Mercurial > hg > truffle
diff src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp @ 2365:a181f3a124dd
6987703: iCMS: Intermittent hang with gc/gctests/CallGC/CallGC01 and +ExplicitGCInvokesConcurrent
Summary: Count enable_icms() and disable_icms() events so as to prevent inteference between concurrent calls, which can cause the iCMS thread to be left stranded in icms_wait() with an unserviced request and no young allocations to unwedge it.
Reviewed-by: jcoomes, poonam
author | ysr |
---|---|
date | Mon, 14 Mar 2011 21:52:24 -0700 |
parents | f95d63e2154a |
children | f08d439fab8c |
line wrap: on
line diff
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp Thu Mar 03 11:35:50 2011 +0100 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp Mon Mar 14 21:52:24 2011 -0700 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 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 @@ -40,7 +40,7 @@ class ConcurrentMarkSweepGeneration; class CMSCollector; -// The Concurrent Mark Sweep GC Thread (could be several in the future). +// The Concurrent Mark Sweep GC Thread class ConcurrentMarkSweepThread: public ConcurrentGCThread { friend class VMStructs; friend class ConcurrentMarkSweepGeneration; // XXX should remove friendship @@ -55,8 +55,6 @@ static SurrogateLockerThread::SLT_msg_type _sltBuffer; static Monitor* _sltMonitor; - ConcurrentMarkSweepThread* _next; - static bool _should_terminate; enum CMS_flag_type { @@ -84,7 +82,7 @@ // Tracing messages, enabled by CMSTraceThreadState. static inline void trace_state(const char* desc); - static volatile bool _icms_enabled; // iCMS enabled? + static volatile int _icms_disabled; // a counter to track #iCMS disable & enable static volatile bool _should_run; // iCMS may run static volatile bool _should_stop; // iCMS should stop @@ -214,10 +212,25 @@ // Incremental mode is enabled globally by the flag CMSIncrementalMode. It // must also be enabled/disabled dynamically to allow foreground collections. - static inline void enable_icms() { _icms_enabled = true; } - static inline void disable_icms() { _icms_enabled = false; } - static inline void set_icms_enabled(bool val) { _icms_enabled = val; } - static inline bool icms_enabled() { return _icms_enabled; } +#define ICMS_ENABLING_ASSERT \ + assert((CMSIncrementalMode && _icms_disabled >= 0) || \ + (!CMSIncrementalMode && _icms_disabled <= 0), "Error") + + static inline void enable_icms() { + ICMS_ENABLING_ASSERT; + Atomic::dec(&_icms_disabled); + } + static inline void disable_icms() { + ICMS_ENABLING_ASSERT; + Atomic::inc(&_icms_disabled); + } + static inline bool icms_is_disabled() { + ICMS_ENABLING_ASSERT; + return _icms_disabled > 0; + } + static inline bool icms_is_enabled() { + return !icms_is_disabled(); + } }; inline void ConcurrentMarkSweepThread::trace_state(const char* desc) {