On Apache/1.3.41 (Unix) PHP/5.2.5 mod_perl/1.30 mod_gzip/1.3.26.1a
Under GNU General Public License
2009-01-10 09:19 @38.103.63.58 CrawledBy CCBot/1.0 (+http://www.commoncrawl.org/bot.html)
SIGSETJMP(P) SIGSETJMP(P)
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 con-
sidered 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 functional-
ity 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 exist-
ing 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
siglongjmp() , signal() , sigprocmask() , sigsuspend() , the Base Definitions vol-
ume of IEEE Std 1003.1-2001, <setjmp.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating
System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C)
2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The
Open Group. 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.opengroup.org/unix/online.html .
POSIX 2003 SIGSETJMP(P)
Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache/1.3.41 (Unix) PHP/5.2.5 mod_perl/1.30 mod_gzip/1.3.26.1a
Under GNU General Public License
2009-01-10 09:19 @38.103.63.58 CrawledBy CCBot/1.0 (+http://www.commoncrawl.org/bot.html)