From 4a16d072723b48699ea162da24eff05eba298834 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Thu, 22 Jan 2009 01:02:35 -0500 Subject: chain kill signals for cleanup functions If a piece of code wanted to do some cleanup before exiting (e.g., cleaning up a lockfile or a tempfile), our usual strategy was to install a signal handler that did something like this: do_cleanup(); /* actual work */ signal(signo, SIG_DFL); /* restore previous behavior */ raise(signo); /* deliver signal, killing ourselves */ For a single handler, this works fine. However, if we want to clean up two _different_ things, we run into a problem. The most recently installed handler will run, but when it removes itself as a handler, it doesn't put back the first handler. This patch introduces sigchain, a tiny library for handling a stack of signal handlers. You sigchain_push each handler, and use sigchain_pop to restore whoever was before you in the stack. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- t/t0005-signals.sh | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100755 t/t0005-signals.sh (limited to 't') diff --git a/t/t0005-signals.sh b/t/t0005-signals.sh new file mode 100755 index 0000000000..9707af7d03 --- /dev/null +++ b/t/t0005-signals.sh @@ -0,0 +1,22 @@ +#!/bin/sh + +test_description='signals work as we expect' +. ./test-lib.sh + +cat >expect <actual + case "$?" in + 130) true ;; # POSIX w/ SIGINT=2 + 3) true ;; # Windows + *) false ;; + esac && + test_cmp expect actual +' + +test_done -- cgit v1.2.3