diff --git a/libretroshare/src/util/rsthreads.cc b/libretroshare/src/util/rsthreads.cc
index d3f87b34a..46021947d 100644
--- a/libretroshare/src/util/rsthreads.cc
+++ b/libretroshare/src/util/rsthreads.cc
@@ -68,11 +68,8 @@ void *RsThread::rsthread_init(void* p)
   thread -> runloop();
   return NULL;
 }
-RsThread::RsThread () : mMutex("RsThread")
+RsThread::RsThread() 
 {
-    sem_init(&mHasStoppedSemaphore,0,1) ;
-    sem_init(&mShouldStopSemaphore,0,0) ;
-
 #ifdef WINDOWS_SYS
     memset (&mTid, 0, sizeof(mTid));
 #else
@@ -82,8 +79,7 @@ RsThread::RsThread () : mMutex("RsThread")
 bool RsThread::isRunning()
 {
     // do we need a mutex for this ?
-    int sval =0;
-    sem_getvalue(&mHasStoppedSemaphore,&sval) ;
+    int sval = mHasStoppedSemaphore.value() ;
 
 #ifdef DEBUG_THREADS
     THREAD_DEBUG << "  isRunning(): returning " << !sval << std::endl;
@@ -93,12 +89,7 @@ bool RsThread::isRunning()
 
 bool RsThread::shouldStop()
 {
-        int sval =0;
-        sem_getvalue(&mShouldStopSemaphore,&sval) ;
-
-#ifdef DEBUG_THREADS
-        THREAD_DEBUG << "  shouldStop(): returning " << (sval > 0) << " (sval=" << sval << ") " << std::endl;
-#endif
+        int sval = mShouldStopSemaphore.value() ;
         return sval > 0;
 }
 
@@ -108,8 +99,7 @@ void RsTickingThread::shutdown()
     THREAD_DEBUG << "pqithreadstreamer::shutdown()" << std::endl;
 #endif
 
-    int sval =0;
-    sem_getvalue(&mHasStoppedSemaphore,&sval) ;
+    int sval = mHasStoppedSemaphore.value() ;
 
     if(sval > 0)
     {
@@ -127,7 +117,7 @@ void RsThread::ask_for_stop()
 #ifdef DEBUG_THREADS
     THREAD_DEBUG << "  calling stop" << std::endl;
 #endif
-    sem_post(&mShouldStopSemaphore) ;
+    mShouldStopSemaphore.post();
 }
 
 void RsTickingThread::fullstop()
@@ -137,7 +127,7 @@ void RsTickingThread::fullstop()
 #ifdef DEBUG_THREADS
     THREAD_DEBUG << "  waiting stop" << std::endl;
 #endif
-    sem_wait(&mHasStoppedSemaphore) ;
+    mHasStoppedSemaphore.wait();
 #ifdef DEBUG_THREADS
     THREAD_DEBUG << "  finished!" << std::endl;
 #endif
@@ -147,12 +137,11 @@ void RsThread::start()
     pthread_t tid;
     void  *data = (void *)this ;
 
-    RS_STACK_MUTEX(mMutex) ;
-
 #ifdef DEBUG_THREADS
     THREAD_DEBUG << "pqithreadstreamer::start() initing should_stop=0, has_stopped=1" << std::endl;
 #endif
-    sem_init(&mHasStoppedSemaphore,0,0) ;
+    mHasStoppedSemaphore.set(0) ;
+    mShouldStopSemaphore.set(0) ;
 
     int err ;
 
@@ -164,7 +153,7 @@ void RsThread::start()
     else
     {
         THREAD_DEBUG << "Fatal error: pthread_create could not create a thread. Error returned: " << err << " !!!!!!!" << std::endl;
-    sem_init(&mHasStoppedSemaphore,0,1) ;
+	mHasStoppedSemaphore.set(1) ;
     }
 }
 
@@ -175,13 +164,11 @@ RsTickingThread::RsTickingThread()
 #ifdef DEBUG_THREADS
     THREAD_DEBUG << "RsTickingThread::RsTickingThread()" << std::endl;
 #endif
-    sem_init(&mShouldStopSemaphore,0,0) ;
 }
 
 void RsSingleJobThread::runloop()
 {
-    sem_init(&mShouldStopSemaphore,0,0) ;
-
+    mShouldStopSemaphore.set(0) ;
     run() ;
 }
 
@@ -190,7 +177,7 @@ void RsTickingThread::runloop()
 #ifdef DEBUG_THREADS
     THREAD_DEBUG << "pqithreadstream::runloop()" << std::endl;
 #endif
-    sem_init(&mShouldStopSemaphore,0,0) ;
+    mShouldStopSemaphore.set(0) ;
 
     while(1)
     {
@@ -199,7 +186,7 @@ void RsTickingThread::runloop()
 #ifdef DEBUG_THREADS
             THREAD_DEBUG << "pqithreadstreamer::runloop(): asked to stop. setting hasStopped=1, and returning. Thread ends." << std::endl;
 #endif
-            sem_post(&mHasStoppedSemaphore) ;
+            mHasStoppedSemaphore.post();
             return ;
         }
 
diff --git a/libretroshare/src/util/rsthreads.h b/libretroshare/src/util/rsthreads.h
index ffce99891..19d48b66f 100644
--- a/libretroshare/src/util/rsthreads.h
+++ b/libretroshare/src/util/rsthreads.h
@@ -29,7 +29,9 @@
 #include <inttypes.h>
 #include <string>
 #include <iostream>
+#include <unistd.h>
 #include <semaphore.h>
+#include <util/rsmemory.h>
 
 /* RsIface Thread Wrappers */
 
@@ -168,6 +170,58 @@ class RsStackMutex
 //
 #define RS_STACK_MUTEX(m) RsStackMutex __local_retroshare_mutex(m,__PRETTY_FUNCTION__,__FILE__,__LINE__) 
 
+// This class handles a Mutex-based semaphore, that makes it cross plateform.
+class RsSemaphore
+{
+	class RsSemStruct
+	{
+	public:
+		RsSemStruct() : mtx("Semaphore mutex"), val(0) {}
+
+		RsMutex mtx ;
+		uint32_t val ;
+	};
+
+public:
+	RsSemaphore()
+	{
+		s = new RsSemStruct ;
+	}
+
+	~RsSemaphore()
+	{
+		delete s ;
+	}
+
+	void set(uint32_t i)
+	{
+		RS_STACK_MUTEX(s->mtx) ;
+		s->val = i ;
+	}
+
+	void post()
+	{
+		RS_STACK_MUTEX(s->mtx) ;
+		++(s->val) ;
+	}
+
+	uint32_t value()
+	{
+		RS_STACK_MUTEX(s->mtx) ;
+		return s->val ;
+	}
+
+	void wait()
+	{
+		while(value() == 0)
+			usleep(1000) ;
+
+		post() ;
+	}
+private:
+	RsSemStruct *s ;
+};
+
 class RsThread;
 
 /* to create a thread! */
@@ -198,11 +252,10 @@ class RsThread
 protected:
     virtual void runloop() =0; /* called once the thread is started. Should be overloaded by subclasses. */
 
-    sem_t mHasStoppedSemaphore;
-    sem_t mShouldStopSemaphore;
+    RsSemaphore mHasStoppedSemaphore;
+    RsSemaphore mShouldStopSemaphore;
 
     static void *rsthread_init(void*) ;
-    RsMutex   mMutex;
     pthread_t mTid;
 };