diff --git a/src/cas/generic/st/casDGIntfOS.cc b/src/cas/generic/st/casDGIntfOS.cc
index 42b6aeaf6..deb286ac1 100644
--- a/src/cas/generic/st/casDGIntfOS.cc
+++ b/src/cas/generic/st/casDGIntfOS.cc
@@ -63,45 +63,15 @@ private:
     void callBack ();
 };
 
-//
-// class casDGEvWakeup
-//
-class casDGEvWakeup : public epicsTimerNotify {
-public:
-	casDGEvWakeup ( casDGIntfOS &osIn );
-	virtual ~casDGEvWakeup();
-	void show ( unsigned level ) const;
-private:
-    epicsTimer &timer;
-	casDGIntfOS	&os;
-	expireStatus expire( const epicsTime & currentTime );
-};
-
-//
-// class casDGIOWakeup
-//
-class casDGIOWakeup : public epicsTimerNotify {
-public:
-	casDGIOWakeup ( casDGIntfOS &osIn );
-	virtual ~casDGIOWakeup ();
-	void show ( unsigned level ) const;
-private:
-    epicsTimer &timer;
-	casDGIntfOS	&os;
-	expireStatus expire( const epicsTime & currentTime );
-};
-
 //
 // casDGIntfOS::casDGIntfOS()
 //
 casDGIntfOS::casDGIntfOS (caServerI &serverIn, const caNetAddr &addr, 
-    bool autoBeaconAddr, bool addConfigBeaconAddr) : 
+        bool autoBeaconAddr, bool addConfigBeaconAddr) : 
 	casDGIntfIO (serverIn, addr, autoBeaconAddr, addConfigBeaconAddr),
-	pRdReg (NULL),
-    pBCastRdReg (NULL),
-    pWtReg (NULL),
-    pEvWk (NULL),
-    pIOWk (NULL),
+	pRdReg ( 0 ),
+    pBCastRdReg ( 0 ),
+    pWtReg ( 0 ),
     sendBlocked (false)
 {
 	this->xSetNonBlocking();
@@ -114,25 +84,15 @@ casDGIntfOS::casDGIntfOS (caServerI &serverIn, const caNetAddr &addr,
 casDGIntfOS::~casDGIntfOS()
 {
 	this->disarmSend();
-
 	this->disarmRecv();
-
-	if (this->pEvWk) {
-		delete this->pEvWk;
-	}
-
-	if (this->pIOWk) {
-		delete this->pIOWk;
-	}
 }
 
 //
 // casDGEvWakeup::casDGEvWakeup()
 //
-casDGEvWakeup::casDGEvWakeup ( casDGIntfOS &osIn ) : 
-		timer ( fileDescriptorManager.createTimer() ), os ( osIn ) 
+casDGEvWakeup::casDGEvWakeup () : 
+		timer ( fileDescriptorManager.createTimer() ), pOS ( 0 ) 
 {
-    this->timer.start ( *this, 0.0 );
 }
 
 //
@@ -140,10 +100,20 @@ casDGEvWakeup::casDGEvWakeup ( casDGIntfOS &osIn ) :
 //
 casDGEvWakeup::~casDGEvWakeup()
 {
-	this->os.pEvWk = NULL;
     delete & this->timer;
 }
 
+void casDGEvWakeup::start ( casDGIntfOS &os )
+{
+    if ( this->pOS ) {
+        assert ( this->pOS == &os );
+    }
+    else {
+        this->pOS = &os;
+        this->timer.start ( *this, 0.0 );
+    }
+}
+
 //
 // casDGEvWakeup::show()
 //
@@ -158,19 +128,19 @@ void casDGEvWakeup::show ( unsigned level ) const
 //
 // casDGEvWakeup::expire()
 //
-epicsTimerNotify::expireStatus casDGEvWakeup::expire( const epicsTime & currentTime )
+epicsTimerNotify::expireStatus casDGEvWakeup::expire ( const epicsTime & currentTime )
 {
-	this->os.casEventSys::process();
+	this->pOS->casEventSys::process();
+    this->pOS = 0;
     return noRestart;
 }
 
