--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancServer/Scheduler/ServerScheduler.cpp	Thu Jul 10 11:38:46 2014 +0200
@@ -0,0 +1,336 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2014 Medical Physics Department, CHU of Liege,
+ * 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 "ServerScheduler.h"
+
+#include "../../Core/OrthancException.h"
+
+#include <glog/logging.h>
+
+namespace Orthanc
+{
+  namespace
+  {
+    // Anonymous namespace to avoid clashes between compilation modules
+    class Sink : public IServerCommand
+    {
+    private:
+      ListOfStrings& target_;
+
+    public:
+      Sink(ListOfStrings& target) : target_(target)
+      {
+      }
+
+      virtual bool Apply(ListOfStrings& outputs,
+                         const ListOfStrings& inputs)
+      {
+        for (ListOfStrings::const_iterator 
+               it = inputs.begin(); it != inputs.end(); it++)
+        {
+          target_.push_back(*it);
+        }
+
+        return true;
+      }    
+    };
+  }
+
+
+  ServerScheduler::JobInfo& ServerScheduler::GetJobInfo(const std::string& jobId)
+  {
+    Jobs::iterator info = jobs_.find(jobId);
+
+    if (info == jobs_.end())
+    {
+      throw OrthancException(ErrorCode_InternalError);
+    }
+
+    return info->second;
+  }
+
+
+  void ServerScheduler::SignalSuccess(const std::string& jobId)
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    JobInfo& info = GetJobInfo(jobId);
+    info.success_++;
+
+    assert(info.failures_ == 0);
+
+    if (info.success_ >= info.size_)
+    {
+      if (info.watched_)
+      {
+        watchedJobStatus_[jobId] = JobStatus_Success;
+        watchedJobFinished_.notify_all();
+      }
+
+      LOG(INFO) << "Job successfully finished (" << info.description_ << ")";
+      jobs_.erase(jobId);
+
+      availableJob_.Release();
+    }
+  }
+
+
+  void ServerScheduler::SignalFailure(const std::string& jobId)
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    JobInfo& info = GetJobInfo(jobId);
+    info.failures_++;
+
+    if (info.success_ + info.failures_ >= info.size_)
+    {
+      if (info.watched_)
+      {
+        watchedJobStatus_[jobId] = JobStatus_Failure;
+        watchedJobFinished_.notify_all();
+      }
+
+      LOG(ERROR) << "Job has failed (" << info.description_ << ")";
+      jobs_.erase(jobId);
+
+      availableJob_.Release();
+    }
+  }
+
+
+  void ServerScheduler::Worker(ServerScheduler* that)
+  {
+    static const int32_t TIMEOUT = 100;
+
+    LOG(WARNING) << "The server scheduler has started";
+
+    while (!that->finish_)
+    {
+      std::auto_ptr<IDynamicObject> object(that->queue_.Dequeue(TIMEOUT));
+      if (object.get() != NULL)
+      {
+        ServerCommandInstance& filter = dynamic_cast<ServerCommandInstance&>(*object);
+
+        // Skip the execution of this filter if its parent job has
+        // previously failed.
