEscapeAnalysis)) {

       FLAG_SET_DEFAULT(DoEscapeAnalysis, true);

     } else if (!DoEscapeAnalysis) {

       // warning("AggressiveUnboxing is disabled because DoEscapeAnalysis is disabled");

       AggressiveUnboxing = false;

     }

   }

   if (AggressiveOpts || !FLAG_IS_DEFAULT(AutoBoxCacheMax)) {

     if (FLAG_IS_DEFAULT(EliminateAutoBox)) {

       FLAG_SET_DEFAULT(EliminateAutoBox, true);

     }

     if (FLAG_IS_DEFAULT(AutoBoxCacheMax)) {

       FLAG_SET_DEFAULT(AutoBoxCacheMax, 20000);

     }

     // Feed the cache size setting into the JDK

     char buffer[1024];

     jio_snprintf(buffer, 1024, "java.lang.Integer.IntegerCache.high=" INTX_FORMAT, AutoBoxCacheMax);

     add_property(buffer);

   }

   if (AggressiveOpts && FLAG_IS_DEFAULT(BiasedLockingStartupDelay)) {

     FLAG_SET_DEFAULT(BiasedLockingStartupDelay, 500);

   }

 #endif

   if (AggressiveOpts) {

 // Sample flag setting code

 //    if (FLAG_IS_DEFAULT(EliminateZeroing)) {

 //      FLAG_SET_DEFAULT(EliminateZeroing, true);

 //    }

   }

 }

 //===========================================================================================================

 // Parsing of java.compiler property

 void Arguments::process_java_compiler_argument(char* arg) {

   // For backwards compatibility, Djava.compiler=NONE or ""

   // causes us to switch to -Xint mode UNLESS -Xdebug

   // is also specified.

   if (strlen(arg) == 0 || strcasecmp(arg, "NONE") == 0) {

     set_java_compiler(true);    // "-Djava.compiler[=...]" most recently seen.

   }

 }

 void Arguments::process_java_launcher_argument(const char* launcher, void* extra_info) {

   _sun_java_launcher = strdup(launcher);

   if (strcmp("gamma", _sun_java_launcher) == 0) {

     _created_by_gamma_launcher = true;

   }

 }

 bool Arguments::created_by_java_launcher() {

   assert(_sun_java_launcher != NULL, "property must have value");

   return strcmp(DEFAULT_JAVA_LAUNCHER, _sun_java_launcher) != 0;

 }

 bool Arguments::created_by_gamma_launcher() {

   return _created_by_gamma_launcher;

 }

 //===========================================================================================================

 // Parsing of main arguments

 bool Arguments::verify_interval(uintx val, uintx min,

                                 uintx max, const char* name) {

   // Returns true iff value is in the inclusive interval [min..max]

   // false, otherwise.

   if (val >= min && val <= max) {

     return true;

   }

   jio_fprintf(defaultStream::error_stream(),

               "%s of " UINTX_FORMAT " is invalid; must be between " UINTX_FORMAT

               " and " UINTX_FORMAT "\n",

               name, val, min, max);

   return false;

 }

 bool Arguments::verify_min_value(intx val, intx min, const char* name) {

   // Returns true if given value is at least specified min threshold

   // false, otherwise.

   if (val >= min ) {

       return true;

   }

   jio_fprintf(defaultStream::error_stream(),

               "%s of " INTX_FORMAT " is invalid; must be at least " INTX_FORMAT "\n",

               name, val, min);

   return false;

 }

 bool Arguments::verify_percentage(uintx value, const char* name) {

   if (is_percentage(value)) {

     return true;

   }

   jio_fprintf(defaultStream::error_stream(),

               "%s of " UINTX_FORMAT " is invalid; must be between 0 and 100\n",

               name, value);

   return false;

 }

 // check if do gclog rotation

 // +UseGCLogFileRotation is a must,

 // no gc log rotation when log file not supplied or

 // NumberOfGCLogFiles is 0

 void check_gclog_consistency() {

   if (UseGCLogFileRotation) {

     if ((Arguments::gc_log_filename() == NULL) || (NumberOfGCLogFiles == 0)) {

       jio_fprintf(defaultStream::output_stream(),

                   "To enable GC log rotation, use -Xloggc:<filename> -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=<num_of_files>\n"

                   "where num_of_file > 0\n"

                   "GC log rotation is turned off\n");

