worker and event mpms: transient thread creation errors shouldn't take down (b2f9dae1) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

CHANGES

+3 −0

Original line number	Diff line number	Diff line
		@@ -2,6 +2,9 @@ Changes with Apache 2.1.5

		[Remove entries to the current 2.0 section below, when backported]

		*) worker and event mpms: don't take down the whole server for a transient
		thread creation failure. PR 34514 [Greg Ames]

		*) ap_get_local_host() rewritten for APR. [Jim Jagielski]

		*) Add the ap_vhost_iterate_given_conn function to expose the information

server/mpm/experimental/event/event.c

+43 −20

Original line number	Diff line number	Diff line
		@@ -160,6 +160,7 @@ static int resource_shortage = 0;
		static fd_queue_t *worker_queue;
		static fd_queue_info_t *worker_queue_info;
		static int mpm_state = AP_MPMQ_STARTING;
		static int sick_child_detected;

		apr_thread_mutex_t *timeout_mutex;
		APR_RING_HEAD(timeout_head_t, conn_state_t);
		@@ -1166,14 +1167,8 @@ static void create_listener_thread(thread_starter * ts)
		if (rv != APR_SUCCESS) {
		ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
		"apr_thread_create: unable to create listener thread");
		/* In case system resources are maxxed out, we don't want
		* Apache running away with the CPU trying to fork over and
		* over and over again if we exit.
		* XXX Jeff doesn't see how Apache is going to try to fork again since
		* the exit code is APEXIT_CHILDFATAL
		*/
		apr_sleep(apr_time_from_sec(10));
		clean_child_exit(APEXIT_CHILDFATAL);
		/* let the parent decide how bad this really is */
		clean_child_exit(APEXIT_CHILDSICK);
		}
		apr_os_thread_get(&listener_os_thread, ts->listener);
		}
		@@ -1251,11 +1246,8 @@ static void APR_THREAD_FUNC start_threads(apr_thread_t thd, void *dummy)
		if (rv != APR_SUCCESS) {
		ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
		"apr_thread_create: unable to create worker thread");
		/* In case system resources are maxxed out, we don't want
		Apache running away with the CPU trying to fork over and
		over and over again if we exit. */
		apr_sleep(apr_time_from_sec(10));
		clean_child_exit(APEXIT_CHILDFATAL);
		/* let the parent decide how bad this really is */
		clean_child_exit(APEXIT_CHILDSICK);
		}
		threads_created++;
		}
		@@ -1627,6 +1619,7 @@ static void perform_idle_server_maintenance(void)
		int free_slots[MAX_SPAWN_RATE];
		int last_non_dead;
		int total_non_dead;
		int active_thread_count = 0;

		/* initialize the free_list */
		free_length = 0;
		@@ -1664,14 +1657,16 @@ static void perform_idle_server_maintenance(void)
		* So we hopefully won't need to fork more if we count it.
		* This depends on the ordering of SERVER_READY and SERVER_STARTING.
		*/
		if (ps->pid != 0) { /* XXX just set all_dead_threads in outer
		for loop if no pid? not much else matters */
		if (status <= SERVER_READY && status != SERVER_DEAD &&
		!ps->quiescing && ps->generation == ap_my_generation &&
		/* XXX the following shouldn't be necessary if we clean up
		* properly after seg faults, but we're not yet GLA
		*/
		ps->pid != 0) {
		!ps->quiescing && ps->generation == ap_my_generation) {
		++idle_thread_count;
		}
		if (status >= SERVER_READY && status < SERVER_GRACEFUL) {
		++active_thread_count;
		}
		}
		}
		if (any_dead_threads
		&& totally_free_length < idle_spawn_rate
		@@ -1702,6 +1697,28 @@ static void perform_idle_server_maintenance(void)
		++total_non_dead;
		}
		}

		if (sick_child_detected) {
		if (active_thread_count > 0) {
		/* some child processes appear to be working. don't kill the
		* whole server.
		*/
		sick_child_detected = 0;
		}
		else {
		/* looks like a basket case. give up.
		*/
		shutdown_pending = 1;
		child_fatal = 1;
		ap_log_error(APLOG_MARK, APLOG_ALERT, 0,
		ap_server_conf,
		"No active workers found..."
		" Apache is exiting!");
		/* the child already logged the failure details */
		return;
		}
		}

		ap_max_daemons_limit = last_non_dead + 1;

		if (idle_thread_count > max_spare_threads) {
		@@ -1775,6 +1792,12 @@ static void server_main_loop(int remaining_children_to_start)
		child_fatal = 1;
		return;
		}
		else if (processed_status == APEXIT_CHILDSICK) {
		/* tell perform_idle_server_maintenance to check into this
		* on the next timer pop
		*/
		sick_child_detected = 1;
		}
		/* non-fatal death... note that it's gone in the scoreboard. */
		child_slot = find_child_by_pid(&pid);
		if (child_slot >= 0) {

server/mpm/worker/worker.c

+44 −21

Original line number	Diff line number	Diff line
		@@ -134,6 +134,7 @@ static int resource_shortage = 0;
		static fd_queue_t *worker_queue;
		static fd_queue_info_t *worker_queue_info;
		static int mpm_state = AP_MPMQ_STARTING;
		static int sick_child_detected;

