Man Page alarm.3f




NAME

     alarm - execute a subroutine after a specified time


SYNOPSIS

     integer*4 function alarm (time, sbrtn)
     integer*4 time
     external sbrtn


USAGE

     integer*4 time /8/
     external sbrtn
     nseconds = alarm(time,sbrtn)


DESCRIPTION

     This routine arranges for  subroutine  sbrtn  to  be  called
     after  time seconds.  If time is 0, the alarm is turned off,
     and no routine is called.  The returned value  is  the  time
     remaining on the last alarm.


RESTRICTIONS

     A subroutine cannot pass its own name to alarm.

     The alarm routine generates  signals  that  could  interfere
     with any I/O. The called routine, sbrtn, must not do any I/O
     itself.

     Calling alarm() from a parallelized or  multi-threaded  pro-
     gram may have unpredictable results.


FILES

     libF77.a


SEE ALSO

     alarm(2), sleep(3F), signal(3F)