rev 52084 : 8211980: Remove ThreadHeapSampler enable/disable/enabled methods
Summary:
Reviewed-by:

   1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2018, Google and/or its affiliates. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 #ifndef RUNTIME_THREADHEAPSAMPLER_HPP
  27 #define RUNTIME_THREADHEAPSAMPLER_HPP
  28 
  29 #include "memory/allocation.hpp"
  30 
  31 class ThreadHeapSampler {
  32  private:
  33   // Statics for the fast log
  34   static const int FastLogNumBits = 10;
  35   static const int FastLogMask = (1 << FastLogNumBits) - 1;
  36 
  37   size_t _bytes_until_sample;
  38   // Cheap random number generator
  39   static uint64_t _rnd;
  40   static bool _log_table_initialized;
  41 
  42   static double _log_table[1<<FastLogNumBits];  // Constant
  43   static int _sampling_interval;
  44 
  45   void pick_next_geometric_sample();
  46   void pick_next_sample(size_t overflowed_bytes = 0);


  47 
  48   // Used for assertion mode to determine if there is a path to a TLAB slow path
  49   // without a collector present.
  50   size_t _collectors_present;
  51 
  52   static double fast_log2(const double& d);
  53   static bool init_log_table();
  54   uint64_t next_random(uint64_t rnd);
  55 
  56  public:
  57   ThreadHeapSampler() : _bytes_until_sample(0) {
  58     _rnd = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(this));
  59     if (_rnd == 0) {
  60       _rnd = 1;
  61     }
  62 
  63     _collectors_present = 0;
  64   }
  65 
  66   size_t bytes_until_sample()                    { return _bytes_until_sample;   }
  67   void set_bytes_until_sample(size_t bytes)      { _bytes_until_sample = bytes;  }
  68 
  69   void check_for_sampling(oop obj, size_t size_in_bytes, size_t bytes_allocated_before);




  70 
  71   static void set_sampling_interval(int sampling_interval);
  72   static int get_sampling_interval();
  73 };
  74 
  75 #endif // SHARE_RUNTIME_THREADHEAPSAMPLER_HPP
--- EOF ---