| 1 | /* |
| 2 | * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com> |
| 3 | * David Goulet <dgoulet@efficios.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License, version 2 only, as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 12 | * more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along with |
| 15 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 16 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #ifndef _SESSION_H |
| 20 | #define _SESSION_H |
| 21 | |
| 22 | #include <limits.h> |
| 23 | #include <inttypes.h> |
| 24 | #include <pthread.h> |
| 25 | #include <urcu/list.h> |
| 26 | |
| 27 | #include <common/hashtable/hashtable.h> |
| 28 | |
| 29 | /* |
| 30 | * Represents a session for the relay point of view |
| 31 | */ |
| 32 | struct relay_session { |
| 33 | /* |
| 34 | * This session id is used to identify a set of stream to a tracing session |
| 35 | * but also make sure we have a unique session id associated with a session |
| 36 | * daemon which can provide multiple data source. |
| 37 | */ |
| 38 | uint64_t id; |
| 39 | char session_name[NAME_MAX]; |
| 40 | char hostname[HOST_NAME_MAX]; |
| 41 | uint32_t live_timer; |
| 42 | struct lttng_ht_node_u64 session_n; |
| 43 | struct rcu_head rcu_node; |
| 44 | uint32_t stream_count; |
| 45 | /* Tell if this session is for a snapshot or not. */ |
| 46 | unsigned int snapshot:1; |
| 47 | /* Tell if the session has been closed on the streaming side. */ |
| 48 | unsigned int close_flag:1; |
| 49 | |
| 50 | /* Number of viewer using it. Set to 0, it should be destroyed. */ |
| 51 | int viewer_refcount; |
| 52 | |
| 53 | /* Contains ctf_trace object of that session indexed by path name. */ |
| 54 | struct lttng_ht *ctf_traces_ht; |
| 55 | |
| 56 | /* |
| 57 | * Indicate version protocol for this session. This is especially useful |
| 58 | * for the data thread that has no idea which version it operates on since |
| 59 | * linking control/data sockets is non trivial. |
| 60 | */ |
| 61 | uint64_t minor; |
| 62 | uint64_t major; |
| 63 | /* |
| 64 | * Flag checked and exchanged with uatomic_cmpxchg to tell the |
| 65 | * viewer-side if new streams got added since the last check. |
| 66 | */ |
| 67 | unsigned long new_streams; |
| 68 | |
| 69 | /* |
| 70 | * Used to synchronize the process where we flag every streams readiness |
| 71 | * for the viewer when the streams_sent message is received and the viewer |
| 72 | * process of sending those streams. |
| 73 | */ |
| 74 | pthread_mutex_t viewer_ready_lock; |
| 75 | |
| 76 | /* |
| 77 | * Member of the session list in struct relay_viewer_session. |
| 78 | */ |
| 79 | struct cds_list_head viewer_session_list; |
| 80 | }; |
| 81 | |
| 82 | struct relay_viewer_session { |
| 83 | struct cds_list_head sessions_head; |
| 84 | }; |
| 85 | |
| 86 | static inline void session_viewer_attach(struct relay_session *session) |
| 87 | { |
| 88 | uatomic_inc(&session->viewer_refcount); |
| 89 | } |
| 90 | |
| 91 | static inline void session_viewer_detach(struct relay_session *session) |
| 92 | { |
| 93 | uatomic_add(&session->viewer_refcount, -1); |
| 94 | } |
| 95 | |
| 96 | struct relay_session *session_find_by_id(struct lttng_ht *ht, uint64_t id); |
| 97 | struct relay_session *session_create(void); |
| 98 | int session_delete(struct lttng_ht *ht, struct relay_session *session); |
| 99 | |
| 100 | /* |
| 101 | * Direct destroy without reading the refcount. |
| 102 | */ |
| 103 | void session_destroy(struct relay_session *session); |
| 104 | |
| 105 | /* |
| 106 | * Destroy the session if the refcount is down to 0. |
| 107 | */ |
| 108 | void session_try_destroy(struct lttng_ht *ht, struct relay_session *session); |
| 109 | |
| 110 | /* |
| 111 | * Decrement the viewer refcount and destroy it if down to 0. |
| 112 | */ |
| 113 | void session_viewer_try_destroy(struct lttng_ht *ht, |
| 114 | struct relay_session *session); |
| 115 | |
| 116 | #endif /* _SESSION_H */ |