Wed, 06 Jan 2010 22:21:39 -0800
Merge
duke@435 | 1 | /* |
xdono@631 | 2 | * Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | # include "incls/_precompiled.incl" |
duke@435 | 26 | # include "incls/_markOop.cpp.incl" |
duke@435 | 27 | |
duke@435 | 28 | |
duke@435 | 29 | void markOopDesc::print_on(outputStream* st) const { |
duke@435 | 30 | if (is_locked()) { |
duke@435 | 31 | st->print("locked(0x%lx)->", value()); |
duke@435 | 32 | markOop(*(markOop*)value())->print_on(st); |
duke@435 | 33 | } else { |
jrose@1474 | 34 | assert(is_unlocked() || has_bias_pattern(), "just checking"); |
duke@435 | 35 | st->print("mark("); |
jrose@1474 | 36 | if (has_bias_pattern()) st->print("biased,"); |
duke@435 | 37 | st->print("hash %#lx,", hash()); |
duke@435 | 38 | st->print("age %d)", age()); |
duke@435 | 39 | } |
duke@435 | 40 | } |
dcubed@483 | 41 | |
dcubed@483 | 42 | |
dcubed@483 | 43 | // Give advice about whether the oop that contains this markOop |
dcubed@483 | 44 | // should be cached or not. |
dcubed@483 | 45 | bool markOopDesc::should_not_be_cached() const { |
dcubed@483 | 46 | // the cast is because decode_pointer() isn't marked const |
dcubed@483 | 47 | if (is_marked() && ((markOopDesc *)this)->decode_pointer() != NULL) { |
dcubed@483 | 48 | // If the oop containing this markOop is being forwarded, then |
dcubed@483 | 49 | // we are in the middle of GC and we do not want the containing |
dcubed@483 | 50 | // oop to be added to a cache. We have no way of knowing whether |
dcubed@483 | 51 | // the cache has already been visited by the current GC phase so |
dcubed@483 | 52 | // we don't know whether the forwarded oop will be properly |
dcubed@483 | 53 | // processed in this phase. If the forwarded oop is not properly |
dcubed@483 | 54 | // processed, then we'll see strange crashes or asserts during |
dcubed@483 | 55 | // the next GC run because the markOop will contain an unexpected |
dcubed@483 | 56 | // value. |
dcubed@483 | 57 | // |
dcubed@483 | 58 | // This situation has been seen when we are GC'ing a methodOop |
dcubed@483 | 59 | // because we use the methodOop while we're GC'ing it. Scary |
dcubed@483 | 60 | // stuff. Some of the uses the methodOop cause the methodOop to |
dcubed@483 | 61 | // be added to the OopMapCache in the instanceKlass as a side |
dcubed@483 | 62 | // effect. This check lets the cache maintainer know when a |
dcubed@483 | 63 | // cache addition would not be safe. |
dcubed@483 | 64 | return true; |
dcubed@483 | 65 | } |
dcubed@483 | 66 | |
dcubed@483 | 67 | // caching the containing oop should be just fine |
dcubed@483 | 68 | return false; |
dcubed@483 | 69 | } |