source3/lib/server_id_watch.c

   1 /*
   2  * Unix SMB/CIFS implementation.
   3  * Wait for process death
   4  * Copyright (C) Volker Lendecke 2016
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "replace.h"
  21 #include <tevent.h>
  22 #include <talloc.h>
  23 #include "serverid.h"
  24 #include "server_id_watch.h"
  25 #include "messages.h"
  26 #include "lib/util/tevent_unix.h"
  27
  28 struct server_id_watch_state {
  29         struct tevent_context *ev;
  30         struct server_id pid;
  31 };
  32
  33 static void server_id_watch_waited(struct tevent_req *subreq);
  34
  35 struct tevent_req *server_id_watch_send(TALLOC_CTX *mem_ctx,
  36                                         struct tevent_context *ev,
  37                                         struct messaging_context *msg,
  38                                         struct server_id pid)
  39 {
  40         struct tevent_req *req, *subreq;
  41         struct server_id_watch_state *state;
  42
  43         req = tevent_req_create(mem_ctx, &state, struct server_id_watch_state);
  44         if (req == NULL) {
  45                 return NULL;
  46         }
  47         state->ev = ev;
  48         state->pid = pid;
  49
  50         if (!serverid_exists(&state->pid)) {
  51                 tevent_req_done(req);
  52                 return tevent_req_post(req, ev);
  53         }
  54
  55         subreq = tevent_wakeup_send(state, ev, timeval_current_ofs(0, 500000));
  56         if (tevent_req_nomem(subreq, req)) {
  57                 return tevent_req_post(req, ev);
  58         }
  59         tevent_req_set_callback(subreq, server_id_watch_waited, req);
  60
  61         return req;
  62 }
  63
  64 static void server_id_watch_waited(struct tevent_req *subreq)
  65 {
  66         struct tevent_req *req = tevent_req_callback_data(
  67                 subreq, struct tevent_req);
  68         struct server_id_watch_state *state = tevent_req_data(
  69                 req, struct server_id_watch_state);
  70         bool ok;
  71
  72         ok = tevent_wakeup_recv(subreq);
  73         TALLOC_FREE(subreq);
  74         if (!ok) {
  75                 tevent_req_oom(req);
  76                 return;
  77         }
  78
  79         if (!serverid_exists(&state->pid)) {
  80                 tevent_req_done(req);
  81                 return;
  82         }
  83
  84         subreq = tevent_wakeup_send(state, state->ev,
  85                                     timeval_current_ofs(0, 500000));
  86         if (tevent_req_nomem(subreq, req)) {
  87                 return;
  88         }
  89         tevent_req_set_callback(subreq, server_id_watch_waited, req);
  90 }
  91
  92 int server_id_watch_recv(struct tevent_req *req, struct server_id *pid)
  93 {
  94         struct server_id_watch_state *state = tevent_req_data(
  95                 req, struct server_id_watch_state);
  96         int err;
  97
  98         if (tevent_req_is_unix_error(req, &err)) {
  99                 return err;
 100         }
 101         if (pid) {
 102                 *pid = state->pid;
 103         }
 104         return 0;
 105 }