PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

NAME

       sigsetjmp — set jump point for a non-local goto

SYNOPSIS

       #include <setjmp.h>

       int sigsetjmp(sigjmp_buf env, int savemask);

DESCRIPTION

       The sigsetjmp() function shall be equivalent to the setjmp() function, except as follows:

        *  References to setjmp() are equivalent to sigsetjmp().

        *  References to longjmp() are equivalent to siglongjmp().

        *  If  the  value of the savemask argument is not 0, sigsetjmp() shall also save the current signal mask
           of the calling thread as part of the calling environment.

RETURN VALUE

       If the return is from a successful direct invocation, sigsetjmp() shall return 0. If the return is from a
       call to siglongjmp(), sigsetjmp() shall return a non-zero value.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       The  distinction between setjmp()/longjmp() and sigsetjmp()/siglongjmp() is only significant for programs
       which use sigaction(), sigprocmask(), or sigsuspend().

       Note that since this function is defined in terms of setjmp(), if savemask is  zero,  it  is  unspecified
       whether the signal mask is saved.

RATIONALE

       The  ISO C  standard specifies various restrictions on the usage of the setjmp() macro in order to permit
       implementors to recognize the name in the compiler and not  implement  an  actual  function.  These  same
       restrictions apply to the sigsetjmp() macro.

       There  are  processors  that  cannot easily support these calls, but this was not considered a sufficient
       reason to exclude them.

       4.2 BSD, 4.3 BSD, and XSI-conformant systems provide  functions  named  _setjmp()  and  _longjmp()  that,
       together with setjmp() and longjmp(), provide the same functionality as sigsetjmp() and siglongjmp().  On
       those systems, setjmp() and longjmp() save and restore signal masks, while _setjmp()  and  _longjmp()  do
       not. On System V Release 3 and in corresponding issues of the SVID, setjmp() and longjmp() are explicitly
       defined not to save and restore signal masks. In order to permit existing practice  in  both  cases,  the
       relation  of  setjmp()  and  longjmp()  to  signal  masks is not specified, and a new set of functions is
       defined instead.

       The longjmp() and siglongjmp() functions operate as in the previous issue provided the matching  setjmp()
       or  sigsetjmp()  has  been  performed  in  the  same thread. Non-local jumps into contexts saved by other
       threads would be at best a questionable practice and were not considered worthy of standardization.

FUTURE DIRECTIONS

       None.

SEE ALSO

       pthread_sigmask(), siglongjmp(), signal(), sigsuspend()

       The Base Definitions volume of POSIX.1‐2008, <setjmp.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers,  Inc
       and  The  Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the event
       of any discrepancy between this version and the original IEEE and 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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .