text: //  MIT License
  //
  //  Copyright (c) 2020, The Regents of the University of California,
  //  through Lawrence Berkeley National Laboratory (subject to receipt of any
  //  required approvals from the U.S. Dept. of Energy).  All rights reserved.
  //
  //  Permission is hereby granted, free of charge, to any person obtaining a copy
  //  of this software and associated documentation files (the "Software"), to deal
  //  in the Software without restriction, including without limitation the rights
  //  to use, copy, modify, merge, publish, distribute, sublicense, and
  //  copies of the Software, and to permit persons to whom the Software is
  //  furnished to do so, subject to the following conditions:
  //
  //  The above copyright notice and this permission notice shall be included in all
  //  copies or substantial portions of the Software.
  //
  //  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  //  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  //  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  //  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  //  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  //  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  //  SOFTWARE.
  
  /**
   * \file timemory/components/gperftools/components.hpp
   * \brief Implementation of the gperftools component(s)
   */
  
  #pragma once
  
  #include "timemory/components/base.hpp"
  #include "timemory/components/gperftools/backends.hpp"
  #include "timemory/components/gperftools/types.hpp"
  #include "timemory/mpl/apply.hpp"
  #include "timemory/mpl/types.hpp"
  #include "timemory/settings/declaration.hpp"
  #include "timemory/units.hpp"
  
  //======================================================================================//
  //
  namespace tim
  {
  namespace component
  {
  //
  //--------------------------------------------------------------------------------------//
  // start/stop gperftools cpu profiler
  //
  struct gperftools_cpu_profiler : public base<gperftools_cpu_profiler, void>
  {
      using value_type = void;
      using this_type  = gperftools_cpu_profiler;
      using base_type  = base<this_type, value_type>;
  
      static std::string label() { return "gperftools_cpu_profiler"; }
      static std::string description()
      {
          return "Control switch for gperftools CPU profiler";
      }
      static value_type record() {}
  
      static void thread_init() { gperf::cpu::register_thread(); }
  
      static void global_finalize()
      {
          if(gperf::cpu::is_running())
          {
              gperf::cpu::profiler_flush();
              gperf::cpu::profiler_stop();
          }
      }
  
      void start()
      {
          if(!gperf::cpu::is_running())
          {
              index                 = this_type::get_index()++;
              const auto& _dmp_info = get_dmp_info();
              bool        _dmp_init = std::get<0>(_dmp_info);
              int32_t     _dmp_rank = std::get<1>(_dmp_info);
              auto        fname     = settings::compose_output_filename(
                  label() + "_" + std::to_string(index), ".dat", _dmp_init, _dmp_rank);
              auto ret = gperf::cpu::profiler_start(fname);
              if(ret == 0)
              {
                  fprintf(stderr, "[gperftools_cpu_profiler]> Error starting %s...",
                          fname.c_str());
              }
          }
      }
  
      void stop()
      {
          if(index >= 0)
          {
              gperf::cpu::profiler_flush();
              gperf::cpu::profiler_stop();
          }
      }
  
  private:
      int32_t index = -1;  // if this is >= zero, then we flush and stop
  
  private:
      static std::atomic<int64_t>& get_index()
      {
          static std::atomic<int64_t> _instance(0);
          return _instance;
      }
  
      using dmp_info_t = std::tuple<bool, int32_t, int32_t>;
  
      static const dmp_info_t& get_dmp_info()
      {
          static dmp_info_t _info{ dmp::is_initialized(), dmp::rank(), dmp::size() };
          return _info;
      }
  };
  //
  //--------------------------------------------------------------------------------------//
  // start/stop gperftools cpu profiler
  //
  struct gperftools_heap_profiler : public base<gperftools_heap_profiler, void>
  {
      using value_type = void;
      using this_type  = gperftools_heap_profiler;
      using base_type  = base<this_type, value_type>;
  
      static std::string label() { return "gperftools_heap_profiler"; }
      static std::string description()
      {
          return "Control switch for the gperftools heap profiler";
      }
      static value_type record() {}
  
      static void global_finalize()
      {
          if(gperf::heap::is_running())
          {
              gperf::heap::profiler_flush("global_finalize");
              gperf::heap::profiler_stop();
          }
      }
  
      void start()
      {
          if(!gperf::heap::is_running())
          {
              index      = this_type::get_index()++;
              auto fname = settings::compose_output_filename(label(), ".dat");
              auto ret   = gperf::heap::profiler_start(fname);
              if(ret > 0)
              {
                  fprintf(stderr, "[gperftools_heap_profiler]> Error starting %s...",
                          prefix.c_str());
              }
          }
      }
  
      void stop()
      {
          if(index >= 0)
          {
              gperf::heap::profiler_flush(prefix);
              gperf::heap::profiler_stop();
          }
      }
  
      void set_prefix(const std::string& _prefix) { prefix = _prefix; }
  
  protected:
      std::string prefix;
      int32_t     index = -1;  // if this is >= zero, then we flush and stop
  
  private:
      static std::atomic<int64_t>& get_index()
      {
          static std::atomic<int64_t> _instance(0);
          return _instance;
      }
  };
  //
  }  // namespace component
  }  // namespace tim
  //
  //======================================================================================//
  