usleep(3) was declared obsolete in POSIX.1-2001 and removed in POSIX.1-2008. nanosleep(2) was recommended to be used instead. `OS::delay_usec()` internally uses `nanosleep()`. This also uses large number separators for improved readability.
usleep(3) was declared obsolete in POSIX.1-2001 and removed in POSIX.1-2008. nanosleep(2) was recommended to be used instead. `OS::delay_usec()` internally uses `nanosleep()`. This also uses large number separators for improved readability.