1 /* 2 * Copyright (c) 2014, 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 25 #include "precompiled.hpp" 26 #include "jfr/leakprofiler/emitEventOperation.hpp" 27 #include "jfr/leakprofiler/leakProfiler.hpp" 28 #include "jfr/leakprofiler/startOperation.hpp" 29 #include "jfr/leakprofiler/stopOperation.hpp" 30 #include "jfr/leakprofiler/sampling/objectSampler.hpp" 31 #include "jfr/recorder/service/jfrOptionSet.hpp" 32 #include "memory/iterator.hpp" 33 #include "oops/oop.hpp" 34 #include "runtime/atomic.hpp" 35 #include "runtime/orderAccess.hpp" 36 #include "runtime/thread.inline.hpp" 37 #include "runtime/vmThread.hpp" 38 #include "utilities/ostream.hpp" 39 40 // Only to be updated during safepoint 41 ObjectSampler* LeakProfiler::_object_sampler = NULL; 42 43 static volatile jbyte suspended = 0; 44 bool LeakProfiler::start(jint sample_count) { 45 if (UseZGC) { 46 log_warning(jfr)("LeakProfiler is currently not supported in combination with ZGC"); 47 return false; 48 } 49 50 if (UseShenandoahGC) { 51 log_warning(jfr)("LeakProfiler is currently not supported in combination with Shenandoah GC"); 52 return false; 53 } 54 55 if (_object_sampler != NULL) { 56 // already started 57 return true; 58 } 59 // Allows user to disable leak profiler on command line by setting queue size to zero. 60 if (sample_count > 0) { 61 StartOperation op(sample_count); 62 VMThread::execute(&op); 63 return _object_sampler != NULL; 64 } 65 return false; 66 } 67 68 bool LeakProfiler::stop() { 69 if (_object_sampler == NULL) { 70 // already stopped/not started 71 return true; 72 } 73 StopOperation op; 74 VMThread::execute(&op); 75 return _object_sampler == NULL; 76 } 77 78 void LeakProfiler::emit_events(jlong cutoff_ticks, bool emit_all) { 79 if (!is_running()) { 80 return; 81 } 82 EmitEventOperation op(cutoff_ticks, emit_all); 83 VMThread::execute(&op); 84 } 85 86 void LeakProfiler::oops_do(BoolObjectClosure* is_alive, OopClosure* f) { 87 assert(SafepointSynchronize::is_at_safepoint(), 88 "Leak Profiler::oops_do(...) may only be called during safepoint"); 89 90 if (_object_sampler != NULL) { 91 _object_sampler->oops_do(is_alive, f); 92 } 93 } 94 95 void LeakProfiler::sample(HeapWord* object, 96 size_t size, 97 JavaThread* thread) { 98 assert(is_running(), "invariant"); 99 assert(thread != NULL, "invariant"); 100 assert(thread->thread_state() == _thread_in_vm, "invariant"); 101 102 // exclude compiler threads and code sweeper thread 103 if (thread->is_hidden_from_external_view()) { 104 return; 105 } 106 107 _object_sampler->add(object, size, thread); 108 } 109 110 ObjectSampler* LeakProfiler::object_sampler() { 111 assert(is_suspended() || SafepointSynchronize::is_at_safepoint(), 112 "Leak Profiler::object_sampler() may only be called during safepoint"); 113 return _object_sampler; 114 } 115 116 void LeakProfiler::set_object_sampler(ObjectSampler* object_sampler) { 117 assert(SafepointSynchronize::is_at_safepoint(), 118 "Leak Profiler::set_object_sampler() may only be called during safepoint"); 119 _object_sampler = object_sampler; 120 } 121 122 bool LeakProfiler::is_running() { 123 return _object_sampler != NULL && !suspended; 124 } 125 126 bool LeakProfiler::is_suspended() { 127 return _object_sampler != NULL && suspended; 128 } 129 130 void LeakProfiler::resume() { 131 assert(is_suspended(), "invariant"); 132 OrderAccess::storestore(); 133 Atomic::store((jbyte)0, &suspended); 134 assert(is_running(), "invariant"); 135 } 136 137 void LeakProfiler::suspend() { 138 assert(SafepointSynchronize::is_at_safepoint(), "invariant"); 139 assert(_object_sampler != NULL, "invariant"); 140 assert(!is_suspended(), "invariant"); 141 suspended = (jbyte)1; // safepoint visible 142 }