Mercurial > hg > graal-jvmci-8
view src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.hpp @ 1716:be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode.
Reviewed-by: chrisphi, johnc, poonam
author | ysr |
---|---|
date | Mon, 16 Aug 2010 15:58:42 -0700 |
parents | c18cbe5936b8 |
children | f95d63e2154a |
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/* * Copyright (c) 2001, 2005, 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. * */ class PSAdaptiveSizePolicy; class PSYoungGen; class PSOldGen; class PSMarkSweep : public MarkSweep { private: static elapsedTimer _accumulated_time; static unsigned int _total_invocations; static jlong _time_of_last_gc; // ms static CollectorCounters* _counters; // Closure accessors static OopClosure* mark_and_push_closure() { return &MarkSweep::mark_and_push_closure; } static VoidClosure* follow_stack_closure() { return (VoidClosure*)&MarkSweep::follow_stack_closure; } static OopClosure* adjust_pointer_closure() { return (OopClosure*)&MarkSweep::adjust_pointer_closure; } static OopClosure* adjust_root_pointer_closure() { return (OopClosure*)&MarkSweep::adjust_root_pointer_closure; } static BoolObjectClosure* is_alive_closure() { return (BoolObjectClosure*)&MarkSweep::is_alive; } debug_only(public:) // Used for PSParallelCompact debugging // Mark live objects static void mark_sweep_phase1(bool clear_all_softrefs); // Calculate new addresses static void mark_sweep_phase2(); debug_only(private:) // End used for PSParallelCompact debugging // Update pointers static void mark_sweep_phase3(); // Move objects to new positions static void mark_sweep_phase4(); debug_only(public:) // Used for PSParallelCompact debugging // Temporary data structures for traversal and storing/restoring marks static void allocate_stacks(); static void deallocate_stacks(); static void set_ref_processor(ReferenceProcessor* rp) { // delete this method _ref_processor = rp; } debug_only(private:) // End used for PSParallelCompact debugging // If objects are left in eden after a collection, try to move the boundary // and absorb them into the old gen. Returns true if eden was emptied. static bool absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy, PSYoungGen* young_gen, PSOldGen* old_gen); // Reset time since last full gc static void reset_millis_since_last_gc(); public: static void invoke(bool clear_all_softrefs); static void invoke_no_policy(bool clear_all_softrefs); static void initialize(); // Public accessors static elapsedTimer* accumulated_time() { return &_accumulated_time; } static unsigned int total_invocations() { return _total_invocations; } static CollectorCounters* counters() { return _counters; } // Time since last full gc (in milliseconds) static jlong millis_since_last_gc(); };