view src/share/vm/runtime/globals.cpp @ 9126:bc26f978b0ce

HotSpotResolvedObjectType: implement hasFinalizeSubclass() correctly don't use the (wrong) cached value, but ask the runtime on each request. Fixes regression on xml.* benchmarks @ specjvm2008. The problem was: After the constructor of Object was deoptimized due to an assumption violation, it was recompiled again after some time. However, on recompilation, the value of hasFinalizeSubclass for the class was not updated and it was compiled again with a, now wrong, assumption, which then triggers deoptimization again. This was repeated until it hit the recompilation limit (defined by PerMethodRecompilationCutoff), and therefore only executed by the interpreter from now on, causing the performance regression.
author Bernhard Urban <bernhard.urban@jku.at>
date Mon, 15 Apr 2013 19:54:58 +0200
parents 5fc51c1ecdeb
children 6b0fd0964b87
line wrap: on
line source

/*
 * Copyright (c) 1997, 2013, 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 "memory/allocation.inline.hpp"
#include "oops/oop.inline.hpp"
#include "runtime/arguments.hpp"
#include "runtime/globals.hpp"
#include "runtime/globals_extension.hpp"
#include "utilities/ostream.hpp"
#include "utilities/macros.hpp"
#include "utilities/top.hpp"
#if INCLUDE_ALL_GCS
#include "gc_implementation/g1/g1_globals.hpp"
#endif // INCLUDE_ALL_GCS
#ifdef COMPILER1
#include "c1/c1_globals.hpp"
#endif
#ifdef GRAAL
#include "graal/graalGlobals.hpp"
#endif
#ifdef COMPILER2
#include "opto/c2_globals.hpp"
#endif
#ifdef SHARK
#include "shark/shark_globals.hpp"
#endif

RUNTIME_FLAGS(MATERIALIZE_DEVELOPER_FLAG, MATERIALIZE_PD_DEVELOPER_FLAG, \
              MATERIALIZE_PRODUCT_FLAG, MATERIALIZE_PD_PRODUCT_FLAG, \
              MATERIALIZE_DIAGNOSTIC_FLAG, MATERIALIZE_EXPERIMENTAL_FLAG, \
              MATERIALIZE_NOTPRODUCT_FLAG, \
              MATERIALIZE_MANAGEABLE_FLAG, MATERIALIZE_PRODUCT_RW_FLAG, \
              MATERIALIZE_LP64_PRODUCT_FLAG)

RUNTIME_OS_FLAGS(MATERIALIZE_DEVELOPER_FLAG, MATERIALIZE_PD_DEVELOPER_FLAG, \
                 MATERIALIZE_PRODUCT_FLAG, MATERIALIZE_PD_PRODUCT_FLAG, \
                 MATERIALIZE_DIAGNOSTIC_FLAG, MATERIALIZE_NOTPRODUCT_FLAG)

ARCH_FLAGS(MATERIALIZE_DEVELOPER_FLAG, MATERIALIZE_PRODUCT_FLAG, \
           MATERIALIZE_DIAGNOSTIC_FLAG, MATERIALIZE_EXPERIMENTAL_FLAG, \
           MATERIALIZE_NOTPRODUCT_FLAG)

MATERIALIZE_FLAGS_EXT


bool Flag::is_unlocker() const {
  return strcmp(name, "UnlockDiagnosticVMOptions") == 0     ||
         strcmp(name, "UnlockExperimentalVMOptions") == 0   ||
         is_unlocker_ext();
}

bool Flag::is_unlocked() const {
  if (strcmp(kind, "{diagnostic}") == 0 ||
      strcmp(kind, "{C2 diagnostic}") == 0 ||
      strcmp(kind, "{ARCH diagnostic}") == 0 ||
      strcmp(kind, "{Shark diagnostic}") == 0) {
    if (strcmp(name, "EnableInvokeDynamic") == 0 && UnlockExperimentalVMOptions && !UnlockDiagnosticVMOptions) {
      // transitional logic to allow tests to run until they are changed
      static int warned;
      if (++warned == 1)  warning("Use -XX:+UnlockDiagnosticVMOptions before EnableInvokeDynamic flag");
      return true;
    }
    return UnlockDiagnosticVMOptions;
  } else if (strcmp(kind, "{experimental}") == 0 ||
             strcmp(kind, "{C2 experimental}") == 0 ||
             strcmp(kind, "{ARCH experimental}") == 0 ||
             strcmp(kind, "{Shark experimental}") == 0) {
    return UnlockExperimentalVMOptions;
  } else {
    return is_unlocked_ext();
  }
}

