src/bin/lttng-sessiond/load-session-thread.c

   1 /*
   2  * Copyright (C) 2014 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #define _LGPL_SOURCE
  20 #include <common/error.h>
  21 #include <common/config/config.h>
  22
  23 #include "load-session-thread.h"
  24 #include "lttng-sessiond.h"
  25
  26 /*
  27  * Destroy the thread data previously created with the init function.
  28  */
  29 void load_session_destroy_data(struct load_session_thread_data *data)
  30 {
  31         if (!data) {
  32                 return;
  33         }
  34
  35         if (data->sem_initialized) {
  36                 int ret;
  37
  38                 ret = sem_destroy(&data->message_thread_ready);
  39                 if (ret) {
  40                         PERROR("sem_destroy message_thread_ready");
  41                 }
  42         }
  43 }
  44
  45 /*
  46  * Initialize the thread data. This MUST be called before the thread load
  47  * session is created.
  48  *
  49  * Return 0 on success else a negative value. Note that the destroy function
  50  * can be called with no or partially initialized data.
  51  */
  52 int load_session_init_data(struct load_session_thread_data **data)
  53 {
  54         int ret;
  55         struct load_session_thread_data *_data = NULL;
  56
  57         assert(data);
  58
  59         /*
  60          * Allocate memory here since this function is called from the main thread
  61          * can die *before* the end of the load session thread.
  62          */
  63         _data = zmalloc(sizeof(*_data));
  64         if (!_data) {
  65                 PERROR("zmalloc load session info");
  66                 goto error;
  67         }
  68         ret = sem_init(&_data->message_thread_ready, 0, 0);
  69         if (ret) {
  70                 PERROR("sem_init message_thread_ready");
  71                 goto error;
  72         }
  73         _data->sem_initialized = 1;
  74
  75         *data = _data;
  76         return 0;
  77
  78 error:
  79         free(_data);
  80         return -1;
  81 }
  82
  83 /*
  84  * This thread loads session configurations once the session daemon is
  85  * ready to process client messages.
  86  */
  87 void *thread_load_session(void *data)
  88 {
  89         int ret;
  90         struct load_session_thread_data *info = data;
  91
  92         DBG("[load-session-thread] Load session");
  93
  94         ret = sem_wait(&info->message_thread_ready);
  95         if (ret) {
  96                 PERROR("sem_wait message_thread_ready");
  97                 goto end;
  98         }
  99
 100         /* Override existing session and autoload also. */
 101         ret = config_load_session(info->path, NULL, 1, 1);
 102         if (ret) {
 103                 ERR("Session load failed: %s", error_get_str(ret));
 104         }
 105
 106 end:
 107         sessiond_notify_ready();
 108         return NULL;
 109 }