1 /* 2 * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/systemDictionary.hpp" 27 #include "gc/shared/concurrentGCThread.hpp" 28 #include "oops/instanceRefKlass.hpp" 29 #include "oops/oop.inline.hpp" 30 #include "runtime/init.hpp" 31 #include "runtime/interfaceSupport.hpp" 32 #include "runtime/java.hpp" 33 #include "runtime/javaCalls.hpp" 34 #include "runtime/os.hpp" 35 36 ConcurrentGCThread::ConcurrentGCThread() : 37 _should_terminate(false), _has_terminated(false) { 38 }; 39 40 void ConcurrentGCThread::create_and_start(ThreadPriority prio) { 41 if (os::create_thread(this, os::cgc_thread)) { 42 // XXX: need to set this to low priority 43 // unless "aggressive mode" set; priority 44 // should be just less than that of VMThread. 45 os::set_priority(this, prio); 46 if (!_should_terminate && !DisableStartThread) { 47 os::start_thread(this); 48 } 49 } 50 } 51 52 void ConcurrentGCThread::initialize_in_thread() { 53 this->record_stack_base_and_size(); 54 this->initialize_named_thread(); 55 this->set_active_handles(JNIHandleBlock::allocate_block()); 56 // From this time Thread::current() should be working. 57 assert(this == Thread::current(), "just checking"); 58 } 59 60 void ConcurrentGCThread::wait_for_universe_init() { 61 MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag); 62 while (!is_init_completed() && !_should_terminate) { 63 CGC_lock->wait(Mutex::_no_safepoint_check_flag, 1); 64 } 65 } 66 67 void ConcurrentGCThread::terminate() { 68 assert(_should_terminate, "Should only be called on terminate request."); 69 // Signal that it is terminated 70 { 71 MutexLockerEx mu(Terminator_lock, 72 Mutex::_no_safepoint_check_flag); 73 _has_terminated = true; 74 Terminator_lock->notify(); 75 } 76 } 77 78 void ConcurrentGCThread::run() { 79 initialize_in_thread(); 80 wait_for_universe_init(); 81 82 run_service(); 83 84 terminate(); 85 } 86 87 void ConcurrentGCThread::stop() { 88 // it is ok to take late safepoints here, if needed 89 { 90 MutexLockerEx mu(Terminator_lock); 91 assert(!_has_terminated, "stop should only be called once"); 92 assert(!_should_terminate, "stop should only be called once"); 93 _should_terminate = true; 94 } 95 96 stop_service(); 97 98 { 99 MutexLockerEx mu(Terminator_lock); 100 while (!_has_terminated) { 101 Terminator_lock->wait(); 102 } 103 } 104 }