110 lines
4.2 KiB
HTML
110 lines
4.2 KiB
HTML
<head>
|
|
<title>setjmp(3) - Plan 9 from User Space</title>
|
|
<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
|
|
</head>
|
|
<body bgcolor=#ffffff>
|
|
<table border=0 cellpadding=0 cellspacing=0 width=100%>
|
|
<tr height=10><td>
|
|
<tr><td width=20><td>
|
|
<tr><td width=20><td><b>SETJMP(3)</b><td align=right><b>SETJMP(3)</b>
|
|
<tr><td width=20><td colspan=2>
|
|
<br>
|
|
<p><font size=+1><b>NAME </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
setjmp, longjmp, notejmp – non-local goto<br>
|
|
|
|
</table>
|
|
<p><font size=+1><b>SYNOPSIS </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
<tt><font size=+1>#include <u.h><br>
|
|
#include <libc.h>
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
</font></tt>
|
|
<tt><font size=+1>int setjmp(jmp_buf env)
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
</font></tt>
|
|
<tt><font size=+1>void longjmp(jmp_buf env, int val)
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
</font></tt>
|
|
<tt><font size=+1>void notejmp(void *uregs, jmp_buf env, int val)<br>
|
|
</font></tt>
|
|
</table>
|
|
<p><font size=+1><b>DESCRIPTION </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
These routines are useful for dealing with errors and interrupts
|
|
encountered in a low-level subroutine of a program.
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
<i>Setjmp</i> saves its stack environment in <i>env</i> for later use by <i>longjmp</i>.
|
|
It returns value 0.
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
<i>Longjmp</i> restores the environment saved by the last call of <i>setjmp</i>.
|
|
It then causes execution to continue as if the call of <i>setjmp</i>
|
|
had just returned with value <i>val</i>. The invoker of <i>setjmp</i> must not
|
|
itself have returned in the interim. All accessible data have
|
|
values as of the time <i>longjmp</i> was called.
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
<i>Notejmp</i> is the same as <i>longjmp</i> except that it is to be called
|
|
from within a note handler (see <a href="../man3/notify.html"><i>notify</i>(3)</a>). The <i>uregs</i> argument
|
|
should be the first argument passed to the note handler.
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
<i>Setjmp</i> and <i>longjmp</i> can also be used to switch stacks.<br>
|
|
|
|
</table>
|
|
<p><font size=+1><b>SOURCE </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
<tt><font size=+1>/usr/local/plan9/src/lib9/jmp.c<br>
|
|
</font></tt>
|
|
</table>
|
|
<p><font size=+1><b>SEE ALSO </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
<a href="../man3/notify.html"><i>notify</i>(3)</a><br>
|
|
|
|
</table>
|
|
<p><font size=+1><b>BUGS </b></font><br>
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
|
|
|
|
<i>Notejmp</i> cannot recover from an address trap or bus error (page
|
|
fault) on the 680x0 architectures.
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
To avoid name conflicts with the underlying system, <i>setjmp</i>, <i>longjmp</i>,
|
|
<i>notejmp</i>, and <i>jmp_buf</i> are preprocessor macros defined as <i>p9setjmp</i>,
|
|
<i>p9longjmp</i>, <i>p9notejmp</i>, and <i>p9jmp_buf</i>; see <a href="../man3/intro.html"><i>intro</i>(3)</a>.
|
|
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
|
|
|
|
<i>P9setjmp</i> is implemented as a preprocessor macro that calls <i>sigsetjmp</i>
|
|
(see Unix’s <i>setjmp</i>(3)).<br>
|
|
|
|
</table>
|
|
|
|
<td width=20>
|
|
<tr height=20><td>
|
|
</table>
|
|
<!-- TRAILER -->
|
|
<table border=0 cellpadding=0 cellspacing=0 width=100%>
|
|
<tr height=15><td width=10><td><td width=10>
|
|
<tr><td><td>
|
|
<center>
|
|
<a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a>
|
|
</center>
|
|
</table>
|
|
<!-- TRAILER -->
|
|
</body></html>
|