		/* The structure used to pass unique initialization info to each thread */
		typedef struct {
		@@ -896,14 +897,8 @@ static void create_listener_thread(thread_starter *ts)
		if (rv != APR_SUCCESS) {
		ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
		"apr_thread_create: unable to create listener thread");
		/* In case system resources are maxxed out, we don't want
		* Apache running away with the CPU trying to fork over and
		* over and over again if we exit.
		* XXX Jeff doesn't see how Apache is going to try to fork again since
		* the exit code is APEXIT_CHILDFATAL
		*/
		apr_sleep(apr_time_from_sec(10));
		clean_child_exit(APEXIT_CHILDFATAL);
		/* let the parent decide how bad this really is */
		clean_child_exit(APEXIT_CHILDSICK);
		}
		apr_os_thread_get(&listener_os_thread, ts->listener);
		}
		@@ -980,11 +975,8 @@ static void * APR_THREAD_FUNC start_threads(apr_thread_t thd, void dummy)
		if (rv != APR_SUCCESS) {
		ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
		"apr_thread_create: unable to create worker thread");
		/* In case system resources are maxxed out, we don't want
		Apache running away with the CPU trying to fork over and
		over and over again if we exit. */
		apr_sleep(apr_time_from_sec(10));
		clean_child_exit(APEXIT_CHILDFATAL);
		/* let the parent decide how bad this really is */
		clean_child_exit(APEXIT_CHILDSICK);
		}
		threads_created++;
		}
		@@ -1373,6 +1365,7 @@ static void perform_idle_server_maintenance(void)
		int free_slots[MAX_SPAWN_RATE];
		int last_non_dead;
		int total_non_dead;
		int active_thread_count = 0;

		/* initialize the free_list */
		free_length = 0;
		@@ -1410,15 +1403,17 @@ static void perform_idle_server_maintenance(void)
		* So we hopefully won't need to fork more if we count it.
		* This depends on the ordering of SERVER_READY and SERVER_STARTING.
		*/
		if (ps->pid != 0) { /* XXX just set all_dead_threads in outer for
		loop if no pid? not much else matters */
		if (status <= SERVER_READY && status != SERVER_DEAD &&
		!ps->quiescing &&
		ps->generation == ap_my_generation &&
		/* XXX the following shouldn't be necessary if we clean up
		* properly after seg faults, but we're not yet GLA
		*/
		ps->pid != 0) {
		ps->generation == ap_my_generation) {
		++idle_thread_count;
		}
		if (status >= SERVER_READY && status < SERVER_GRACEFUL) {
		++active_thread_count;
		}
		}
		}
		if (any_dead_threads && totally_free_length < idle_spawn_rate
		&& free_length < MAX_SPAWN_RATE
		@@ -1448,6 +1443,28 @@ static void perform_idle_server_maintenance(void)
		++total_non_dead;
		}
		}

		if (sick_child_detected) {
		if (active_thread_count > 0) {
		/* some child processes appear to be working. don't kill the
		* whole server.
		*/
		sick_child_detected = 0;
		}
		else {
		/* looks like a basket case. give up.
		*/
		shutdown_pending = 1;
		child_fatal = 1;
		ap_log_error(APLOG_MARK, APLOG_ALERT, 0,
		ap_server_conf,
		"No active workers found..."
		" Apache is exiting!");
		/* the child already logged the failure details */
		return;
		}
		}

		ap_max_daemons_limit = last_non_dead + 1;

		if (idle_thread_count > max_spare_threads) {
		@@ -1521,6 +1538,12 @@ static void server_main_loop(int remaining_children_to_start)
		child_fatal = 1;
		return;
		}
		else if (processed_status == APEXIT_CHILDSICK) {
		/* tell perform_idle_server_maintenance to check into this
		* on the next timer pop
		*/
		sick_child_detected = 1;
		}
		/* non-fatal death... note that it's gone in the scoreboard. */
		child_slot = find_child_by_pid(&pid);
		if (child_slot >= 0) {