#include <urcu.h>
#include <dirent.h>
#include <sys/types.h>
+#include <pthread.h>
#include <common/common.h>
#include <common/sessiond-comm/sessiond-comm.h>
+#include <lttng/location-internal.h>
+#include "lttng-sessiond.h"
+#include "kernel.h"
#include "session.h"
#include "utils.h"
+#include "trace-ust.h"
+#include "timer.h"
/*
* NOTES:
static struct ltt_session_list ltt_session_list = {
.head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
.lock = PTHREAD_MUTEX_INITIALIZER,
+ .removal_cond = PTHREAD_COND_INITIALIZER,
.next_uuid = 0,
};
return <t_session_list;
}
+/*
+ * Returns once the session list is empty.
+ */
+void session_list_wait_empty(void)
+{
+ pthread_mutex_lock(<t_session_list.lock);
+ while (!cds_list_empty(<t_session_list.head)) {
+ pthread_cond_wait(<t_session_list.removal_cond,
+ <t_session_list.lock);
+ }
+ pthread_mutex_unlock(<t_session_list.lock);
+}
+
/*
* Acquire session list lock
*/
pthread_mutex_lock(<t_session_list.lock);
}
+/*
+ * Try to acquire session list lock
+ */
+int session_trylock_list(void)
+{
+ return pthread_mutex_trylock(<t_session_list.lock);
+}
+
/*
* Release session list lock
*/
pthread_mutex_unlock(<t_session_list.lock);
}
+/*
+ * Get the session's consumer destination type.
+ *
+ * The caller must hold the session lock.
+ */
+enum consumer_dst_type session_get_consumer_destination_type(
+ const struct ltt_session *session)
+{
+ /*
+ * The output information is duplicated in both of those session types.
+ * Hence, it doesn't matter from which it is retrieved. However, it is
+ * possible for only one of them to be set.
+ */
+ return session->kernel_session ?
+ session->kernel_session->consumer->type :
+ session->ust_session->consumer->type;
+}
+
+/*
+ * Get the session's consumer network hostname.
+ * The caller must ensure that the destination is of type "net".
+ *
+ * The caller must hold the session lock.
+ */
+const char *session_get_net_consumer_hostname(const struct ltt_session *session)
+{
+ const char *hostname = NULL;
+ const struct consumer_output *output;
+
+ output = session->kernel_session ?
+ session->kernel_session->consumer :
+ session->ust_session->consumer;
+
+ /*
+ * hostname is assumed to be the same for both control and data
+ * connections.
+ */
+ switch (output->dst.net.control.dtype) {
+ case LTTNG_DST_IPV4:
+ hostname = output->dst.net.control.dst.ipv4;
+ break;
+ case LTTNG_DST_IPV6:
+ hostname = output->dst.net.control.dst.ipv6;
+ break;
+ default:
+ abort();
+ }
+ return hostname;
+}
+
+/*
+ * Get the session's consumer network control and data ports.
+ * The caller must ensure that the destination is of type "net".
+ *
+ * The caller must hold the session lock.
+ */
+void session_get_net_consumer_ports(const struct ltt_session *session,
+ uint16_t *control_port, uint16_t *data_port)
+{
+ const struct consumer_output *output;
+
+ output = session->kernel_session ?
+ session->kernel_session->consumer :
+ session->ust_session->consumer;
+ *control_port = output->dst.net.control.port;
+ *data_port = output->dst.net.data.port;
+}
+
+/*
+ * Get the location of the latest trace archive produced by a rotation.
+ *
+ * The caller must hold the session lock.
