alarm
=====

POSIX specification:
 https://pubs.opengroup.org/onlinepubs/9699919799/functions/alarm.html

Gnulib module: ---

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  * This function has no impact if <code>SIGALRM</code> is inherited as ignored; programs should use <code>signal (SIGALRM, SIG_DFL)</code> if it is important to ensure the alarm will fire.

  * Use of this function in multi-threaded applications is not advised.

  * This function is missing on some platforms: mingw (2011), MSVC 14.

  * This function is conditionally declared in the non-standard <io.h> header on some platforms: mingw (2012 or newer).