X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fstructure%2Fcommands.cxx;h=b2391e3ba7f1cff7986f8eacf5364e985739ee56;hb=7e7d877874fcd67cad0152bd1a2a073e0337235f;hp=2e2c59215494430a72498266e4617960d4f0bab9;hpb=d22640ef4e938b523bdc30cd83370977d30de856;p=simgear.git

diff --git a/simgear/structure/commands.cxx b/simgear/structure/commands.cxx
index 2e2c5921..b2391e3b 100644
--- a/simgear/structure/commands.cxx
+++ b/simgear/structure/commands.cxx
@@ -4,10 +4,20 @@
 //
 // $Id$
 
+#ifdef HAVE_CONFIG_H
+#  include <simgear_config.h>
+#endif
+
+#include <memory>
 #include <simgear/props/props_io.hxx>
 
+#include <OpenThreads/Mutex>
+#include <OpenThreads/ScopedLock>
+
 #include "commands.hxx"
 
+#include <simgear/math/SGMath.hxx>
+
 
 
 ////////////////////////////////////////////////////////////////////////
@@ -25,6 +35,23 @@ SGCommandMgr::~SGCommandMgr ()
   // no-op
 }
 
+OpenThreads::Mutex SGCommandMgr::_instanceMutex;
+
+SGCommandMgr*
+SGCommandMgr::instance()
+{
+  static std::auto_ptr<SGCommandMgr> mgr;
+  if (mgr.get())
+    return mgr.get();
+
+  OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_instanceMutex);
+  if (mgr.get())
+    return mgr.get();
+
+  mgr = std::auto_ptr<SGCommandMgr>(new SGCommandMgr);
+  return mgr.get();
+}
+
 void
 SGCommandMgr::addCommand (const string &name, command_t command)
 {