Win32: Graceful restart is working again, and better than before. (c945b17b) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

server/mpm/winnt/mpm_winnt.c

+67 −49

Original line number	Diff line number	Diff line
		@@ -825,13 +825,13 @@ static void drain_acceptex_complport(HANDLE hComplPort, BOOLEAN bCleanUp)
		lastError = GetLastError();
		if (lastError == ERROR_OPERATION_ABORTED) {
		ap_log_error(APLOG_MARK,APLOG_INFO,lastError, server_conf,
		"Child: %d - Draining a packet off the completion port.", my_pid);
		"Child %d: - Draining a packet off the completion port.", my_pid);
		continue;
		}
		break;
		}
		ap_log_error(APLOG_MARK,APLOG_INFO,APR_SUCCESS, server_conf,
		"Child: %d - Nuking an active connection. context = %x", my_pid, context);
		"Child %d: - Nuking an active connection. context = %x", my_pid, context);
		context = (PCOMP_CONTEXT) pol;
		if (context && bCleanUp) {
		/* It is only valid to clean-up in the process that initiated the I/O */
		@@ -994,28 +994,41 @@ static PCOMP_CONTEXT winnt_get_connection(PCOMP_CONTEXT context)
		INFINITE);
		if (!rc) {
		ap_log_error(APLOG_MARK,APLOG_ERR, GetLastError(), server_conf,
		"Child: %d - GetQueuedCompletionStatus() failed", my_pid);
		/* Todo: What to do when we receive an error here? */
		// continue;
		"Child %d: - GetQueuedCompletionStatus() failed", my_pid);
		/* During a restart, the new child process can catch
		* ERROR_OPERATION_ABORTED completion packets
		* posted by the old child process. Just continue...
		*/
		continue;
		}
		break;

		/* Check the Completion Key.
		* == my_pid indicate this process wants to exit
		* == 0 implies valid i/o completion
		* != 0 implies a posted completion packet by an old
		* process. Just ignore it.
		*/
		if (CompKey == my_pid) {
		return NULL;
		}
		if (CompKey != 0)
		continue;

		context = (PCOMP_CONTEXT) pol;
		if ((CompKey == 999) \|\| workers_may_exit) {
		ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf,
		"Child: %d - Completion port posted.", my_pid);
		return NULL;
		break;
		}

		/* Check to see if we need to create more completion contexts */
		/* Check to see if we need to create more completion contexts,
		* but only if we are not in the process of shutting down
		*/
		if (!workers_may_exit) {
		ap_lock(allowed_globals.jobmutex);
		context->lr->count--;
		if (context->lr->count < 2) {
		ap_log_error(APLOG_MARK, APLOG_INFO, APR_SUCCESS, server_conf,
		"Child %d: Signaling child maintenance event...", my_pid);
		SetEvent(maintenance_event);
		}
		ap_unlock(allowed_globals.jobmutex);
		}

		/* Received a connection */
		context->conn_io->incnt = BytesRead;
		@@ -1128,7 +1141,6 @@ static void create_listeners()
		* - sets up the worker thread pool
		* - starts the accept thread (Win 9x)
		* - creates AcceptEx contexts (Win NT)
		* This thread also does async Acceptex for the server (Win NT)
		* - waits for exit_event, maintenance_event or maintenance timeout
		* and does the right thing depending on which event is received.
		*/
		@@ -1184,15 +1196,6 @@ static void child_main()
		allowed_globals.jobsemaphore = create_semaphore(0);
		ap_create_lock(&allowed_globals.jobmutex, APR_MUTEX, APR_INTRAPROCESS, NULL, pchild);

		/* Create the worker thread pool */
		ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf,
		"Child %d: Starting %d worker threads.", my_pid, nthreads);
		child_handles = (thread ) alloca(nthreads sizeof(int));
		for (i = 0; i < nthreads; i++) {
		child_handles[i] = (thread *) _beginthreadex(NULL, 0, (LPTHREAD_START_ROUTINE) worker_main,
		NULL, 0, &thread_id);
		}