       UseGCLogFileRotation = false;

     }

   }

   if (UseGCLogFileRotation && (GCLogFileSize != 0) && (GCLogFileSize < 8*K)) {

     FLAG_SET_CMDLINE(uintx, GCLogFileSize, 8*K);

     jio_fprintf(defaultStream::output_stream(),

                 "GCLogFileSize changed to minimum 8K\n");

   }

 }

 // This function is called for -Xloggc:<filename>, it can be used

 // to check if a given file name(or string) conforms to the following

 // specification:

 // A valid string only contains "[A-Z][a-z][0-9].-_%[p|t]"

 // %p and %t only allowed once. We only limit usage of filename not path

 bool is_filename_valid(const char *file_name) {

   const char* p = file_name;

   char file_sep = os::file_separator()[0];

   const char* cp;

   // skip prefix path

   for (cp = file_name; *cp != '\0'; cp++) {

     if (*cp == '/' || *cp == file_sep) {

       p = cp + 1;

     }

   }

   int count_p = 0;

   int count_t = 0;

   while (*p != '\0') {

     if ((*p >= '0' && *p <= '9') ||

         (*p >= 'A' && *p <= 'Z') ||

         (*p >= 'a' && *p <= 'z') ||

          *p == '-'               ||

          *p == '_'               ||

          *p == '.') {

        p++;

        continue;

     }

     if (*p == '%') {

       if(*(p + 1) == 'p') {

         p += 2;

         count_p ++;

         continue;

       }

       if (*(p + 1) == 't') {

         p += 2;

         count_t ++;

         continue;

       }

     }

     return false;

   }

   return count_p < 2 && count_t < 2;

 }

 bool Arguments::verify_MinHeapFreeRatio(FormatBuffer<80>& err_msg, uintx min_heap_free_ratio) {

   if (!is_percentage(min_heap_free_ratio)) {

     err_msg.print("MinHeapFreeRatio must have a value between 0 and 100");

     return false;

   }

   if (min_heap_free_ratio > MaxHeapFreeRatio) {

     err_msg.print("MinHeapFreeRatio (" UINTX_FORMAT ") must be less than or "

                   "equal to MaxHeapFreeRatio (" UINTX_FORMAT ")", min_heap_free_ratio,

                   MaxHeapFreeRatio);

     return false;

   }

   // This does not set the flag itself, but stores the value in a safe place for later usage.

   _min_heap_free_ratio = min_heap_free_ratio;

   return true;

 }

 bool Arguments::verify_MaxHeapFreeRatio(FormatBuffer<80>& err_msg, uintx max_heap_free_ratio) {

   if (!is_percentage(max_heap_free_ratio)) {

     err_msg.print("MaxHeapFreeRatio must have a value between 0 and 100");

     return false;

   }

   if (max_heap_free_ratio < MinHeapFreeRatio) {

     err_msg.print("MaxHeapFreeRatio (" UINTX_FORMAT ") must be greater than or "

                   "equal to MinHeapFreeRatio (" UINTX_FORMAT ")", max_heap_free_ratio,

                   MinHeapFreeRatio);

     return false;

   }

   // This does not set the flag itself, but stores the value in a safe place for later usage.

   _max_heap_free_ratio = max_heap_free_ratio;

   return true;

 }

 // Check consistency of GC selection

 bool Arguments::check_gc_consistency() {

   check_gclog_consistency();

   bool status = true;

   // Ensure that the user has not selected conflicting sets

   // of collectors. [Note: this check is merely a user convenience;

   // collectors over-ride each other so that only a non-conflicting

   // set is selected; however what the user gets is not what they

   // may have expected from the combination they asked for. It's

   // better to reduce user confusion by not allowing them to

   // select conflicting combinations.

   uint i = 0;

   if (UseSerialGC)                       i++;

   if (UseConcMarkSweepGC || UseParNewGC) i++;

   if (UseParallelGC || UseParallelOldGC) i++;

   if (UseG1GC)                           i++;

   if (i > 1) {

     jio_fprintf(defaultStream::error_stream(),

                 "Conflicting collector combinations in option list; "

                 "please refer to the release notes for the combinations "

                 "allowed\n");

     status = false;

   }

   return status;

 }

 void Arguments::check_deprecated_gcs() {

   if (UseConcMarkSweepGC && !UseParNewGC) {

     warning("Using the DefNew young collector with the CMS collector is deprecated "

