sigsetjmp.3

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3 代码 · 共 86 行

.\" SCCSID: @(#)sigsetjmp.3	8.2	1/28/91
.TH sigsetjmp 3
.SH Name
sigsetjmp, siglongjmp \- nonlocal goto
.SH Syntax
.nf
.B #include <setjmp.h>
.PP
.B sigsetjmp(\fIenv, savemask\fP)
.B sigjmp_buf \fIenv\fP;
.PP
.B void siglongjmp(\fIenv, val\fP)
.B sigjmp_buf \fIenv\fP;
.fi
.SH Description
.NXR "sigsetjmp subroutine"
.NXR "siglongjmp subroutine"
.NXR "program" "debugging"
These routines deal with errors 
and interrupts encountered in
a low-level subroutine of a program.
.PP
The
.PN sigsetjmp 
subroutine
saves its stack environment in
.I env
for later use by
.PN siglongjmp .
It returns a value of 0.  If the value of the
.I savemask
argument is not zero, the
.PN sigsetjmp
subroutine also saves the process\' current signal mask as part of the
calling environment.
.PP
The
.PN siglongjmp
subroutine
restores the environment saved by the last call of
.PN sigsetjmp
with the supplied
.I env
buffer.
If the
.I env
argument was initialized by a call to the
.PN sigsetjmp
subroutine with a nonzero
.I savemask
argument, the
.PN siglongjmp
subroutine restores the saved signal mask.
It then returns in such a way that execution
continues as if the call of 
.PN sigsetjmp
had just returned the value
.I val
to the subroutine that invoked
.PN sigsetjmp ,
which must not itself have returned in the interim.
However, 
.PN siglongjmp
cannot cause 
.PN sigsetjmp
to return the value 0. If 
.PN siglongjmp
is invoked with a 
.I val
of 0, 
.PN sigsetjmp
returns a value of 1.
All accessible data have values as of the time
.PN siglongjmp
was called. 
.SH Restrictions
The
.PN sigsetjmp
subroutine
does not save the current notion of whether the process is
executing on the signal stack.  When you invoke the
.PN siglongjmp
subroutine, the signal stack is left in an incorrect state.
.SH See Also
sigstack(2), sigvec(2), signal(3), sigprocmask(3)