annotate src/share/vm/oops/markOop.cpp @ 2796:f08d439fab8c

7089790: integrate bsd-port changes Reviewed-by: kvn, twisti, jrose Contributed-by: Kurt Miller <kurt@intricatesoftware.com>, Greg Lewis <glewis@eyesbeyond.com>, Jung-uk Kim <jkim@freebsd.org>, Christos Zoulas <christos@zoulas.com>, Landon Fuller <landonf@plausible.coop>, The FreeBSD Foundation <board@freebsdfoundation.org>, Michael Franz <mvfranz@gmail.com>, Roger Hoover <rhoover@apple.com>, Alexander Strange <astrange@apple.com>
author never
date Sun, 25 Sep 2011 16:03:29 -0700
parents f95d63e2154a
children de5e8c8a9b87
rev   line source
duke@0 1 /*
stefank@1879 2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
duke@0 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@0 4 *
duke@0 5 * This code is free software; you can redistribute it and/or modify it
duke@0 6 * under the terms of the GNU General Public License version 2 only, as
duke@0 7 * published by the Free Software Foundation.
duke@0 8 *
duke@0 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@0 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@0 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@0 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@0 13 * accompanied this code).
duke@0 14 *
duke@0 15 * You should have received a copy of the GNU General Public License version
duke@0 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@0 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@0 18 *
trims@1472 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1472 20 * or visit www.oracle.com if you need additional information or have any
trims@1472 21 * questions.
duke@0 22 *
duke@0 23 */
duke@0 24
stefank@1879 25 #include "precompiled.hpp"
stefank@1879 26 #include "oops/markOop.hpp"
stefank@1879 27 #ifdef TARGET_OS_FAMILY_linux
stefank@1879 28 # include "thread_linux.inline.hpp"
stefank@1879 29 #endif
stefank@1879 30 #ifdef TARGET_OS_FAMILY_solaris
stefank@1879 31 # include "thread_solaris.inline.hpp"
stefank@1879 32 #endif
stefank@1879 33 #ifdef TARGET_OS_FAMILY_windows
stefank@1879 34 # include "thread_windows.inline.hpp"
stefank@1879 35 #endif
never@2796 36 #ifdef TARGET_OS_FAMILY_bsd
never@2796 37 # include "thread_bsd.inline.hpp"
never@2796 38 #endif
duke@0 39
duke@0 40
duke@0 41 void markOopDesc::print_on(outputStream* st) const {
duke@0 42 if (is_locked()) {
duke@0 43 st->print("locked(0x%lx)->", value());
duke@0 44 markOop(*(markOop*)value())->print_on(st);
duke@0 45 } else {
jrose@1039 46 assert(is_unlocked() || has_bias_pattern(), "just checking");
duke@0 47 st->print("mark(");
jrose@1039 48 if (has_bias_pattern()) st->print("biased,");
duke@0 49 st->print("hash %#lx,", hash());
duke@0 50 st->print("age %d)", age());
duke@0 51 }
duke@0 52 }
dcubed@48 53
dcubed@48 54
dcubed@48 55 // Give advice about whether the oop that contains this markOop
dcubed@48 56 // should be cached or not.
dcubed@48 57 bool markOopDesc::should_not_be_cached() const {
dcubed@48 58 // the cast is because decode_pointer() isn't marked const
dcubed@48 59 if (is_marked() && ((markOopDesc *)this)->decode_pointer() != NULL) {
dcubed@48 60 // If the oop containing this markOop is being forwarded, then
dcubed@48 61 // we are in the middle of GC and we do not want the containing
dcubed@48 62 // oop to be added to a cache. We have no way of knowing whether
dcubed@48 63 // the cache has already been visited by the current GC phase so
dcubed@48 64 // we don't know whether the forwarded oop will be properly
dcubed@48 65 // processed in this phase. If the forwarded oop is not properly
dcubed@48 66 // processed, then we'll see strange crashes or asserts during
dcubed@48 67 // the next GC run because the markOop will contain an unexpected
dcubed@48 68 // value.
dcubed@48 69 //
dcubed@48 70 // This situation has been seen when we are GC'ing a methodOop
dcubed@48 71 // because we use the methodOop while we're GC'ing it. Scary
dcubed@48 72 // stuff. Some of the uses the methodOop cause the methodOop to
dcubed@48 73 // be added to the OopMapCache in the instanceKlass as a side
dcubed@48 74 // effect. This check lets the cache maintainer know when a
dcubed@48 75 // cache addition would not be safe.
dcubed@48 76 return true;
dcubed@48 77 }
dcubed@48 78
dcubed@48 79 // caching the containing oop should be just fine
dcubed@48 80 return false;
dcubed@48 81 }