 //
 // casDGIOWakeup::casDGIOWakeup()
 //
-casDGIOWakeup::casDGIOWakeup ( casDGIntfOS &osIn ) : 
-	timer ( fileDescriptorManager.createTimer() ), os ( osIn ) 
+casDGIOWakeup::casDGIOWakeup () : 
+	timer ( fileDescriptorManager.createTimer() ), pOS ( 0 ) 
 {
-    this->timer.start ( *this, 0.0 );
 }
 
 //
@@ -178,7 +148,6 @@ casDGIOWakeup::casDGIOWakeup ( casDGIntfOS &osIn ) :
 //
 casDGIOWakeup::~casDGIOWakeup()
 {
-	this->os.pIOWk = NULL;
     delete & this->timer;
 }
 
@@ -200,10 +169,25 @@ epicsTimerNotify::expireStatus casDGIOWakeup::expire( const epicsTime & currentT
 	// the input buffer, and there eventually will
 	// be something to read from TCP this works
 	//
-	this->os.processInput ();
+	this->pOS->processInput ();
+    this->pOS = 0;
     return noRestart;
 }
 
+//
+// casDGIOWakeup::show()
+//
+void casDGIOWakeup::start ( casDGIntfOS &os ) 
+{
+    if ( this->pOS ) {
+        assert ( this->pOS == &os );
+    }
+    else {
+        this->pOS = &os;
+        this->timer.start ( *this, 0.0 );
+    }
+}
+
 //
 // casDGIOWakeup::show()
 //
@@ -284,14 +268,7 @@ void casDGIntfOS::disarmSend ()
 //
 void casDGIntfOS::ioBlockedSignal()
 {
-	if (!this->pIOWk) {
-		this->pIOWk = new casDGIOWakeup(*this);
-		if (!this->pIOWk) {
-			errMessage (S_cas_noMemory,
-				"casDGIntfOS::ioBlockedSignal()");
-            throw S_cas_noMemory;
-		}			
-	}
+    this->ioWk.start ( *this );
 }
 
 //
@@ -299,14 +276,7 @@ void casDGIntfOS::ioBlockedSignal()
 //
 void casDGIntfOS::eventSignal()
 {
-	if (!this->pEvWk) {
-		this->pEvWk = new casDGEvWakeup (*this);
-		if (!this->pEvWk) {
-			errMessage (S_cas_noMemory, 
-				"casDGIntfOS::eventSignal ()");
-            throw S_cas_noMemory;
-		}
-	}
+    this->evWk.start ( *this );
 }
 
 //
@@ -339,12 +309,8 @@ void casDGIntfOS::show(unsigned level) const
     if (this->pBCastRdReg) {
 		this->pBCastRdReg->show (level);
     }
-    if (this->pEvWk) {
-		this->pEvWk->show (level);
-    }
-    if (this->pIOWk) {
-		this->pIOWk->show (level);
-    }
+	this->evWk.show (level);
+	this->ioWk.show (level);
     this->casDGIntfIO::show (level);
 }
 
@@ -436,7 +402,7 @@ void casDGWriteReg::show(unsigned level) const
 //
 void casDGIntfOS::sendBlockSignal()
 {
-	this->sendBlocked=TRUE;
+	this->sendBlocked = true;
 	this->armSend();
 }
 
@@ -453,7 +419,7 @@ void casDGIntfOS::sendCB()
 	flushCond = this->flush();
 	if (flushCond==flushProgress) {
 		if (this->sendBlocked) {
-			this->sendBlocked = FALSE;
+			this->sendBlocked = false;
 		}
         //
         // this reenables receipt of incoming frames once
diff --git a/src/cas/generic/st/casOSD.h b/src/cas/generic/st/casOSD.h
index 381cca0aa..8ba707c22 100644
--- a/src/cas/generic/st/casOSD.h
+++ b/src/cas/generic/st/casOSD.h
@@ -41,8 +41,36 @@ private:
 class casDGReadReg;
 class casDGBCastReadReg;
 class casDGWriteReg;
-class casDGEvWakeup;
-class casDGIOWakeup;
+
+//
+// class casDGEvWakeup
+//
+class casDGEvWakeup : public epicsTimerNotify {
+public:
+	casDGEvWakeup ();
+	virtual ~casDGEvWakeup();
+	void show ( unsigned level ) const;
+    void start ( class casDGIntfOS &osIn );
+private:
+    epicsTimer &timer;
+	class casDGIntfOS *pOS;
+	expireStatus expire( const epicsTime & currentTime );
+};
+
+//
+// class casDGIOWakeup
+//
+class casDGIOWakeup : public epicsTimerNotify {
+public:
+	casDGIOWakeup ();
+	virtual ~casDGIOWakeup ();
+	void show ( unsigned level ) const;
+    void start ( class casDGIntfOS &osIn );
+private:
+    epicsTimer &timer;
+	class casDGIntfOS *pOS;
+	expireStatus expire( const epicsTime & currentTime );
+};
 