// Get custom message for this locked flag, or return NULL if
// none is available.
void Flag::get_locked_message(char* buf, int buflen) const {
  get_locked_message_ext(buf, buflen);
}

bool Flag::is_writeable() const {
  return strcmp(kind, "{manageable}") == 0 ||
         strcmp(kind, "{product rw}") == 0 ||
         is_writeable_ext();
}

// All flags except "manageable" are assumed to be internal flags.
// Long term, we need to define a mechanism to specify which flags
// are external/stable and change this function accordingly.
bool Flag::is_external() const {
  return strcmp(kind, "{manageable}") == 0 || is_external_ext();
}


// Length of format string (e.g. "%.1234s") for printing ccstr below
#define FORMAT_BUFFER_LEN 16

void Flag::print_on(outputStream* st, bool withComments) {
  st->print("%9s %-40s %c= ", type, name, (origin != DEFAULT ? ':' : ' '));
  if (is_bool())     st->print("%-16s", get_bool() ? "true" : "false");
  if (is_intx())     st->print("%-16ld", get_intx());
  if (is_uintx())    st->print("%-16lu", get_uintx());
  if (is_uint64_t()) st->print("%-16lu", get_uint64_t());
  if (is_double())   st->print("%-16f", get_double());

  if (is_ccstr()) {
     const char* cp = get_ccstr();
     if (cp != NULL) {
       const char* eol;
       while ((eol = strchr(cp, '\n')) != NULL) {
         char format_buffer[FORMAT_BUFFER_LEN];
         size_t llen = pointer_delta(eol, cp, sizeof(char));
         jio_snprintf(format_buffer, FORMAT_BUFFER_LEN,
                     "%%." SIZE_FORMAT "s", llen);
         st->print(format_buffer, cp);
         st->cr();
         cp = eol+1;
         st->print("%5s %-35s += ", "", name);
       }
       st->print("%-16s", cp);
     }
     else st->print("%-16s", "");
  }
  st->print("%-20s", kind);
  if (withComments) {
#ifndef PRODUCT
    st->print("%s", doc );
#endif
  }
  st->cr();
}

void Flag::print_as_flag(outputStream* st) {
  if (is_bool()) {
    st->print("-XX:%s%s", get_bool() ? "+" : "-", name);
  } else if (is_intx()) {
    st->print("-XX:%s=" INTX_FORMAT, name, get_intx());
  } else if (is_uintx()) {
    st->print("-XX:%s=" UINTX_FORMAT, name, get_uintx());
  } else if (is_uint64_t()) {
    st->print("-XX:%s=" UINT64_FORMAT, name, get_uint64_t());
  } else if (is_double()) {
    st->print("-XX:%s=%f", name, get_double());
  } else if (is_ccstr()) {
    st->print("-XX:%s=", name);
    const char* cp = get_ccstr();
    if (cp != NULL) {
      // Need to turn embedded '\n's back into separate arguments
      // Not so efficient to print one character at a time,
      // but the choice is to do the transformation to a buffer
      // and print that.  And this need not be efficient.
      for (; *cp != '\0'; cp += 1) {
        switch (*cp) {
          default:
            st->print("%c", *cp);
            break;
          case '\n':
            st->print(" -XX:%s=", name);
            break;
        }
      }
    }
  } else {
    ShouldNotReachHere();
  }
}

// 4991491 do not "optimize out" the was_set false values: omitting them
// tickles a Microsoft compiler bug causing flagTable to be malformed

