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 (_object_sampler != NULL) { 51 // already started 52 return true; 53 } 54 // Allows user to disable leak profiler on command line by setting queue size to zero. 55 if (sample_count > 0) { 56 StartOperation op(sample_count); 57 VMThread::execute(&op); 58 return _object_sampler != NULL; 59 } 60 return false; 61 } 62 63 bool LeakProfiler::stop() { 64 if (_object_sampler == NULL) { 65 // already stopped/not started 66 return true; 67 } 68 StopOperation op; 69 VMThread::execute(&op); 70 return _object_sampler == NULL; 71 } 72 73 void LeakProfiler::emit_events(jlong cutoff_ticks, bool emit_all) { 74 if (!is_running()) { 75 return; 76 } 77 EmitEventOperation op(cutoff_ticks, emit_all); 78 VMThread::execute(&op); 79 } 80 81 void LeakProfiler::oops_do(BoolObjectClosure* is_alive, OopClosure* f) { 82 assert(SafepointSynchronize::is_at_safepoint(), 83 "Leak Profiler::oops_do(...) may only be called during safepoint"); 84 85 if (_object_sampler != NULL) { 86 _object_sampler->oops_do(is_alive, f); 87 } 88 } 89 90 void LeakProfiler::sample(HeapWord* object, 91 size_t size, 92 JavaThread* thread) { 93 assert(is_running(), "invariant"); 94 assert(thread != NULL, "invariant"); 95 assert(thread->thread_state() == _thread_in_vm, "invariant"); 96 97 // exclude compiler threads and code sweeper thread 98 if (thread->is_hidden_from_external_view()) { 99 return; 100 } 101 102 _object_sampler->add(object, size, thread); 103 } 104 105 ObjectSampler* LeakProfiler::object_sampler() { 106 assert(is_suspended() || SafepointSynchronize::is_at_safepoint(), 107 "Leak Profiler::object_sampler() may only be called during safepoint"); 108 return _object_sampler; 109 } 110 111 void LeakProfiler::set_object_sampler(ObjectSampler* object_sampler) { 112 assert(SafepointSynchronize::is_at_safepoint(), 113 "Leak Profiler::set_object_sampler() may only be called during safepoint"); 114 _object_sampler = object_sampler; 115 } 116 117 bool LeakProfiler::is_running() { 118 return _object_sampler != NULL && !suspended; 119 } 120 121 bool LeakProfiler::is_suspended() { 122 return _object_sampler != NULL && suspended; 123 } 124 125 void LeakProfiler::resume() { 126 assert(is_suspended(), "invariant"); 127 OrderAccess::storestore(); 128 Atomic::store((jbyte)0, &suspended); 129 assert(is_running(), "invariant"); 130 } 131 132 void LeakProfiler::suspend() { 133 assert(SafepointSynchronize::is_at_safepoint(), "invariant"); 134 assert(_object_sampler != NULL, "invariant"); 135 assert(!is_suspended(), "invariant"); 136 suspended = (jbyte)1; // safepoint visible 137 }