added event thread executor timeFunction showConstructDestruct timeStamp

pvDataApp/misc/timeFunction.cpp

@@ -0,0 +1,49 @@
+/* timeFunction.cpp */
+#include "noDefaultMethods.h"
+#include "pvType.h"
+#include "timeStamp.h"
+
+namespace epics { namespace pvData { 
+
+class TimeFunctionRequester {
+public:
+    virtual void function() = 0;
+};
+
+class TimeFunction : private NoDefaultMethods {
+public:
+    TimeFunction(TimeFunctionRequester *requester);
+    ~TimeFunction();
+    double timeCall();
+private:
+    TimeFunctionRequester *requester;
+};
+  
+TimeFunction::TimeFunction(TimeFunctionRequester *requester)
+: requester(requester) {}
+
+
+TimeFunction::~TimeFunction() {}
+
+double TimeFunction::timeCall()
+{
+    TimeStamp startTime(0,0);
+    TimeStamp endTime(0,0);
+    double perCall = 0.0;
+    long ntimes = 1;
+    while(true) {
+        startTime.getCurrent();
+        for(long i=0; i<ntimes; i++) requester->function();
+        endTime.getCurrent();
+        double diff = TimeStamp::diffInSeconds(&endTime,&startTime);
+        if(diff>=1.0) {
+            perCall = diff/(double)ntimes;
+            break;
+        }
+        ntimes *= 2;
+    }
+    return perCall;
+
+}
+
+}}