1 /* 2 * Copyright (c) 2018, 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 #include "precompiled.hpp" 25 #include "runtime/atomic.hpp" 26 #include "runtime/orderAccess.hpp" 27 #include "runtime/os.hpp" 28 #include "utilities/globalCounter.hpp" 29 #include "utilities/globalCounter.inline.hpp" 30 #include "threadHelper.inline.hpp" 31 32 #define GOOD_VALUE 1337 33 #define BAD_VALUE 4711 34 35 struct TestData { 36 long test_value; 37 }; 38 39 class RCUReaderThread : public JavaTestThread { 40 public: 41 static volatile bool _exit; 42 volatile TestData** _test; 43 Semaphore* _wrt_start; 44 RCUReaderThread(Semaphore* post, volatile TestData** test, Semaphore* wrt_start) 45 : JavaTestThread(post), _test(test), _wrt_start(wrt_start) {}; 46 virtual ~RCUReaderThread(){} 47 void main_run() { 48 _wrt_start->signal(); 49 while (!_exit) { 50 GlobalCounter::critical_section_begin(this); 51 volatile TestData* test = OrderAccess::load_acquire(_test); 52 long value = OrderAccess::load_acquire(&test->test_value); 53 ASSERT_EQ(value, GOOD_VALUE); 54 GlobalCounter::critical_section_end(this); 55 { 56 GlobalCounter::CriticalSection cs(this); 57 volatile TestData* test = OrderAccess::load_acquire(_test); 58 long value = OrderAccess::load_acquire(&test->test_value); 59 ASSERT_EQ(value, GOOD_VALUE); 60 } 61 } 62 } 63 }; 64 65 volatile bool RCUReaderThread::_exit = false; 66 67 class RCUWriterThread : public JavaTestThread { 68 public: 69 RCUWriterThread(Semaphore* post) : JavaTestThread(post) { 70 }; 71 virtual ~RCUWriterThread(){} 72 void main_run() { 73 static const int NUMBER_OF_READERS = 4; 74 Semaphore post; 75 Semaphore wrt_start; 76 volatile TestData* test = NULL; 77 78 RCUReaderThread* reader1 = new RCUReaderThread(&post, &test, &wrt_start); 79 RCUReaderThread* reader2 = new RCUReaderThread(&post, &test, &wrt_start); 80 RCUReaderThread* reader3 = new RCUReaderThread(&post, &test, &wrt_start); 81 RCUReaderThread* reader4 = new RCUReaderThread(&post, &test, &wrt_start); 82 83 TestData* tmp = new TestData(); 84 tmp->test_value = GOOD_VALUE; 85 OrderAccess::release_store_fence(&test, tmp); 86 87 reader1->doit(); 88 reader2->doit(); 89 reader3->doit(); 90 reader4->doit(); 91 92 int nw = NUMBER_OF_READERS; 93 while (nw > 0) { 94 wrt_start.wait(); 95 --nw; 96 } 97 jlong stop_ms = os::javaTimeMillis() + 1000; // 1 seconds max test time 98 for (int i = 0; i < 100000 && stop_ms > os::javaTimeMillis(); i++) { 99 volatile TestData* free_tmp = test; 100 tmp = new TestData(); 101 tmp->test_value = GOOD_VALUE; 102 OrderAccess::release_store(&test, tmp); 103 GlobalCounter::write_synchronize(); 104 free_tmp->test_value = BAD_VALUE; 105 delete free_tmp; 106 } 107 RCUReaderThread::_exit = true; 108 for (int i = 0; i < NUMBER_OF_READERS; i++) { 109 post.wait(); 110 } 111 } 112 }; 113 114 TEST_VM(GlobalCounter, critical_section) { 115 RCUReaderThread::_exit = false; 116 mt_test_doer<RCUWriterThread>(); 117 }