#define RUNTIME_PRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{product}", DEFAULT },
#define RUNTIME_PD_PRODUCT_FLAG_STRUCT(type, name, doc)     { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{pd product}", DEFAULT },
#define RUNTIME_DIAGNOSTIC_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{diagnostic}", DEFAULT },
#define RUNTIME_EXPERIMENTAL_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{experimental}", DEFAULT },
#define RUNTIME_MANAGEABLE_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{manageable}", DEFAULT },
#define RUNTIME_PRODUCT_RW_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{product rw}", DEFAULT },

#ifdef PRODUCT
  #define RUNTIME_DEVELOP_FLAG_STRUCT(type, name, value, doc) /* flag is constant */
  #define RUNTIME_PD_DEVELOP_FLAG_STRUCT(type, name, doc)     /* flag is constant */
  #define RUNTIME_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc)
#else
  #define RUNTIME_DEVELOP_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "", DEFAULT },
  #define RUNTIME_PD_DEVELOP_FLAG_STRUCT(type, name, doc)     { #type, XSTR(name), &name, doc, "{pd}", DEFAULT },
  #define RUNTIME_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{notproduct}", DEFAULT },
#endif

#ifdef _LP64
  #define RUNTIME_LP64_PRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{lp64_product}", DEFAULT },
#else
  #define RUNTIME_LP64_PRODUCT_FLAG_STRUCT(type, name, value, doc) /* flag is constant */
#endif // _LP64

#define C1_PRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{C1 product}", DEFAULT },
#define C1_PD_PRODUCT_FLAG_STRUCT(type, name, doc)     { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{C1 pd product}", DEFAULT },
#ifdef PRODUCT
  #define C1_DEVELOP_FLAG_STRUCT(type, name, value, doc) /* flag is constant */
  #define C1_PD_DEVELOP_FLAG_STRUCT(type, name, doc)     /* flag is constant */
  #define C1_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc)
#else
  #define C1_DEVELOP_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{C1}", DEFAULT },
  #define C1_PD_DEVELOP_FLAG_STRUCT(type, name, doc)     { #type, XSTR(name), &name, doc, "{C1 pd}", DEFAULT },
  #define C1_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{C1 notproduct}", DEFAULT },
#endif

#define GRAAL_PRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{Graal product}", DEFAULT },
#define GRAAL_PD_PRODUCT_FLAG_STRUCT(type, name, doc)     { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{Graal pd product}", DEFAULT },
#ifdef PRODUCT
  #define GRAAL_DEVELOP_FLAG_STRUCT(type, name, value, doc) /* flag is constant */
  #define GRAAL_PD_DEVELOP_FLAG_STRUCT(type, name, doc)     /* flag is constant */
  #define GRAAL_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc)
#else
  #define GRAAL_DEVELOP_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{Graal}", DEFAULT },
  #define GRAAL_PD_DEVELOP_FLAG_STRUCT(type, name, doc)     { #type, XSTR(name), &name, doc, "{Graal pd}", DEFAULT },
  #define GRAAL_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{Graal notproduct}", DEFAULT },
#endif

#define C2_PRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{C2 product}", DEFAULT },
#define C2_PD_PRODUCT_FLAG_STRUCT(type, name, doc)     { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{C2 pd product}", DEFAULT },
#define C2_DIAGNOSTIC_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{C2 diagnostic}", DEFAULT },
#define C2_EXPERIMENTAL_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{C2 experimental}", DEFAULT },
#ifdef PRODUCT
  #define C2_DEVELOP_FLAG_STRUCT(type, name, value, doc) /* flag is constant */
  #define C2_PD_DEVELOP_FLAG_STRUCT(type, name, doc)     /* flag is constant */
  #define C2_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc)
#else
  #define C2_DEVELOP_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{C2}", DEFAULT },
  #define C2_PD_DEVELOP_FLAG_STRUCT(type, name, doc)     { #type, XSTR(name), &name, doc, "{C2 pd}", DEFAULT },
  #define C2_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{C2 notproduct}", DEFAULT },
#endif