         "and will likely be removed in a future release");

   }

   if (UseParNewGC && !UseConcMarkSweepGC) {

     // !UseConcMarkSweepGC means that we are using serial old gc. Unfortunately we don't

     // set up UseSerialGC properly, so that can't be used in the check here.

     warning("Using the ParNew young collector with the Serial old collector is deprecated "

         "and will likely be removed in a future release");

   }

   if (CMSIncrementalMode) {

     warning("Using incremental CMS is deprecated and will likely be removed in a future release");

   }

 }

 void Arguments::check_deprecated_gc_flags() {

   if (FLAG_IS_CMDLINE(MaxGCMinorPauseMillis)) {

     warning("Using MaxGCMinorPauseMillis as minor pause goal is deprecated"

             "and will likely be removed in future release");

   }

   if (FLAG_IS_CMDLINE(DefaultMaxRAMFraction)) {

     warning("DefaultMaxRAMFraction is deprecated and will likely be removed in a future release. "

         "Use MaxRAMFraction instead.");

   }

   if (FLAG_IS_CMDLINE(UseCMSCompactAtFullCollection)) {

     warning("UseCMSCompactAtFullCollection is deprecated and will likely be removed in a future release.");

   }

   if (FLAG_IS_CMDLINE(CMSFullGCsBeforeCompaction)) {

     warning("CMSFullGCsBeforeCompaction is deprecated and will likely be removed in a future release.");

   }

   if (FLAG_IS_CMDLINE(UseCMSCollectionPassing)) {

     warning("UseCMSCollectionPassing is deprecated and will likely be removed in a future release.");

   }

 }

 // Check stack pages settings

 bool Arguments::check_stack_pages()

 {

   bool status = true;

   status = status && verify_min_value(StackYellowPages, 1, "StackYellowPages");

   status = status && verify_min_value(StackRedPages, 1, "StackRedPages");

   // greater stack shadow pages can't generate instruction to bang stack

   status = status && verify_interval(StackShadowPages, 1, 50, "StackShadowPages");

   return status;

 }

 // Check the consistency of vm_init_args

 bool Arguments::check_vm_args_consistency() {

   // Method for adding checks for flag consistency.

   // The intent is to warn the user of all possible conflicts,

   // before returning an error.

   // Note: Needs platform-dependent factoring.

   bool status = true;

   // Allow both -XX:-UseStackBanging and -XX:-UseBoundThreads in non-product

   // builds so the cost of stack banging can be measured.

 #if (defined(PRODUCT) && defined(SOLARIS))

   if (!UseBoundThreads && !UseStackBanging) {

     jio_fprintf(defaultStream::error_stream(),

                 "-UseStackBanging conflicts with -UseBoundThreads\n");

      status = false;

   }

 #endif

   if (TLABRefillWasteFraction == 0) {

     jio_fprintf(defaultStream::error_stream(),

                 "TLABRefillWasteFraction should be a denominator, "

                 "not " SIZE_FORMAT "\n",

                 TLABRefillWasteFraction);

     status = false;

   }

   status = status && verify_interval(AdaptiveSizePolicyWeight, 0, 100,

                               "AdaptiveSizePolicyWeight");

   status = status && verify_percentage(ThresholdTolerance, "ThresholdTolerance");

   // Divide by bucket size to prevent a large size from causing rollover when

   // calculating amount of memory needed to be allocated for the String table.

   status = status && verify_interval(StringTableSize, minimumStringTableSize,

     (max_uintx / StringTable::bucket_size()), "StringTable size");

   status = status && verify_interval(SymbolTableSize, minimumSymbolTableSize,

     (max_uintx / SymbolTable::bucket_size()), "SymbolTable size");

   {

     // Using "else if" below to avoid printing two error messages if min > max.

     // This will also prevent us from reporting both min>100 and max>100 at the

     // same time, but that is less annoying than printing two identical errors IMHO.

