alarm(2)                                                    alarm(2)


       NAME
             alarm - set process alarm clock

       SYNOPSIS
             #include <unistd.h>
             unsigned alarm(unsigned sec);

       DESCRIPTION
             alarm instructs the alarm clock of the process to send the
             signal SIGALRM to the process after the number of real time
             seconds specified by sec have elapsed [see signal(2)].

             Alarm requests are not stacked; successive calls reset the
             alarm clock of the calling process.

             If sec is 0, any previously made alarm request is canceled.

             A newly created process has no pending alarm; they are not
             inherited.  Any pending alarm is preserved across calls to any
             of the exec family of routines.

          Return Values
             alarm returns the amount of time previously remaining in the
             alarm clock of the calling process.

       REFERENCES
             exec(2), fork(2), pause(2), signal(2)

       NOTICES
          Considerations for Threads Programming
             In multithreaded applications, the alarm signal is delivered
             to only the requesting thread, no other.

             A thread cannot respond to a signal until it is scheduled for
             execution. For multiplexed threads, there may be a time lag
             between delivery of the signal and the time it is scheduled to
             run.  For improved response, consider using bound threads.

          Considerations for Lightweight Processes
             Internally, alarms are maintained per LWP.  The Threads
             Library arranges for the signal to be delivered to the
             requesting thread, even if the thread has been picked up by
             another LWP between the time of request and the time of
             response.




                           Copyright 1994 Novell, Inc.               Page 1

      alarm(2)                                                    alarm(2)


            Only the pending alarm (if any) of the calling LWP is
            preserved across the exec(2) system call.














































                          Copyright 1994 Novell, Inc.               Page 2