#define ARCH_PRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{ARCH product}", DEFAULT },
#define ARCH_DIAGNOSTIC_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{ARCH diagnostic}", DEFAULT },
#define ARCH_EXPERIMENTAL_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{ARCH experimental}", DEFAULT },
#ifdef PRODUCT
  #define ARCH_DEVELOP_FLAG_STRUCT(type, name, value, doc) /* flag is constant */
  #define ARCH_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc)
#else
  #define ARCH_DEVELOP_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{ARCH}", DEFAULT },
  #define ARCH_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{ARCH notproduct}", DEFAULT },
#endif

#define SHARK_PRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{Shark product}", DEFAULT },
#define SHARK_PD_PRODUCT_FLAG_STRUCT(type, name, doc)     { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{Shark pd product}", DEFAULT },
#define SHARK_DIAGNOSTIC_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, NOT_PRODUCT_ARG(doc) "{Shark diagnostic}", DEFAULT },
#ifdef PRODUCT
  #define SHARK_DEVELOP_FLAG_STRUCT(type, name, value, doc) /* flag is constant */
  #define SHARK_PD_DEVELOP_FLAG_STRUCT(type, name, doc)     /* flag is constant */
  #define SHARK_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc)
#else
  #define SHARK_DEVELOP_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{Shark}", DEFAULT },
  #define SHARK_PD_DEVELOP_FLAG_STRUCT(type, name, doc)     { #type, XSTR(name), &name, doc, "{Shark pd}", DEFAULT },
  #define SHARK_NOTPRODUCT_FLAG_STRUCT(type, name, value, doc) { #type, XSTR(name), &name, doc, "{Shark notproduct}", DEFAULT },
#endif

static Flag flagTable[] = {
 RUNTIME_FLAGS(RUNTIME_DEVELOP_FLAG_STRUCT, RUNTIME_PD_DEVELOP_FLAG_STRUCT, RUNTIME_PRODUCT_FLAG_STRUCT, RUNTIME_PD_PRODUCT_FLAG_STRUCT, RUNTIME_DIAGNOSTIC_FLAG_STRUCT, RUNTIME_EXPERIMENTAL_FLAG_STRUCT, RUNTIME_NOTPRODUCT_FLAG_STRUCT, RUNTIME_MANAGEABLE_FLAG_STRUCT, RUNTIME_PRODUCT_RW_FLAG_STRUCT, RUNTIME_LP64_PRODUCT_FLAG_STRUCT)
 RUNTIME_OS_FLAGS(RUNTIME_DEVELOP_FLAG_STRUCT, RUNTIME_PD_DEVELOP_FLAG_STRUCT, RUNTIME_PRODUCT_FLAG_STRUCT, RUNTIME_PD_PRODUCT_FLAG_STRUCT, RUNTIME_DIAGNOSTIC_FLAG_STRUCT, RUNTIME_NOTPRODUCT_FLAG_STRUCT)
#if INCLUDE_ALL_GCS
 G1_FLAGS(RUNTIME_DEVELOP_FLAG_STRUCT, RUNTIME_PD_DEVELOP_FLAG_STRUCT, RUNTIME_PRODUCT_FLAG_STRUCT, RUNTIME_PD_PRODUCT_FLAG_STRUCT, RUNTIME_DIAGNOSTIC_FLAG_STRUCT, RUNTIME_EXPERIMENTAL_FLAG_STRUCT, RUNTIME_NOTPRODUCT_FLAG_STRUCT, RUNTIME_MANAGEABLE_FLAG_STRUCT, RUNTIME_PRODUCT_RW_FLAG_STRUCT)
#endif // INCLUDE_ALL_GCS
#ifdef COMPILER1
 C1_FLAGS(C1_DEVELOP_FLAG_STRUCT, C1_PD_DEVELOP_FLAG_STRUCT, C1_PRODUCT_FLAG_STRUCT, C1_PD_PRODUCT_FLAG_STRUCT, C1_NOTPRODUCT_FLAG_STRUCT)
#endif
#ifdef GRAAL
 GRAAL_FLAGS(GRAAL_DEVELOP_FLAG_STRUCT, GRAAL_PD_DEVELOP_FLAG_STRUCT, GRAAL_PRODUCT_FLAG_STRUCT, GRAAL_PD_PRODUCT_FLAG_STRUCT, GRAAL_NOTPRODUCT_FLAG_STRUCT)
#endif
#ifdef COMPILER2
 C2_FLAGS(C2_DEVELOP_FLAG_STRUCT, C2_PD_DEVELOP_FLAG_STRUCT, C2_PRODUCT_FLAG_STRUCT, C2_PD_PRODUCT_FLAG_STRUCT, C2_DIAGNOSTIC_FLAG_STRUCT, C2_EXPERIMENTAL_FLAG_STRUCT, C2_NOTPRODUCT_FLAG_STRUCT)
#endif
#ifdef SHARK
 SHARK_FLAGS(SHARK_DEVELOP_FLAG_STRUCT, SHARK_PD_DEVELOP_FLAG_STRUCT, SHARK_PRODUCT_FLAG_STRUCT, SHARK_PD_PRODUCT_FLAG_STRUCT, SHARK_DIAGNOSTIC_FLAG_STRUCT, SHARK_NOTPRODUCT_FLAG_STRUCT)
#endif
 ARCH_FLAGS(ARCH_DEVELOP_FLAG_STRUCT, ARCH_PRODUCT_FLAG_STRUCT, ARCH_DIAGNOSTIC_FLAG_STRUCT, ARCH_EXPERIMENTAL_FLAG_STRUCT, ARCH_NOTPRODUCT_FLAG_STRUCT)
 FLAGTABLE_EXT
 {0, NULL, NULL}
};

