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 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   JfrTicks _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 JfrTicks& last_sweep() const;

    76 };

    77 

    78 #endif // SHARE_VM_LEAKPROFILER_SAMPLING_OBJECTSAMPLER_HPP