Commit fe7c68cc authored by Jeff Trawick's avatar Jeff Trawick
Browse files

Simplify the interface to ap_reclaim_child_processes() and 

ap_relieve_child_processes(): instead of requiring the MPM
to implement an otherwise-useless hook, just use a callback
function.

As I don't expect third-party MPM devs are following our day
to day progress, the API changes are considered part of
yesterday's MMN change.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1087085 13f79535-47bb-0310-9956-ffa450edef68
parent 1cd992cf

docs/manual/developer/new_api_2_4.xml

+3 −1
Changes for docs/manual/developer/new_api_2_4.xml: 3 added lines, 1 removed line.
Original line number Diff line number Diff line
@@ -222,7 +222,9 @@ 
      <li>REMOVES: accept, lockfile, lock_mech, set_scoreboard (locking uses the new ap_mutex API)</li>

      <li>NEW API to drop privileges (delegates this platform-dependent

          function to modules)</li>

      <li>NEW Hooks: mpm_query, mpm_note_child_killed, timed_callback, and get_name</li>

      <li>NEW Hooks: mpm_query, timed_callback, and get_name</li>

      <li>CHANGED interfaces: monitor hook,

      ap_reclaim_child_processes, ap_relieve_child_processes</li>

    </ul>

  </section>

include/ap_mmn.h

+3 −0
Changes for include/ap_mmn.h: 3 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -313,6 +313,9 @@ 
 *                         proxy and cache interfaces.

 *                         Change ap_configfile_t/ap_cfg_getline()/

 *                         ap_cfg_getc() API, add ap_pcfg_strerror()

 *                         Axe mpm_note_child_killed hook, change

 *                         ap_reclaim_child_process and ap_recover_child_process

 *                         interfaces.

 */



#define MODULE_MAGIC_COOKIE 0x41503234UL /* "AP24" */

include/mpm_common.h

+10 −16
Changes for include/mpm_common.h: 10 added lines, 16 removed lines.
Original line number Diff line number Diff line
@@ -80,35 +80,36 @@ extern "C" { 
/* Signal used to gracefully stop (as a quoted string) */

#define AP_SIG_GRACEFUL_STOP_STRING "SIGWINCH"



/**

 * Callback function used for ap_reclaim_child_processes() and

 * ap_relieve_child_processes().  The callback function will be

 * called for each terminated child process.

 */

typedef void ap_reclaim_callback_fn_t(int childnum);



/**

 * Make sure all child processes that have been spawned by the parent process

 * have died.  This includes process registered as "other_children".

 * @param terminate Either 1 or 0.  If 1, send the child processes SIGTERM

 *        each time through the loop.  If 0, give the process time to die

 *        on its own before signalling it.

 * @note This function requires that a hook is implemented by the MPM: <pre>

 *  mpm_note_child_killed -- Note the child died in the scoreboard

 * </pre>

 *

 * @note The MPM child processes which are reclaimed are those listed

 * in the scoreboard as well as those currently registered via

 * ap_register_extra_mpm_process().

 */

void ap_reclaim_child_processes(int terminate);

void ap_reclaim_child_processes(int terminate,

                                ap_reclaim_callback_fn_t *mpm_callback);



/**

 * Catch any child processes that have been spawned by the parent process

 * which have exited. This includes processes registered as "other_children".

 *

 * @note This function requires that a hook is implemented by the MPM: <pre>

 *  mpm_note_child_killed -- Note the child died in the scoreboard

 * </pre>

 *

 * @note The MPM child processes which are relieved are those listed

 * in the scoreboard as well as those currently registered via

 * ap_register_extra_mpm_process().

 */

void ap_relieve_child_processes(void);

void ap_relieve_child_processes(ap_reclaim_callback_fn_t *mpm_callback);



/**

 * Tell ap_reclaim_child_processes() and ap_relieve_child_processes() about
@@ -333,13 +334,6 @@ AP_DECLARE_HOOK(int, drop_privileges, (apr_pool_t * pchild, server_rec * s)) 
 */

AP_DECLARE_HOOK(int, mpm_query, (int query_code, int *result, apr_status_t *rv))



/* child specified by index has been killed; MPMs which use

 * ap_reclaim_child_processes() or ap_relieve_child_processes() must

 * implement this in order to update the scoreboard and handle any

 * MPM-specific actions

 */

AP_DECLARE_HOOK(apr_status_t, mpm_note_child_killed, (int childnum))



/* register the specified callback */

AP_DECLARE_HOOK(apr_status_t, mpm_register_timed_callback,

                (apr_time_t t, ap_mpm_callback_fn_t *cbfn, void *baton))

server/mpm/event/event.c

+8 −8
Changes for server/mpm/event/event.c: 8 added lines, 8 removed lines.
Original line number Diff line number Diff line
@@ -424,10 +424,9 @@ static int event_query(int query_code, int *result, apr_status_t *rv) 
    return OK;

}



static apr_status_t event_note_child_killed(int childnum)

static void event_note_child_killed(int childnum)

{

    ap_scoreboard_image->parent[childnum].pid = 0;

    return APR_SUCCESS;

}



static const char *event_get_name(void)
@@ -2256,7 +2255,8 @@ static int event_run(apr_pool_t * _pconf, apr_pool_t * plog, server_rec * s) 
         * Kill child processes, tell them to call child_exit, etc...

