| /* |
| * Copyright (c) 2002, 2015, 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 |
| * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "gc/cms/cmsLockVerifier.hpp" |
| #include "gc/cms/concurrentMarkSweepThread.hpp" |
| #include "runtime/vmThread.hpp" |
| |
| ///////////// Locking verification specific to CMS ////////////// |
| // Much like "assert_lock_strong()", except that it relaxes the |
| // assertion somewhat for the parallel GC case, where VM thread |
| // or the CMS thread might hold the lock on behalf of the parallel |
| // threads. The second argument is in support of an extra locking |
| // check for CFL spaces' free list locks. |
| #ifndef PRODUCT |
| void CMSLockVerifier::assert_locked(const Mutex* lock, |
| const Mutex* p_lock1, |
| const Mutex* p_lock2) { |
| if (!Universe::is_fully_initialized()) { |
| return; |
| } |
| |
| Thread* myThread = Thread::current(); |
| |
| if (lock == NULL) { // a "lock-free" structure, e.g. MUT, protected by CMS token |
| assert(p_lock1 == NULL && p_lock2 == NULL, "Unexpected caller error"); |
| if (myThread->is_ConcurrentGC_thread()) { |
| // This test might have to change in the future, if there can be |
| // multiple peer CMS threads. But for now, if we're testing the CMS |
| assert(myThread == ConcurrentMarkSweepThread::cmst(), |
| "In CMS, CMS thread is the only Conc GC thread."); |
| assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), |
| "CMS thread should have CMS token"); |
| } else if (myThread->is_VM_thread()) { |
| assert(ConcurrentMarkSweepThread::vm_thread_has_cms_token(), |
| "VM thread should have CMS token"); |
| } else { |
| // Token should be held on our behalf by one of the other |
| // of CMS or VM thread; not enough easily testable |
| // state info to test which here. |
| assert(myThread->is_GC_task_thread(), "Unexpected thread type"); |
| } |
| return; |
| } |
| |
| if (myThread->is_VM_thread() |
| || myThread->is_ConcurrentGC_thread() |
| || myThread->is_Java_thread()) { |
| // Make sure that we are holding the associated lock. |
| assert_lock_strong(lock); |
| // The checking of p_lock is a spl case for CFLS' free list |
| // locks: we make sure that none of the parallel GC work gang |
| // threads are holding "sub-locks" of freeListLock(). We check only |
| // the parDictionaryAllocLock because the others are too numerous. |
| // This spl case code is somewhat ugly and any improvements |
| // are welcome. |
| assert(p_lock1 == NULL || !p_lock1->is_locked() || p_lock1->owned_by_self(), |
| "Possible race between this and parallel GC threads"); |
| assert(p_lock2 == NULL || !p_lock2->is_locked() || p_lock2->owned_by_self(), |
| "Possible race between this and parallel GC threads"); |
| } else if (myThread->is_GC_task_thread()) { |
| // Make sure that the VM or CMS thread holds lock on our behalf |
| // XXX If there were a concept of a gang_master for a (set of) |
| // gang_workers, we could have used the identity of that thread |
| // for checking ownership here; for now we just disjunct. |
| assert(lock->owner() == VMThread::vm_thread() || |
| lock->owner() == ConcurrentMarkSweepThread::cmst(), |
| "Should be locked by VM thread or CMS thread on my behalf"); |
| if (p_lock1 != NULL) { |
| assert_lock_strong(p_lock1); |
| } |
| if (p_lock2 != NULL) { |
| assert_lock_strong(p_lock2); |
| } |
| } else { |
| // Make sure we didn't miss some other thread type calling into here; |
| // perhaps as a result of future VM evolution. |
| ShouldNotReachHere(); |
| } |
| } |
| #endif |