 //
 // casDGIntfOS
@@ -51,10 +79,7 @@ class casDGIntfOS : public casDGIntfIO {
     friend class casDGReadReg;
     friend class casDGBCastReadReg;
     friend class casDGWriteReg;
-    friend class casDGEvWakeup;
-    friend class casDGIOWakeup;
 public:
-
     casDGIntfOS (caServerI &serverIn, const caNetAddr &addr, 
         bool autoBeaconAddr=TRUE, bool addConfigBeaconAddr=FALSE);
 
@@ -62,13 +87,15 @@ public:
 
 	virtual void show (unsigned level) const;
 
+    void processInput();
+
 private:
+    casDGIOWakeup       ioWk;
+    casDGEvWakeup       evWk;
 	casDGReadReg        *pRdReg;
 	casDGBCastReadReg   *pBCastRdReg; // fix for solaris bug
 	casDGWriteReg       *pWtReg;
-	casDGEvWakeup       *pEvWk;
-	casDGIOWakeup       *pIOWk;
-	unsigned char		sendBlocked;
+	bool		        sendBlocked;
 
     void armRecv ();
     void armSend ();
@@ -86,7 +113,6 @@ private:
 	void eventSignal ();
 	void eventFlush ();
 
-    void processInput();
 };
 
 //
@@ -95,7 +121,6 @@ private:
 class casIntfOS : public casIntfIO, public tsDLNode<casIntfOS>, 
     public casDGIntfOS
 {
-	friend class casDGEvWakeup;
 	friend class casServerReg;
 public:
 	casIntfOS (caServerI &casIn, const caNetAddr &addr, 
@@ -113,8 +138,36 @@ private:
 
 class casStreamWriteReg;
 class casStreamReadReg;
-class casStreamEvWakeup;
-class casStreamIOWakeup;
+
+//
+// class casStreamIOWakeup
+//
+class casStreamIOWakeup : public epicsTimerNotify {
+public:
+	casStreamIOWakeup ();
+	virtual ~casStreamIOWakeup ();
+	void show ( unsigned level ) const;
+    void start ( casStreamOS &osIn );
+private:
+    epicsTimer &timer;
+	casStreamOS	*pOS;
+	expireStatus expire ( const epicsTime & currentTime );
+};
+
+//
+// class casStreamEvWakeup
+//
+class casStreamEvWakeup : public epicsTimerNotify {
+public:
+	casStreamEvWakeup ();
+	virtual ~casStreamEvWakeup ();
+	void show ( unsigned level ) const;
+    void start ( casStreamOS &osIn );
+private:
+    epicsTimer &timer;
+	casStreamOS	*pOS;
+	expireStatus expire ( const epicsTime & currentTime );
+};
 
 //
 // casStreamOS
@@ -122,19 +175,20 @@ class casStreamIOWakeup;
 class casStreamOS : public casStreamIO {
     friend class casStreamWriteReg;
     friend class casStreamReadReg;
-	friend class casStreamEvWakeup;
-	friend class casStreamIOWakeup;
 public:
 	casStreamOS (caServerI &, const ioArgsToNewStreamIO &ioArgs);
 	~casStreamOS ();
 
 	void show (unsigned level) const;
+
+	casProcCond processInput ();
+
 private:
+	casStreamEvWakeup	evWk;
+	casStreamIOWakeup	ioWk;
 	casStreamWriteReg	*pWtReg;
 	casStreamReadReg	*pRdReg;
-	casStreamEvWakeup	*pEvWk;
-	casStreamIOWakeup	*pIOWk;
-	unsigned char		sendBlocked;
+	bool		        sendBlocked;
 	//
 	//
 	//
@@ -143,11 +197,6 @@ private:
 	inline void disarmSend();
 	inline void disarmRecv();
 