     FormatBuffer<80> err_msg("%s","");

     if (!verify_MinHeapFreeRatio(err_msg, MinHeapFreeRatio)) {

       jio_fprintf(defaultStream::error_stream(), "%s\n", err_msg.buffer());

       status = false;

     } else if (!verify_MaxHeapFreeRatio(err_msg, MaxHeapFreeRatio)) {

       jio_fprintf(defaultStream::error_stream(), "%s\n", err_msg.buffer());

       status = false;

     }

   }

   // Min/MaxMetaspaceFreeRatio

   status = status && verify_percentage(MinMetaspaceFreeRatio, "MinMetaspaceFreeRatio");

   status = status && verify_percentage(MaxMetaspaceFreeRatio, "MaxMetaspaceFreeRatio");

   if (MinMetaspaceFreeRatio > MaxMetaspaceFreeRatio) {

     jio_fprintf(defaultStream::error_stream(),

                 "MinMetaspaceFreeRatio (%s" UINTX_FORMAT ") must be less than or "

                 "equal to MaxMetaspaceFreeRatio (%s" UINTX_FORMAT ")\n",

                 FLAG_IS_DEFAULT(MinMetaspaceFreeRatio) ? "Default: " : "",

                 MinMetaspaceFreeRatio,

                 FLAG_IS_DEFAULT(MaxMetaspaceFreeRatio) ? "Default: " : "",

                 MaxMetaspaceFreeRatio);

     status = false;

   }

   // Trying to keep 100% free is not practical

   MinMetaspaceFreeRatio = MIN2(MinMetaspaceFreeRatio, (uintx) 99);

   if (FullGCALot && FLAG_IS_DEFAULT(MarkSweepAlwaysCompactCount)) {

     MarkSweepAlwaysCompactCount = 1;  // Move objects every gc.

   }

   if (UseParallelOldGC && ParallelOldGCSplitALot) {

     // Settings to encourage splitting.

     if (!FLAG_IS_CMDLINE(NewRatio)) {

       FLAG_SET_CMDLINE(uintx, NewRatio, 2);

     }

     if (!FLAG_IS_CMDLINE(ScavengeBeforeFullGC)) {

       FLAG_SET_CMDLINE(bool, ScavengeBeforeFullGC, false);

     }

   }

   status = status && verify_percentage(GCHeapFreeLimit, "GCHeapFreeLimit");

   status = status && verify_percentage(GCTimeLimit, "GCTimeLimit");

   if (GCTimeLimit == 100) {

     // Turn off gc-overhead-limit-exceeded checks

     FLAG_SET_DEFAULT(UseGCOverheadLimit, false);

   }

   status = status && check_gc_consistency();

   status = status && check_stack_pages();

   if (CMSIncrementalMode) {

     if (!UseConcMarkSweepGC) {

       jio_fprintf(defaultStream::error_stream(),

                   "error:  invalid argument combination.\n"

                   "The CMS collector (-XX:+UseConcMarkSweepGC) must be "

                   "selected in order\nto use CMSIncrementalMode.\n");

       status = false;

     } else {

       status = status && verify_percentage(CMSIncrementalDutyCycle,

                                   "CMSIncrementalDutyCycle");

       status = status && verify_percentage(CMSIncrementalDutyCycleMin,

                                   "CMSIncrementalDutyCycleMin");

       status = status && verify_percentage(CMSIncrementalSafetyFactor,

                                   "CMSIncrementalSafetyFactor");

       status = status && verify_percentage(CMSIncrementalOffset,

                                   "CMSIncrementalOffset");

       status = status && verify_percentage(CMSExpAvgFactor,

                                   "CMSExpAvgFactor");

       // If it was not set on the command line, set

       // CMSInitiatingOccupancyFraction to 1 so icms can initiate cycles early.

       if (CMSInitiatingOccupancyFraction < 0) {

         FLAG_SET_DEFAULT(CMSInitiatingOccupancyFraction, 1);

       }

     }

   }

   // CMS space iteration, which FLSVerifyAllHeapreferences entails,

   // insists that we hold the requisite locks so that the iteration is

   // MT-safe. For the verification at start-up and shut-down, we don't

   // yet have a good way of acquiring and releasing these locks,

   // which are not visible at the CollectedHeap level. We want to

   // be able to acquire these locks and then do the iteration rather

   // than just disable the lock verification. This will be fixed under

   // bug 4788986.

   if (UseConcMarkSweepGC && FLSVerifyAllHeapReferences) {

     if (VerifyDuringStartup) {

       warning("Heap verification at start-up disabled "

               "(due to current incompatibility with FLSVerifyAllHeapReferences)");

       VerifyDuringStartup = false; // Disable verification at start-up

     }

     if (VerifyBeforeExit) {

       warning("Heap verification at shutdown disabled "

