Question

On Windows I have a problem I never encountered on Unix. That is how to get a thread to sleep for less than one millisecond. On Unix you typically have a number of choices (sleep, usleep and nanosleep) to fit your needs. On Windows, however, there is only Sleep with millisecond granularity.

On Unix, I can use the use the select system call to create a microsecond sleep which is pretty straightforward:

int usleep(long usec) {     struct timeval tv;     tv.tv_sec = usec/1000000L;     tv.tv_usec = usec%1000000L;     return select(0, 0, 0, 0, &tv); } 

How can I achieve the same on Windows?

Answer 1

On Windows the use of select forces you to include the Winsock library which has to be initialized like this in your application:

WORD wVersionRequested = MAKEWORD(1,0); WSADATA wsaData; WSAStartup(wVersionRequested, &wsaData); 

And then the select won’t allow you to be called without any socket so you have to do a little more to create a microsleep method:

int usleep(long usec) {     struct timeval tv;     fd_set dummy;     SOCKET s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);     FD_ZERO(&dummy);     FD_SET(s, &dummy);     tv.tv_sec = usec/1000000L;     tv.tv_usec = usec%1000000L;     return select(0, 0, 0, &dummy, &tv); } 

All these created usleep methods return zero when successful and non-zero for errors.