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Posted to cvs@httpd.apache.org by sf...@apache.org on 2011/10/10 01:10:13 UTC

svn commit: r1180742 - in /httpd/httpd/trunk: CHANGES server/mpm/event/event.c server/mpm/prefork/prefork.c server/mpm/worker/worker.c

Author: sf
Date: Sun Oct  9 23:10:12 2011
New Revision: 1180742

URL: http://svn.apache.org/viewvc?rev=1180742&view=rev
Log:
If a child is created just before graceful restart and then exits because
of a missing lock file, don't shutdown the whole server.

PR: 39311
Submitted by: Shawn Michael <smichael rightnow com>

Modified:
    httpd/httpd/trunk/CHANGES
    httpd/httpd/trunk/server/mpm/event/event.c
    httpd/httpd/trunk/server/mpm/prefork/prefork.c
    httpd/httpd/trunk/server/mpm/worker/worker.c

Modified: httpd/httpd/trunk/CHANGES
URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/CHANGES?rev=1180742&r1=1180741&r2=1180742&view=diff
==============================================================================
--- httpd/httpd/trunk/CHANGES [utf-8] (original)
+++ httpd/httpd/trunk/CHANGES [utf-8] Sun Oct  9 23:10:12 2011
@@ -12,6 +12,11 @@ Changes with Apache 2.3.15
      PR 51714. [Stefan Fritsch, Jim Jagielski, Ruediger Pluem, Eric Covener,
      <lowprio20 gmail.com>]
 
+  *) mpm_prefork, mpm_worker, mpm_event: If a child is created just before
+     graceful restart and then exits because of a missing lock file, don't
+     shutdown the whole server. PR 39311. [Shawn Michael
+     <smichael rightnow com>]
+
   *) mpm_event: Check the return value from ap_run_create_connection.
      PR: 41194. [Davi Arnaut]
 

Modified: httpd/httpd/trunk/server/mpm/event/event.c
URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/server/mpm/event/event.c?rev=1180742&r1=1180741&r2=1180742&view=diff
==============================================================================
--- httpd/httpd/trunk/server/mpm/event/event.c (original)
+++ httpd/httpd/trunk/server/mpm/event/event.c Sun Oct  9 23:10:12 2011
@@ -2421,10 +2421,27 @@ static void server_main_loop(int remaini
 
         if (pid.pid != -1) {
             processed_status = ap_process_child_status(&pid, exitwhy, status);
+            child_slot = ap_find_child_by_pid(&pid);
             if (processed_status == APEXIT_CHILDFATAL) {
-                shutdown_pending = 1;
-                child_fatal = 1;
-                return;
+                /* fix race condition found in PR 39311
+                 * A child created at the same time as a graceful happens 
+                 * can find the lock missing and create a fatal error.
+                 * It is not fatal for the last generation to be in this state.
+                 */
+                if (child_slot < 0
+                    || ap_get_scoreboard_process(child_slot)->generation
+                       == retained->my_generation) {
+                    shutdown_pending = 1;
+                    child_fatal = 1;
+                    return;
+                }
+                else {
+                    ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ap_server_conf,
+                                 "Ignoring fatal error in child of previous "
+                                 "generation (pid %ld).",
+                                 (long)pid.pid);
+                    retained->sick_child_detected = 1;
+                }
             }
             else if (processed_status == APEXIT_CHILDSICK) {
                 /* tell perform_idle_server_maintenance to check into this
@@ -2433,7 +2450,6 @@ static void server_main_loop(int remaini
                 retained->sick_child_detected = 1;
             }
             /* non-fatal death... note that it's gone in the scoreboard. */
-            child_slot = ap_find_child_by_pid(&pid);
             if (child_slot >= 0) {
                 for (i = 0; i < threads_per_child; i++)
                     ap_update_child_status_from_indexes(child_slot, i,

Modified: httpd/httpd/trunk/server/mpm/prefork/prefork.c
URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/server/mpm/prefork/prefork.c?rev=1180742&r1=1180741&r2=1180742&view=diff
==============================================================================
--- httpd/httpd/trunk/server/mpm/prefork/prefork.c (original)
+++ httpd/httpd/trunk/server/mpm/prefork/prefork.c Sun Oct  9 23:10:12 2011
@@ -1004,13 +1004,28 @@ static int prefork_run(apr_pool_t *_pcon
          */
         if (pid.pid != -1) {
             processed_status = ap_process_child_status(&pid, exitwhy, status);
+            child_slot = ap_find_child_by_pid(&pid);
             if (processed_status == APEXIT_CHILDFATAL) {
-                mpm_state = AP_MPMQ_STOPPING;
-                return DONE;
+                /* fix race condition found in PR 39311
+                 * A child created at the same time as a graceful happens 
+                 * can find the lock missing and create a fatal error.
+                 * It is not fatal for the last generation to be in this state.
+                 */
+                if (child_slot < 0
+                    || ap_get_scoreboard_process(child_slot)->generation
+                       == retained->my_generation) {
+                    mpm_state = AP_MPMQ_STOPPING;
+                    return DONE;
+                }
+                else {
+                    ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ap_server_conf,
+                                 "Ignoring fatal error in child of previous "
+                                 "generation (pid %ld).",
+                                 (long)pid.pid);
+                }
             }
 
             /* non-fatal death... note that it's gone in the scoreboard. */
-            child_slot = ap_find_child_by_pid(&pid);
             if (child_slot >= 0) {
                 (void) ap_update_child_status_from_indexes(child_slot, 0, SERVER_DEAD,
                                                            (request_rec *) NULL);

Modified: httpd/httpd/trunk/server/mpm/worker/worker.c
URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/server/mpm/worker/worker.c?rev=1180742&r1=1180741&r2=1180742&view=diff
==============================================================================
--- httpd/httpd/trunk/server/mpm/worker/worker.c (original)
+++ httpd/httpd/trunk/server/mpm/worker/worker.c Sun Oct  9 23:10:12 2011
@@ -1647,10 +1647,27 @@ static void server_main_loop(int remaini
 
         if (pid.pid != -1) {
             processed_status = ap_process_child_status(&pid, exitwhy, status);
+            child_slot = ap_find_child_by_pid(&pid);
             if (processed_status == APEXIT_CHILDFATAL) {
-                shutdown_pending = 1;
-                child_fatal = 1;
-                return;
+                /* fix race condition found in PR 39311
+                 * A child created at the same time as a graceful happens 
+                 * can find the lock missing and create a fatal error.
+                 * It is not fatal for the last generation to be in this state.
+                 */
+                if (child_slot < 0
+                    || ap_get_scoreboard_process(child_slot)->generation
+                       == retained->my_generation) {
+                    shutdown_pending = 1;
+                    child_fatal = 1;
+                    return;
+                }
+                else {
+                    ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ap_server_conf,
+                                 "Ignoring fatal error in child of previous "
+                                 "generation (pid %ld).",
+                                 (long)pid.pid);
+                    retained->sick_child_detected = 1;
+                }
             }
             else if (processed_status == APEXIT_CHILDSICK) {
                 /* tell perform_idle_server_maintenance to check into this
@@ -1659,7 +1676,6 @@ static void server_main_loop(int remaini
                 retained->sick_child_detected = 1;
             }
             /* non-fatal death... note that it's gone in the scoreboard. */
-            child_slot = ap_find_child_by_pid(&pid);
             if (child_slot >= 0) {
                 for (i = 0; i < threads_per_child; i++)
                     ap_update_child_status_from_indexes(child_slot, i, SERVER_DEAD,