Merge r1821558, r1821561, r1821595 from trunk: (844964d8) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

CHANGES

+3 −0

Original line number	Diff line number	Diff line
		-- coding: utf-8 --
		Changes with Apache 2.4.30

		*) mpm_event: Let the listener thread do its maintenance job on resources
		shortage. PR 61979. [Yann Ylavic]

		*) mpm_event: Wakeup the listener to re-enable listening sockets.
		[Yann Ylavic]

server/mpm/event/event.c

+64 −42

Original line number	Diff line number	Diff line
		@@ -177,7 +177,6 @@ static volatile int dying = 0;
		static volatile int workers_may_exit = 0;
		static volatile int start_thread_may_exit = 0;
		static volatile int listener_may_exit = 0;
		static volatile int listeners_disabled = 0;
		static int listener_is_wakeable = 0; /* Pollset supports APR_POLLSET_WAKEABLE */
		static int num_listensocks = 0;
		static apr_int32_t conns_this_child; /* MaxConnectionsPerChild, only access
		@@ -441,6 +440,8 @@ static pid_t ap_my_pid; /* Linux getpid() doesn't work except in main
		static pid_t parent_pid;
		static apr_os_thread_t *listener_os_thread;

		static int ap_child_slot; /* Current child process slot in scoreboard */

		/* The LISTENER_SIGNAL signal will be sent from the main thread to the
		* listener thread to wake it up for graceful termination (what a child
		* process from an old generation does when the admin does "apachectl
		@@ -454,23 +455,29 @@ static apr_os_thread_t *listener_os_thread;
		*/
		static apr_socket_t **worker_sockets;

		static void disable_listensocks(int process_slot)
		static volatile apr_uint32_t listensocks_disabled;

		static void disable_listensocks(void)
		{
		int i;
		listeners_disabled = 1;
		if (apr_atomic_cas32(&listensocks_disabled, 1, 0) != 0) {
		return;
		}
		if (event_pollset) {
		for (i = 0; i < num_listensocks; i++) {
		apr_pollset_remove(event_pollset, &listener_pollfd[i]);
		}
		ap_scoreboard_image->parent[process_slot].not_accepting = 1;
		}
		ap_scoreboard_image->parent[ap_child_slot].not_accepting = 1;
		}

		static void enable_listensocks(int process_slot)
		static void enable_listensocks(void)
		{
		int i;
		if (listener_may_exit) {
		if (listener_may_exit
		\|\| apr_atomic_cas32(&listensocks_disabled, 0, 1) != 1) {
		return;
		}
		listeners_disabled = 0;
		ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(00457)
		"Accepting new connections again: "
		"%u active conns (%u lingering/%u clogged/%u suspended), "
		@@ -486,7 +493,12 @@ static void enable_listensocks(int process_slot)
		* XXX: This is not yet optimal. If many workers suddenly become available,
		* XXX: the parent may kill some processes off too soon.
		*/
		ap_scoreboard_image->parent[process_slot].not_accepting = 0;
		ap_scoreboard_image->parent[ap_child_slot].not_accepting = 0;
		}

		static APR_INLINE apr_uint32_t listeners_disabled(void)
		{
		return apr_atomic_read32(&listensocks_disabled);
		}

		static APR_INLINE int connections_above_limit(void)
		@@ -496,9 +508,9 @@ static APR_INLINE int connections_above_limit(void)
		apr_uint32_t c_count = apr_atomic_read32(&connection_count);
		apr_uint32_t l_count = apr_atomic_read32(&lingering_count);
		if (c_count <= l_count
		/* Off by 'listeners_disabled' to avoid flip flop */
		/* Off by 'listeners_disabled()' to avoid flip flop */
		\|\| c_count - l_count < (apr_uint32_t)threads_per_child +
		(i_count - (listeners_disabled != 0)) *
		(i_count - listeners_disabled()) *
		(worker_factor / WORKER_FACTOR_SCALE)) {
		return 0;
		}
		@@ -561,6 +573,7 @@ static void close_worker_sockets(void)
		static void wakeup_listener(void)
		{
		listener_may_exit = 1;
		disable_listensocks();

		/* Unblock the listener if it's poll()ing */
		if (event_pollset && listener_is_wakeable) {
		@@ -754,7 +767,7 @@ static apr_status_t decrement_connection_count(void *cs_)
		is_last_connection = !apr_atomic_dec32(&connection_count);
		if (listener_is_wakeable
		&& ((is_last_connection && listener_may_exit)
		\|\| (listeners_disabled && !connections_above_limit()))) {
		\|\| (listeners_disabled() && !connections_above_limit()))) {
		apr_pollset_wakeup(event_pollset);
		}
		return APR_SUCCESS;
		@@ -1206,17 +1219,16 @@ static void check_infinite_requests(void)
		}
		}

		static void close_listeners(int process_slot, int *closed)
		static void close_listeners(int *closed)
		{
		if (!*closed) {
		int i;
		disable_listensocks(process_slot);
		ap_close_listeners_ex(my_bucket->listeners);
		*closed = 1;
		dying = 1;
		ap_scoreboard_image->parent[process_slot].quiescing = 1;
		ap_scoreboard_image->parent[ap_child_slot].quiescing = 1;
		for (i = 0; i < threads_per_child; ++i) {
		ap_update_child_status_from_indexes(process_slot, i,
		ap_update_child_status_from_indexes(ap_child_slot, i,
		SERVER_GRACEFUL, NULL);
		}
		/* wake up the main thread */
		@@ -1590,8 +1602,9 @@ static void * APR_THREAD_FUNC listener_thread(apr_thread_t * thd, void *dummy)
		if (rc != APR_SUCCESS) {
		ap_log_error(APLOG_MARK, APLOG_ERR, rc, ap_server_conf,
		"failed to initialize pollset, "
		"attempting to shutdown process gracefully");
		signal_threads(ST_GRACEFUL);
		"shutdown process now");
		resource_shortage = 1;
		signal_threads(ST_UNGRACEFUL);
		return NULL;
		}

