The sigchain APIs require user to code like:
void clean_foo_on_signal(int sig)
{
clean_foo();
sigchain_pop(sig);
raise(sig);
}
this force user to know how sigchain works internally, and
sigchain_pop is something like hard-coded constant value, if we change
it someday, we shall change it everywhere where we use sigchain APIs.
We could use macro to override this. The HANDLER_WRAPPER take two
arguments: one for the function name it will define, and another for
clean function which handler should call before sigchain_pop(sig) and
raise(sig).
The only problem of this patch is HANDLER_WRAPPER is not generic
enough, some clean function requires one argument which is signo to
finish its work, but the only example of this is the function named
'cleanup_children' from run-command.c. Maybe we should force every
clean function take signo argument?
Signed-off-by: Xu Di <xudifsd@xxxxxxxxx>
---
Documentation/technical/api-sigchain.txt | 19 +++++++++++++------
credential-cache--daemon.c | 7 +------
diff.c | 7 +------
http-push.c | 7 +------
lockfile.c | 7 +------
pager.c | 7 +------
sigchain.h | 8 ++++++++
7 files changed, 26 insertions(+), 36 deletions(-)
diff --git a/Documentation/technical/api-sigchain.txt
b/Documentation/technical/api-sigchain.txt
index 9e1189e..b6a0b88 100644
--- a/Documentation/technical/api-sigchain.txt
+++ b/Documentation/technical/api-sigchain.txt
@@ -17,12 +17,7 @@ Sigchain is a tiny library for keeping a stack of
handlers. Your handler
and installation code should look something like:
------------------------------------------
- void clean_foo_on_signal(int sig)
- {
- clean_foo();
- sigchain_pop(sig);
- raise(sig);
- }
+ HANDLER_WRAPPER(clean_foo_on_signal, clean_foo)
void other_func()
{
@@ -32,6 +27,18 @@ and installation code should look something like:
}
------------------------------------------
+We use the macro which is named HANDLER_WRAPPER to help us wrap the
+clean function, the macro above will finally expanded into:
+
+------------------------------------------
+ void clean_foo_on_signal(int sig)
+ {
+ clean_foo();
+ sigchain_pop(sig);
+ raise(sig);
+ }
+------------------------------------------
+
Handlers are given the typedef of sigchain_fun. This is the same type
that is given to signal() or sigaction(). It is perfectly reasonable to
push SIG_DFL or SIG_IGN onto the stack.
diff --git a/credential-cache--daemon.c b/credential-cache--daemon.c
index 390f194..8bb983d 100644
--- a/credential-cache--daemon.c
+++ b/credential-cache--daemon.c
@@ -11,12 +11,7 @@ static void cleanup_socket(void)
unlink(socket_path);
}
-static void cleanup_socket_on_signal(int sig)
-{
- cleanup_socket();
- sigchain_pop(sig);
- raise(sig);
-}
+static HANDLER_WRAPPER(cleanup_socket_on_signal, cleanup_socket)
struct credential_cache_entry {
struct credential item;
diff --git a/diff.c b/diff.c
index 377ec1e..9535171 100644
--- a/diff.c
+++ b/diff.c
@@ -525,12 +525,7 @@ static void remove_tempfile(void)
}
}
-static void remove_tempfile_on_signal(int signo)
-{
- remove_tempfile();
- sigchain_pop(signo);
- raise(signo);
-}
+static HANDLER_WRAPPER(remove_tempfile_on_signal, remove_tempfile)
static void print_line_count(FILE *file, int count)
{
diff --git a/http-push.c b/http-push.c
index f22f7e4..b2e33a7 100644
--- a/http-push.c
+++ b/http-push.c
@@ -1027,12 +1027,7 @@ static void remove_locks(void)
}
}
-static void remove_locks_on_signal(int signo)
-{
- remove_locks();
- sigchain_pop(signo);
- raise(signo);
-}
+static HANDLER_WRAPPER(remove_locks_on_signal, remove_locks)
static void remote_ls(const char *path, int flags,
void (*userFunc)(struct remote_ls_ctx *ls),
diff --git a/lockfile.c b/lockfile.c
index c6fb77b..fd972f3 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -22,12 +22,7 @@ static void remove_lock_file(void)
}
}
-static void remove_lock_file_on_signal(int signo)
-{
- remove_lock_file();
- sigchain_pop(signo);
- raise(signo);
-}
+static HANDLER_WRAPPER(remove_lock_file_on_signal, remove_lock_file)
/*
* p = absolute or relative path name
diff --git a/pager.c b/pager.c
index 05584de..4ba2b41 100644
--- a/pager.c
+++ b/pager.c
@@ -39,12 +39,7 @@ static void wait_for_pager(void)
finish_command(&pager_process);
}
-static void wait_for_pager_signal(int signo)
-{
- wait_for_pager();
- sigchain_pop(signo);
- raise(signo);
-}
+static HANDLER_WRAPPER(wait_for_pager_signal, wait_for_pager)
const char *git_pager(int stdout_is_tty)
{
diff --git a/sigchain.h b/sigchain.h
index 618083b..949f0d4 100644
--- a/sigchain.h
+++ b/sigchain.h
@@ -1,6 +1,14 @@
#ifndef SIGCHAIN_H
#define SIGCHAIN_H
+#define HANDLER_WRAPPER(name, handler) \
+void name(int sig) \
+{ \
+ handler(); \
+ sigchain_pop(sig); \
+ raise(sig); \
+}
+
typedef void (*sigchain_fun)(int);
int sigchain_push(int sig, sigchain_fun f);
--
1.7.9.1.265.gb3a76
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