1SIGSETJMP(3P)              POSIX Programmer's Manual             SIGSETJMP(3P)
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PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
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11

NAME

13       sigsetjmp — set jump point for a non-local goto
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SYNOPSIS

16       #include <setjmp.h>
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18       int sigsetjmp(sigjmp_buf env, int savemask);
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DESCRIPTION

21       The sigsetjmp() function shall be equivalent to the setjmp()  function,
22       except as follows:
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24        *  References to setjmp() are equivalent to sigsetjmp().
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26        *  References to longjmp() are equivalent to siglongjmp().
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28        *  If  the  value of the savemask argument is not 0, sigsetjmp() shall
29           also save the current signal mask of the calling thread as part  of
30           the calling environment.
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RETURN VALUE

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

38       No errors are defined.
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40       The following sections are informative.
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EXAMPLES

43       None.
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APPLICATION USAGE

46       The distinction between setjmp()/longjmp() and sigsetjmp()/siglongjmp()
47       is only significant for programs which use sigaction(),  sigprocmask(),
48       or sigsuspend().
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50       Note that since this function is defined in terms of setjmp(), if save‐
51       mask is zero, it is unspecified whether the signal mask is saved.
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RATIONALE

54       The ISO C standard specifies various restrictions on the usage  of  the
55       setjmp() macro in order to permit implementors to recognize the name in
56       the compiler and not implement an actual function. These same  restric‐
57       tions apply to the sigsetjmp() macro.
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59       There  are  processors that cannot easily support these calls, but this
60       was not considered a sufficient reason to exclude them.
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62       4.2 BSD, 4.3 BSD, and XSI-conformant systems  provide  functions  named
63       _setjmp()  and  _longjmp()  that, together with setjmp() and longjmp(),
64       provide the same functionality as  sigsetjmp()  and  siglongjmp().   On
65       those  systems,  setjmp()  and longjmp() save and restore signal masks,
66       while _setjmp() and _longjmp() do not. On System V  Release  3  and  in
67       corresponding issues of the SVID, setjmp() and longjmp() are explicitly
68       defined not to save and restore signal masks. In order to permit exist‐
69       ing  practice  in both cases, the relation of setjmp() and longjmp() to
70       signal masks is not specified, and a new set of  functions  is  defined
71       instead.
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73       The  longjmp()  and  siglongjmp()  functions operate as in the previous
74       issue provided the matching setjmp() or sigsetjmp() has been  performed
75       in  the  same  thread.  Non-local  jumps  into  contexts saved by other
76       threads would be at best a questionable practice and were  not  consid‐
77       ered worthy of standardization.
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FUTURE DIRECTIONS

80       None.
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SEE ALSO

83       pthread_sigmask(), siglongjmp(), signal(), sigsuspend()
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85       The Base Definitions volume of POSIX.1‐2008, <setjmp.h>
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88       Portions  of  this text are reprinted and reproduced in electronic form
89       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
90       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
91       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
92       cal  and  Electronics  Engineers,  Inc  and  The  Open Group.  (This is
93       POSIX.1-2008 with the 2013 Technical Corrigendum  1  applied.)  In  the
94       event of any discrepancy between this version and the original IEEE and
95       The Open Group Standard, the original IEEE and The Open Group  Standard
96       is  the  referee document. The original Standard can be obtained online
97       at http://www.unix.org/online.html .
98
99       Any typographical or formatting errors that appear  in  this  page  are
100       most likely to have been introduced during the conversion of the source
101       files to man page format. To report such errors,  see  https://www.ker
102       nel.org/doc/man-pages/reporting_bugs.html .
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106IEEE/The Open Group                  2013                        SIGSETJMP(3P)
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