Mercurial > hg > truffle
view src/share/vm/gc_implementation/g1/concurrentG1RefineThread.hpp @ 1886:72a161e62cc4
6991377: G1: race between concurrent refinement and humongous object allocation
Summary: There is a race between the concurrent refinement threads and the humongous object allocation that can cause the concurrent refinement threads to corrupt the part of the BOT that it is being initialized by the humongous object allocation operation. The solution is to do the humongous object allocation in careful steps to ensure that the concurrent refinement threads always have a consistent view over the BOT, region contents, and top. The fix includes some very minor tidying up in sparsePRT.
Reviewed-by: jcoomes, johnc, ysr
author | tonyp |
---|---|
date | Sat, 16 Oct 2010 17:12:19 -0400 |
parents | c18cbe5936b8 |
children | f95d63e2154a |
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/* * Copyright (c) 2001, 2009, 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. * */ // Forward Decl. class ConcurrentG1Refine; // The G1 Concurrent Refinement Thread (could be several in the future). class ConcurrentG1RefineThread: public ConcurrentGCThread { friend class VMStructs; friend class G1CollectedHeap; double _vtime_start; // Initial virtual time. double _vtime_accum; // Initial virtual time. int _worker_id; int _worker_id_offset; // The refinement threads collection is linked list. A predecessor can activate a successor // when the number of the rset update buffer crosses a certain threshold. A successor // would self-deactivate when the number of the buffers falls below the threshold. bool _active; ConcurrentG1RefineThread* _next; Monitor* _monitor; ConcurrentG1Refine* _cg1r; int _thread_threshold_step; // This thread activation threshold int _threshold; // This thread deactivation threshold int _deactivation_threshold; void sample_young_list_rs_lengths(); void run_young_rs_sampling(); void wait_for_completed_buffers(); void set_active(bool x) { _active = x; } bool is_active(); void activate(); void deactivate(); // For use by G1CollectedHeap, which is a friend. static SuspendibleThreadSet* sts() { return &_sts; } public: virtual void run(); // Constructor ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r, ConcurrentG1RefineThread* next, int worker_id_offset, int worker_id); void initialize(); // Printing void print() const; void print_on(outputStream* st) const; // Total virtual time so far. double vtime_accum() { return _vtime_accum; } ConcurrentG1Refine* cg1r() { return _cg1r; } // Yield for GC void yield(); // shutdown void stop(); };