+#ifndef _SESSION_H
+#define _SESSION_H
+
/*
* Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
* David Goulet <dgoulet@efficios.com>
+ * 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License, version 2 only, as
* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#ifndef _SESSION_H
-#define _SESSION_H
-
#include <limits.h>
#include <inttypes.h>
#include <pthread.h>
+#include <urcu/list.h>
+#include <urcu/ref.h>
+#include <lttng/constant.h>
#include <common/hashtable/hashtable.h>
/*
*/
struct relay_session {
/*
- * This session id is used to identify a set of stream to a tracing session
- * but also make sure we have a unique session id associated with a session
- * daemon which can provide multiple data source.
+ * This session id is generated by the relay daemon to guarantee
+ * its uniqueness even when serving multiple session daemons.
+ * It is used to match a set of streams to their session.
*/
uint64_t id;
- char session_name[NAME_MAX];
+ char session_name[LTTNG_NAME_MAX];
char hostname[HOST_NAME_MAX];
uint32_t live_timer;
- struct lttng_ht_node_u64 session_n;
- struct rcu_head rcu_node;
- uint32_t stream_count;
- /* Tell if this session is for a snapshot or not. */
- unsigned int snapshot:1;
- /* Tell if the session has been closed on the streaming side. */
- unsigned int close_flag:1;
- /* Number of viewer using it. Set to 0, it should be destroyed. */
- int viewer_refcount;
+ /* Session in snapshot mode. */
+ bool snapshot;
+
+ /*
+ * Session has no back reference to its connection because it
+ * has a life-time that can be longer than the consumer connection's
+ * life-time; a reference can still be held by the viewer
+ * connection through the viewer streams.
+ */
+
+ struct urcu_ref ref;
+ /* session reflock nests inside ctf_trace reflock. */
+ pthread_mutex_t reflock;
+
+ pthread_mutex_t lock;
+
+ /* major/minor version used for this session. */
+ uint32_t major;
+ uint32_t minor;
+
+ bool viewer_attached;
+ /* Tell if the session connection has been closed on the streaming side. */
+ bool connection_closed;
/* Contains ctf_trace object of that session indexed by path name. */
struct lttng_ht *ctf_traces_ht;
/*
- * Indicate version protocol for this session. This is especially useful
- * for the data thread that has no idea which version it operates on since
- * linking control/data sockets is non trivial.
+ * This contains streams that are received on that connection.
+ * It's used to store them until we get the streams sent
+ * command. When this is received, we remove those streams from
+ * the list and publish them.
+ *
+ * Updates are protected by the recv_list_lock.
+ * Traversals are protected by RCU.
+ * recv_list_lock also protects stream_count.
*/
- uint64_t minor;
- uint64_t major;
+ struct cds_list_head recv_list; /* RCU list. */
+ uint32_t stream_count;
+ pthread_mutex_t recv_list_lock;
+
/*
* Flag checked and exchanged with uatomic_cmpxchg to tell the
* viewer-side if new streams got added since the last check.
unsigned long new_streams;
/*
- * Used to synchronize the process where we flag every streams readiness
- * for the viewer when the streams_sent message is received and the viewer
- * process of sending those streams.
+ * Node in the global session hash table.
+ */
+ struct lttng_ht_node_u64 session_n;
+ /*
+ * Member of the session list in struct relay_viewer_session.
+ * Updates are protected by the relay_viewer_session
+ * session_list_lock. Traversals are protected by RCU.
*/
- pthread_mutex_t viewer_ready_lock;
+ struct cds_list_head viewer_session_node;
+ struct rcu_head rcu_node; /* For call_rcu teardown. */
};
-static inline void session_viewer_attach(struct relay_session *session)
-{
- uatomic_inc(&session->viewer_refcount);
-}
-
-static inline void session_viewer_detach(struct relay_session *session)
-{
- uatomic_add(&session->viewer_refcount, -1);
-}
+struct relay_session *session_create(const char *session_name,
+ const char *hostname, uint32_t live_timer,
+ bool snapshot, uint32_t major, uint32_t minor);
+struct relay_session *session_get_by_id(uint64_t id);
+bool session_get(struct relay_session *session);
+void session_put(struct relay_session *session);
-struct relay_session *session_find_by_id(struct lttng_ht *ht, uint64_t id);
-struct relay_session *session_create(void);
-int session_delete(struct lttng_ht *ht, struct relay_session *session);
-
-/*
- * Direct destroy without reading the refcount.
- */
-void session_destroy(struct relay_session *session);
-
-/*
- * Destroy the session if the refcount is down to 0.
- */
-void session_try_destroy(struct lttng_ht *ht, struct relay_session *session);
-
-/*
- * Decrement the viewer refcount and destroy it if down to 0.
- */
-void session_viewer_try_destroy(struct lttng_ht *ht,
- struct relay_session *session);
+int session_close(struct relay_session *session);
+void print_sessions(void);
#endif /* _SESSION_H */
projects / lttng-tools.git / blobdiff