--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/MultiThreading/Semaphore.cpp	Mon Oct 08 12:12:39 2018 +0200
@@ -0,0 +1,50 @@
+/**
+ * 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 Affero General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * 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
+ * Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "Semaphore.h"
+
+
+namespace OrthancWSI
+{
+  Semaphore::Semaphore(unsigned int count) : count_(count)
+  {
+  }
+
+  void Semaphore::Release()
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    count_++;
+    condition_.notify_one(); 
+  }
+
+  void Semaphore::Acquire()
+  {
+    boost::mutex::scoped_lock lock(mutex_);
+
+    while (count_ == 0)
+    {
+      condition_.wait(lock);
+    }
+
+    count_++;
+  }
+}