Make the Prefork MPM use SIGWINCH instead of SIGUSR1 for graceful restarts. (16bac49b) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

CHANGES

+3 −0

Original line number	Diff line number	Diff line
		Changes with Apache 2.0b1

		*) Change the Prefork MPM to use SIGWINCH instead of SIGUSR1 for graceful
		restarts. [Ryan Bloom]

		*) Modify the apr_stat/lstat/getfileinfo calls within apache to use
		the most optimal APR_FINFO_wanted bits. This spares Win32 from
		performing very expensive owner, group and permission lookups

server/mpm/prefork/prefork.c

+20 −20

Original line number	Diff line number	Diff line
		@@ -157,7 +157,7 @@ static int maintain_connection_status = 1;

		/*
		* The max child slot ever assigned, preserved across restarts. Necessary
		* to deal with MaxClients changes across SIGUSR1 restarts. We use this
		* to deal with MaxClients changes across SIGWINCH restarts. We use this
		* value to optimize routines that have to scan the entire scoreboard.
		*/
		int ap_max_daemons_limit = -1;
		@@ -635,7 +635,7 @@ static void restart(int sig)
		return;
		}
		restart_pending = 1;
		if ((is_graceful = (sig == SIGUSR1))) {
		if ((is_graceful = (sig == SIGWINCH))) {
		apr_kill_cleanup(pconf, NULL, cleanup_shared_mem);
		}
		}
		@@ -698,14 +698,14 @@ static void set_signals(void)
		ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGPIPE)");
		#endif

		/* we want to ignore HUPs and USR1 while we're busy processing one */
		/* we want to ignore HUPs and WINCH while we're busy processing one */
		sigaddset(&sa.sa_mask, SIGHUP);
		sigaddset(&sa.sa_mask, SIGUSR1);
		sigaddset(&sa.sa_mask, SIGWINCH);
		sa.sa_handler = restart;
		if (sigaction(SIGHUP, &sa, NULL) < 0)
		ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGHUP)");
		if (sigaction(SIGUSR1, &sa, NULL) < 0)
		ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGUSR1)");
		if (sigaction(SIGWINCH, &sa, NULL) < 0)
		ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGWINCH)");
		#else
		if (!one_process) {
		apr_signal(SIGSEGV, sig_coredump);
		@@ -733,9 +733,9 @@ static void set_signals(void)
		#ifdef SIGHUP
		apr_signal(SIGHUP, restart);
		#endif /* SIGHUP */
		#ifdef SIGUSR1
		apr_signal(SIGUSR1, restart);
		#endif /* SIGUSR1 */
		#ifdef SIGWINCH
		apr_signal(SIGWINCH, restart);
		#endif /* SIGWINCH */
		#ifdef SIGPIPE
		apr_signal(SIGPIPE, SIG_IGN);
		#endif /* SIGPIPE */
		@@ -812,11 +812,11 @@ static void child_main(int child_num_arg)

		while (!ap_graceful_stop_signalled()) {

		/* Prepare to receive a SIGUSR1 due to graceful restart so that
		/* Prepare to receive a SIGWINCH due to graceful restart so that
		* we can exit cleanly.
		*/
		usr1_just_die = 1;
		apr_signal(SIGUSR1, usr1_handler);
		apr_signal(SIGWINCH, usr1_handler);

		/*
		* (Re)initialize this child to a pre-connection state.
		@@ -1018,7 +1018,7 @@ static void child_main(int child_num_arg)
		* the signal to ignore because we don't want to disturb any
		* third party code.
		*/
		apr_signal(SIGUSR1, SIG_IGN);
		apr_signal(SIGWINCH, SIG_IGN);
		/*
		* We now have a connection, so set it up with the appropriate
		* socket options, file descriptors, and read/write buffers.
		@@ -1118,7 +1118,7 @@ static int make_child(server_rec *s, int slot, time_t now)
		* requested there's no race condition here.
		*/
		apr_signal(SIGHUP, just_die);
		apr_signal(SIGUSR1, just_die);
		apr_signal(SIGWINCH, just_die);
		apr_signal(SIGTERM, just_die);
		child_main(slot);
		}
		@@ -1223,11 +1223,11 @@ static void perform_idle_server_maintenance(void)
		}
		ap_max_daemons_limit = last_non_dead + 1;
		if (idle_count > ap_daemons_max_free) {
		/* kill off one child... we use SIGUSR1 because that'll cause it to
		/* kill off one child... we use SIGWINCH because that'll cause it to
		* shut down gracefully, in case it happened to pick up a request
		* while we were counting
		*/
		kill(ap_scoreboard_image->parent[to_kill].pid, SIGUSR1);
		kill(ap_scoreboard_image->parent[to_kill].pid, SIGWINCH);
		idle_spawn_rate = 1;
		}
		else if (idle_count < ap_daemons_min_free) {
		@@ -1359,7 +1359,7 @@ int ap_mpm_run(apr_pool_t _pconf, apr_pool_t plog, server_rec *s)

		/* If we're doing a graceful_restart then we're going to see a lot
		* of children exiting immediately when we get into the main loop
		* below (because we just sent them SIGUSR1). This happens pretty
		* below (because we just sent them SIGWINCH). This happens pretty
		* rapidly... and for each one that exits we'll start a new one until
		* we reach at least daemons_min_free. But we may be permitted to
		* start more than that, so we'll just keep track of how many we're
		@@ -1486,7 +1486,7 @@ int ap_mpm_run(apr_pool_t _pconf, apr_pool_t plog, server_rec *s)

		/* we've been told to restart */
		apr_signal(SIGHUP, SIG_IGN);
		apr_signal(SIGUSR1, SIG_IGN);
		apr_signal(SIGWINCH, SIG_IGN);
		if (one_process) {
		/* not worth thinking about */
		return 1;
		@@ -1505,11 +1505,11 @@ int ap_mpm_run(apr_pool_t _pconf, apr_pool_t plog, server_rec *s)
		int i;
		#endif
		ap_log_error(APLOG_MARK, APLOG_NOERRNO\|APLOG_NOTICE, 0, ap_server_conf,
		"SIGUSR1 received. Doing graceful restart");
		"SIGWINCH received. Doing graceful restart");

		/* kill off the idle ones */
		if (unixd_killpg(getpgrp(), SIGUSR1) < 0) {
		ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGUSR1");
		if (unixd_killpg(getpgrp(), SIGWINCH) < 0) {
		ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGWINCH");
		}
		#ifndef SCOREBOARD_FILE
		/* This is mostly for debugging... so that we know what is still

server/mpm_common.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -229,7 +229,7 @@ void ap_process_child_status(apr_proc_t *pid, apr_wait_t status)
		switch (WTERMSIG(status)) {
		case SIGTERM:
		case SIGHUP:
		case SIGUSR1:
		case SIGWINCH:
		case SIGKILL:
		break;
		default: