view src/share/vm/runtime/atomic.cpp @ 2368:dde920245681

6896099: Integrate CMS heap ergo with default heap sizing ergo 6627787: CMS: JVM refuses to start up with -Xms16m -Xmx16m 7000125: CMS: Anti-monotone young gen sizing with respect to maximum whole heap size specification 7027529: CMS: retire CMSUseOldDefaults flag Summary: Simplify CMS heap sizing code, relying on ergonomic initial sizing consistent with other collectors for the most part, controlling only young gen sizing to rein in pause times. Make CMS young gen sizing default statically cpu-dependant. Remove inconsistencies wrt generation sizing and policy code, allowing for the fixing for 6627787 and 7000125. For 7027529, retire the flag CMSUseOldDefaults which had been introduced as a bridge from JDK 5 to JDK 6 a number of years ago. Reviewed-by: brutisso, poonam
author ysr
date Wed, 16 Mar 2011 10:37:08 -0700
parents f95d63e2154a
children 2a241e764894
line wrap: on
line source

/*
 * Copyright (c) 2001, 2010, 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 "runtime/atomic.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_ARCH_linux_x86
# include "atomic_linux_x86.inline.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_sparc
# include "atomic_linux_sparc.inline.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_zero
# include "atomic_linux_zero.inline.hpp"
#endif
#ifdef TARGET_OS_ARCH_solaris_x86
# include "atomic_solaris_x86.inline.hpp"
#endif
#ifdef TARGET_OS_ARCH_solaris_sparc
# include "atomic_solaris_sparc.inline.hpp"
#endif
#ifdef TARGET_OS_ARCH_windows_x86
# include "atomic_windows_x86.inline.hpp"
#endif

jbyte Atomic::cmpxchg(jbyte exchange_value, volatile jbyte* dest, jbyte compare_value) {
  assert(sizeof(jbyte) == 1, "assumption.");
  uintptr_t dest_addr = (uintptr_t)dest;
  uintptr_t offset = dest_addr % sizeof(jint);
  volatile jint* dest_int = (volatile jint*)(dest_addr - offset);
  jint cur = *dest_int;
  jbyte* cur_as_bytes = (jbyte*)(&cur);
  jint new_val = cur;
  jbyte* new_val_as_bytes = (jbyte*)(&new_val);
  new_val_as_bytes[offset] = exchange_value;
  while (cur_as_bytes[offset] == compare_value) {
    jint res = cmpxchg(new_val, dest_int, cur);
    if (res == cur) break;
    cur = res;
    new_val = cur;
    new_val_as_bytes[offset] = exchange_value;
  }
  return cur_as_bytes[offset];
}

unsigned Atomic::xchg(unsigned int exchange_value, volatile unsigned int* dest) {
  assert(sizeof(unsigned int) == sizeof(jint), "more work to do");
  return (unsigned int)Atomic::xchg((jint)exchange_value, (volatile jint*)dest);
}

unsigned Atomic::cmpxchg(unsigned int exchange_value,
                         volatile unsigned int* dest, unsigned int compare_value) {
  assert(sizeof(unsigned int) == sizeof(jint), "more work to do");
  return (unsigned int)Atomic::cmpxchg((jint)exchange_value, (volatile jint*)dest,
                                       (jint)compare_value);
}