use rtl::Static where double-locked pattern used

sal/rtl/source/logfile.cxx

@@ -42,6 +42,7 @@
 #include <rtl/ustring.hxx>
 #include <rtl/ustrbuf.hxx>
 #include <rtl/alloc.h>
+#include <rtl/instance.hxx>
 #include "osl/thread.h"
 
 #include <algorithm>
@@ -90,19 +91,14 @@ LoggerGuard::~LoggerGuard()
 // g_buffer in init():
 LoggerGuard loggerGuard;
 
-Mutex & getLogMutex()
+namespace
 {
-    static Mutex *pMutex = 0;
-    if( !pMutex )
-    {
-        MutexGuard guard( Mutex::getGlobalMutex() );
-        if( ! pMutex )
-        {
-            static Mutex mutex;
-            pMutex = &mutex;
-        }
-    }
-    return *pMutex;
+    class theLogMutex : public rtl::Static<osl::Mutex, theLogMutex>{};
+}
+
+static Mutex & getLogMutex()
+{
+    return theLogMutex::get();
 }
 
 OUString getFileUrl( const OUString &name )

sal/rtl/source/unload.cxx

@@ -31,6 +31,7 @@
 #include <rtl/unload.h>
 #include <rtl/alloc.h>
 #include <rtl/ustring.hxx>
+#include <rtl/instance.hxx>
 #include <osl/mutex.hxx>
 #include <boost/unordered_map.hpp>
 #include "rtl/allocator.hxx"
@@ -109,19 +110,14 @@ static sal_Bool hasEnoughTimePassed( const TimeValue* unusedSince, const TimeVal
     return retval;
 }
 
-static osl::Mutex* getUnloadingMutex()
+namespace
 {
-    static osl::Mutex * g_pMutex= NULL;
-    if (!g_pMutex)
-    {
-        MutexGuard guard( osl::Mutex::getGlobalMutex() );
-        if (!g_pMutex)
-        {
-            static osl::Mutex g_aMutex;
-            g_pMutex= &g_aMutex;
-        }
-    }
-    return g_pMutex;
+    class theUnloadingMutex : public rtl::Static<osl::Mutex, theUnloadingMutex>{};
+}
+
+static osl::Mutex& getUnloadingMutex()
+{
+    return theUnloadingMutex::get();
 }
 
 extern "C" void rtl_moduleCount_acquire(rtl_ModuleCount * that )