Mercurial > hg > truffle
view src/share/vm/memory/referencePolicy.cpp @ 12301:2c022e432e10
8024974: Incorrect use of GC_locker::is_active()
Summary: SymbolTable and StringTable can make calls to GC_locker::is_active() outside a safepoint. This isn't safe because the GC_locker active state (lock count) is only updated at a safepoint and only remains valid as long as _needs_gc is true. However, outside a safepoint_needs_gc can change to false at any time, which makes it impossible to do a correct call to is_active() in that context. In this case these calls can just be removed since the input argument to basic_add() should never be on the heap and so there's no need to check the GC_locker state. This change also adjusts the assert() in is_active() to makes sure all calls to this function are always done under a safepoint.
Reviewed-by: brutisso, dcubed
Contributed-by: per.liden@oracle.com
author | stefank |
---|---|
date | Fri, 20 Sep 2013 10:53:28 +0200 |
parents | d1bdeef3e3e2 |
children |
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/* * Copyright (c) 2000, 2011, 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/javaClasses.hpp" #include "memory/referencePolicy.hpp" #include "memory/universe.hpp" #include "runtime/arguments.hpp" #include "runtime/globals.hpp" LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() { setup(); } // Capture state (of-the-VM) information needed to evaluate the policy void LRUCurrentHeapPolicy::setup() { _max_interval = (Universe::get_heap_free_at_last_gc() / M) * SoftRefLRUPolicyMSPerMB; assert(_max_interval >= 0,"Sanity check"); } // The oop passed in is the SoftReference object, and not // the object the SoftReference points to. bool LRUCurrentHeapPolicy::should_clear_reference(oop p, jlong timestamp_clock) { jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p); assert(interval >= 0, "Sanity check"); // The interval will be zero if the ref was accessed since the last scavenge/gc. if(interval <= _max_interval) { return false; } return true; } /////////////////////// MaxHeap ////////////////////// LRUMaxHeapPolicy::LRUMaxHeapPolicy() { setup(); } // Capture state (of-the-VM) information needed to evaluate the policy void LRUMaxHeapPolicy::setup() { size_t max_heap = MaxHeapSize; max_heap -= Universe::get_heap_used_at_last_gc(); max_heap /= M; _max_interval = max_heap * SoftRefLRUPolicyMSPerMB; assert(_max_interval >= 0,"Sanity check"); } // The oop passed in is the SoftReference object, and not // the object the SoftReference points to. bool LRUMaxHeapPolicy::should_clear_reference(oop p, jlong timestamp_clock) { jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p); assert(interval >= 0, "Sanity check"); // The interval will be zero if the ref was accessed since the last scavenge/gc. if(interval <= _max_interval) { return false; } return true; }