26 Mar
2007
26 Mar
'07
2:07 p.m.
Yuval Ronen wrote:
One overhead I can think of is the need to call CloseHandle after the WaitForSingleObject, which means another OS call (kernel?). This doesn't exist on pthreads where calling pthread_join is enough.
The overhead in this case is not measured in cycles or kernel transitions (remember that you called a blocking function because you have nothing better to do with the CPU). It's measured in kernel objects; these come from the nonpaged pool and are a (relatively) limited resource. Since (today) a cv under Windows is usually ~3 kernel objects, a mutex one more, adding a mutex+cv to every thread increases its kernel footprint five times.