1 /* 2 * Copyright (c) 2014, 2019, 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/leakProfiler.hpp" 27 #include "jfr/leakprofiler/startOperation.hpp" 28 #include "jfr/leakprofiler/stopOperation.hpp" 29 #include "jfr/leakprofiler/checkpoint/eventEmitter.hpp" 30 #include "jfr/leakprofiler/sampling/objectSampler.hpp" 31 #include "jfr/recorder/service/jfrOptionSet.hpp" 32 #include "logging/log.hpp" 33 #include "memory/iterator.hpp" 34 #include "runtime/thread.inline.hpp" 35 #include "runtime/vmThread.hpp" 36 37 bool LeakProfiler::is_running() { 38 return ObjectSampler::is_created(); 39 } 40 41 bool LeakProfiler::start(int sample_count) { 42 if (is_running()) { 43 return true; 44 } 45 46 // Allows user to disable leak profiler on command line by setting queue size to zero. 47 if (sample_count == 0) { 48 return false; 49 } 50 51 if (UseZGC) { 52 log_warning(jfr)("LeakProfiler is currently not supported in combination with ZGC"); 53 return false; 54 } 55 56 if (UseShenandoahGC) { 57 log_warning(jfr)("LeakProfiler is currently not supported in combination with Shenandoah GC"); 58 return false; 59 } 60 61 assert(!is_running(), "invariant"); 62 assert(sample_count > 0, "invariant"); 63 64 // schedule the safepoint operation for installing the object sampler 65 StartOperation op(sample_count); 66 VMThread::execute(&op); 67 68 if (!is_running()) { 69 log_trace(jfr, system)("Object sampling could not be started because the sampler could not be allocated"); 70 return false; 71 } 72 assert(is_running(), "invariant"); 73 log_trace(jfr, system)("Object sampling started"); 74 return true; 75 } 76 77 bool LeakProfiler::stop() { 78 if (!is_running()) { 79 return false; 80 } 81 82 // schedule the safepoint operation for uninstalling and destroying the object sampler 83 StopOperation op; 84 VMThread::execute(&op); 85 86 assert(!is_running(), "invariant"); 87 log_trace(jfr, system)("Object sampling stopped"); 88 return true; 89 } 90 91 void LeakProfiler::emit_events(int64_t cutoff_ticks, bool emit_all) { 92 if (!is_running()) { 93 return; 94 } 95 // exclusive access to object sampler instance 96 ObjectSampler* const sampler = ObjectSampler::acquire(); 97 assert(sampler != NULL, "invariant"); 98 EventEmitter::emit(sampler, cutoff_ticks, emit_all); 99 ObjectSampler::release(); 100 } 101 102 void LeakProfiler::oops_do(BoolObjectClosure* is_alive, OopClosure* f) { 103 assert(SafepointSynchronize::is_at_safepoint(), 104 "Leak Profiler::oops_do(...) may only be called during safepoint"); 105 if (is_running()) { 106 ObjectSampler::oops_do(is_alive, f); 107 } 108 } 109 110 void LeakProfiler::sample(HeapWord* object, size_t size, JavaThread* thread) { 111 assert(is_running(), "invariant"); 112 assert(thread != NULL, "invariant"); 113 assert(thread->thread_state() == _thread_in_vm, "invariant"); 114 115 // exclude compiler threads and code sweeper thread 116 if (thread->is_hidden_from_external_view()) { 117 return; 118 } 119 120 ObjectSampler::sample(object, size, thread); 121 }