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 #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/jfrTraceTime.hpp"
  30 
  31 class BoolObjectClosure;
  32 class OopClosure;
  33 class ObjectSample;
  34 class ObjectSampler;
  35 class SampleList;
  36 class SamplePriorityQueue;
  37 class Thread;
  38 
  39 // Class reponsible for holding samples and
  40 // making sure the samples are evenly distributed as
  41 // new entries are added and removed.
  42 class ObjectSampler : public CHeapObj<mtTracing> {
  43   friend class LeakProfiler;
  44   friend class ObjectSampleCheckpoint;
  45   friend class StartOperation;
  46   friend class StopOperation;
  47   friend class EmitEventOperation;
  48  private:
  49   SamplePriorityQueue* _priority_queue;
  50   SampleList* _list;
  51   JfrTraceTime _last_sweep;
  52   size_t _total_allocated;
  53   size_t _threshold;
  54   size_t _size;
  55   volatile int _tryLock;
  56   bool _dead_samples;
  57 
  58   explicit ObjectSampler(size_t size);
  59   ~ObjectSampler();
  60 
  61   void add(HeapWord* object, size_t size, JavaThread* thread);
  62   void remove_dead(ObjectSample* sample);
  63   void scavenge();
  64 
  65   // Called by GC
  66   void oops_do(BoolObjectClosure* is_alive, OopClosure* f);
  67 
  68  public:
  69   const ObjectSample* item_at(int index) const;
  70   ObjectSample* item_at(int index);
  71   int item_count() const;
  72   const ObjectSample* last() const;
  73   const ObjectSample* last_resolved() const;
  74   void set_last_resolved(const ObjectSample* sample);
  75   const JfrTraceTime& last_sweep() const;
  76 };
  77 
  78 #endif // SHARE_VM_LEAKPROFILER_SAMPLING_OBJECTSAMPLER_HPP