Flag* Flag::flags = flagTable;
size_t Flag::numFlags = (sizeof(flagTable) / sizeof(Flag));

inline bool str_equal(const char* s, char* q, size_t len) {
  // s is null terminated, q is not!
  if (strlen(s) != (unsigned int) len) return false;
  return strncmp(s, q, len) == 0;
}

// Search the flag table for a named flag
Flag* Flag::find_flag(char* name, size_t length, bool allow_locked) {
  for (Flag* current = &flagTable[0]; current->name != NULL; current++) {
    if (str_equal(current->name, name, length)) {
      // Found a matching entry.  Report locked flags only if allowed.
      if (!(current->is_unlocked() || current->is_unlocker())) {
        if (!allow_locked) {
          // disable use of locked flags, e.g. diagnostic, experimental,
          // commercial... until they are explicitly unlocked
          return NULL;
        }
      }
      return current;
    }
  }
  // Flag name is not in the flag table
  return NULL;
}

// Returns the address of the index'th element
static Flag* address_of_flag(CommandLineFlagWithType flag) {
  assert((size_t)flag < Flag::numFlags, "bad command line flag index");
  return &Flag::flags[flag];
}

bool CommandLineFlagsEx::is_default(CommandLineFlag flag) {
  assert((size_t)flag < Flag::numFlags, "bad command line flag index");
  Flag* f = &Flag::flags[flag];
  return (f->origin == DEFAULT);
}

bool CommandLineFlagsEx::is_ergo(CommandLineFlag flag) {
  assert((size_t)flag < Flag::numFlags, "bad command line flag index");
  Flag* f = &Flag::flags[flag];
  return (f->origin == ERGONOMIC);
}

bool CommandLineFlagsEx::is_cmdline(CommandLineFlag flag) {
  assert((size_t)flag < Flag::numFlags, "bad command line flag index");
  Flag* f = &Flag::flags[flag];
  return (f->origin == COMMAND_LINE);
}

bool CommandLineFlags::wasSetOnCmdline(const char* name, bool* value) {
  Flag* result = Flag::find_flag((char*)name, strlen(name));
  if (result == NULL) return false;
  *value = (result->origin == COMMAND_LINE);
  return true;
}

