dovecot-2.0: lib_signals_set_handler(): Changed API to take flag...

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-2.0/rev/86e4023d08e4
changeset: 12842:86e4023d08e4
user:      Timo Sirainen <tss at iki.fi>
date:      Mon Jun 06 18:25:52 2011 +0300
description:
lib_signals_set_handler(): Changed API to take flags instead of boolean.
This is still compatible with the old API, because using FALSE/TRUE as the
flags still maps to the same behavior.

diffstat:

 src/lib/lib-signals.c |  20 +++++++++++---------
 src/lib/lib-signals.h |  14 +++++++++++---
 2 files changed, 22 insertions(+), 12 deletions(-)

diffs (113 lines):

diff -r 0c6a9b907656 -r 86e4023d08e4 src/lib/lib-signals.c
--- a/src/lib/lib-signals.c	Mon Jun 06 18:06:22 2011 +0300
+++ b/src/lib/lib-signals.c	Mon Jun 06 18:25:52 2011 +0300
@@ -24,7 +24,7 @@
 	signal_handler_t *handler;
 	void *context;
 
-	bool delayed;
+	enum libsig_flags flags;
         struct signal_handler *next;
 };
 
@@ -124,7 +124,7 @@
 	   called at any time. don't do anything that's unsafe. we might also
 	   get interrupted by another signal while inside this handler. */
 	for (h = signal_handlers[signo]; h != NULL; h = h->next) {
-		if (!h->delayed)
+		if ((h->flags & LIBSIG_FLAG_DELAYED) == 0)
 			h->handler(si, h->context);
 		else if (pending_signals[signo].si_signo == 0) {
 			pending_signals[signo] = *si;
@@ -190,13 +190,13 @@
 			continue;
 
 		for (h = signal_handlers[signo]; h != NULL; h = h->next) {
-			if (h->delayed)
+			if ((h->flags & LIBSIG_FLAG_DELAYED) != 0)
 				h->handler(&signals[signo], h->context);
 		}
 	}
 }
 
-static void lib_signals_set(int signo)
+static void lib_signals_set(int signo, enum libsig_flags flags)
 {
 	struct sigaction act;
 
@@ -209,11 +209,13 @@
 	act.sa_flags = 0;
 	act.sa_handler = sig_handler;
 #endif
+	if ((flags & LIBSIG_FLAG_RESTART) != 0)
+		act.sa_flags |= SA_RESTART;
 	if (sigaction(signo, &act, NULL) < 0)
 		i_fatal("sigaction(%d): %m", signo);
 }
 
-void lib_signals_set_handler(int signo, bool delayed,
+void lib_signals_set_handler(int signo, enum libsig_flags flags,
 			     signal_handler_t *handler, void *context)
 {
 	struct signal_handler *h;
@@ -226,9 +228,9 @@
 	}
 
 	if (signal_handlers[signo] == NULL && signals_initialized)
-		lib_signals_set(signo);
+		lib_signals_set(signo, flags);
 
-	if (delayed && sig_pipe_fd[0] == -1) {
+	if ((flags & LIBSIG_FLAG_DELAYED) != 0 && sig_pipe_fd[0] == -1) {
 		/* first delayed handler */
 		if (pipe(sig_pipe_fd) < 0)
 			i_fatal("pipe() failed: %m");
@@ -245,7 +247,7 @@
 	h = i_new(struct signal_handler, 1);
 	h->handler = handler;
 	h->context = context;
-	h->delayed = delayed;
+	h->flags = flags;
 
 	/* atomically set to signal_handlers[] list */
 	h->next = signal_handlers[signo];
@@ -317,7 +319,7 @@
 	/* add signals that were already registered */
 	for (i = 0; i < MAX_SIGNAL_VALUE; i++) {
 		if (signal_handlers[i] != NULL)
-			lib_signals_set(i);
+			lib_signals_set(i, signal_handlers[i]->flags);
 	}
 
 	if (sig_pipe_fd[0] != -1)
diff -r 0c6a9b907656 -r 86e4023d08e4 src/lib/lib-signals.h
--- a/src/lib/lib-signals.h	Mon Jun 06 18:06:22 2011 +0300
+++ b/src/lib/lib-signals.h	Mon Jun 06 18:25:52 2011 +0300
@@ -3,6 +3,15 @@
 
 #include <signal.h>
 
+enum libsig_flags {
+	/* Signal handler will be called later from IO loop when it's safe to
+	   do any kind of work */
+	LIBSIG_FLAG_DELAYED	= 0x01,
+	/* Restart syscalls instead of having them fail with EINTR */
+	LIBSIG_FLAG_RESTART	= 0x02
+};
+#define LIBSIG_FLAGS_SAFE (LIBSIG_FLAG_DELAYED | LIBSIG_FLAG_RESTART)
+
 typedef void signal_handler_t(const siginfo_t *si, void *context);
 
 /* Number of times a "termination signal" has been received.
@@ -19,9 +28,8 @@
 /* Convert si_code to string */
 const char *lib_signal_code_to_str(int signo, int sicode);
 
-/* Set signal handler for specific signal. If delayed is TRUE, the handler
-   will be called later, ie. not as a real signal handler. */
-void lib_signals_set_handler(int signo, bool delayed,
+/* Set signal handler for specific signal. */
+void lib_signals_set_handler(int signo, enum libsig_flags flags,
 			     signal_handler_t *handler, void *context);
 /* Ignore given signal. */
 void lib_signals_ignore(int signo, bool restart_syscalls);