dovecot-2.0: lib-signals: Don't assert-crash with nested signal ...

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-2.0/rev/54c0c2c24f2c
changeset: 9905:54c0c2c24f2c
user:      Timo Sirainen <tss at iki.fi>
date:      Tue Sep 08 14:49:35 2009 -0400
description:
lib-signals: Don't assert-crash with nested signal handler calls.

diffstat:

1 file changed, 5 insertions(+), 3 deletions(-)
src/lib/lib-signals.c |    8 +++++---

diffs (33 lines):

diff -r 88801acf025a -r 54c0c2c24f2c src/lib/lib-signals.c
--- a/src/lib/lib-signals.c	Tue Sep 08 14:48:54 2009 -0400
+++ b/src/lib/lib-signals.c	Tue Sep 08 14:49:35 2009 -0400
@@ -95,7 +95,8 @@ static void sig_handler(int signo, sigin
 		return;
 
 	/* remember that we're inside a signal handler which might have been
-	   called at any time. don't do anything that's unsafe. */
+	   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)
 			h->handler(si, h->context);
@@ -125,7 +126,7 @@ static void signal_read(void *context AT
 	siginfo_t signals[MAX_SIGNAL_VALUE+1];
 	sigset_t fullset, oldset;
 	struct signal_handler *h;
-	char buf[2];
+	char buf[64];
 	int signo;
 	ssize_t ret;
 
@@ -134,8 +135,9 @@ static void signal_read(void *context AT
 	if (sigprocmask(SIG_BLOCK, &fullset, &oldset) < 0)
 		i_fatal("sigprocmask() failed: %m");
 
+	/* typically we should read only a single byte, but if a signal
+	   is sent while signal handler is running we might get more. */
 	ret = read(sig_pipe_fd[0], buf, sizeof(buf));
-	i_assert(ret <= 1);
 	if (ret > 0) {
 		memcpy(signals, pending_signals, sizeof(signals));
 		memset(pending_signals, 0, sizeof(pending_signals));