bool CommandLineFlags::boolAt(char* name, size_t len, bool* value) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_bool()) return false;
  *value = result->get_bool();
  return true;
}

bool CommandLineFlags::boolAtPut(char* name, size_t len, bool* value, FlagValueOrigin origin) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_bool()) return false;
  bool old_value = result->get_bool();
  result->set_bool(*value);
  *value = old_value;
  result->origin = origin;
  return true;
}

void CommandLineFlagsEx::boolAtPut(CommandLineFlagWithType flag, bool value, FlagValueOrigin origin) {
  Flag* faddr = address_of_flag(flag);
  guarantee(faddr != NULL && faddr->is_bool(), "wrong flag type");
  faddr->set_bool(value);
  faddr->origin = origin;
}

bool CommandLineFlags::intxAt(char* name, size_t len, intx* value) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_intx()) return false;
  *value = result->get_intx();
  return true;
}

bool CommandLineFlags::intxAtPut(char* name, size_t len, intx* value, FlagValueOrigin origin) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_intx()) return false;
  intx old_value = result->get_intx();
  result->set_intx(*value);
  *value = old_value;
  result->origin = origin;
  return true;
}

void CommandLineFlagsEx::intxAtPut(CommandLineFlagWithType flag, intx value, FlagValueOrigin origin) {
  Flag* faddr = address_of_flag(flag);
  guarantee(faddr != NULL && faddr->is_intx(), "wrong flag type");
  faddr->set_intx(value);
  faddr->origin = origin;
}

bool CommandLineFlags::uintxAt(char* name, size_t len, uintx* value) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_uintx()) return false;
  *value = result->get_uintx();
  return true;
}

bool CommandLineFlags::uintxAtPut(char* name, size_t len, uintx* value, FlagValueOrigin origin) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_uintx()) return false;
  uintx old_value = result->get_uintx();
  result->set_uintx(*value);
  *value = old_value;
  result->origin = origin;
  return true;
}

void CommandLineFlagsEx::uintxAtPut(CommandLineFlagWithType flag, uintx value, FlagValueOrigin origin) {
  Flag* faddr = address_of_flag(flag);
  guarantee(faddr != NULL && faddr->is_uintx(), "wrong flag type");
  faddr->set_uintx(value);
  faddr->origin = origin;
}

bool CommandLineFlags::uint64_tAt(char* name, size_t len, uint64_t* value) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_uint64_t()) return false;
  *value = result->get_uint64_t();
  return true;
}

bool CommandLineFlags::uint64_tAtPut(char* name, size_t len, uint64_t* value, FlagValueOrigin origin) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_uint64_t()) return false;
  uint64_t old_value = result->get_uint64_t();
  result->set_uint64_t(*value);
  *value = old_value;
  result->origin = origin;
  return true;
}

void CommandLineFlagsEx::uint64_tAtPut(CommandLineFlagWithType flag, uint64_t value, FlagValueOrigin origin) {
  Flag* faddr = address_of_flag(flag);
  guarantee(faddr != NULL && faddr->is_uint64_t(), "wrong flag type");
  faddr->set_uint64_t(value);
  faddr->origin = origin;
}

bool CommandLineFlags::doubleAt(char* name, size_t len, double* value) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_double()) return false;
  *value = result->get_double();
  return true;
}

bool CommandLineFlags::doubleAtPut(char* name, size_t len, double* value, FlagValueOrigin origin) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_double()) return false;
  double old_value = result->get_double();
  result->set_double(*value);
  *value = old_value;
  result->origin = origin;
  return true;
}

void CommandLineFlagsEx::doubleAtPut(CommandLineFlagWithType flag, double value, FlagValueOrigin origin) {
  Flag* faddr = address_of_flag(flag);
  guarantee(faddr != NULL && faddr->is_double(), "wrong flag type");
  faddr->set_double(value);
  faddr->origin = origin;
}

bool CommandLineFlags::ccstrAt(char* name, size_t len, ccstr* value) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_ccstr()) return false;
  *value = result->get_ccstr();
  return true;
}

