--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Core/JobsEngine/JobsEngine.cpp	Mon May 07 15:37:20 2018 +0200
@@ -0,0 +1,267 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2018 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * In addition, as a special exception, the copyright holders of this
+ * program give permission to link the code of its release with the
+ * OpenSSL project's "OpenSSL" library (or with modified versions of it
+ * that use the same license as the "OpenSSL" library), and distribute
+ * the linked executables. You must obey the GNU General Public License
+ * in all respects for all of the code used other than "OpenSSL". If you
+ * modify file(s) with this exception, you may extend this exception to
+ * your version of the file(s), but you are not obligated to do so. If
+ * you do not wish to do so, delete this exception statement from your
+ * version. If you delete this exception statement from all source files
+ * in the program, then also delete it here.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "../PrecompiledHeaders.h"
+#include "JobsEngine.h"
+
+#include "JobStepRetry.h"
+
+#include "../Logging.h"
+#include "../OrthancException.h"
+
+namespace Orthanc
+{
+  bool JobsEngine::ExecuteStep(JobsRegistry::RunningJob& running,
+                               size_t workerIndex)
+  {
+    assert(running.IsValid());
+
+    LOG(INFO) << "Executing job with priority " << running.GetPriority()
+              << " in worker thread " << workerIndex << ": " << running.GetId();
+
+    if (running.IsPauseScheduled())
+    {
+      running.GetJob().ReleaseResources();
+      running.MarkPause();
+      return false;
+    }
+
+    std::auto_ptr<JobStepResult> result;
+
+    {
+      try
+      {
+        result.reset(running.GetJob().ExecuteStep());
+
+        if (result->GetCode() == JobStepCode_Failure)
+        {
+          running.UpdateStatus(ErrorCode_InternalError);
+        }
+        else
+        {
+          running.UpdateStatus(ErrorCode_Success);
+        }
+      }
+      catch (OrthancException& e)
+      {
+        running.UpdateStatus(e.GetErrorCode());
+      }
+      catch (boost::bad_lexical_cast&)
+      {
+        running.UpdateStatus(ErrorCode_BadFileFormat);
+      }
+      catch (...)
+      {
+        running.UpdateStatus(ErrorCode_InternalError);
+      }
+
+      if (result.get() == NULL)
+      {
+        result.reset(new JobStepResult(JobStepCode_Failure));
+      }
+    }
+
+    switch (result->GetCode())
+    {
+      case JobStepCode_Success:
+        running.MarkSuccess();
+        return false;
+
+      case JobStepCode_Failure:
+        running.MarkFailure();
+        return false;
+
+      case JobStepCode_Retry:
+        running.MarkRetry(dynamic_cast<JobStepRetry&>(*result).GetTimeout());
+        return false;
+
+      case JobStepCode_Continue:
+        return true;
+            
+      default:
+        throw OrthancException(ErrorCode_InternalError);
+    }
+  }
+
+    
+  void JobsEngine::RetryHandler(JobsEngine* engine)
+  {
+    assert(engine != NULL);
+
+    for (;;)
+    {
+      boost::this_thread::sleep(boost::posix_time::milliseconds(200));
+
+      {
+        boost::mutex::scoped_lock lock(engine->stateMutex_);
+
+        if (engine->state_ != State_Running)
+        {
+          return;
+        }
+      }
+
+      engine->GetRegistry().ScheduleRetries();
+    }
+  }
+
+    
+  void JobsEngine::Worker(JobsEngine* engine,
+                          size_t workerIndex)
+  {
+    assert(engine != NULL);
+
+    LOG(INFO) << "Worker thread " << workerIndex << " has started";
+
+    for (;;)
+    {
+      {
+        boost::mutex::scoped_lock lock(engine->stateMutex_);
+
+        if (engine->state_ != State_Running)
+        {
+          return;
+        }
+      }
+
+      JobsRegistry::RunningJob running(engine->GetRegistry(), 100);
+
+      if (running.IsValid())
+      {
+        for (;;)
+        {
+          if (!engine->ExecuteStep(running, workerIndex))
+          {
+            break;
+          }
+        }
+      }
+    }      
+  }
+
+
+  JobsEngine::JobsEngine() :
+    state_(State_Setup),
+    workers_(1)
+  {
+  }
+
+    
+  JobsEngine::~JobsEngine()
+  {
+    if (state_ != State_Setup &&
+        state_ != State_Done)
+    {
+      LOG(ERROR) << "INTERNAL ERROR: JobsEngine::Stop() should be invoked manually to avoid mess in the destruction order!";
+      Stop();
+    }
+  }
+
+    
+  void JobsEngine::SetWorkersCount(size_t count)
+  {
+    if (count == 0)
+    {
+      throw OrthancException(ErrorCode_ParameterOutOfRange);
+    }
+      
+    boost::mutex::scoped_lock lock(stateMutex_);
+      
+    if (state_ != State_Setup)
+    {
+      // Can only be invoked before calling "Start()"
+      throw OrthancException(ErrorCode_BadSequenceOfCalls);
+    }
+
+    workers_.resize(count);
+  }
+    
+
+  void JobsEngine::Start()
+  {
+    boost::mutex::scoped_lock lock(stateMutex_);
+
+    if (state_ != State_Setup)
+    {
+      throw OrthancException(ErrorCode_BadSequenceOfCalls);
+    }
+
+    retryHandler_ = boost::thread(RetryHandler, this);
+
+    for (size_t i = 0; i < workers_.size(); i++)
+    {
+      workers_[i] = boost::thread(Worker, this, i);
+    }
+
+    state_ = State_Running;
+
+    LOG(WARNING) << "The jobs engine has started";
+  }
+
+
+  void JobsEngine::Stop()
+  {
+    {
+      boost::mutex::scoped_lock lock(stateMutex_);
+
+      if (state_ != State_Running)
+      {
+        return;
+      }
+        
+      state_ = State_Stopping;
+    }
+
+    LOG(INFO) << "Stopping the jobs engine";
+      
+    if (retryHandler_.joinable())
+    {
+      retryHandler_.join();
+    }
+      
+    for (size_t i = 0; i < workers_.size(); i++)
+    {
+      if (workers_[i].joinable())
+      {
+        workers_[i].join();
+      }
+    }
+      
+    {
+      boost::mutex::scoped_lock lock(stateMutex_);
+      state_ = State_Done;
+    }
+
+    LOG(WARNING) << "The jobs engine has stopped";
+  }
+}