--- /dev/null
+/*
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ *
+ * 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; 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
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#define _GNU_SOURCE
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <urcu.h>
+
+#include <lttng-sessiond-comm.h>
+#include <lttngerr.h>
+
+#include "hashtable.h"
+#include "session.h"
+
+#include "../hashtable/hash.h"
+
+/*
+ * 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 session_lock() and session_unlock().
+ */
+
+/*
+ * 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,
+};
+
+/*
+ * 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.
+ *
+ * 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 *session_get_list(void)
+{
+ return <t_session_list;
+}
+
+/*
+ * Acquire session list lock
+ */
+void session_lock_list(void)
+{
+ pthread_mutex_lock(<t_session_list.lock);
+}
+
+/*
+ * Release session list lock
+ */
+void session_unlock_list(void)
+{
+ pthread_mutex_unlock(<t_session_list.lock);
+}
+
+/*
+ * Acquire session lock
+ */
+void session_lock(struct ltt_session *session)
+{
+ pthread_mutex_lock(&session->lock);
+}
+
+/*
+ * Release session lock
+ */
+void session_unlock(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. This must be called with the session lock held using
+ * session_lock_list and session_unlock_list.
+ */
+struct ltt_session *session_find_by_name(char *name)
+{
+ struct ltt_session *iter;
+
+ DBG2("Trying to find session by name %s", name);
+
+ cds_list_for_each_entry(iter, <t_session_list.head, list) {
+ if (strncmp(iter->name, name, NAME_MAX) == 0) {
+ goto found;
+ }
+ }
+
+ iter = NULL;
+
+found:
+ return iter;
+}
+
+/*
+ * Delete session from the session list and free the memory.
+ *
+ * Return -1 if no session is found. On success, return 1;
+ */
+int session_destroy(struct ltt_session *session)
+{
+ /* Safety check */
+ if (session == NULL) {
+ ERR("Session pointer was null on session destroy");
+ return LTTCOMM_OK;
+ }
+
+ DBG("Destroying session %s", session->name);
+ del_session_list(session);
+ pthread_mutex_destroy(&session->lock);
+ free(session);
+
+ return LTTCOMM_OK;
+}
+
+/*
+ * Create a brand new session and add it to the session list.
+ */
+int session_create(char *name, char *path)
+{
+ int ret;
+ struct ltt_session *new_session;
+
+ new_session = session_find_by_name(name);
+ if (new_session != NULL) {
+ ret = LTTCOMM_EXIST_SESS;
+ goto error_exist;
+ }
+
+ /* Allocate session data structure */
+ new_session = malloc(sizeof(struct ltt_session));
+ if (new_session == NULL) {
+ perror("malloc");
+ ret = LTTCOMM_FATAL;
+ goto error_malloc;
+ }
+
+ /* Define session name */
+ if (name != NULL) {
+ if (snprintf(new_session->name, NAME_MAX, "%s", name) < 0) {
+ ret = LTTCOMM_FATAL;
+ goto error_asprintf;
+ }
+ } else {
+ ERR("No session name given");
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
+ /* Define session system path */
+ if (path != NULL) {
+ if (snprintf(new_session->path, PATH_MAX, "%s", path) < 0) {
+ ret = LTTCOMM_FATAL;
+ goto error_asprintf;
+ }
+ } else {
+ ERR("No session path given");
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
+ /* Init kernel session */
+ new_session->kernel_session = NULL;
+ new_session->ust_session = NULL;
+
+ /* Init lock */
+ pthread_mutex_init(&new_session->lock, NULL);
+
+ /* Add new session to the session list */
+ session_lock_list();
+ add_session_list(new_session);
+ session_unlock_list();
+
+ DBG("Tracing session %s created in %s", name, path);
+
+ return LTTCOMM_OK;
+
+error:
+error_asprintf:
+ if (new_session != NULL) {
+ free(new_session);
+ }
+
+error_exist:
+error_malloc:
+ return ret;
+}
projects / lttng-tools.git / blobdiff