Re: [PATCH] Fix signal handler
Hello,
How do Git software developers think about the appended update suggestion? Would you like to integrate such adjustments into your source code repository?
Regards, Markus
>From c37d8dafef11168d8302d40c8d1453943a058d95 Mon Sep 17 00:00:00 2001
From: Markus Elfring <Markus.Elfring@web.de>
Date: Wed, 10 Feb 2010 17:05:45 +0100
Subject: [PATCH] Fix a signal handler
A global flag can only be set by a signal handler in a portable way if it has got the data type "sig_atomic_t". The previously used assignment of a function pointer in the function "early_output" was moved to another variable in the function "setup_early_output".
The involved software design details were also mentioned on the mailing list.
---
builtin-log.c | 12 +++---------
revision.c | 14 ++++++--------
revision.h | 3 ++-
3 files changed, 11 insertions(+), 18 deletions(-)
diff --git a/builtin-log.c b/builtin-log.c
index 8d16832..358c98b 100644
--- a/builtin-log.c
+++ b/builtin-log.c
@@ -123,7 +123,7 @@ static void show_early_header(struct rev_info *rev, const char *stage, int nr)
static struct itimerval early_output_timer;
-static void log_show_early(struct rev_info *revs, struct commit_list *list)
+extern void log_show_early(struct rev_info *revs, struct commit_list *list)
{
int i = revs->early_output;
int show_header = 1;
@@ -170,20 +170,14 @@ static void log_show_early(struct rev_info *revs, struct commit_list *list)
static void early_output(int signal)
{
- show_early_output = log_show_early;
+ show_early_output = 1;
}
static void setup_early_output(struct rev_info *rev)
{
struct sigaction sa;
- /*
- * Set up the signal handler, minimally intrusively:
- * we only set a single volatile integer word (not
- * using sigatomic_t - trying to avoid unnecessary
- * system dependencies and headers), and using
- * SA_RESTART.
- */
+ early_output_function = &log_show_early;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = early_output;
sigemptyset(&sa.sa_mask);
diff --git a/revision.c b/revision.c
index 3ba6d99..62402fb 100644
--- a/revision.c
+++ b/revision.c
@@ -13,7 +13,8 @@
#include "decorate.h"
#include "log-tree.h"
-volatile show_early_output_fn_t show_early_output;
+sig_atomic_t show_early_output = 0;
+show_early_output_fn_t early_output_function = NULL;
char *path_name(const struct name_path *path, const char *name)
{
@@ -654,7 +655,6 @@ static int limit_list(struct rev_info *revs)
struct commit_list *entry = list;
struct commit *commit = list->item;
struct object *obj = &commit->object;
- show_early_output_fn_t show;
list = list->next;
free(entry);
@@ -680,12 +680,10 @@ static int limit_list(struct rev_info *revs)
date = commit->date;
p = &commit_list_insert(commit, p)->next;
- show = show_early_output;
- if (!show)
- continue;
-
- show(revs, newlist);
- show_early_output = NULL;
+ if (show_early_output) {
+ (*early_output_function)(revs, newlist);
+ show_early_output = 0;
+ }
}
if (revs->cherry_pick)
cherry_pick_list(newlist, revs);
diff --git a/revision.h b/revision.h
index a14deef..93a8ffc 100644
--- a/revision.h
+++ b/revision.h
@@ -135,7 +135,8 @@ struct rev_info {
/* revision.c */
typedef void (*show_early_output_fn_t)(struct rev_info *, struct commit_list *);
-extern volatile show_early_output_fn_t show_early_output;
+extern show_early_output_fn_t early_output_function;
+extern sig_atomic_t show_early_output;
extern void init_revisions(struct rev_info *revs, const char *prefix);
extern int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def);
--
1.6.6.1
