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 _LGPL_SOURCE
  19 #include <common/error.h>
  20 #include <common/config/config.h>
  21
  22 #include "load-session-thread.h"
  23 #include "lttng-sessiond.h"
  24
  25 /*
  26  * Destroy the thread data previously created with the init function.
  27  */
  28 void load_session_destroy_data(struct load_session_thread_data *data)
  29 {
  30         if (!data) {
  31                 return;
  32         }
  33
  34         if (data->sem_initialized) {
  35                 int ret;
  36
  37                 ret = sem_destroy(&data->message_thread_ready);
  38                 if (ret) {
  39                         PERROR("sem_destroy message_thread_ready");
  40                 }
  41         }
  42 }
  43
  44 /*
  45  * Initialize the thread data. This MUST be called before the thread load
  46  * session is created.
  47  *
  48  * Return 0 on success else a negative value. Note that the destroy function
  49  * can be called with no or partially initialized data.
  50  */
  51 int load_session_init_data(struct load_session_thread_data **data)
  52 {
  53         int ret;
  54         struct load_session_thread_data *_data = NULL;
  55
  56         assert(data);
  57
  58         /*
  59          * Allocate memory here since this function is called from the main thread
  60          * can die *before* the end of the load session thread.
  61          */
  62         _data = zmalloc(sizeof(*_data));
  63         if (!_data) {
  64                 PERROR("zmalloc load session info");
  65                 goto error;
  66         }
  67         ret = sem_init(&_data->message_thread_ready, 0, 0);
  68         if (ret) {
  69                 PERROR("sem_init message_thread_ready");
  70                 goto error;
  71         }
  72         _data->sem_initialized = 1;
  73
  74         *data = _data;
  75         return 0;
  76
  77 error:
  78         free(_data);
  79         return -1;
  80 }
  81
  82 /*
  83  * This thread loads session configurations once the session daemon is
  84  * ready to process client messages.
  85  */
  86 void *thread_load_session(void *data)
  87 {
  88         int ret;
  89         struct load_session_thread_data *info = data;
  90
  91         DBG("[load-session-thread] Load session");
  92
  93         ret = sem_wait(&info->message_thread_ready);
  94         if (ret) {
  95                 PERROR("sem_wait message_thread_ready");
  96                 goto end;
  97         }
  98
  99         /* Override existing session and autoload also. */
 100         ret = config_load_session(info->path, NULL, 1, 1);
 101         if (ret) {
 102                 ERR("Session load failed: %s", error_get_str(ret));
 103         }
 104
 105 end:
 106         sessiond_notify_ready();
 107         return NULL;
 108 }