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5b74c7b1 DG |
1 | /* |
2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
82a3637f DG |
6 | * as published by the Free Software Foundation; only version 2 |
7 | * of the License. | |
91d76f53 | 8 | * |
5b74c7b1 DG |
9 | * This program is distributed in the hope that it will be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
050349bb | 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
5b74c7b1 DG |
12 | * GNU General Public License for more details. |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | */ | |
18 | ||
19 | #define _GNU_SOURCE | |
6c9cc2ab | 20 | #include <limits.h> |
5b74c7b1 DG |
21 | #include <stdio.h> |
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
f6a9efaa | 24 | #include <urcu.h> |
5b74c7b1 | 25 | |
54d01ffb | 26 | #include <lttng-sessiond-comm.h> |
1e307fab DG |
27 | #include <lttngerr.h> |
28 | ||
f6a9efaa | 29 | #include "hashtable.h" |
5b74c7b1 DG |
30 | #include "session.h" |
31 | ||
f6a9efaa DG |
32 | #include "../hashtable/hash.h" |
33 | ||
8c0faa1d | 34 | /* |
b5541356 | 35 | * NOTES: |
8c0faa1d | 36 | * |
b5541356 DG |
37 | * No ltt_session.lock is taken here because those data structure are widely |
38 | * spread across the lttng-tools code base so before caling functions below | |
39 | * that can read/write a session, the caller MUST acquire the session lock | |
54d01ffb | 40 | * using session_lock() and session_unlock(). |
8c0faa1d | 41 | */ |
8c0faa1d | 42 | |
5b74c7b1 | 43 | /* |
b5541356 | 44 | * Init tracing session list. |
5b74c7b1 | 45 | * |
b5541356 | 46 | * Please see session.h for more explanation and correct usage of the list. |
5b74c7b1 | 47 | */ |
b5541356 DG |
48 | static struct ltt_session_list ltt_session_list = { |
49 | .head = CDS_LIST_HEAD_INIT(ltt_session_list.head), | |
50 | .lock = PTHREAD_MUTEX_INITIALIZER, | |
51 | .count = 0, | |
52 | }; | |
5b74c7b1 DG |
53 | |
54 | /* | |
050349bb | 55 | * Add a ltt_session structure to the global list. |
5b74c7b1 | 56 | * |
050349bb | 57 | * The caller MUST acquire the session list lock before. |
5b74c7b1 DG |
58 | */ |
59 | static void add_session_list(struct ltt_session *ls) | |
60 | { | |
61 | cds_list_add(&ls->list, <t_session_list.head); | |
b5541356 | 62 | ltt_session_list.count++; |
5b74c7b1 DG |
63 | } |
64 | ||
65 | /* | |
050349bb | 66 | * Delete a ltt_session structure to the global list. |
b5541356 | 67 | * |
050349bb | 68 | * The caller MUST acquire the session list lock before. |
5b74c7b1 DG |
69 | */ |
70 | static void del_session_list(struct ltt_session *ls) | |
71 | { | |
72 | cds_list_del(&ls->list); | |
73 | /* Sanity check */ | |
b5541356 DG |
74 | if (ltt_session_list.count > 0) { |
75 | ltt_session_list.count--; | |
5b74c7b1 DG |
76 | } |
77 | } | |
78 | ||
b5541356 | 79 | /* |
050349bb | 80 | * Return a pointer to the session list. |
b5541356 | 81 | */ |
54d01ffb | 82 | struct ltt_session_list *session_get_list(void) |
b5541356 DG |
83 | { |
84 | return <t_session_list; | |
85 | } | |
86 | ||
87 | /* | |
6c9cc2ab | 88 | * Acquire session list lock |
b5541356 | 89 | */ |
54d01ffb | 90 | void session_lock_list(void) |
b5541356 | 91 | { |
6c9cc2ab | 92 | pthread_mutex_lock(<t_session_list.lock); |
b5541356 DG |
93 | } |
94 | ||
95 | /* | |
6c9cc2ab | 96 | * Release session list lock |
b5541356 | 97 | */ |
54d01ffb | 98 | void session_unlock_list(void) |
b5541356 | 99 | { |
6c9cc2ab | 100 | pthread_mutex_unlock(<t_session_list.lock); |
b5541356 DG |
101 | } |
102 | ||
103 | /* | |
6c9cc2ab | 104 | * Acquire session lock |
b5541356 | 105 | */ |
54d01ffb | 106 | void session_lock(struct ltt_session *session) |
b5541356 | 107 | { |
6c9cc2ab DG |
108 | pthread_mutex_lock(&session->lock); |
109 | } | |
b5541356 | 110 | |
6c9cc2ab DG |
111 | /* |
112 | * Release session lock | |
113 | */ | |
54d01ffb | 114 | void session_unlock(struct ltt_session *session) |
6c9cc2ab DG |
115 | { |
116 | pthread_mutex_unlock(&session->lock); | |
b5541356 DG |
117 | } |
118 | ||
5b74c7b1 | 119 | /* |
74babd95 DG |
120 | * Return a ltt_session structure ptr that matches name. If no session found, |