               "(due to current incompatibility with FLSVerifyAllHeapReferences)");

       VerifyBeforeExit = false; // Disable verification at shutdown

     }

   }

   // Note: only executed in non-PRODUCT mode

   if (!UseAsyncConcMarkSweepGC &&

       (ExplicitGCInvokesConcurrent ||

        ExplicitGCInvokesConcurrentAndUnloadsClasses)) {

     jio_fprintf(defaultStream::error_stream(),

                 "error: +ExplicitGCInvokesConcurrent[AndUnloadsClasses] conflicts"

                 " with -UseAsyncConcMarkSweepGC");

     status = false;

   }

   status = status && verify_min_value(ParGCArrayScanChunk, 1, "ParGCArrayScanChunk");

 #if INCLUDE_ALL_GCS

   if (UseG1GC) {

     status = status && verify_percentage(G1NewSizePercent, "G1NewSizePercent");

     status = status && verify_percentage(G1MaxNewSizePercent, "G1MaxNewSizePercent");

     status = status && verify_interval(G1NewSizePercent, 0, G1MaxNewSizePercent, "G1NewSizePercent");

     status = status && verify_percentage(InitiatingHeapOccupancyPercent,

                                          "InitiatingHeapOccupancyPercent");

     status = status && verify_min_value(G1RefProcDrainInterval, 1,

                                         "G1RefProcDrainInterval");

     status = status && verify_min_value((intx)G1ConcMarkStepDurationMillis, 1,

                                         "G1ConcMarkStepDurationMillis");

     status = status && verify_interval(G1ConcRSHotCardLimit, 0, max_jubyte,

                                        "G1ConcRSHotCardLimit");

     status = status && verify_interval(G1ConcRSLogCacheSize, 0, 27,

                                        "G1ConcRSLogCacheSize");

     status = status && verify_interval(StringDeduplicationAgeThreshold, 1, markOopDesc::max_age,

                                        "StringDeduplicationAgeThreshold");

   }

   if (UseConcMarkSweepGC) {

     status = status && verify_min_value(CMSOldPLABNumRefills, 1, "CMSOldPLABNumRefills");

     status = status && verify_min_value(CMSOldPLABToleranceFactor, 1, "CMSOldPLABToleranceFactor");

     status = status && verify_min_value(CMSOldPLABMax, 1, "CMSOldPLABMax");

     status = status && verify_interval(CMSOldPLABMin, 1, CMSOldPLABMax, "CMSOldPLABMin");

     status = status && verify_min_value(CMSYoungGenPerWorker, 1, "CMSYoungGenPerWorker");

     status = status && verify_min_value(CMSSamplingGrain, 1, "CMSSamplingGrain");

     status = status && verify_interval(CMS_SweepWeight, 0, 100, "CMS_SweepWeight");

     status = status && verify_interval(CMS_FLSWeight, 0, 100, "CMS_FLSWeight");

     status = status && verify_interval(FLSCoalescePolicy, 0, 4, "FLSCoalescePolicy");

     status = status && verify_min_value(CMSRescanMultiple, 1, "CMSRescanMultiple");

     status = status && verify_min_value(CMSConcMarkMultiple, 1, "CMSConcMarkMultiple");

     status = status && verify_interval(CMSPrecleanIter, 0, 9, "CMSPrecleanIter");

     status = status && verify_min_value(CMSPrecleanDenominator, 1, "CMSPrecleanDenominator");

     status = status && verify_interval(CMSPrecleanNumerator, 0, CMSPrecleanDenominator - 1, "CMSPrecleanNumerator");

     status = status && verify_percentage(CMSBootstrapOccupancy, "CMSBootstrapOccupancy");

     status = status && verify_min_value(CMSPrecleanThreshold, 100, "CMSPrecleanThreshold");

     status = status && verify_percentage(CMSScheduleRemarkEdenPenetration, "CMSScheduleRemarkEdenPenetration");

     status = status && verify_min_value(CMSScheduleRemarkSamplingRatio, 1, "CMSScheduleRemarkSamplingRatio");

     status = status && verify_min_value(CMSBitMapYieldQuantum, 1, "CMSBitMapYieldQuantum");

     status = status && verify_percentage(CMSTriggerRatio, "CMSTriggerRatio");

     status = status && verify_percentage(CMSIsTooFullPercentage, "CMSIsTooFullPercentage");

