1 /*
   2  * Copyright (c) 2012, 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_JFR_PERIODIC_SAMPLING_JFRTHREADSAMPLER_HPP
  26 #define SHARE_VM_JFR_PERIODIC_SAMPLING_JFRTHREADSAMPLER_HPP
  27 
  28 #include "jfr/utilities/jfrAllocation.hpp"
  29 #include "runtime/thread.hpp"
  30 
  31 class Monitor;
  32 class JfrStackFrame;
  33 
  34 enum JfrSampleType {
  35   NO_SAMPLE = 0,
  36   JAVA_SAMPLE = 1,
  37   NATIVE_SAMPLE = 2
  38 };
  39 
  40 class JfrThreadSampler : public Thread {
  41   friend class JfrThreadSampling;
  42  private:
  43   JfrStackFrame* const _frames;
  44   JavaThread* _last_thread_java;
  45   JavaThread* _last_thread_native;
  46   size_t _interval_java;
  47   size_t _interval_native;
  48   int _cur_index;
  49   const u4 _max_frames;
  50   bool _should_terminate;
  51   static Monitor* _transition_block_lock;
  52 
  53   int find_index_of_JavaThread(JavaThread** t_list, uint length, JavaThread *target);
  54   JavaThread* next_thread(JavaThread** t_list, uint length, JavaThread* first_sampled, JavaThread* current);
  55   void task_stacktrace(JfrSampleType type, JavaThread** last_thread);
  56   JfrThreadSampler(size_t interval_java, size_t interval_native, u4 max_frames);
  57   ~JfrThreadSampler();
  58   void enroll();
  59   void disenroll();
  60   void set_java_interval(size_t interval) { _interval_java = interval; };
  61   void set_native_interval(size_t interval) { _interval_native = interval; };
  62   size_t get_java_interval() { return _interval_java; };
  63   size_t get_native_interval() { return _interval_native; };
  64 
  65  public:
  66   void run();
  67   static Monitor* transition_block() { return _transition_block_lock; }
  68   static void on_javathread_suspend(JavaThread* thread);
  69 };
  70 
  71 class JfrThreadSampling : public JfrCHeapObj {
  72   friend class JfrRecorder;
  73  private:
  74   JfrThreadSampler* _sampler;
  75   void start_sampler(size_t interval_java, size_t interval_native);
  76   void stop_sampler();
  77   void set_sampling_interval(bool java_interval, size_t period);
  78 
  79   JfrThreadSampling();
  80   ~JfrThreadSampling();
  81 
  82   static JfrThreadSampling& instance();
  83   static JfrThreadSampling* create();
  84   static void destroy();
  85 
  86  public:
  87   static void set_java_sample_interval(size_t period);
  88   static void set_native_sample_interval(size_t period);
  89 };
  90 
  91 #endif // SHARE_VM_JFR_PERIODIC_SAMPLING_JFRTHREADSAMPLER_HPP
  92