Mercurial > hg > truffle
diff src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.cpp @ 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 | 436b4a3231bf |
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--- a/src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.cpp Thu Mar 03 11:35:50 2011 +0100 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.cpp Mon Mar 14 21:52:24 2011 -0700 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2005, 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 @@ -192,14 +192,18 @@ "total_collections() should be monotonically increasing"); MutexLockerEx x(FullGCCount_lock, Mutex::_no_safepoint_check_flag); + assert(_full_gc_count_before <= gch->total_full_collections(), "Error"); if (gch->total_full_collections() == _full_gc_count_before) { - // Disable iCMS until the full collection is done. + // Disable iCMS until the full collection is done, and + // remember that we did so. CMSCollector::disable_icms(); + _disabled_icms = true; // In case CMS thread was in icms_wait(), wake it up. CMSCollector::start_icms(); // Nudge the CMS thread to start a concurrent collection. CMSCollector::request_full_gc(_full_gc_count_before); } else { + assert(_full_gc_count_before < gch->total_full_collections(), "Error"); FullGCCount_lock->notify_all(); // Inform the Java thread its work is done } } @@ -259,6 +263,8 @@ FullGCCount_lock->wait(Mutex::_no_safepoint_check_flag); } } - // Enable iCMS back. - CMSCollector::enable_icms(); + // Enable iCMS back if we disabled it earlier. + if (_disabled_icms) { + CMSCollector::enable_icms(); + } }