1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/cmsLockVerifier.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,102 @@
1.4 +/*
1.5 + * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "gc_implementation/concurrentMarkSweep/cmsLockVerifier.hpp"
1.30 +#include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp"
1.31 +#include "runtime/vmThread.hpp"
1.32 +
1.33 +///////////// Locking verification specific to CMS //////////////
1.34 +// Much like "assert_lock_strong()", except that it relaxes the
1.35 +// assertion somewhat for the parallel GC case, where VM thread
1.36 +// or the CMS thread might hold the lock on behalf of the parallel
1.37 +// threads. The second argument is in support of an extra locking
1.38 +// check for CFL spaces' free list locks.
1.39 +#ifndef PRODUCT
1.40 +void CMSLockVerifier::assert_locked(const Mutex* lock,
1.41 + const Mutex* p_lock1,
1.42 + const Mutex* p_lock2) {
1.43 + if (!Universe::is_fully_initialized()) {
1.44 + return;
1.45 + }
1.46 +
1.47 + Thread* myThread = Thread::current();
1.48 +
1.49 + if (lock == NULL) { // a "lock-free" structure, e.g. MUT, protected by CMS token
1.50 + assert(p_lock1 == NULL && p_lock2 == NULL, "Unexpected caller error");
1.51 + if (myThread->is_ConcurrentGC_thread()) {
1.52 + // This test might have to change in the future, if there can be
1.53 + // multiple peer CMS threads. But for now, if we're testing the CMS
1.54 + assert(myThread == ConcurrentMarkSweepThread::cmst(),
1.55 + "In CMS, CMS thread is the only Conc GC thread.");
1.56 + assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(),
1.57 + "CMS thread should have CMS token");
1.58 + } else if (myThread->is_VM_thread()) {
1.59 + assert(ConcurrentMarkSweepThread::vm_thread_has_cms_token(),
1.60 + "VM thread should have CMS token");
1.61 + } else {
1.62 + // Token should be held on our behalf by one of the other
1.63 + // of CMS or VM thread; not enough easily testable
1.64 + // state info to test which here.
1.65 + assert(myThread->is_GC_task_thread(), "Unexpected thread type");
1.66 + }
1.67 + return;
1.68 + }
1.69 +
1.70 + if (myThread->is_VM_thread()
1.71 + || myThread->is_ConcurrentGC_thread()
1.72 + || myThread->is_Java_thread()) {
1.73 + // Make sure that we are holding the associated lock.
1.74 + assert_lock_strong(lock);
1.75 + // The checking of p_lock is a spl case for CFLS' free list
1.76 + // locks: we make sure that none of the parallel GC work gang
1.77 + // threads are holding "sub-locks" of freeListLock(). We check only
1.78 + // the parDictionaryAllocLock because the others are too numerous.
1.79 + // This spl case code is somewhat ugly and any improvements
1.80 + // are welcome.
1.81 + assert(p_lock1 == NULL || !p_lock1->is_locked() || p_lock1->owned_by_self(),
1.82 + "Possible race between this and parallel GC threads");
1.83 + assert(p_lock2 == NULL || !p_lock2->is_locked() || p_lock2->owned_by_self(),
1.84 + "Possible race between this and parallel GC threads");
1.85 + } else if (myThread->is_GC_task_thread()) {
1.86 + // Make sure that the VM or CMS thread holds lock on our behalf
1.87 + // XXX If there were a concept of a gang_master for a (set of)
1.88 + // gang_workers, we could have used the identity of that thread
1.89 + // for checking ownership here; for now we just disjunct.
1.90 + assert(lock->owner() == VMThread::vm_thread() ||
1.91 + lock->owner() == ConcurrentMarkSweepThread::cmst(),
1.92 + "Should be locked by VM thread or CMS thread on my behalf");
1.93 + if (p_lock1 != NULL) {
1.94 + assert_lock_strong(p_lock1);
1.95 + }
1.96 + if (p_lock2 != NULL) {
1.97 + assert_lock_strong(p_lock2);
1.98 + }
1.99 + } else {
1.100 + // Make sure we didn't miss some other thread type calling into here;
1.101 + // perhaps as a result of future VM evolution.
1.102 + ShouldNotReachHere();
1.103 + }
1.104 +}
1.105 +#endif