+ */
+struct lttng_trace_archive_location *session_get_trace_archive_location(
+ struct ltt_session *session)
+{
+ struct lttng_trace_archive_location *location = NULL;
+
+ if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
+ goto end;
+ }
+
+ switch (session_get_consumer_destination_type(session)) {
+ case CONSUMER_DST_LOCAL:
+ location = lttng_trace_archive_location_local_create(
+ session->rotation_chunk.current_rotate_path);
+ break;
+ case CONSUMER_DST_NET:
+ {
+ const char *hostname;
+ uint16_t control_port, data_port;
+
+ hostname = session_get_net_consumer_hostname(session);
+ session_get_net_consumer_ports(session,
+ &control_port,
+ &data_port);
+ location = lttng_trace_archive_location_relay_create(
+ hostname,
+ LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP,
+ control_port, data_port,
+ session->rotation_chunk.current_rotate_path);
+ break;
+ }
+ default:
+ abort();
+ }
+end:
+ return location;
+}
+
/*
* Allocate the ltt_sessions_ht_by_id HT.
*
*
* The session list lock must be held.
*/
-void ltt_sessions_ht_destroy(void)
+static void ltt_sessions_ht_destroy(void)
{
if (!ltt_sessions_ht_by_id) {
return;
pthread_mutex_unlock(&session->lock);
}
+static
+void session_release(struct urcu_ref *ref)
+{
+ int ret;
+ struct ltt_ust_session *usess;
+ struct ltt_kernel_session *ksess;
+ struct ltt_session *session = container_of(ref, typeof(*session), ref);
+
+ usess = session->ust_session;
+ ksess = session->kernel_session;
+
+ /* Clean kernel session teardown */
+ kernel_destroy_session(ksess);
+
+ /* UST session teardown */
+ if (usess) {
+ /* Close any relayd session */
+ consumer_output_send_destroy_relayd(usess->consumer);
+
+ /* Destroy every UST application related to this session. */
+ ret = ust_app_destroy_trace_all(usess);
+ if (ret) {
+ ERR("Error in ust_app_destroy_trace_all");
+ }
+
+ /* Clean up the rest. */
+ trace_ust_destroy_session(usess);
+ }
+
+ /*
+ * Must notify the kernel thread here to update it's poll set in order to
+ * remove the channel(s)' fd just destroyed.
+ */
+ ret = notify_thread_pipe(kernel_poll_pipe[1]);
+ if (ret < 0) {
+ PERROR("write kernel poll pipe");
+ }
+
+ DBG("Destroying session %s (id %" PRIu64 ")", session->name, session->id);
+ pthread_mutex_destroy(&session->lock);
+
+ consumer_output_put(session->consumer);
+ snapshot_destroy(&session->snapshot);
+
+ if (session->published) {
+ ASSERT_LOCKED(ltt_session_list.lock);
+ del_session_list(session);
+ del_session_ht(session);
+ pthread_cond_broadcast(<t_session_list.removal_cond);
+ }
+ free(session);
+}
+
+/*
+ * Acquire a reference to a session.
+ * This function may fail (return false); its return value must be checked.
+ */
+bool session_get(struct ltt_session *session)
+{
+ return urcu_ref_get_unless_zero(&session->ref);
+}
+
+/*
+ * Release a reference to a session.
+ */
+void session_put(struct ltt_session *session)
+{
+ /*
+ * The session list lock must be held as any session_put()
+ * may cause the removal of the session from the session_list.
+ */
+ ASSERT_LOCKED(ltt_session_list.lock);
+ assert(session->ref.refcount);
+ urcu_ref_put(&session->ref, session_release);
+}
+
+/*
+ * Destroy a session.
+ *
+ * This method does not immediately release/free the session as other
+ * components may still hold a reference to the session. However,
+ * the session should no longer be presented to the user.
+ *
+ * Releases the session list's reference to the session
+ * and marks it as destroyed. Iterations on the session list should be
+ * mindful of the "destroyed" flag.
+ */
+void session_destroy(struct ltt_session *session)
+{
+ assert(!session->destroyed);
+ session->destroyed = true;
+ session_put(session);
+}
+
/*
* Return a ltt_session structure ptr that matches name. If no session found,
* NULL is returned. This must be called with the session list lock held using
* session_lock_list and session_unlock_list.
+ * A reference to the session is implicitly acquired by this function.
