Commit 14774214 authored by Chris Darroch's avatar Chris Darroch
Browse files

On graceless shutdown or restart, send AP_SIG_GRACEFUL to all worker 

threads so that any that are polling on Keep-Alive connections will
wake up and exit promptly.  Otherwise, on Linux, they wait until
poll()'s timeout interval completes, which is often too long for
the parent process; the parent issues SIGKILL before the child's main
thread manages to re-join all the worker threads.  PR 38737.

On Solaris, by contrast, the close_worker_sockets() function
successfully alerts all worker threads that they should exit quickly.
On Linux, this side-effect of one thread closing another's socket
doesn't occur; see:

http://bugme.osdl.org/show_bug.cgi?id=546

Also, expand on the placeholder in CHANGES regarding previous
cleanups to scoreboard.c and scoreboard.h in r404848 and r404849.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@409715 13f79535-47bb-0310-9956-ffa450edef68
parent abf3e701

CHANGES

+11 −1
Changes for CHANGES: 11 added lines, 1 removed line.
Original line number Diff line number Diff line
@@ -2,6 +2,10 @@ 
Changes with Apache 2.3.0

  [Remove entries to the current 2.0 and 2.2 section below, when backported]









  *) Worker MPM: On graceless shutdown or restart, send signals to









     each worker thread to wake them up if they're polling on a









     Keep-Alive connection.  PR 38737.  [Chris Darroch]

















  *) Worker and event MPMs: Remove improper scoreboard updates which were









     performed in the event of a fork() failure.  [Chris Darroch]


















@@ -11,7 +15,13 @@ Changes with Apache 2.3.0







  *) Add support for fcgi:// proxies to mod_rewrite.









     [Markus Schiegl <ms schiegl.com>]

















  *) Tidy up scoreboard [Chris Darroch <chrisd pearsoncmg.com> ]









  *) Remove incorrect comments from scoreboard.h regarding conditional









     loading of worker_score structure with mod_status, and remove unused









     definitions relating to old life_status field.









     [Chris Darroch <chrisd pearsoncmg.com>]

















  *) Remove allocation of memory for unused array of lb_score pointers









     in ap_init_scoreboard().  [Chris Darroch <chrisd pearsoncmg.com>]

















  *) core, mod_http: add optional 'scheme://' prefix to ServerName directive. 









     For 'https', mod_http returns "https" for the ap_hook_http_scheme and


































server/mpm/worker/worker.c



+25
−0



























Changes for server/mpm/worker/worker.c: 25 added lines, 0 removed lines.



Original line number
Diff line number
Diff line







@@ -213,6 +213,19 @@ static apr_proc_mutex_t *accept_mutex;







 */









#define LISTENER_SIGNAL     SIGHUP



















/* The WORKER_SIGNAL signal will be sent from the main thread to the









 * worker threads during an ungraceful restart or shutdown.









 * This ensures that on systems (i.e., Linux) where closing the worker









 * socket doesn't awake the worker thread when it is polling on the socket









 * (especially in apr_wait_for_io_or_timeout() when handling









 * Keep-Alive connections), close_worker_sockets() and join_workers()









 * still function in timely manner and allow ungraceful shutdowns to









 * proceed to completion.  Otherwise join_workers() doesn't return









 * before the main process decides the child process is non-responsive









 * and sends a SIGKILL.









 */









#define WORKER_SIGNAL       AP_SIG_GRACEFUL



















/* An array of socket descriptors in use by each thread used to









 * perform a non-graceful (forced) shutdown of the server. */









static apr_socket_t **worker_sockets;










@@ -822,6 +835,11 @@ static void * APR_THREAD_FUNC worker_thread(apr_thread_t *thd, void * dummy)







    ap_scoreboard_image->servers[process_slot][thread_slot].generation = ap_my_generation;









    ap_update_child_status_from_indexes(process_slot, thread_slot, SERVER_STARTING, NULL);



















#ifdef HAVE_PTHREAD_KILL









    unblock_signal(WORKER_SIGNAL);









    apr_signal(WORKER_SIGNAL, dummy_signal_handler);









#endif



















    while (!workers_may_exit) {









        if (!is_idle) {









            rv = ap_queue_info_set_idle(worker_queue_info, last_ptrans);










@@ -1077,6 +1095,13 @@ static void join_workers(apr_thread_t *listener, apr_thread_t **threads)

















    for (i = 0; i < ap_threads_per_child; i++) {









        if (threads[i]) { /* if we ever created this thread */









#ifdef HAVE_PTHREAD_KILL









            apr_os_thread_t *worker_os_thread;



















            apr_os_thread_get(&worker_os_thread, threads[i]);









            pthread_kill(*worker_os_thread, WORKER_SIGNAL);









#endif



















            rv = apr_thread_join(&thread_rv, threads[i]);









            if (rv != APR_SUCCESS) {









                ap_log_error(APLOG_MARK, APLOG_CRIT, rv, ap_server_conf,