useconds          101 win32/time.c   PHPAPI int usleep(unsigned int useconds)
useconds          106 win32/time.c   	due.QuadPart = -(10 * (__int64)useconds);
useconds           53 win32/time.h   PHPAPI int usleep(unsigned int useconds);
useconds            3 win32/unistd.h PHPAPI int usleep(unsigned int useconds);