*/
struct ltt_session *session_find_by_name(const char *name)
{
struct ltt_session *iter;
assert(name);
+ ASSERT_LOCKED(ltt_session_list.lock);
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) {
+ if (!strncmp(iter->name, name, NAME_MAX) &&
+ !iter->destroyed) {
goto found;
}
}
- iter = NULL;
-
+ return NULL;
found:
- return iter;
+ return session_get(iter) ? iter : NULL;
}
/*
struct lttng_ht_iter iter;
struct ltt_session *ls;
+ ASSERT_LOCKED(ltt_session_list.lock);
+
+ if (!ltt_sessions_ht_by_id) {
+ goto end;
+ }
+
lttng_ht_lookup(ltt_sessions_ht_by_id, &id, &iter);
node = lttng_ht_iter_get_node_u64(&iter);
if (node == NULL) {
- goto error;
+ goto end;
}
ls = caa_container_of(node, struct ltt_session, node);
DBG3("Session %" PRIu64 " found by id.", id);
- return ls;
+ return session_get(ls) ? ls : NULL;
-error:
+end:
DBG3("Session %" PRIu64 " NOT found by id", id);
return NULL;
}
-/*
- * Delete session from the session list and free the memory.
- *
- * Return -1 if no session is found. On success, return 1;
- * Should *NOT* be called with RCU read-side lock held.
- */
-int session_destroy(struct ltt_session *session)
-{
- /* Safety check */
- assert(session);
-
- DBG("Destroying session %s", session->name);
- del_session_list(session);
- pthread_mutex_destroy(&session->lock);
- del_session_ht(session);
-
- consumer_output_put(session->consumer);
- snapshot_destroy(&session->snapshot);
- free(session);
-
- return LTTNG_OK;
-}
-
/*
* Create a brand new session and add it to the session list.
*/
goto error_malloc;
}
+ urcu_ref_init(&new_session->ref);
+
/* Define session name */
if (name != NULL) {
if (snprintf(new_session->name, NAME_MAX, "%s", name) < 0) {
goto error;
}
+ new_session->rotation_pending_local = false;
+ new_session->rotation_pending_relay = false;
+ new_session->rotation_state = LTTNG_ROTATION_STATE_NO_ROTATION;
+
+ new_session->rotation_pending_check_timer_enabled = false;
+ new_session->rotation_schedule_timer_enabled = false;
+
/* Add new session to the session list */
session_lock_list();
new_session->id = add_session_list(new_session);
* by session id.
*/
add_session_ht(new_session);
+ new_session->published = true;
session_unlock_list();
/*
error:
error_asprintf:
- free(new_session);
+ session_lock_list();
+ session_put(new_session);
+ session_unlock_list();
error_malloc:
return ret;
return 1;
}
}
+
+/*
+ * Set a session's rotation state and reset all associated state.
+ *
+ * This function resets the rotation state (check timers, pending
+ * flags, etc.) and sets the result of the last rotation. The result
+ * can be queries by a liblttng-ctl client.
+ *
+ * Be careful of the result passed to this function. For instance,
+ * on failure to launch a rotation, a client will expect the rotation
+ * state to be set to "NO_ROTATION". If an error occured while the
+ * rotation was "ONGOING", result should be set to "ERROR", which will
+ * allow a client to report it.
+ *
+ * Must be called with the session and session_list locks held.
+ */
+int session_reset_rotation_state(struct ltt_session *session,
+ enum lttng_rotation_state result)
+{
+ int ret = 0;
+
+ ASSERT_LOCKED(ltt_session_list.lock);
+ ASSERT_LOCKED(session->lock);
+
+ session->rotation_pending_local = false;
+ session->rotation_pending_relay = false;
+ session->rotated_after_last_stop = false;
+ session->rotation_state = result;
+ if (session->rotation_pending_check_timer_enabled) {
+ ret = timer_session_rotation_pending_check_stop(session);
+ }
+ return ret;
+}