From f4e3e7fe3b81ebbe21992d3a900f002b191fba3e Mon Sep 17 00:00:00 2001 From: chuck Date: Mon, 12 Jun 2006 16:45:14 +0000 Subject: sigtimedwait: if we collect a queued signal via pt_siglist, do not forget to clear it out of pt_siglist, otherwise we will keep getting it over and over again. fixes a problem introduced in rev 1.43. problem observed with mysqld where sending it a SIGHUP after it has set an alarm (e.g. due to some package like rt3 using it) caused the signal handler thread to go into a tight loop (collecting a SIGALRM [via sigwait() in mysqld.cc] that would not go away due to the above issue). mysqld appears to get a SIGHUP when /etc/rc exits, so it can go into this tight loop after a reboot (but not if you restart it by hand). the bad sequence is: /etc/rc runs: - starts mysqld - starts web server with rt3 fastcgi starts - fastcgi/rt3 talks to mysqld (causing it to set an alarm) - /etc/rc exits, SIGHUP goes to mysqld - mysqld catches SIGHUP, signal handler thread gets stuck in loop (database continues to operate, slowly). you can also trigger the problem by sending mysqld a SIGHUP by hand after you've caused it to set an alarm by connecting to it. --- lib/libpthread/pthread_sig.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'lib/libpthread') diff --git a/lib/libpthread/pthread_sig.c b/lib/libpthread/pthread_sig.c index 518a819aad6..17ad6f22adc 100644 --- a/lib/libpthread/pthread_sig.c +++ b/lib/libpthread/pthread_sig.c @@ -1,4 +1,4 @@ -/* $NetBSD: pthread_sig.c,v 1.45 2006/04/24 19:00:30 snj Exp $ */ +/* $NetBSD: pthread_sig.c,v 1.46 2006/06/12 16:45:14 chuck Exp $ */ /*- * Copyright (c) 2001 The NetBSD Foundation, Inc. @@ -37,7 +37,7 @@ */ #include -__RCSID("$NetBSD: pthread_sig.c,v 1.45 2006/04/24 19:00:30 snj Exp $"); +__RCSID("$NetBSD: pthread_sig.c,v 1.46 2006/06/12 16:45:14 chuck Exp $"); /* We're interposing a specific version of the signal interface. */ #define __LIBC12_SOURCE__ @@ -326,6 +326,7 @@ sigtimedwait(const sigset_t * __restrict set, siginfo_t * __restrict info, sig = firstsig(&wset); if (sig) { info->si_signo = sig; + __sigdelset14(&self->pt_siglist, sig); /* clear it */ pthread_spinunlock(self, &self->pt_siglock); pthread__testcancel(self); return 0; -- cgit