121 | * NULL is returned. This must be called with the session lock held using | |
122 | * session_lock_list and session_unlock_list. | |
5b74c7b1 | 123 | */ |
54d01ffb | 124 | struct ltt_session *session_find_by_name(char *name) |
5b74c7b1 | 125 | { |
5b74c7b1 DG |
126 | struct ltt_session *iter; |
127 | ||
5f822d0a DG |
128 | DBG2("Trying to find session by name %s", name); |
129 | ||
5b74c7b1 | 130 | cds_list_for_each_entry(iter, <t_session_list.head, list) { |
1b110e1b | 131 | if (strncmp(iter->name, name, NAME_MAX) == 0) { |
74babd95 | 132 | goto found; |
5b74c7b1 DG |
133 | } |
134 | } | |
135 | ||
74babd95 | 136 | iter = NULL; |
5b74c7b1 | 137 | |
74babd95 | 138 | found: |
5b74c7b1 DG |
139 | return iter; |
140 | } | |
141 | ||
142 | /* | |
050349bb | 143 | * Delete session from the session list and free the memory. |
5b74c7b1 | 144 | * |
050349bb | 145 | * Return -1 if no session is found. On success, return 1; |
5b74c7b1 | 146 | */ |
271933a4 | 147 | int session_destroy(struct ltt_session *session) |
5b74c7b1 | 148 | { |
271933a4 DG |
149 | /* Safety check */ |
150 | if (session == NULL) { | |
151 | ERR("Session pointer was null on session destroy"); | |
152 | return LTTCOMM_OK; | |
5b74c7b1 | 153 | } |
271933a4 DG |
154 | |
155 | DBG("Destroying session %s", session->name); | |
156 | del_session_list(session); | |
271933a4 DG |
157 | pthread_mutex_destroy(&session->lock); |
158 | free(session); | |
5b74c7b1 | 159 | |
54d01ffb | 160 | return LTTCOMM_OK; |
5b74c7b1 DG |
161 | } |
162 | ||
163 | /* | |
050349bb | 164 | * Create a brand new session and add it to the session list. |
5b74c7b1 | 165 | */ |
54d01ffb | 166 | int session_create(char *name, char *path) |
5b74c7b1 | 167 | { |
f3ed775e | 168 | int ret; |
5b74c7b1 | 169 | struct ltt_session *new_session; |
e07ae692 | 170 | |
54d01ffb | 171 | new_session = session_find_by_name(name); |
5b74c7b1 | 172 | if (new_session != NULL) { |
54d01ffb | 173 | ret = LTTCOMM_EXIST_SESS; |
f3ed775e | 174 | goto error_exist; |
5b74c7b1 DG |
175 | } |
176 | ||
177 | /* Allocate session data structure */ | |
178 | new_session = malloc(sizeof(struct ltt_session)); | |
179 | if (new_session == NULL) { | |
180 | perror("malloc"); | |
54d01ffb | 181 | ret = LTTCOMM_FATAL; |
f3ed775e | 182 | goto error_malloc; |
5b74c7b1 DG |
183 | } |
184 | ||
f3ed775e | 185 | /* Define session name */ |
5b74c7b1 | 186 | if (name != NULL) { |
74babd95 | 187 | if (snprintf(new_session->name, NAME_MAX, "%s", name) < 0) { |
54d01ffb | 188 | ret = LTTCOMM_FATAL; |
f3ed775e | 189 | goto error_asprintf; |
5b74c7b1 DG |
190 | } |
191 | } else { | |
f3ed775e | 192 | ERR("No session name given"); |
54d01ffb | 193 | ret = LTTCOMM_FATAL; |
f3ed775e DG |
194 | goto error; |
195 | } | |
196 | ||
197 | /* Define session system path */ | |
198 | if (path != NULL) { | |
74babd95 | 199 | if (snprintf(new_session->path, PATH_MAX, "%s", path) < 0) { |
54d01ffb | 200 | ret = LTTCOMM_FATAL; |
f3ed775e | 201 | goto error_asprintf; |
5b74c7b1 | 202 | } |
f3ed775e DG |
203 | } else { |
204 | ERR("No session path given"); | |
54d01ffb | 205 | ret = LTTCOMM_FATAL; |
f3ed775e | 206 | goto error; |
5b74c7b1 DG |
207 | } |
208 | ||
1d4b027a DG |
209 | /* Init kernel session */ |
210 | new_session->kernel_session = NULL; | |
f6a9efaa | 211 | new_session->ust_session = NULL; |
1657e9bb | 212 | |
0177d773 DG |
213 | /* Init lock */ |
214 | pthread_mutex_init(&new_session->lock, NULL); | |
5b74c7b1 | 215 | |
b5541356 | 216 | /* Add new session to the session list */ |
54d01ffb | 217 | session_lock_list(); |
5b74c7b1 | 218 | add_session_list(new_session); |
54d01ffb | 219 | session_unlock_list(); |
b5541356 | 220 | |
0177d773 | 221 | DBG("Tracing session %s created in %s", name, path); |
b082db07 | 222 | |
54d01ffb | 223 | return LTTCOMM_OK; |
5b74c7b1 DG |
224 | |
225 | error: | |
f3ed775e DG |
226 | error_asprintf: |
227 | if (new_session != NULL) { | |
228 | free(new_session); | |
229 | } | |
5b74c7b1 | 230 | |
f3ed775e DG |
231 | error_exist: |
232 | error_malloc: | |
233 | return ret; | |
5b74c7b1 | 234 | } |