   }

   if (UseParallelGC || UseParallelOldGC) {

     status = status && verify_interval(ParallelOldDeadWoodLimiterMean, 0, 100, "ParallelOldDeadWoodLimiterMean");

     status = status && verify_interval(ParallelOldDeadWoodLimiterStdDev, 0, 100, "ParallelOldDeadWoodLimiterStdDev");

     status = status && verify_percentage(YoungGenerationSizeIncrement, "YoungGenerationSizeIncrement");

     status = status && verify_percentage(TenuredGenerationSizeIncrement, "TenuredGenerationSizeIncrement");

     status = status && verify_min_value(YoungGenerationSizeSupplementDecay, 1, "YoungGenerationSizeSupplementDecay");

     status = status && verify_min_value(TenuredGenerationSizeSupplementDecay, 1, "TenuredGenerationSizeSupplementDecay");

     status = status && verify_min_value(ParGCCardsPerStrideChunk, 1, "ParGCCardsPerStrideChunk");

     status = status && verify_min_value(ParallelOldGCSplitInterval, 0, "ParallelOldGCSplitInterval");

   }

 #endif // INCLUDE_ALL_GCS

   status = status && verify_interval(RefDiscoveryPolicy,

                                      ReferenceProcessor::DiscoveryPolicyMin,

                                      ReferenceProcessor::DiscoveryPolicyMax,

                                      "RefDiscoveryPolicy");

   // Limit the lower bound of this flag to 1 as it is used in a division

   // expression.

   status = status && verify_interval(TLABWasteTargetPercent,

                                      1, 100, "TLABWasteTargetPercent");

   status = status && verify_object_alignment();

   status = status && verify_interval(CompressedClassSpaceSize, 1*M, 3*G,

                                       "CompressedClassSpaceSize");

   status = status && verify_interval(MarkStackSizeMax,

                                   1, (max_jint - 1), "MarkStackSizeMax");

   status = status && verify_interval(NUMAChunkResizeWeight, 0, 100, "NUMAChunkResizeWeight");

   status = status && verify_min_value(LogEventsBufferEntries, 1, "LogEventsBufferEntries");

   status = status && verify_min_value(HeapSizePerGCThread, (uintx) os::vm_page_size(), "HeapSizePerGCThread");

   status = status && verify_min_value(GCTaskTimeStampEntries, 1, "GCTaskTimeStampEntries");

   status = status && verify_percentage(ParallelGCBufferWastePct, "ParallelGCBufferWastePct");

   status = status && verify_interval(TargetPLABWastePct, 1, 100, "TargetPLABWastePct");

   status = status && verify_min_value(ParGCStridesPerThread, 1, "ParGCStridesPerThread");

   status = status && verify_min_value(MinRAMFraction, 1, "MinRAMFraction");

   status = status && verify_min_value(InitialRAMFraction, 1, "InitialRAMFraction");

   status = status && verify_min_value(MaxRAMFraction, 1, "MaxRAMFraction");

   status = status && verify_min_value(DefaultMaxRAMFraction, 1, "DefaultMaxRAMFraction");

   status = status && verify_interval(AdaptiveTimeWeight, 0, 100, "AdaptiveTimeWeight");

   status = status && verify_min_value(AdaptiveSizeDecrementScaleFactor, 1, "AdaptiveSizeDecrementScaleFactor");

   status = status && verify_interval(TLABAllocationWeight, 0, 100, "TLABAllocationWeight");

   status = status && verify_min_value(MinTLABSize, 1, "MinTLABSize");

   status = status && verify_min_value(TLABRefillWasteFraction, 1, "TLABRefillWasteFraction");

   status = status && verify_percentage(YoungGenerationSizeSupplement, "YoungGenerationSizeSupplement");

   status = status && verify_percentage(TenuredGenerationSizeSupplement, "TenuredGenerationSizeSupplement");

   // the "age" field in the oop header is 4 bits; do not want to pull in markOop.hpp

   // just for that, so hardcode here.

   status = status && verify_interval(MaxTenuringThreshold, 0, 15, "MaxTenuringThreshold");

   status = status && verify_interval(InitialTenuringThreshold, 0, MaxTenuringThreshold, "MaxTenuringThreshold");

   status = status && verify_percentage(TargetSurvivorRatio, "TargetSurvivorRatio");

   status = status && verify_percentage(MarkSweepDeadRatio, "MarkSweepDeadRatio");

   status = status && verify_min_value(MarkSweepAlwaysCompactCount, 1, "MarkSweepAlwaysCompactCount");

