usleep
======

POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/usleep.html

Gnulib module: usleep

Portability problems fixed by Gnulib:

  * On some systems, usleep rejects attempts to sleep longer than 1 second, as allowed by POSIX: mingw.

Portability problems not fixed by Gnulib:

  * According to POSIX, the usleep function may interfere with the program's use of the SIGALRM signal.  On Linux, it doesn't; on other platforms, it may.