--- a/Framework/Semaphore.cpp	Tue Jul 17 09:55:24 2018 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,50 +0,0 @@
-/**
- * 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_++;
-  }
-}

--- a/Framework/Semaphore.h	Tue Jul 17 09:55:24 2018 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,61 +0,0 @@
-/**
- * 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/>.
- **/
-
-
-#pragma once
-
-#include <boost/noncopyable.hpp>
-#include <boost/thread.hpp>
-
-namespace OrthancWSI
-{
-  class Semaphore : public boost::noncopyable
-  {
-  private:
-    unsigned int count_;
-    boost::mutex mutex_;
-    boost::condition_variable condition_;
-
-  public:
-    explicit Semaphore(unsigned int count);
-
-    void Release();
-
-    void Acquire();
-
-    class Locker : public boost::noncopyable
-    {
-    private:
-      Semaphore&  that_;
-
-    public:
-      explicit Locker(Semaphore& that) :
-        that_(that)
-      {
-        that_.Acquire();
-      }
-
-      ~Locker()
-      {
-        that_.Release();
-      }
-    };
-  };
-}

--- a/ViewerPlugin/CMakeLists.txt	Tue Jul 17 09:55:24 2018 +0200
+++ b/ViewerPlugin/CMakeLists.txt	Fri Jul 27 14:06:26 2018 +0200
@@ -154,7 +154,6 @@
   ${ORTHANC_WSI_DIR}/Framework/Inputs/PyramidWithRawTiles.cpp
   ${ORTHANC_WSI_DIR}/Framework/Jpeg2000Reader.cpp
   ${ORTHANC_WSI_DIR}/Framework/Jpeg2000Writer.cpp
-  ${ORTHANC_WSI_DIR}/Framework/Semaphore.cpp
 
   ${ORTHANC_ROOT}/Plugins/Samples/Common/DicomDatasetReader.cpp
   ${ORTHANC_ROOT}/Plugins/Samples/Common/DicomPath.cpp

--- a/ViewerPlugin/Plugin.cpp	Tue Jul 17 09:55:24 2018 +0200
+++ b/ViewerPlugin/Plugin.cpp	Fri Jul 27 14:06:26 2018 +0200
@@ -23,11 +23,12 @@
 
 #include "DicomPyramidCache.h"
 #include "../Framework/Jpeg2000Reader.h"
-#include "../Framework/Semaphore.h"
 
 #include <Core/Images/ImageProcessing.h>
 #include <Core/Images/PngWriter.h>
+#include <Core/MultiThreading/Semaphore.h>
 #include <Core/OrthancException.h>
+#include <Core/SystemToolbox.h>
 #include <Plugins/Samples/Common/OrthancPluginCppWrapper.h>
 #include <Plugins/Samples/Common/OrthancPluginConnection.h>
 
@@ -39,7 +40,7 @@
 
 std::auto_ptr<OrthancPlugins::OrthancPluginConnection>  orthanc_;
 std::auto_ptr<OrthancWSI::DicomPyramidCache>            cache_;
-std::auto_ptr<OrthancWSI::Semaphore>                    transcoderSemaphore_;
+std::auto_ptr<Orthanc::Semaphore>                       transcoderSemaphore_;
 
 
 static void AnswerSparseTile(OrthancPluginRestOutput* output,
@@ -183,7 +184,7 @@
   // decompress the raw tile
   std::auto_ptr<Orthanc::ImageAccessor> decoded;
 
-  OrthancWSI::Semaphore::Locker locker(*transcoderSemaphore_);
+  Orthanc::Semaphore::Locker locker(*transcoderSemaphore_);
 
   switch (compression)
   {
@@ -312,14 +313,8 @@
     // Limit the number of PNG transcoders to the number of available
     // hardware threads (e.g. number of CPUs or cores or
     // hyperthreading units)
-    unsigned int threads = boost::thread::hardware_concurrency();
-    
-    if (threads <= 0)
-    {
-      threads = 1;
-    }
-    
-    transcoderSemaphore_.reset(new OrthancWSI::Semaphore(threads));
+    unsigned int threads = Orthanc::SystemToolbox::GetHardwareConcurrency();
+    transcoderSemaphore_.reset(new Orthanc::Semaphore(threads));
 
     char info[1024];
     sprintf(info, "The whole-slide imaging plugin will use at most %u threads to transcode the tiles", threads);