hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.cpp
author ysr
Thu, 21 Oct 2010 17:29:24 -0700
changeset 6984 c6718f921eb6
parent 5547 f4b087cbb361
child 7397 5b173b4ca846
permissions -rw-r--r--
6992998: CMSWaitDuration=0 causes hangs with +ExplicitGCInvokesConcurrent Summary: Closed a timing hole during which concurrent full gc requests can be missed. The hole can increase the latency of the response to a full gc request by up to the value of CMSWaitDuration. If CMSWaitDuration=0 is, as currently, interpreted as an unbounded wait, suitable in certain tuning scenarios, the application can potentially hang. Made two obscure tunables, including CMSWaitDuration, manageable. Reviewed-by: jcoomes, tonyp
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/*
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 * Copyright (c) 2002, 2004, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 *
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 */
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# include "incls/_precompiled.incl"
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# include "incls/_freeBlockDictionary.cpp.incl"
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#ifndef PRODUCT
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Mutex* FreeBlockDictionary::par_lock() const {
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  return _lock;
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}
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void FreeBlockDictionary::set_par_lock(Mutex* lock) {
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  _lock = lock;
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}
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void FreeBlockDictionary::verify_par_locked() const {
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#ifdef ASSERT
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  if (ParallelGCThreads > 0) {
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    Thread* myThread = Thread::current();
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    if (myThread->is_GC_task_thread()) {
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      assert(par_lock() != NULL, "Should be using locking?");
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      assert_lock_strong(par_lock());
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    }
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  }
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#endif // ASSERT
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}
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#endif