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 --- builtin-fetch--tool.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'builtin-fetch--tool.c') diff --git a/builtin-fetch--tool.c b/builtin-fetch--tool.c index 469b07e240..b1d7f8fb32 100644 --- a/builtin-fetch--tool.c +++ b/builtin-fetch--tool.c @@ -2,6 +2,7 @@ #include "cache.h" #include "refs.h" #include "commit.h" +#include "sigchain.h" static char *get_stdin(void) { @@ -186,7 +187,7 @@ static void remove_keep(void) static void remove_keep_on_signal(int signo) { remove_keep(); - signal(SIGINT, SIG_DFL); + sigchain_pop(signo); raise(signo); } @@ -245,7 +246,7 @@ static int fetch_native_store(FILE *fp, char buffer[1024]; int err = 0; - signal(SIGINT, remove_keep_on_signal); + sigchain_push(SIGINT, remove_keep_on_signal); atexit(remove_keep); while (fgets(buffer, sizeof(buffer), stdin)) { -- cgit v1.2.3