-	//
-	// process any incomming messages
-	//
-	casProcCond processInput ();
-
 	void recvCB ();
 	void sendCB ();
 
diff --git a/src/cas/generic/st/casStreamOS.cc b/src/cas/generic/st/casStreamOS.cc
index 60bc57e58..47fa9d011 100644
--- a/src/cas/generic/st/casStreamOS.cc
+++ b/src/cas/generic/st/casStreamOS.cc
@@ -104,27 +104,12 @@ inline casStreamWriteReg::~casStreamWriteReg ()
 #	endif
 }
 
-//
-// class casStreamEvWakeup
-//
-class casStreamEvWakeup : public epicsTimerNotify {
-public:
-	casStreamEvWakeup(casStreamOS &osIn);
-	virtual ~casStreamEvWakeup ();
-	void show ( unsigned level ) const;
-private:
-    epicsTimer &timer;
-	casStreamOS	&os;
-	expireStatus expire ( const epicsTime & currentTime );
-};
-
 //
 // casStreamEvWakeup()
 //
-casStreamEvWakeup::casStreamEvWakeup ( casStreamOS &osIn ) : 
-		timer ( fileDescriptorManager.createTimer() ), os(osIn) 
+casStreamEvWakeup::casStreamEvWakeup () : 
+		timer ( fileDescriptorManager.createTimer() ), pOS ( 0 ) 
 {
-    this->timer.start ( *this, 0.0 );
 }
 
 //
@@ -132,7 +117,6 @@ casStreamEvWakeup::casStreamEvWakeup ( casStreamOS &osIn ) :
 //
 casStreamEvWakeup::~casStreamEvWakeup()
 {
-	this->os.pEvWk = NULL;
     delete & this->timer;
 }
 
@@ -152,9 +136,10 @@ void casStreamEvWakeup::show(unsigned level) const
 //
 epicsTimerNotify::expireStatus casStreamEvWakeup::expire( const epicsTime & currentTime )
 {
-	casProcCond cond;
-	cond = this->os.casEventSys::process();
-	if (cond != casProcOk) {
+    casStreamOS &os = *this->pOS;
+    this->pOS = 0;
+	casProcCond cond = os.casEventSys::process();
+	if ( cond != casProcOk ) {
 		//
 		// ok to delete the client here
 		// because casStreamEvWakeup::expire()
@@ -163,7 +148,7 @@ epicsTimerNotify::expireStatus casStreamEvWakeup::expire( const epicsTime & curr
 		// called from a client member function
 		// higher up on the stack
 		//
-		this->os.destroy();	
+		os.destroy();	
 
 		//
 		// must not touch the "this" pointer
@@ -174,26 +159,25 @@ epicsTimerNotify::expireStatus casStreamEvWakeup::expire( const epicsTime & curr
 }
 
 //
-// class casStreamIOWakeup
+// casStreamEvWakeup::start()
 //
-class casStreamIOWakeup : public epicsTimerNotify {
-public:
-	casStreamIOWakeup(casStreamOS &osIn);
-	virtual ~casStreamIOWakeup();
-	void show ( unsigned level ) const;
-private:
-    epicsTimer &timer;
-	casStreamOS	&os;
-	expireStatus expire ( const epicsTime & currentTime );
-};
+void casStreamEvWakeup::start( casStreamOS &os )
+{    
+    if ( this->pOS ) {
+        assert ( this->pOS == &os );
+    }
+    else {
+        this->pOS = &os;
+        this->timer.start ( *this, 0.0 );
+    }
+}
 
 //
 // casStreamIOWakeup::casStreamIOWakeup()
 //
-casStreamIOWakeup::casStreamIOWakeup ( casStreamOS &osIn ) : 
-	timer ( fileDescriptorManager.createTimer() ), os(osIn) 
+casStreamIOWakeup::casStreamIOWakeup () : 
+	timer ( fileDescriptorManager.createTimer() ), pOS ( 0 )
 {
-    this->timer.start ( *this, 0.0 );
 }
 