 #ifdef COMPILER1

   status = status && verify_min_value(ValueMapInitialSize, 1, "ValueMapInitialSize");

 #endif

   if (PrintNMTStatistics) {

 #if INCLUDE_NMT

     if (MemTracker::tracking_level() == NMT_off) {

 #endif // INCLUDE_NMT

       warning("PrintNMTStatistics is disabled, because native memory tracking is not enabled");

       PrintNMTStatistics = false;

 #if INCLUDE_NMT

     }

 #endif

   }

   // Need to limit the extent of the padding to reasonable size.

   // 8K is well beyond the reasonable HW cache line size, even with the

   // aggressive prefetching, while still leaving the room for segregating

   // among the distinct pages.

   if (ContendedPaddingWidth < 0 || ContendedPaddingWidth > 8192) {

     jio_fprintf(defaultStream::error_stream(),

                 "ContendedPaddingWidth=" INTX_FORMAT " must be in between %d and %d\n",

                 ContendedPaddingWidth, 0, 8192);

     status = false;

   }

   // Need to enforce the padding not to break the existing field alignments.

   // It is sufficient to check against the largest type size.

   if ((ContendedPaddingWidth % BytesPerLong) != 0) {

     jio_fprintf(defaultStream::error_stream(),

                 "ContendedPaddingWidth=" INTX_FORMAT " must be a multiple of %d\n",

                 ContendedPaddingWidth, BytesPerLong);

     status = false;

   }

   // Check lower bounds of the code cache

   // Template Interpreter code is approximately 3X larger in debug builds.

   uint min_code_cache_size = (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3)) + CodeCacheMinimumFreeSpace;

   if (InitialCodeCacheSize < (uintx)os::vm_page_size()) {

     jio_fprintf(defaultStream::error_stream(),

                 "Invalid InitialCodeCacheSize=%dK. Must be at least %dK.\n", InitialCodeCacheSize/K,

                 os::vm_page_size()/K);

     status = false;

   } else if (ReservedCodeCacheSize < InitialCodeCacheSize) {

     jio_fprintf(defaultStream::error_stream(),

                 "Invalid ReservedCodeCacheSize: %dK. Must be at least InitialCodeCacheSize=%dK.\n",

                 ReservedCodeCacheSize/K, InitialCodeCacheSize/K);

     status = false;

   } else if (ReservedCodeCacheSize < min_code_cache_size) {

     jio_fprintf(defaultStream::error_stream(),

                 "Invalid ReservedCodeCacheSize=%dK. Must be at least %uK.\n", ReservedCodeCacheSize/K,

                 min_code_cache_size/K);

     status = false;

   } else if (ReservedCodeCacheSize > 2*G) {

     // Code cache size larger than MAXINT is not supported.

     jio_fprintf(defaultStream::error_stream(),

                 "Invalid ReservedCodeCacheSize=%dM. Must be at most %uM.\n", ReservedCodeCacheSize/M,

                 (2*G)/M);

     status = false;

   }

   status &= verify_interval(NmethodSweepFraction, 1, ReservedCodeCacheSize/K, "NmethodSweepFraction");

   status &= verify_interval(NmethodSweepActivity, 0, 2000, "NmethodSweepActivity");

   if (!FLAG_IS_DEFAULT(CICompilerCount) && !FLAG_IS_DEFAULT(CICompilerCountPerCPU) && CICompilerCountPerCPU) {

     warning("The VM option CICompilerCountPerCPU overrides CICompilerCount.");

   }

 #ifdef COMPILER1

   status &= verify_interval(SafepointPollOffset, 0, os::vm_page_size() - BytesPerWord, "SafepointPollOffset");

 #endif

   int min_number_of_compiler_threads = get_min_number_of_compiler_threads();

   // The default CICompilerCount's value is CI_COMPILER_COUNT.

   assert(min_number_of_compiler_threads <= CI_COMPILER_COUNT, "minimum should be less or equal default number");

   // Check the minimum number of compiler threads

   status &=verify_min_value(CICompilerCount, min_number_of_compiler_threads, "CICompilerCount");

   return status;

 }

 bool Arguments::is_bad_option(const JavaVMOption* option, jboolean ignore,

   const char* option_type) {