175 lines
4.7 KiB
Groff
175 lines
4.7 KiB
Groff
.\" Copyright (c) 1990, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to Berkeley by
|
|
.\" the American National Standards Committee X3, on Information
|
|
.\" Processing Systems.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)setjmp.3 8.1 (Berkeley) 6/4/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd June 4, 1993
|
|
.Dt SETJMP 3
|
|
.Os BSD 4
|
|
.Sh NAME
|
|
.Nm sigsetjmp ,
|
|
.Nm siglongjmp ,
|
|
.Nm setjmp ,
|
|
.Nm longjmp ,
|
|
.Nm _setjmp ,
|
|
.Nm _longjmp ,
|
|
.Nm longjmperror
|
|
.Nd non-local jumps
|
|
.Sh SYNOPSIS
|
|
.Fd #include <setjmp.h>
|
|
.Ft int
|
|
.Fn sigsetjmp "sigjmp_buf env" "int savemask"
|
|
.Ft void
|
|
.Fn siglongjmp "sigjmp_buf env" "int val"
|
|
.Ft int
|
|
.Fn setjmp "jmp_buf env"
|
|
.Ft void
|
|
.Fn longjmp "jmp_buf env" "int val"
|
|
.Ft int
|
|
.Fn _setjmp "jmp_buf env"
|
|
.Ft void
|
|
.Fn _longjmp "jmp_buf env" "int val"
|
|
.Ft void
|
|
.Fn longjmperror void
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn sigsetjmp ,
|
|
.Fn setjmp ,
|
|
and
|
|
.Fn _setjmp
|
|
functions save their calling environment in
|
|
.Fa env .
|
|
Each of these functions returns 0.
|
|
.Pp
|
|
The corresponding
|
|
.Fn longjmp
|
|
functions restore the environment saved by their most recent respective
|
|
invocations
|
|
of the
|
|
.Fn setjmp
|
|
function.
|
|
They then return so that program execution continues as if the corresponding
|
|
invocation of the
|
|
.Fn setjmp
|
|
call had just returned the value specified by
|
|
.Fa val ,
|
|
instead of 0.
|
|
.Pp
|
|
Pairs of calls may be intermixed, i.e. both
|
|
.Fn sigsetjmp
|
|
and
|
|
.Fn siglongjmp
|
|
and
|
|
.Fn setjmp
|
|
and
|
|
.Fn longjmp
|
|
combinations may be used in the same program, however, individual
|
|
calls may not, e.g. the
|
|
.Fa env
|
|
argument to
|
|
.Fn setjmp
|
|
may not be passed to
|
|
.Fn siglongjmp .
|
|
.Pp
|
|
The
|
|
.Fn longjmp
|
|
routines may not be called after the routine which called the
|
|
.Fn setjmp
|
|
routines returns.
|
|
.Pp
|
|
All accessible objects have values as of the time
|
|
.Fn longjmp
|
|
routine was called, except that the values of objects of automatic storage
|
|
invocation duration that do not have the
|
|
.Em volatile
|
|
type and have been changed between the
|
|
.Fn setjmp
|
|
invocation and
|
|
.Fn longjmp
|
|
call are indeterminate.
|
|
.Pp
|
|
The
|
|
.Fn setjmp Ns / Ns Fn longjmp
|
|
pairs save and restore the signal mask while
|
|
.Fn _setjmp Ns / Ns Fn _longjmp
|
|
pairs save and restore only the register set and the stack.
|
|
(See
|
|
.Fn sigprocmask 2 . )
|
|
.Pp
|
|
The
|
|
.Fn sigsetjmp Ns / Ns Fn siglongjmp
|
|
function
|
|
pairs save and restore the signal mask if the argument
|
|
.Fa savemask
|
|
is non-zero, otherwise only the register set and the stack are saved.
|
|
.Sh ERRORS
|
|
If the contents of the
|
|
.Fa env
|
|
are corrupted, or correspond to an environment that has already returned,
|
|
the
|
|
.Fn longjmp
|
|
routine calls the routine
|
|
.Fn longjmperror 3 .
|
|
If
|
|
.Fn longjmperror
|
|
returns the program is aborted (see
|
|
.Xr abort 3 ) .
|
|
The default version of
|
|
.Fn longjmperror
|
|
prints the message
|
|
.Dq Li longjmp botch
|
|
to standard error and returns.
|
|
User programs wishing to exit more gracefully should write their own
|
|
versions of
|
|
.Fn longjmperror .
|
|
.Sh SEE ALSO
|
|
.Xr sigaction 2 ,
|
|
.Xr sigaltstack 2 ,
|
|
.Xr signal 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn setjmp
|
|
and
|
|
.Fn longjmp
|
|
functions conform to
|
|
.St -ansiC .
|
|
The
|
|
.Fn sigsetjmp
|
|
and
|
|
.Fn siglongjmp
|
|
functions conform to
|
|
.St -p1003.1-88 .
|