src/bin/lttng-sessiond/notification-thread-commands.c

   1 /*
   2  * Copyright (C) 2017 - 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 #include <lttng/trigger/trigger.h>
  19 #include <lttng/lttng-error.h>
  20 #include "notification-thread.h"
  21 #include "notification-thread-commands.h"
  22 #include <common/error.h>
  23 #include <common/futex.h>
  24 #include <unistd.h>
  25 #include <stdint.h>
  26 #include <inttypes.h>
  27
  28 static
  29 void init_notification_thread_command(struct notification_thread_command *cmd)
  30 {
  31         memset(cmd, 0, sizeof(*cmd));
  32         CDS_INIT_LIST_HEAD(&cmd->cmd_list_node);
  33 }
  34
  35 static
  36 int run_command_wait(struct notification_thread_handle *handle,
  37                 struct notification_thread_command *cmd)
  38 {
  39         int ret;
  40         uint64_t notification_counter = 1;
  41
  42         futex_nto1_prepare(&cmd->reply_futex);
  43
  44         pthread_mutex_lock(&handle->cmd_queue.lock);
  45         /* Add to queue. */
  46         cds_list_add_tail(&cmd->cmd_list_node,
  47                         &handle->cmd_queue.list);
  48         /* Wake-up thread. */
  49         ret = write(handle->cmd_queue.event_fd,
  50                         &notification_counter, sizeof(notification_counter));
  51         if (ret < 0) {
  52                 PERROR("write to notification thread's queue event fd");
  53                 /*
  54                  * Remove the command from the list so the notification
  55                  * thread does not process it.
  56                  */
  57                 cds_list_del(&cmd->cmd_list_node);
  58                 goto error_unlock_queue;
  59         }
  60         pthread_mutex_unlock(&handle->cmd_queue.lock);
  61
  62         futex_nto1_wait(&cmd->reply_futex);
  63         return 0;
  64 error_unlock_queue:
  65         pthread_mutex_unlock(&handle->cmd_queue.lock);
  66         return -1;
  67 }
  68
  69 enum lttng_error_code notification_thread_command_register_trigger(
  70                 struct notification_thread_handle *handle,
  71                 struct lttng_trigger *trigger)
  72 {
  73         int ret;
  74         enum lttng_error_code ret_code;
  75         struct notification_thread_command cmd;
  76
  77         init_notification_thread_command(&cmd);
  78
  79         cmd.type = NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER;
  80         cmd.parameters.trigger = trigger;
  81
  82         ret = run_command_wait(handle, &cmd);
  83         if (ret) {
  84                 ret_code = LTTNG_ERR_UNK;
  85                 goto end;
  86         }
  87         ret_code = cmd.reply_code;
  88 end:
  89         return ret_code;
  90 }
  91
  92 enum lttng_error_code notification_thread_command_unregister_trigger(
  93                 struct notification_thread_handle *handle,
  94                 struct lttng_trigger *trigger)
  95 {
  96         int ret;
  97         enum lttng_error_code ret_code;
  98         struct notification_thread_command cmd;
  99
 100         init_notification_thread_command(&cmd);
 101
 102         cmd.type = NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER;
 103         cmd.parameters.trigger = trigger;
 104
 105         ret = run_command_wait(handle, &cmd);
 106         if (ret) {
 107                 ret_code = LTTNG_ERR_UNK;
 108                 goto end;
 109         }
 110         ret_code = cmd.reply_code;
 111 end:
 112         return ret_code;
 113 }
 114
 115 enum lttng_error_code notification_thread_command_add_channel(
 116                 struct notification_thread_handle *handle,
 117                 char *session_name, uid_t uid, gid_t gid,
 118                 char *channel_name, uint64_t key,
 119                 enum lttng_domain_type domain, uint64_t capacity)
 120 {
 121         int ret;
 122         enum lttng_error_code ret_code;
 123         struct notification_thread_command cmd;
 124
 125         init_notification_thread_command(&cmd);
 126
 127         cmd.type = NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL;
 128         cmd.parameters.add_channel.session_name = session_name;
 129         cmd.parameters.add_channel.uid = uid;
 130         cmd.parameters.add_channel.gid = gid;
 131         cmd.parameters.add_channel.channel_name = channel_name;
 132         cmd.parameters.add_channel.key.key = key;
 133         cmd.parameters.add_channel.key.domain = domain;
 134         cmd.parameters.add_channel.capacity = capacity;
 135
 136         ret = run_command_wait(handle, &cmd);
 137         if (ret) {
 138                 ret_code = LTTNG_ERR_UNK;
 139                 goto end;
 140         }
 141         ret_code = cmd.reply_code;
 142 end:
 143         return ret_code;
 144 }
 145
 146 enum lttng_error_code notification_thread_command_remove_channel(
 147                 struct notification_thread_handle *handle,
 148                 uint64_t key, enum lttng_domain_type domain)
 149 {
 150         int ret;
 151         enum lttng_error_code ret_code;
 152         struct notification_thread_command cmd;
 153
 154         init_notification_thread_command(&cmd);
 155
 156         cmd.type = NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL;
 157         cmd.parameters.remove_channel.key = key;
 158         cmd.parameters.remove_channel.domain = domain;
 159
 160         ret = run_command_wait(handle, &cmd);
 161         if (ret) {
 162                 ret_code = LTTNG_ERR_UNK;
 163                 goto end;
 164         }
 165         ret_code = cmd.reply_code;
 166 end:
 167         return ret_code;
 168 }
 169
 170 void notification_thread_command_quit(
 171                 struct notification_thread_handle *handle)
 172 {
 173         int ret;
 174         struct notification_thread_command cmd;
 175
 176         init_notification_thread_command(&cmd);
 177
 178         cmd.type = NOTIFICATION_COMMAND_TYPE_QUIT;
 179         ret = run_command_wait(handle, &cmd);
 180         assert(!ret && cmd.reply_code == LTTNG_OK);
 181 }