*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
+ * as published by the Free Software Foundation; only version 2
+ * of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
*/
#define _GNU_SOURCE
+#include <limits.h>
+#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "lttngerr.h"
#include "session.h"
-/* Variables */
-static unsigned int session_count;
-
-/* Static internal function */
-static void add_session_list(struct ltt_session *ls);
-static void del_session_list(struct ltt_session *ls);
+/*
+ * NOTES:
+ *
+ * No ltt_session.lock is taken here because those data structure are widely
+ * spread across the lttng-tools code base so before caling functions below
+ * that can read/write a session, the caller MUST acquire the session lock
+ * using lock_session() and unlock_session().
+ */
-/* Init global session list */
-struct ltt_session_list ltt_session_list = {
+/*
+ * Init tracing session list.
+ *
+ * Please see session.h for more explanation and correct usage of the list.
+ */
+static struct ltt_session_list ltt_session_list = {
.head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
+ .lock = PTHREAD_MUTEX_INITIALIZER,
+ .count = 0,
};
/*
- * get_session_list
+ * Add a ltt_session structure to the global list.
+ *
+ * The caller MUST acquire the session list lock before.
+ */
+static void add_session_list(struct ltt_session *ls)
+{
+ cds_list_add(&ls->list, <t_session_list.head);
+ ltt_session_list.count++;
+}
+
+/*
+ * Delete a ltt_session structure to the global list.
*
- * Return a pointer to the session list.
+ * The caller MUST acquire the session list lock before.
+ */
+static void del_session_list(struct ltt_session *ls)
+{
+ cds_list_del(&ls->list);
+ /* Sanity check */
+ if (ltt_session_list.count > 0) {
+ ltt_session_list.count--;
+ }
+}
+
+/*
+ * Return a pointer to the session list.
*/
struct ltt_session_list *get_session_list(void)
{
}
/*
- * get_session_count
- *
- * Return session_count
+ * Acquire session list lock
*/
-unsigned int get_session_count(void)
+void lock_session_list(void)
{
- return session_count;
+ pthread_mutex_lock(<t_session_list.lock);
}
/*
- * add_session_list
- *
- * Add a ltt_session structure to the global list.
+ * Release session list lock
*/
-static void add_session_list(struct ltt_session *ls)
+void unlock_session_list(void)
{
- cds_list_add(&ls->list, <t_session_list.head);
- session_count++;
+ pthread_mutex_unlock(<t_session_list.lock);
}
/*
- * del_session_list
- *
- * Delete a ltt_session structure to the global list.
+ * Acquire session lock
*/
-static void del_session_list(struct ltt_session *ls)
+void lock_session(struct ltt_session *session)
{
- cds_list_del(&ls->list);
- /* Sanity check */
- if (session_count != 0) {
- session_count--;
- }
+ pthread_mutex_lock(&session->lock);
}
/*
- * find_session_by_name
- *
- * Return a ltt_session structure ptr that matches name.
- * If no session found, NULL is returned.
+ * Release session lock
+ */
+void unlock_session(struct ltt_session *session)
+{
+ pthread_mutex_unlock(&session->lock);
+}
+
+/*
+ * Return a ltt_session structure ptr that matches name.
+ * If no session found, NULL is returned.
*/
struct ltt_session *find_session_by_name(char *name)
{
int found = 0;
struct ltt_session *iter;
+ lock_session_list();
cds_list_for_each_entry(iter, <t_session_list.head, list) {
- if (strncmp(iter->name, name, strlen(name)) == 0) {
+ if (strncmp(iter->name, name, NAME_MAX) == 0) {
found = 1;
break;
}
}
+ unlock_session_list();
if (!found) {
iter = NULL;
}
/*
- * destroy_session
- *
- * Delete session from the global session list
- * and free the memory.
+ * Delete session from the session list and free the memory.
*
- * Return -1 if no session is found.
- * On success, return 1;
+ * Return -1 if no session is found. On success, return 1;
*/
int destroy_session(char *name)
{
int found = -1;
- struct ltt_session *iter;
+ struct ltt_session *iter, *tmp;
- cds_list_for_each_entry(iter, <t_session_list.head, list) {
+ lock_session_list();
+ cds_list_for_each_entry_safe(iter, tmp, <t_session_list.head, list) {
if (strcmp(iter->name, name) == 0) {
DBG("Destroying session %s", iter->name);
del_session_list(iter);
+ free(iter->name);
+ free(iter->path);
+ pthread_mutex_destroy(&iter->lock);
free(iter);
found = 1;
break;
}
}
+ unlock_session_list();
return found;
}
/*
- * create_session
- *
- * Create a brand new session and add it to the global session list.
+ * Create a brand new session and add it to the session list.
*/
int create_session(char *name, char *path)
{
int ret;
- char date_time[NAME_MAX];
struct ltt_session *new_session;
- time_t rawtime;
- struct tm *timeinfo;
new_session = find_session_by_name(name);
if (new_session != NULL) {
/* Define session system path */
if (path != NULL) {
- if (strstr(name, "auto-") == NULL) {
- time(&rawtime);
- timeinfo = localtime(&rawtime);
- strftime(date_time, sizeof(date_time), "-%Y%m%d-%H%M%S", timeinfo);
- } else {
- date_time[0] = '\0';
- }
-
- if (asprintf(&new_session->path, "%s/%s%s", path, name, date_time) < 0) {
+ if (asprintf(&new_session->path, "%s", path) < 0) {
ret = -ENOMEM;
goto error_asprintf;
}
goto error;
}
- /*
- * Set consumer (identifier) to 0. This means that there is
- * NO consumer attach to that session yet.
- */
- new_session->ust_consumer = 0;
-
/* Init kernel session */
new_session->kernel_session = NULL;
/* Set trace list counter */
new_session->ust_trace_count = 0;
- /* Add new session to the global session list */
+ /* Add new session to the session list */
+ lock_session_list();
add_session_list(new_session);
+ unlock_session_list();
+
+ /* Init lock */
+ pthread_mutex_init(&new_session->lock, NULL);
- DBG("Tracing session %s created in %s", name, new_session->path);
+ DBG("Tracing session %s created in %s", new_session->name, new_session->path);
return 0;
error_malloc:
return ret;
}
-
-/*
- * get_lttng_session
- *
- * Iterate over the global session list and fill the lttng_session array.
- */
-void get_lttng_session(struct lttng_session *sessions)
-{
- int i = 0;
- struct ltt_session *iter;
- struct lttng_session lsess;
-
- DBG("Getting all available session");
-
- /* Iterate over session list and append data after
- * the control struct in the buffer.
- */
- cds_list_for_each_entry(iter, <t_session_list.head, list) {
- strncpy(lsess.path, iter->path, sizeof(lsess.path));
- lsess.path[sizeof(lsess.path) - 1] = '\0';
- strncpy(lsess.name, iter->name, sizeof(lsess.name));
- lsess.name[sizeof(lsess.name) - 1] = '\0';
- memcpy(&sessions[i], &lsess, sizeof(lsess));
- i++;
- /* Reset struct for next pass */
- memset(&lsess, 0, sizeof(lsess));
- }
-}
-
projects / lttng-tools.git / blobdiff