src/workloadmanager/WorkloadManager.cxx

   1 // Copyright (C) 2020-2021  CEA/DEN, EDF R&D
   2 //
   3 // This library is free software; you can redistribute it and/or
   4 // modify it under the terms of the GNU Lesser General Public
   5 // License as published by the Free Software Foundation; either
   6 // version 2.1 of the License, or (at your option) any later version.
   7 //
   8 // This library is distributed in the hope that it will be useful,
   9 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11 // Lesser General Public License for more details.
  12 //
  13 // You should have received a copy of the GNU Lesser General Public
  14 // License along with this library; if not, write to the Free Software
  15 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  16 //
  17 // See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
  18 //
  19 #include "WorkloadManager.hxx"
  20 #include "Task.hxx"
  21
  22 namespace WorkloadManager
  23 {
  24   WorkloadManager::WorkloadManager(WorkloadAlgorithm& algo)
  25   : _runningTasks()
  26   , _finishedTasks()
  27   , _nextIndex(0)
  28   , _data_mutex()
  29   , _startCondition()
  30   , _endCondition()
  31   , _stop(true)
  32   , _otherThreads()
  33   , _algo(algo)
  34   {
  35   }
  36
  37   WorkloadManager::~WorkloadManager()
  38   {
  39     stop();
  40   }
  41
  42   void WorkloadManager::addResource(const Resource& r)
  43   {
  44     std::unique_lock<std::mutex> lock(_data_mutex);
  45     _algo.addResource(r);
  46     _startCondition.notify_one();
  47   }
  48
  49   void WorkloadManager::freezeResources()
  50   {
  51     std::unique_lock<std::mutex> lock(_data_mutex);
  52     _algo.freezeResources();
  53     _startCondition.notify_one();
  54   }
  55
  56   void WorkloadManager::addTask(Task* t)
  57   {
  58     std::unique_lock<std::mutex> lock(_data_mutex);
  59     _algo.addTask(t);
  60     _startCondition.notify_one();
  61   }
  62
  63   void WorkloadManager::start()
  64   {
  65     {
  66       std::unique_lock<std::mutex> lock(_data_mutex);
  67       if(!_stop)
  68         return; // already started
  69       _stop = false;
  70     }
  71     _otherThreads.emplace_back(std::async(std::launch::async, [this]
  72       {
  73         runTasks();
  74       }));
  75     _otherThreads.emplace_back(std::async(std::launch::async, [this]
  76       {
  77         endTasks();
  78       }));
  79   }
  80
  81   void WorkloadManager::stop()
  82   {
  83     {
  84       std::unique_lock<std::mutex> lock(_data_mutex);
  85       _stop = true;
  86       _algo.freezeResources();
  87     }
  88     _startCondition.notify_one();
  89     _endCondition.notify_one();
  90    for(std::future<void>& th : _otherThreads)
  91      th.wait();
  92   }
  93
  94   void WorkloadManager::runTasks()
  95   {
  96     bool threadStop = false;
  97     while(!threadStop)
  98     {
  99       std::unique_lock<std::mutex> lock(_data_mutex);
 100       _startCondition.wait(lock, [this] {return !_algo.empty() || _stop;});
 101       RunningInfo taskInfo;
 102       while(chooseTaskToRun(taskInfo))
 103       {
 104         _runningTasks.emplace(taskInfo.id, std::async(std::launch::async, [this, taskInfo]
 105           {
 106             runOneTask(taskInfo);
 107           }));
 108       }
 109       threadStop = _stop && _algo.empty();
 110     }
 111   }
 112
 113   void WorkloadManager::runOneTask(const RunningInfo& taskInfo)
 114   {
 115     taskInfo.info.task->run(taskInfo.info.worker);
 116
 117     {
 118       std::unique_lock<std::mutex> lock(_data_mutex);
 119       _finishedTasks.push(taskInfo);
 120       _endCondition.notify_one();
 121     }
 122   }
 123
 124   void WorkloadManager::endTasks()
 125   {
 126     bool threadStop = false;
 127     while(!threadStop)
 128     {
 129       std::unique_lock<std::mutex> lock(_data_mutex);
 130       _endCondition.wait(lock, [this]
 131                             {
 132                               return !_finishedTasks.empty() ||
 133                               (_stop && _runningTasks.empty() && _algo.empty());
 134                             });
 135       while(!_finishedTasks.empty())
 136       {
 137         RunningInfo taskInfo = _finishedTasks.front();
 138         _finishedTasks.pop();
 139         _runningTasks[taskInfo.id].wait();
 140         _runningTasks.erase(taskInfo.id);
 141         _algo.liberate(taskInfo.info);
 142       }
 143       threadStop = _stop && _runningTasks.empty() && _algo.empty();
 144       _startCondition.notify_one();
 145     }
 146   }
 147
 148   bool WorkloadManager::chooseTaskToRun(RunningInfo& taskInfo)
 149   {
 150     // We are already under the lock
 151     taskInfo.id = _nextIndex;
 152     taskInfo.info = _algo.chooseTask();
 153     if(taskInfo.info.taskFound)
 154       _nextIndex ++;
 155     return taskInfo.info.taskFound;
 156   }
 157
 158 }