add example from appDevGuide

src/libCom/test/epicsTimerExample.cpp

@@ -0,0 +1,31 @@
+#include <stdio.h>
+
+#include "epicsTimer.h"
+
+class something : public epicsTimerNotify {
+public:
+    something(const char* nm,epicsTimerQueueActive &queue)
+    : name(nm), timer(queue.createTimer()) {}
+    virtual ~something() { timer.destroy();}
+    void start(double delay) {timer.start(*this,delay);}
+    virtual expireStatus expire(const epicsTime & currentTime) {
+        printf("%s\n",name);
+        currentTime.show(1);
+        return(noRestart);
+    }
+private:
+    const char* name;
+    epicsTimer &timer;
+};
+
+void epicsTimerExample()
+{
+    epicsTimerQueueActive &queue = epicsTimerQueueActive::allocate(true);
+    something first("first",queue);
+    something second("second",queue);
+
+    first.start(1.0);
+    second.start(1.5);
+    epicsThreadSleep(2.0);
+    queue.release();
+}