+        bool jobHasFailed;
+        {
+          boost::mutex::scoped_lock lock(that->mutex_);
+          JobInfo& info = that->GetJobInfo(filter.GetJobId());
+          jobHasFailed = (info.failures_ > 0 || info.cancel_); 
+        }
+
+        if (jobHasFailed)
+        {
+          that->SignalFailure(filter.GetJobId());
+        }
+        else
+        {
+          filter.Execute(*that);
+        }
+      }
+    }
+  }
+
+
+  void ServerScheduler::SubmitInternal(ServerJob& job,
+                                       bool watched)
+  {
+    availableJob_.Acquire();
+
+    boost::mutex::scoped_lock lock(mutex_);
+
+    JobInfo info;
+    info.size_ = job.Submit(queue_, *this);
+    info.cancel_ = false;
+    info.success_ = 0;
+    info.failures_ = 0;
+    info.description_ = job.GetDescription();
+    info.watched_ = watched;
+
+    assert(info.size_ > 0);
+
+    if (watched)
+    {
+      watchedJobStatus_[job.GetId()] = JobStatus_Running;
+    }
+
+    jobs_[job.GetId()] = info;
+
+    LOG(INFO) << "New job submitted (" << job.description_ << ")";
+  }
+
+
+  ServerScheduler::ServerScheduler(unsigned int maxJobs) : availableJob_(maxJobs)
+  {
+    finish_ = false;
+    worker_ = boost::thread(Worker, this);
+  }
+
+
+  ServerScheduler::~ServerScheduler()
+  {
+    finish_ = true;
+    worker_.join();
+  }
+
+
+  void ServerScheduler::Submit(ServerJob& job)
+  {
+    if (job.filters_.empty())
+    {
+      return;
+    }
+
+    SubmitInternal(job, false);
+  }
+
+
+  bool ServerScheduler::SubmitAndWait(ListOfStrings& outputs,
+                                      ServerJob& job)
+  {
+    std::string jobId = job.GetId();
+
+    outputs.clear();
+
+    if (job.filters_.empty())
+    {
+      return true;
+    }
+
+    // Add a sink filter to collect all the results of the filters
+    // that have no next filter.
+    ServerCommandInstance& sink = job.AddCommand(new Sink(outputs));
+
+    for (std::list<ServerCommandInstance*>::iterator
+           it = job.filters_.begin(); it != job.filters_.end(); it++)
+    {
+      if ((*it) != &sink &&
+          (*it)->IsConnectedToSink())
+      {
+        (*it)->ConnectOutput(sink);
+      }
+    }
+
+    // Submit the job
+    SubmitInternal(job, true);
+
+    // Wait for the job to complete (either success or failure)
+    JobStatus status;
+
+    {
+      boost::mutex::scoped_lock lock(mutex_);
+
+      assert(watchedJobStatus_.find(jobId) != watchedJobStatus_.end());
+        
+      while (watchedJobStatus_[jobId] == JobStatus_Running)
+      {
+        watchedJobFinished_.wait(lock);
+      }
+
+      status = watchedJobStatus_[jobId];
+      watchedJobStatus_.erase(jobId);
+    }
+
+    return (status == JobStatus_Success);
+  }
+
+
+  bool ServerScheduler::SubmitAndWait(ServerJob& job)
+  {
+    ListOfStrings ignoredSink;
+    return SubmitAndWait(ignoredSink, job);
+  }
+
+
+  bool ServerScheduler::IsRunning(const std::string& jobId)
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+    return jobs_.find(jobId) != jobs_.end();
+  }
+
+
+  void ServerScheduler::Cancel(const std::string& jobId)
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    Jobs::iterator job = jobs_.find(jobId);
+
+    if (job != jobs_.end())
+    {
+      job->second.cancel_ = true;
+      LOG(WARNING) << "Canceling a job (" << job->second.description_ << ")";
+    }
+  }
+
+
+  float ServerScheduler::GetProgress(const std::string& jobId) 
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    Jobs::iterator job = jobs_.find(jobId);
+
+    if (job == jobs_.end() || 
+        job->second.size_ == 0  /* should never happen */)
+    {
+      // This job is not running
+      return 1;
+    }
+
+    if (job->second.failures_ != 0)
+    {
+      return 1;
+    }
+
+    if (job->second.size_ == 1)
+    {
+      return job->second.success_;
+    }
+
+    return (static_cast<float>(job->second.success_) / 
+            static_cast<float>(job->second.size_ - 1));
+  }
+
+
+  void ServerScheduler::GetListOfJobs(ListOfStrings& jobs)
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    jobs.clear();
+
+    for (Jobs::const_iterator 
+           it = jobs_.begin(); it != jobs_.end(); it++)
+    {
+      jobs.push_back(it->first);
+    }
+  }
+}