		/*
		* Wait until we have permission to start accepting connections.
		* start_mutex is used to ensure that only one child ever
		@@ -1208,6 +1211,15 @@ static void child_main()
		ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf,
		"Child %d: Acquired the start mutex.", my_pid);

		/* Create the worker thread pool */
		ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf,
		"Child %d: Starting %d worker threads.", my_pid, nthreads);
		child_handles = (thread ) alloca(nthreads sizeof(int));
		for (i = 0; i < nthreads; i++) {
		child_handles[i] = (thread *) _beginthreadex(NULL, 0, (LPTHREAD_START_ROUTINE) worker_main,
		NULL, 0, &thread_id);
		}

		/* Begin accepting connections */
		if (osver.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS) {
		/* Win95/98: Start the accept thread */
		@@ -1239,6 +1251,14 @@ static void child_main()
		workers_may_exit = 1;
		ap_log_error(APLOG_MARK, APLOG_CRIT, GetLastError(), server_conf,
		"Child %d: WaitForMultipeObjects WAIT_FAILED -- doing server shutdown");
		/* Give a busy server the chance to drain AcceptEx completion contexts
		* by servicing connections. Note that the setting of workers_may_exit
		* prevents new AcceptEx completion contexts from being created.
		*/
		Sleep(1000);

		/* Drain any remaining contexts. May loose a few connections here. */
		drain_acceptex_complport(AcceptExCompPort, FALSE);
		}
		else if (rv == WAIT_TIMEOUT) {
		/* Hey, this cannot happen */
		@@ -1253,8 +1273,9 @@ static void child_main()
		}
		else {
		/* Child maintenance event signaled */
		if (osver.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS)
		if (osver.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS) {
		create_listeners();
		}
		ResetEvent(maintenance_event);
		ap_log_error(APLOG_MARK, APLOG_INFO, APR_SUCCESS, server_conf,
		"Child %d: Child maintenance event signaled...", my_pid);
		@@ -1268,33 +1289,32 @@ static void child_main()
		}
		}
		else { /* Windows NT/2000 */
		ap_listen_rec *lr;
		SOCKET nsd;
		for (lr = ap_listeners; lr != NULL; lr = lr->next) {
		ap_get_os_sock(&nsd, lr->sd);
		CancelIo((HANDLE)nsd);
		}

		/* Tell the worker threads to exit. */
		for (i=0; i < nthreads; i++) {
		if (!PostQueuedCompletionStatus(AcceptExCompPort, 0, 999, NULL)) {
		/* Sometimes posted completion contexts intended for this process
		* are consumed by the new process (during restart). Send a few
		* extra to compensate. At worst, this process may hang around
		* for several minutes because a thread is not exiting because
		* it is blocked on GetQueuedCompletionStatus.
		*/
		for (i=0; i < 2*nthreads; i++) {
		if (!PostQueuedCompletionStatus(AcceptExCompPort, 0, my_pid, NULL)) {
		ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf,
		"PostQueuedCompletionStatus failed");
		}
		}
		}

		ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf,
		"Child %d: Waiting for %d threads to die.", my_pid, nthreads);

		/* Give the workers a chance to pick-up the posted completion context */
		Sleep(1000);

		/* Release the start_mutex to let the new process (in the restart
		* scenario) a chance to begin servicing requests
		*/
		ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf,
		"Child %d: Releasing the start mutex", my_pid);
		ap_unlock(start_mutex);

		/* Wait for the worker threads to die */
		/* Give busy worker threads a chance to service their connections.
		* Kill them off if they take too long
		*/
		ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf,
		"Child %d: Waiting for %d threads to die.", my_pid, nthreads);
		end_time = time(NULL) + 180;
		while (nthreads) {
		rv = wait_for_many_objects(nthreads, child_handles, end_time - time(NULL));
		@@ -1302,8 +1322,6 @@ static void child_main()
		rv = rv - WAIT_OBJECT_0;
		ap_assert((rv >= 0) && (rv < nthreads));
		cleanup_thread(child_handles, &nthreads, rv);
		ap_log_error(APLOG_MARK,APLOG_INFO, APR_SUCCESS, server_conf,
		"Child %d: Cleanup thread now.", my_pid);
		continue;
		}
		break;