bdhar bdhar - 1 month ago 21
C++ Question

Significance of Sleep(0)

I used to see

Sleep(0)
in some part of my code where some infinite/long
while
loops are available. I was informed that it would make the time-slice available for other waiting processes. Is this true? Is there any significance for
Sleep(0)
?

Answer

According to MSDN's documentation for Sleep:

A value of zero causes the thread to relinquish the remainder of its time slice to any other thread that is ready to run. If there are no other threads ready to run, the function returns immediately, and the thread continues execution.

The important thing to realize is that yes, this gives other threads a chance to run, but if there are none ready to run, then your thread continues -- leaving the CPU usage at 100% since something will always be running. If your while loop is just spinning while waiting for some condition, you might want to consider using a synchronization primitive like an event to sleep until the condition is satisfied or sleep for a small amount of time to prevent maxing out the CPU.