C/C++ code for calculating delta time. Output in seconds.

delta.cpp

timeval t1, t2;
double elapsedTime;

//start timer
gettimeofday(&t1, NULL);

//do stuff...

//stop timer
gettimeofday(&t2, NULL);

//compute
elapsedTime = (t2.tv_sec - t1.tv_sec) * 1000.0;
elapsedTime += (t2.tv_usec - t1.tv_usec) / 1000.0;

//convert to seconds
delta = elapsedTime /1000;