sigsuspend(2)                                                 sigsuspend(2)




 NAME    [Toc]    [Back]
      sigsuspend - wait for a signal

 SYNOPSIS    [Toc]    [Back]
      #include <signal.h>

      int sigsuspend(const sigset_t *sigmask);

 DESCRIPTION    [Toc]    [Back]
      The sigsuspend() function replaces the current signal mask of the
      calling thread with the set of signals pointed to by sigmask and then
      suspends the thread until delivery of a signal whose action is either
      to execute a signal-catching function or to terminate the process.
      This will not cause any other signals that may have been pending on
      the process to become pending on the thread.

      If the action is to terminate the process then sigsuspend() will never
      return. If the action is to execute  a  signal-catching function, then
      sigsuspend() will  return after the signal-catching function returns,
      with the signal mask restored to the set that existed prior to the
      sigsuspend() call.

      It is not possible to block signals that cannot be ignored. This is
      enforced by the system without causing an error to be indicated.

 RETURN VALUE    [Toc]    [Back]
      Since sigsuspend() suspends thread execution indefinitely, there is no
      successful completion return value. If a return occurs, -1 is returned
      and errno is set to indicate the error.

 ERRORS    [Toc]    [Back]
      The sigsuspend() function will fail if:

           [EINTR]        A signal is caught by the calling process and
                          control is returned from the signal-catching
                          function.

           [EFAULT]       sigmask points to an invalid address.  The
                          reliable detection of this error is
                          implementation-dependent.

 APPLICATION USAGE    [Toc]    [Back]
    Threads Considerations
      Since blocked signal masks are maintained at the thread level,
      sigsuspend() modifies only the calling thread's blocked signal mask.
      sigsuspend() suspends only the calling thread until it receives a
      signal.

      If other threads in the process do not block the signal, the signal
      may be delivered to another thread in the process and the thread in
      sigsuspend() may continue waiting.  For this reason, the use of



 Hewlett-Packard Company            - 1 -   HP-UX 11i Version 2: August 2003






 sigsuspend(2)                                                 sigsuspend(2)




      sigwait(2) is recommended instead of sigsuspend() for multi-threaded
      applications.

      For more information regarding signals and threads, refer to
      signal(5).

    LWP (Lightweight Processes) Considerations    [Toc]    [Back]
      sigsuspend() modifies only the calling LWP's signal mask and suspends
      only the calling LWP until receipt of a signal.

 AUTHOR    [Toc]    [Back]
      sigsuspend() was derived from the IEEE POSIX 1003.1-1988 Standard.

 SEE ALSO    [Toc]    [Back]
      pause(2), sigaction(2), sigpending(2), sigprocmask(2), sigsetops(3C),
      sigwait(2), signal(5).

 CHANGE HISTORY    [Toc]    [Back]
      First released in Issue 3.

      Entry included for alignment with the POSIX.1-1988 standard.

 STANDARDS CONFORMANCE    [Toc]    [Back]
      sigsuspend(): AES, SVID3, XPG3, XPG4, FIPS 151-2, POSIX.1


 Hewlett-Packard Company            - 2 -   HP-UX 11i Version 2: August 2003