         */

        ap_event_pod_killpg(pod, ap_daemons_limit, FALSE);

        ap_reclaim_child_processes(1);  /* Start with SIGTERM */

        ap_reclaim_child_processes(1, /* Start with SIGTERM */

                                   event_note_child_killed);



        if (!child_fatal) {

            /* cleanup pid file on normal shutdown */
@@ -2276,7 +2276,7 @@ static int event_run(apr_pool_t * _pconf, apr_pool_t * plog, server_rec * s) 
        /* Close our listeners, and then ask our children to do same */

        ap_close_listeners();

        ap_event_pod_killpg(pod, ap_daemons_limit, TRUE);

        ap_relieve_child_processes();

        ap_relieve_child_processes(event_note_child_killed);



        if (!child_fatal) {

            /* cleanup pid file on normal shutdown */
@@ -2298,7 +2298,7 @@ static int event_run(apr_pool_t * _pconf, apr_pool_t * plog, server_rec * s) 
            apr_sleep(apr_time_from_sec(1));



            /* Relieve any children which have now exited */

            ap_relieve_child_processes();

            ap_relieve_child_processes(event_note_child_killed);



            active_children = 0;

            for (index = 0; index < ap_daemons_limit; ++index) {
@@ -2316,7 +2316,7 @@ static int event_run(apr_pool_t * _pconf, apr_pool_t * plog, server_rec * s) 
         * really dead.

         */

        ap_event_pod_killpg(pod, ap_daemons_limit, FALSE);

        ap_reclaim_child_processes(1);

        ap_reclaim_child_processes(1, event_note_child_killed);



        return DONE;

    }
@@ -2356,7 +2356,8 @@ static int event_run(apr_pool_t * _pconf, apr_pool_t * plog, server_rec * s) 
         */

        ap_event_pod_killpg(pod, ap_daemons_limit, FALSE);



        ap_reclaim_child_processes(1);  /* Start with SIGTERM */

        ap_reclaim_child_processes(1,  /* Start with SIGTERM */

                                   event_note_child_killed);

        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,

                     "SIGHUP received.  Attempting to restart");

    }
@@ -2720,7 +2721,6 @@ static void event_hooks(apr_pool_t * p) 
    ap_hook_check_config(event_check_config, NULL, NULL, APR_HOOK_MIDDLE);

    ap_hook_mpm(event_run, NULL, NULL, APR_HOOK_MIDDLE);

    ap_hook_mpm_query(event_query, NULL, NULL, APR_HOOK_MIDDLE);

    ap_hook_mpm_note_child_killed(event_note_child_killed, NULL, NULL, APR_HOOK_MIDDLE);

    ap_hook_mpm_register_timed_callback(event_register_timed_callback, NULL, NULL,

                                        APR_HOOK_MIDDLE);

    ap_hook_mpm_get_name(event_get_name, NULL, NULL, APR_HOOK_MIDDLE);

server/mpm/prefork/prefork.c

+7 −7
Changes for server/mpm/prefork/prefork.c: 7 added lines, 7 removed lines.
Original line number Diff line number Diff line
@@ -306,10 +306,9 @@ static int prefork_query(int query_code, int *result, apr_status_t *rv) 
    return OK;

}



static apr_status_t prefork_note_child_killed(int childnum)

static void prefork_note_child_killed(int childnum)

{

    ap_scoreboard_image->parent[childnum].pid = 0;

    return APR_SUCCESS;

}



static const char *prefork_get_name(void)
@@ -1059,7 +1058,8 @@ static int prefork_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) 
        if (ap_unixd_killpg(getpgrp(), SIGTERM) < 0) {

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

        }

        ap_reclaim_child_processes(1);          /* Start with SIGTERM */

        ap_reclaim_child_processes(1, /* Start with SIGTERM */

                                   prefork_note_child_killed);



        /* cleanup pid file on normal shutdown */

        ap_remove_pid(pconf, ap_pid_fname);
@@ -1093,7 +1093,7 @@ static int prefork_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) 
        }



        /* Allow each child which actually finished to exit */

        ap_relieve_child_processes();

        ap_relieve_child_processes(prefork_note_child_killed);



        /* cleanup pid file */

        ap_remove_pid(pconf, ap_pid_fname);
@@ -1112,7 +1112,7 @@ static int prefork_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) 
            sleep(1);



            /* Relieve any children which have now exited */

            ap_relieve_child_processes();

            ap_relieve_child_processes(prefork_note_child_killed);



            active_children = 0;

            for (index = 0; index < ap_daemons_limit; ++index) {
@@ -1180,7 +1180,8 @@ static int prefork_run(apr_pool_t *_pconf, apr_pool_t *plog, server_rec *s) 
        if (ap_unixd_killpg(getpgrp(), SIGHUP) < 0) {

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

        }

        ap_reclaim_child_processes(0);          /* Not when just starting up */

        ap_reclaim_child_processes(0, /* Not when just starting up */

                                   prefork_note_child_killed);

        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf,

                    "SIGHUP received.  Attempting to restart");

    }
@@ -1415,7 +1416,6 @@ static void prefork_hooks(apr_pool_t *p) 
    ap_hook_check_config(prefork_check_config, NULL, NULL, APR_HOOK_MIDDLE);

    ap_hook_mpm(prefork_run, NULL, NULL, APR_HOOK_MIDDLE);

    ap_hook_mpm_query(prefork_query, NULL, NULL, APR_HOOK_MIDDLE);

    ap_hook_mpm_note_child_killed(prefork_note_child_killed, NULL, NULL, APR_HOOK_MIDDLE);

    ap_hook_mpm_get_name(prefork_get_name, NULL, NULL, APR_HOOK_MIDDLE);

}