		@@ -1613,7 +1626,7 @@ static void * APR_THREAD_FUNC listener_thread(apr_thread_t * thd, void *dummy)
		check_infinite_requests();

		if (listener_may_exit) {
		close_listeners(process_slot, &closed);
		close_listeners(&closed);
		if (terminate_mode == ST_UNGRACEFUL
		\|\| apr_atomic_read32(&connection_count) == 0)
		break;
		@@ -1699,7 +1712,7 @@ static void * APR_THREAD_FUNC listener_thread(apr_thread_t * thd, void *dummy)
		* need to update timeouts (logic is above, so simply restart
		* the loop).
		*/
		if (!listener_may_exit && !listeners_disabled) {
		if (!listener_may_exit && !listeners_disabled()) {
		continue;
		}
		timeout_time = 0;
		@@ -1714,13 +1727,13 @@ static void * APR_THREAD_FUNC listener_thread(apr_thread_t * thd, void *dummy)
		}

		if (listener_may_exit) {
		close_listeners(process_slot, &closed);
		close_listeners(&closed);
		if (terminate_mode == ST_UNGRACEFUL
		\|\| apr_atomic_read32(&connection_count) == 0)
		break;
		}

		while (num) {
		for (; num; --num, ++out_pfd) {
		listener_poll_type pt = (listener_poll_type ) out_pfd->client_data;
		if (pt->type == PT_CSD) {
		/* one of the sockets is readable */
		@@ -1781,16 +1794,16 @@ static void * APR_THREAD_FUNC listener_thread(apr_thread_t * thd, void *dummy)
		ap_assert(0);
		}
		}
		else if (pt->type == PT_ACCEPT && !listeners_disabled) {
		else if (pt->type == PT_ACCEPT && !listeners_disabled()) {
		/* A Listener Socket is ready for an accept() */
		if (workers_were_busy) {
		disable_listensocks(process_slot);
		disable_listensocks();
		ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
		"All workers busy, not accepting new conns "
		"in this process");
		}
		else if (connections_above_limit()) {
		disable_listensocks(process_slot);
		disable_listensocks();
		ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
		"Too many open connections (%u), "
		"not accepting new conns in this process",
		@@ -1808,22 +1821,31 @@ static void * APR_THREAD_FUNC listener_thread(apr_thread_t * thd, void *dummy)

		if (ptrans == NULL) {
		/* create a new transaction pool for each accepted socket */
		apr_allocator_t *allocator;
		apr_allocator_t *allocator = NULL;

		apr_allocator_create(&allocator);
		rc = apr_allocator_create(&allocator);
		if (rc == APR_SUCCESS) {
		apr_allocator_max_free_set(allocator,
		ap_max_mem_free);
		apr_pool_create_ex(&ptrans, pconf, NULL, allocator);
		rc = apr_pool_create_ex(&ptrans, pconf, NULL,
		allocator);
		if (rc == APR_SUCCESS) {
		apr_pool_tag(ptrans, "transaction");
		apr_allocator_owner_set(allocator, ptrans);
		if (ptrans == NULL) {
		}
		}
		if (rc != APR_SUCCESS) {
		ap_log_error(APLOG_MARK, APLOG_CRIT, rc,
		ap_server_conf, APLOGNO(03097)
		"Failed to create transaction pool");
		if (allocator) {
		apr_allocator_destroy(allocator);
		}
		resource_shortage = 1;
		signal_threads(ST_GRACEFUL);
		return NULL;
		continue;
		}
		}
		apr_pool_tag(ptrans, "transaction");

		get_worker(&have_idle_worker, 1, &workers_were_busy);
		rc = lr->accept_func(&csd, lr, ptrans);
		@@ -1850,9 +1872,7 @@ static void * APR_THREAD_FUNC listener_thread(apr_thread_t * thd, void *dummy)
		}
		}
		} /* if:else on pt->type */
		out_pfd++;
		num--;
		} /* while for processing poll */
		} /* for processing poll */

		/* XXX possible optimization: stash the current time for use as
		* r->request_time for new requests
		@@ -1924,14 +1944,14 @@ static void * APR_THREAD_FUNC listener_thread(apr_thread_t * thd, void *dummy)
		}
		}

		if (listeners_disabled
		if (listeners_disabled()
		&& !workers_were_busy
		&& !connections_above_limit()) {
		enable_listensocks(process_slot);
		enable_listensocks();
		}
		} /* listener main loop */

		close_listeners(process_slot, &closed);
		close_listeners(&closed);
		ap_queue_term(worker_queue);

		apr_thread_exit(thd, APR_SUCCESS);
		@@ -2379,6 +2399,7 @@ static void child_main(int child_num_arg, int child_bucket)
		retained->mpm->mpm_state = AP_MPMQ_STARTING;

		ap_my_pid = getpid();
		ap_child_slot = child_num_arg;
		ap_fatal_signal_child_setup(ap_server_conf);
		apr_pool_create(&pchild, pconf);

		@@ -3356,6 +3377,7 @@ static int event_pre_config(apr_pool_t * pconf, apr_pool_t * plog,
		event_pollset = NULL;
		worker_queue_info = NULL;
		listener_os_thread = NULL;
		listensocks_disabled = 0;

		return OK;
		}