*
* 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 <time.h>
#include <urcu/list.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);
-
-/* Init session's list */
-static struct ltt_session_list ltt_session_list = {
- .head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
-};
+/*
+ * 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().
+ */
/*
- * get_session_count
+ * Init tracing session list.
*
- * Return session_count
+ * Please see session.h for more explanation and correct usage of the list.
*/
-unsigned int get_session_count(void)
-{
- return session_count;
-}
+static struct ltt_session_list ltt_session_list = {
+ .head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
+ .lock = PTHREAD_MUTEX_INITIALIZER,
+ .count = 0,
+};
/*
- * add_session_list
+ * Add a ltt_session structure to the global 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);
- session_count++;
+ ltt_session_list.count++;
}
/*
- * del_session_list
+ * Delete a ltt_session structure to the global list.
*
- * Delete a ltt_session structure to the global 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 (session_count != 0) {
- session_count--;
+ if (ltt_session_list.count > 0) {
+ ltt_session_list.count--;
}
}
/*
- * find_session_by_uuid
- *
- * Return a ltt_session structure ptr that matches the uuid.
+ * Return a pointer to the session list.
*/
-struct ltt_session *find_session_by_uuid(uuid_t session_id)
+struct ltt_session_list *get_session_list(void)
{
- int found = 0;
- struct ltt_session *iter;
+ return <t_session_list;
+}
- /* Sanity check for NULL session_id */
- if (uuid_is_null(session_id)) {
- goto end;
- }
+/*
+ * Acquire session list lock
+ */
+void lock_session_list(void)
+{
+ pthread_mutex_lock(<t_session_list.lock);
+}
- cds_list_for_each_entry(iter, <t_session_list.head, list) {
- if (uuid_compare(iter->uuid, session_id) == 0) {
- found = 1;
- break;
- }
- }
+/*
+ * Release session list lock
+ */
+void unlock_session_list(void)
+{
+ pthread_mutex_unlock(<t_session_list.lock);
+}
-end:
- if (!found) {
- iter = NULL;
- }
- return iter;
+/*
+ * Acquire session lock
+ */
+void lock_session(struct ltt_session *session)
+{
+ 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(uuid_t *uuid)
+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) {
- if (uuid_compare(iter->uuid, *uuid) == 0) {
+ 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, uuid_t *session_id)
+int create_session(char *name, char *path)
{
+ int ret;
struct ltt_session *new_session;
- DBG("Creating session %s", name);
-
new_session = find_session_by_name(name);
if (new_session != NULL) {
- goto error;
+ ret = -EEXIST;
+ goto error_exist;
}
/* Allocate session data structure */
new_session = malloc(sizeof(struct ltt_session));
if (new_session == NULL) {
perror("malloc");
- goto error_mem;
+ ret = -ENOMEM;
+ goto error_malloc;
}
+ /* Define session name */
if (name != NULL) {
if (asprintf(&new_session->name, "%s", name) < 0) {
- goto error_mem;
+ ret = -ENOMEM;
+ goto error_asprintf;
}
} else {
- /* Generate session name based on the session count */
- if (asprintf(&new_session->name, "%s%d", "lttng-", session_count) < 0) {
- goto error_mem;
- }
+ ERR("No session name given");
+ ret = -1;
+ goto error;
}
- /* UUID generation */
- uuid_generate(new_session->uuid);
- uuid_copy(*session_id, new_session->uuid);
+ /* Define session system path */
+ if (path != NULL) {
+ if (asprintf(&new_session->path, "%s", path) < 0) {
+ ret = -ENOMEM;
+ goto error_asprintf;
+ }
+ } else {
+ ERR("No session path given");
+ ret = -1;
+ goto error;
+ }
- /* Set consumer (identifier) to 0. This means that there is
- * NO consumer attach to that session yet.
- */
- new_session->ust_consumer = 0;
- new_session->kernel_consumer = 0;
+ /* Init kernel session */
+ new_session->kernel_session = NULL;
/* Init list */
CDS_INIT_LIST_HEAD(&new_session->ust_traces);
- CDS_INIT_LIST_HEAD(&new_session->kernel_traces);
/* Set trace list counter */
new_session->ust_trace_count = 0;
- new_session->kern_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();
- return 0;
-
-error:
- return -1;
+ /* Init lock */
+ pthread_mutex_init(&new_session->lock, NULL);
-error_mem:
- return -ENOMEM;
-}
-
-/*
- * get_lttng_session
- *
- * Iterate over the global session list and
- * fill the lttng_session array.
- */
-void get_lttng_session(struct lttng_session *lt)
-{
- int i = 0;
- struct ltt_session *iter;
- struct lttng_session lsess;
+ DBG("Tracing session %s created in %s", new_session->name, new_session->path);
- DBG("Getting all available session");
+ return 0;
- /* 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) {
- /* Copy name and uuid */
- uuid_unparse(iter->uuid, lsess.uuid);
- strncpy(lsess.name, iter->name, sizeof(lsess.name));
- lsess.name[sizeof(lsess.name) - 1] = '\0';
- memcpy(<[i], &lsess, sizeof(lsess));
- i++;
- /* Reset struct for next pass */
- memset(&lsess, 0, sizeof(lsess));
+error:
+error_asprintf:
+ if (new_session != NULL) {
+ free(new_session);
}
-}
+error_exist:
+error_malloc:
+ return ret;
+}
projects / lttng-tools.git / blobdiff