Added TNL/Debugging directory

src/TNL/CMakeLists.txt

 ADD_SUBDIRECTORY( Config )
 ADD_SUBDIRECTORY( Containers )
+ADD_SUBDIRECTORY( Debugging )
 ADD_SUBDIRECTORY( Devices )
 ADD_SUBDIRECTORY( Experimental )
 ADD_SUBDIRECTORY( Functions )

src/TNL/Debugging/CMakeLists.txt

+SET( headers
+         MemoryUsage.h
+)
+   
+INSTALL( FILES ${headers} DESTINATION include/tnl-${tnlVersion}/TNL/Debugging )

src/TNL/Debugging/MemoryUsage.h

+/***************************************************************************
+                          MeshConfigBase.h  -  description
+                             -------------------
+    begin                : Nov 6, 2016
+    copyright            : (C) 2016 by Tomas Oberhuber et al.
+    email                : tomas.oberhuber@fjfi.cvut.cz
+ ***************************************************************************/
+
+/* See Copyright Notice in tnl/Copyright */
+
+#pragma once
+
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <limits>
+
+namespace TNL {
+namespace Debugging {
+
+/*
+ * Prints memory usage of the current process into the specified stream.
+ *
+ * The information is obtained from /proc/self/status, which is assumed to be
+ * present on the system. The meaning of the printed values is following:
+ *  
+ *  - VmSize: Virtual memory size.
+ *  - VmRSS: Resident set size.
+ *  - VmHWM: Peak resident set size ("high water mark").
+ *
+ * See the proc(5) manual on Linux for details.
+ */
+void printMemoryUsage( std::ostream& str = std::cerr )
+{
+   std::ifstream meminfo("/proc/self/status");
+   if( meminfo.fail() ) {
+      std::cerr << "error: unable to open /proc/self/status" << std::endl;
+      return;
+   }
+
+   unsigned vm = 0;
+   unsigned rss = 0;
+   unsigned hwm = 0;
+
+   std::string desc;
+   while( meminfo.good() ) {
+       // extract description (first column)
+       meminfo >> desc;
+
+       if( desc == "VmSize:" )
+           meminfo >> vm;
+       if( desc == "VmHWM:" )
+           meminfo >> hwm;
+       if( desc == "VmRSS:" )
+           meminfo >> rss;
+
+       // ignore the rest of irrelevant lines
+       meminfo.ignore( std::numeric_limits< std::streamsize >::max(), '\n' );
+   }
+
+   str << "Memory usage (MiB): "
+       << "VmSize = " << vm / 1024 << "MiB, "
+       << "VmRSS = " << rss / 1024 << "MiB, "
+       << "VmHWM = " << hwm / 1024 << "MiB, "
+       << std::endl;
+}
+
+} // namespace Debugging
+} // namespace TNL