Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.cpp @ 1022:4c3458a31e17
6888316: G1: has_aborted() || _cm->region_stack_empty() fails
Summary: Remove incorrect guarantee.
Reviewed-by: apetrusenko, iveresov
author | tonyp |
---|---|
date | Wed, 07 Oct 2009 09:42:18 -0400 |
parents | a61af66fc99e |
children | bb843ebc7c55 |
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/* * Copyright 2005-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ # include "incls/_precompiled.incl" # include "incls/_vmCMSOperations.cpp.incl" HS_DTRACE_PROBE_DECL(hs_private, cms__initmark__begin); HS_DTRACE_PROBE_DECL(hs_private, cms__initmark__end); HS_DTRACE_PROBE_DECL(hs_private, cms__remark__begin); HS_DTRACE_PROBE_DECL(hs_private, cms__remark__end); ////////////////////////////////////////////////////////// // Methods in abstract class VM_CMS_Operation ////////////////////////////////////////////////////////// void VM_CMS_Operation::acquire_pending_list_lock() { // The caller may block while communicating // with the SLT thread in order to acquire/release the PLL. ConcurrentMarkSweepThread::slt()-> manipulatePLL(SurrogateLockerThread::acquirePLL); } void VM_CMS_Operation::release_and_notify_pending_list_lock() { // The caller may block while communicating // with the SLT thread in order to acquire/release the PLL. ConcurrentMarkSweepThread::slt()-> manipulatePLL(SurrogateLockerThread::releaseAndNotifyPLL); } void VM_CMS_Operation::verify_before_gc() { if (VerifyBeforeGC && GenCollectedHeap::heap()->total_collections() >= VerifyGCStartAt) { HandleMark hm; FreelistLocker x(_collector); MutexLockerEx y(_collector->bitMapLock(), Mutex::_no_safepoint_check_flag); Universe::heap()->prepare_for_verify(); Universe::verify(true); } } void VM_CMS_Operation::verify_after_gc() { if (VerifyAfterGC && GenCollectedHeap::heap()->total_collections() >= VerifyGCStartAt) { HandleMark hm; FreelistLocker x(_collector); MutexLockerEx y(_collector->bitMapLock(), Mutex::_no_safepoint_check_flag); Universe::verify(true); } } bool VM_CMS_Operation::lost_race() const { if (CMSCollector::abstract_state() == CMSCollector::Idling) { // We lost a race to a foreground collection // -- there's nothing to do return true; } assert(CMSCollector::abstract_state() == legal_state(), "Inconsistent collector state?"); return false; } bool VM_CMS_Operation::doit_prologue() { assert(Thread::current()->is_ConcurrentGC_thread(), "just checking"); assert(!CMSCollector::foregroundGCShouldWait(), "Possible deadlock"); assert(!ConcurrentMarkSweepThread::cms_thread_has_cms_token(), "Possible deadlock"); if (needs_pll()) { acquire_pending_list_lock(); } // Get the Heap_lock after the pending_list_lock. Heap_lock->lock(); if (lost_race()) { assert(_prologue_succeeded == false, "Initialized in c'tor"); Heap_lock->unlock(); if (needs_pll()) { release_and_notify_pending_list_lock(); } } else { _prologue_succeeded = true; } return _prologue_succeeded; } void VM_CMS_Operation::doit_epilogue() { assert(Thread::current()->is_ConcurrentGC_thread(), "just checking"); assert(!CMSCollector::foregroundGCShouldWait(), "Possible deadlock"); assert(!ConcurrentMarkSweepThread::cms_thread_has_cms_token(), "Possible deadlock"); // Release the Heap_lock first. Heap_lock->unlock(); if (needs_pll()) { release_and_notify_pending_list_lock(); } } ////////////////////////////////////////////////////////// // Methods in class VM_CMS_Initial_Mark ////////////////////////////////////////////////////////// void VM_CMS_Initial_Mark::doit() { if (lost_race()) { // Nothing to do. return; } HS_DTRACE_PROBE(hs_private, cms__initmark__begin); GenCollectedHeap* gch = GenCollectedHeap::heap(); GCCauseSetter gccs(gch, GCCause::_cms_initial_mark); VM_CMS_Operation::verify_before_gc(); IsGCActiveMark x; // stop-world GC active _collector->do_CMS_operation(CMSCollector::CMS_op_checkpointRootsInitial); VM_CMS_Operation::verify_after_gc(); HS_DTRACE_PROBE(hs_private, cms__initmark__end); } ////////////////////////////////////////////////////////// // Methods in class VM_CMS_Final_Remark_Operation ////////////////////////////////////////////////////////// void VM_CMS_Final_Remark::doit() { if (lost_race()) { // Nothing to do. return; } HS_DTRACE_PROBE(hs_private, cms__remark__begin); GenCollectedHeap* gch = GenCollectedHeap::heap(); GCCauseSetter gccs(gch, GCCause::_cms_final_remark); VM_CMS_Operation::verify_before_gc(); IsGCActiveMark x; // stop-world GC active _collector->do_CMS_operation(CMSCollector::CMS_op_checkpointRootsFinal); VM_CMS_Operation::verify_after_gc(); HS_DTRACE_PROBE(hs_private, cms__remark__end); } // VM operation to invoke a concurrent collection of a // GenCollectedHeap heap. void VM_GenCollectFullConcurrent::doit() { assert(Thread::current()->is_VM_thread(), "Should be VM thread"); GenCollectedHeap* gch = GenCollectedHeap::heap(); if (_gc_count_before == gch->total_collections()) { // The "full" of do_full_collection call below "forces" // a collection; the second arg, 0, below ensures that // only the young gen is collected. XXX In the future, // we'll probably need to have something in this interface // to say do this only if we are sure we will not bail // out to a full collection in this attempt, but that's // for the future. assert(SafepointSynchronize::is_at_safepoint(), "We can only be executing this arm of if at a safepoint"); GCCauseSetter gccs(gch, _gc_cause); gch->do_full_collection(gch->must_clear_all_soft_refs(), 0 /* collect only youngest gen */); } // Else no need for a foreground young gc assert((_gc_count_before < gch->total_collections()) || (GC_locker::is_active() /* gc may have been skipped */ && (_gc_count_before == gch->total_collections())), "total_collections() should be monotonically increasing"); MutexLockerEx x(FullGCCount_lock, Mutex::_no_safepoint_check_flag); if (gch->total_full_collections() == _full_gc_count_before) { // Disable iCMS until the full collection is done. CMSCollector::disable_icms(); // 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 { FullGCCount_lock->notify_all(); // Inform the Java thread its work is done } } bool VM_GenCollectFullConcurrent::evaluate_at_safepoint() const { Thread* thr = Thread::current(); assert(thr != NULL, "Unexpected tid"); if (!thr->is_Java_thread()) { assert(thr->is_VM_thread(), "Expected to be evaluated by VM thread"); GenCollectedHeap* gch = GenCollectedHeap::heap(); if (_gc_count_before != gch->total_collections()) { // No need to do a young gc, we'll just nudge the CMS thread // in the doit() method above, to be executed soon. assert(_gc_count_before < gch->total_collections(), "total_collections() should be monotnically increasing"); return false; // no need for foreground young gc } } return true; // may still need foreground young gc } void VM_GenCollectFullConcurrent::doit_epilogue() { Thread* thr = Thread::current(); assert(thr->is_Java_thread(), "just checking"); JavaThread* jt = (JavaThread*)thr; // Release the Heap_lock first. Heap_lock->unlock(); release_and_notify_pending_list_lock(); // It is fine to test whether completed collections has // exceeded our request count without locking because // the completion count is monotonically increasing; // this will break for very long-running apps when the // count overflows and wraps around. XXX fix me !!! // e.g. at the rate of 1 full gc per ms, this could // overflow in about 1000 years. GenCollectedHeap* gch = GenCollectedHeap::heap(); if (gch->total_full_collections_completed() <= _full_gc_count_before) { // Now, wait for witnessing concurrent gc cycle to complete, // but do so in native mode, because we want to lock the // FullGCEvent_lock, which may be needed by the VM thread // or by the CMS thread, so we do not want to be suspended // while holding that lock. ThreadToNativeFromVM native(jt); MutexLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag); // Either a concurrent or a stop-world full gc is sufficient // witness to our request. while (gch->total_full_collections_completed() <= _full_gc_count_before) { FullGCCount_lock->wait(Mutex::_no_safepoint_check_flag); } } // Enable iCMS back. CMSCollector::enable_icms(); }