Commit 9e19abd4 authored by Greg Ames's avatar Greg Ames
Browse files 

Fix shutdown/restart hangs in the threaded MPM.

After removing mod_cgid from my build (thanks, Jeff), I can do:
* apachectl graceful, followed by
* apachectl restart, followed by
* apachectl stop

...and get the results you would expect.

Submitted by: Jeff Trawick, Greg Ames, Ryan Bloom


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@88941 13f79535-47bb-0310-9956-ffa450edef68
parent a5be2e76

CHANGES

+3 −0
Original line number Diff line number Diff line 
Changes with Apache 2.0.18-dev



  *) Fix shutdown/restart hangs in the threaded MPM.

     [Jeff Trawick, Greg Ames, Ryan Bloom]

  

  *) Removed the keptalive boolean from conn_rec because it is now only

     used by a single routine and can be replaced by a local variable.

     [Greg Stein, Ryan Bloom, Roy Fielding]

server/mpm/threaded/threaded.c

+41 −14
Original line number Diff line number Diff line
@@ -705,12 +705,22 @@ static void child_main(int child_num_arg) 
    

    /* What state should this child_main process be listed as in the scoreboard...?

     *  ap_update_child_status(my_child_num, i, SERVER_STARTING, (request_rec *) NULL);

     * 

     *  This state should be listed separately in the scoreboard, in some kind

     *  of process_status, not mixed in with the worker threads' status.   

     *  "life_status" is almost right, but it's in the worker's structure, and 

     *  the name could be clearer.   gla

     */



    apr_signal_thread(check_signal);



    workers_may_exit = 1;   /* helps us terminate a little more quickly when 

                             * the dispatch of the signal thread

                             * beats the Pipe of Death and the browsers

                             */

    

    /* A terminating signal was received. Now join each of the workers to clean them up.

     *   If the worker already exitted, then the join frees their resources and returns.

     *   If the worker already exited, then the join frees their resources and returns.

     *   If the worker hasn't exited, then this blocks until they have (then cleans up).

     */

    for (i = 0; i < ap_threads_per_child; i++) {
@@ -781,6 +791,29 @@ static int make_child(server_rec *s, int slot) 
    return 0;

}



/* If there aren't many connections coming in from the network, the child 

 * processes may need to be awakened from their network i/o waits.

 * The pipe of death is an effective prod.

 */

   

static void wake_up_and_die(void) 

{

    int i;

    char char_of_death = '!';

    apr_size_t one = 1;

    apr_status_t rv;

    

    for (i = 0; i < ap_daemons_limit;) {

        if ((rv = apr_file_write(pipe_of_death_out, &char_of_death, &one)) 

                                 != APR_SUCCESS) {

            if (APR_STATUS_IS_EINTR(rv)) continue;

            ap_log_error(APLOG_MARK, APLOG_WARNING, rv, ap_server_conf, 

                         "write pipe_of_death");

        }

        i++;

    }

}



/* start up a bunch of children */

static void startup_children(int number_to_start)

{
@@ -994,7 +1027,6 @@ int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) 
{

    int remaining_children_to_start;

    apr_status_t rv;

    apr_size_t one = 1;



    pconf = _pconf;

    ap_server_conf = s;
@@ -1078,6 +1110,8 @@ int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) 
        /* Time to gracefully shut down:

         * Kill child processes, tell them to call child_exit, etc...

         */

        wake_up_and_die();



        if (unixd_killpg(getpgrp(), SIGTERM) < 0) {

            ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "killpg SIGTERM");

        }
@@ -1116,22 +1150,15 @@ int ap_mpm_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) 
    ap_scoreboard_image->global.running_generation = ap_my_generation;

    update_scoreboard_global();

    

    /* wake up the children...time to die.  But we'll have more soon */

    wake_up_and_die();

    

    if (is_graceful) {

        int i, j;

        char char_of_death = '!';



	ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, 0, ap_server_conf,

		    "SIGWINCH received.  Doing graceful restart");



	/* give the children the signal to die */

        for (i = 0; i < ap_daemons_limit;) {

            if ((rv = apr_file_write(pipe_of_death_out, &char_of_death, &one)) != APR_SUCCESS) {

                if (APR_STATUS_IS_EINTR(rv)) continue;

                ap_log_error(APLOG_MARK, APLOG_WARNING, rv, ap_server_conf, "write pipe_of_death");

            }

            i++;

        }



	/* This is mostly for debugging... so that we know what is still

         * gracefully dealing with existing request.

         */