// Contract:  Flag will make private copy of the incoming value.
// Outgoing value is always malloc-ed, and caller MUST call free.
bool CommandLineFlags::ccstrAtPut(char* name, size_t len, ccstr* value, FlagValueOrigin origin) {
  Flag* result = Flag::find_flag(name, len);
  if (result == NULL) return false;
  if (!result->is_ccstr()) return false;
  ccstr old_value = result->get_ccstr();
  char* new_value = NULL;
  if (*value != NULL) {
    new_value = NEW_C_HEAP_ARRAY(char, strlen(*value)+1, mtInternal);
    strcpy(new_value, *value);
  }
  result->set_ccstr(new_value);
  if (result->origin == DEFAULT && old_value != NULL) {
    // Prior value is NOT heap allocated, but was a literal constant.
    char* old_value_to_free = NEW_C_HEAP_ARRAY(char, strlen(old_value)+1, mtInternal);
    strcpy(old_value_to_free, old_value);
    old_value = old_value_to_free;
  }
  *value = old_value;
  result->origin = origin;
  return true;
}

// Contract:  Flag will make private copy of the incoming value.
void CommandLineFlagsEx::ccstrAtPut(CommandLineFlagWithType flag, ccstr value, FlagValueOrigin origin) {
  Flag* faddr = address_of_flag(flag);
  guarantee(faddr != NULL && faddr->is_ccstr(), "wrong flag type");
  ccstr old_value = faddr->get_ccstr();
  char* new_value = NEW_C_HEAP_ARRAY(char, strlen(value)+1, mtInternal);
  strcpy(new_value, value);
  faddr->set_ccstr(new_value);
  if (faddr->origin != DEFAULT && old_value != NULL) {
    // Prior value is heap allocated so free it.
    FREE_C_HEAP_ARRAY(char, old_value, mtInternal);
  }
  faddr->origin = origin;
}

extern "C" {
  static int compare_flags(const void* void_a, const void* void_b) {
    return strcmp((*((Flag**) void_a))->name, (*((Flag**) void_b))->name);
  }
}

void CommandLineFlags::printSetFlags(outputStream* out) {
  // Print which flags were set on the command line
  // note: this method is called before the thread structure is in place
  //       which means resource allocation cannot be used.

  // Compute size
  int length= 0;
  while (flagTable[length].name != NULL) length++;

  // Sort
  Flag** array = NEW_C_HEAP_ARRAY(Flag*, length, mtInternal);
  for (int index = 0; index < length; index++) {
    array[index] = &flagTable[index];
  }
  qsort(array, length, sizeof(Flag*), compare_flags);

  // Print
  for (int i = 0; i < length; i++) {
    if (array[i]->origin /* naked field! */) {
      array[i]->print_as_flag(out);
      out->print(" ");
    }
  }
  out->cr();
  FREE_C_HEAP_ARRAY(Flag*, array, mtInternal);
}

#ifndef PRODUCT


void CommandLineFlags::verify() {
  assert(Arguments::check_vm_args_consistency(), "Some flag settings conflict");
}

#endif // PRODUCT

void CommandLineFlags::printFlags(outputStream* out, bool withComments) {
  // Print the flags sorted by name
  // note: this method is called before the thread structure is in place
  //       which means resource allocation cannot be used.

  // Compute size
  int length= 0;
  while (flagTable[length].name != NULL) length++;

  // Sort
  Flag** array = NEW_C_HEAP_ARRAY(Flag*, length, mtInternal);
  for (int index = 0; index < length; index++) {
    array[index] = &flagTable[index];
  }
  qsort(array, length, sizeof(Flag*), compare_flags);

  // Print
  out->print_cr("[Global flags]");
  for (int i = 0; i < length; i++) {
    if (array[i]->is_unlocked()) {
      array[i]->print_on(out, withComments);
    }
  }
  FREE_C_HEAP_ARRAY(Flag*, array, mtInternal);
}