diff options
Diffstat (limited to 'lib/libc/gen/setjmp.3')
-rw-r--r-- | lib/libc/gen/setjmp.3 | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/lib/libc/gen/setjmp.3 b/lib/libc/gen/setjmp.3 new file mode 100644 index 0000000..5c995f0 --- /dev/null +++ b/lib/libc/gen/setjmp.3 @@ -0,0 +1,172 @@ +.\" 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. +.\" 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 +.Sh NAME +.Nm sigsetjmp , +.Nm siglongjmp , +.Nm setjmp , +.Nm longjmp , +.Nm _setjmp , +.Nm _longjmp , +.Nm longjmperror +.Nd non-local jumps +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In 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 +.Vt 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 -isoC . +The +.Fn sigsetjmp +and +.Fn siglongjmp +functions conform to +.St -p1003.1-88 . |