SYNOPSIS
       #include <signal.h>

       int sigsuspend(const sigset_t *sigmask);


DESCRIPTION
       The  sigsuspend() function shall replace the current signal mask of the
       calling thread with the set of signals pointed to by sigmask  and  then
       suspend the thread until delivery of a signal whose action is either to
       execute a signal-catching function or to terminate  the  process.  This
       shall  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() shall never
       return.  If  the  action is to execute a signal-catching function, then
       sigsuspend() shall return after the signal-catching  function  returns,
       with the signal mask restored to the set that existed prior to the sig-
       suspend() 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
       Since  sigsuspend() suspends thread execution indefinitely, there is no
       successful completion return value. If a return  occurs,  -1  shall  be
       returned and errno set to indicate the error.

ERRORS
       The sigsuspend() function shall fail if:

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


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       Normally, at the beginning of a critical code section, a specified  set
       of  signals  is  blocked  using  the  sigprocmask() function.  When the
       thread has completed the critical section and needs  to  wait  for  the
       previously  blocked  signal(s),  it pauses by calling sigsuspend() with
       the mask that was returned by the sigprocmask() call.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

       The Open Group Standard, the original IEEE and The Open Group  Standard
       is  the  referee document. The original Standard can be obtained online
       at http://www.opengroup.org/unix/online.html .