usleep
======

POSIX specification: http://www.opengroup.org/susv3xsh/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.

  * This function is missing on some platforms.  However, the replacement is designed to be lightweight, and may round to the nearest second; use select or nanosleep if better resolution is needed: IRIX 5.3, Solaris 2.4, older mingw, MSVC 9, BeOS.

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.