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/*
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* Copyright 2002-2005 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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* CA 95054 USA or visit www.sun.com if you need additional information or
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* have any questions.
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*
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*/
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# include "incls/_precompiled.incl"
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# include "incls/_cmsLockVerifier.cpp.incl"
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///////////// Locking verification specific to CMS //////////////
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// Much like "assert_lock_strong()", except that it relaxes the
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// assertion somewhat for the parallel GC case, where VM thread
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// or the CMS thread might hold the lock on behalf of the parallel
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// threads. The second argument is in support of an extra locking
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// check for CFL spaces' free list locks.
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#ifndef PRODUCT
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void CMSLockVerifier::assert_locked(const Mutex* lock, const Mutex* p_lock) {
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if (!Universe::is_fully_initialized()) {
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return;
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}
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Thread* myThread = Thread::current();
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if (lock == NULL) { // a "lock-free" structure, e.g. MUT, protected by CMS token
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assert(p_lock == NULL, "Unexpected state");
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if (myThread->is_ConcurrentGC_thread()) {
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// This test might have to change in the future, if there can be
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// multiple peer CMS threads. But for now, if we're testing the CMS
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assert(myThread == ConcurrentMarkSweepThread::cmst(),
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"In CMS, CMS thread is the only Conc GC thread.");
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assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(),
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"CMS thread should have CMS token");
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} else if (myThread->is_VM_thread()) {
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assert(ConcurrentMarkSweepThread::vm_thread_has_cms_token(),
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"VM thread should have CMS token");
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} else {
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// Token should be held on our behalf by one of the other
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// of CMS or VM thread; not enough easily testable
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// state info to test which here.
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assert(myThread->is_GC_task_thread(), "Unexpected thread type");
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}
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return;
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}
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if (ParallelGCThreads == 0) {
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assert_lock_strong(lock);
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} else {
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if (myThread->is_VM_thread()
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|| myThread->is_ConcurrentGC_thread()
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|| myThread->is_Java_thread()) {
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// Make sure that we are holding the associated lock.
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assert_lock_strong(lock);
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// The checking of p_lock is a spl case for CFLS' free list
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// locks: we make sure that none of the parallel GC work gang
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// threads are holding "sub-locks" of freeListLock(). We check only
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// the parDictionaryAllocLock because the others are too numerous.
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// This spl case code is somewhat ugly and any improvements
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// are welcome XXX FIX ME!!
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if (p_lock != NULL) {
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assert(!p_lock->is_locked() || p_lock->owned_by_self(),
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"Possible race between this and parallel GC threads");
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}
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} else if (myThread->is_GC_task_thread()) {
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// Make sure that the VM or CMS thread holds lock on our behalf
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// XXX If there were a concept of a gang_master for a (set of)
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// gang_workers, we could have used the identity of that thread
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// for checking ownership here; for now we just disjunct.
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assert(lock->owner() == VMThread::vm_thread() ||
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lock->owner() == ConcurrentMarkSweepThread::cmst(),
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"Should be locked by VM thread or CMS thread on my behalf");
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} else {
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// Make sure we didn't miss some obscure corner case
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ShouldNotReachHere();
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}
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}
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}
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#endif
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