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 #ifndef SHARE_VM_LEAKPROFILER_SAMPLING_OBJECTSAMPLER_HPP 26 #define SHARE_VM_LEAKPROFILER_SAMPLING_OBJECTSAMPLER_HPP 27 28 #include "memory/allocation.hpp" 29 #include "jfr/utilities/jfrTime.hpp" 30 31 typedef u8 traceid; 32 33 class BoolObjectClosure; 34 class JfrStackTrace; 35 class OopClosure; 36 class ObjectSample; 37 class ObjectSampler; 38 class SampleList; 39 class SamplePriorityQueue; 40 class Thread; 41 42 // Class reponsible for holding samples and 43 // making sure the samples are evenly distributed as 44 // new entries are added and removed. 45 class ObjectSampler : public CHeapObj<mtTracing> { 46 friend class EventEmitter; 47 friend class JfrRecorderService; 48 friend class LeakProfiler; 49 friend class StartOperation; 50 friend class StopOperation; 51 friend class ObjectSampleCheckpoint; 52 friend class WriteObjectSampleStacktrace; 53 private: 54 SamplePriorityQueue* _priority_queue; 55 SampleList* _list; 56 JfrTicks _last_sweep; 57 size_t _total_allocated; 58 size_t _threshold; 59 size_t _size; 60 bool _dead_samples; 61 62 // Lifecycle 63 explicit ObjectSampler(size_t size); 64 ~ObjectSampler(); 65 static bool create(size_t size); 66 static bool is_created(); 67 static ObjectSampler* sampler(); 68 static void destroy(); 69 70 // For operations that require exclusive access (non-safepoint) 71 static ObjectSampler* acquire(); 72 static void release(); 73 74 // Stacktrace 75 static void fill_stacktrace(JfrStackTrace* stacktrace, JavaThread* thread); 76 traceid stacktrace_id(const JfrStackTrace* stacktrace, JavaThread* thread); 77 78 // Sampling 79 static void sample(HeapWord* object, size_t size, JavaThread* thread); 80 void add(HeapWord* object, size_t size, traceid thread_id, JfrStackTrace* stacktrace, JavaThread* thread); 81 void scavenge(); 82 void remove_dead(ObjectSample* sample); 83 84 // Called by GC 85 static void oops_do(BoolObjectClosure* is_alive, OopClosure* f); 86 87 const ObjectSample* item_at(int index) const; 88 ObjectSample* item_at(int index); 89 int item_count() const; 90 const ObjectSample* first() const; 91 const ObjectSample* last() const; 92 const ObjectSample* last_resolved() const; 93 void set_last_resolved(const ObjectSample* sample); 94 const JfrTicks& last_sweep() const; 95 }; 96 97 #endif // SHARE_VM_LEAKPROFILER_SAMPLING_OBJECTSAMPLER_HPP