 //
@@ -201,7 +185,6 @@ casStreamIOWakeup::casStreamIOWakeup ( casStreamOS &osIn ) :
 //
 casStreamIOWakeup::~casStreamIOWakeup()
 {
-	this->os.pIOWk = NULL;
     delete & this->timer;
 }
 
@@ -216,22 +199,6 @@ void casStreamIOWakeup::show(unsigned level) const
 	printf ( "}\n" );
 }
 
-//
-// casStreamOS::armRecv ()
-//
-inline void casStreamOS::armRecv()
-{
-	if (!this->pRdReg) {
-		if (!this->inBuf::full()) {
-			this->pRdReg = new casStreamReadReg(*this);
-			if (!this->pRdReg) {
-				errMessage(S_cas_noMemory, "armRecv()");
-                throw S_cas_noMemory;
-			}
-		}
-	}
-}
-
 //
 // casStreamIOWakeup::expire()
 //
@@ -250,10 +217,41 @@ epicsTimerNotify::expireStatus casStreamIOWakeup::expire ( const epicsTime & cur
 	// the input buffer, and there eventually will
 	// be something to read from TCP this works
 	//
-	this->os.processInput();
+	this->pOS->processInput();
+    this->pOS = 0;
     return noRestart;
 }
 
+//
+// casStreamIOWakeup::start()
+//
+void casStreamIOWakeup::start ( casStreamOS &os  )
+{
+    if ( this->pOS ) {
+        assert ( this->pOS == &os );
+    }
+    else {
+        this->pOS = &os;
+        this->timer.start ( *this, 0.0 );
+    }
+}
+
+//
+// casStreamOS::armRecv ()
+//
+inline void casStreamOS::armRecv()
+{
+	if (!this->pRdReg) {
+		if (!this->inBuf::full()) {
+			this->pRdReg = new casStreamReadReg(*this);
+			if (!this->pRdReg) {
+				errMessage(S_cas_noMemory, "armRecv()");
+                throw S_cas_noMemory;
+			}
+		}
+	}
+}
+
 //
 // casStreamOS::disarmRecv()
 //
@@ -297,14 +295,7 @@ inline void casStreamOS::disarmSend ()
 //
 void casStreamOS::ioBlockedSignal()
 {
-	if (!this->pIOWk) {
-		this->pIOWk = new casStreamIOWakeup(*this);
-		if (!this->pIOWk) {
-			errMessage(S_cas_noMemory,
-				"casStreamOS::ioBlockedSignal()");
-            throw S_cas_noMemory;
-		}			
-	}
+    this->ioWk.start ( *this );
 }
 
 //
@@ -312,14 +303,7 @@ void casStreamOS::ioBlockedSignal()
 //
 void casStreamOS::eventSignal()
 {
-	if (!this->pEvWk) {
-		this->pEvWk = new casStreamEvWakeup(*this);
-		if (!this->pEvWk) {
-			errMessage(S_cas_noMemory, 
-				"casStreamOS::eventSignal()");
-            throw S_cas_noMemory;
-		}
-	}
+    this->evWk.start ( *this );
 }
 
 //
@@ -343,8 +327,6 @@ casStreamOS::casStreamOS(caServerI &cas, const ioArgsToNewStreamIO &ioArgs) :
 	casStreamIO (cas, ioArgs),
 	pWtReg (NULL),
 	pRdReg (NULL),
-	pEvWk (NULL),
-	pIOWk (NULL),
 	sendBlocked (FALSE)
 {
 	this->xSetNonBlocking();
@@ -363,14 +345,6 @@ casStreamOS::~casStreamOS()
 
 	this->disarmSend();
 	this->disarmRecv();
-
-	if (this->pEvWk) {
-		delete this->pEvWk;
-	}
-
-	if (this->pIOWk) {
-		delete this->pIOWk;
-	}
 }
 
 //
@@ -388,12 +362,8 @@ void casStreamOS::show(unsigned level) const
 	if (this->pRdReg) {
 		this->pRdReg->show(level);
 	}
-	if (this->pEvWk) {
-		this->pEvWk->show(level);
-	}
-	if (this->pIOWk) {
-		this->pIOWk->show(level);
-	}
+	this->evWk.show ( level );
+	this->ioWk.show ( level );
 }
 
 //