Commit | Line | Data |
---|---|---|
a58c490f JG |
1 | /* |
2 | * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
3 | * | |
4 | * This library is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU Lesser General Public License, version 2.1 only, | |
6 | * as published by the Free Software Foundation. | |
7 | * | |
8 | * This library is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License | |
11 | * for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU Lesser General Public License | |
14 | * along with this library; if not, write to the Free Software Foundation, | |
15 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
16 | */ | |
17 | ||
18 | #ifndef LTTNG_NOTIFICATION_CHANNEL_INTERNAL_H | |
19 | #define LTTNG_NOTIFICATION_CHANNEL_INTERNAL_H | |
20 | ||
21 | #include <lttng/notification/channel.h> | |
22 | #include <common/macros.h> | |
23 | #include <common/dynamic-buffer.h> | |
24 | #include <stdint.h> | |
25 | #include <stdbool.h> | |
26 | #include <pthread.h> | |
27 | #include <urcu/list.h> | |
28 | ||
29 | #define LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR 1 | |
30 | #define LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR 0 | |
31 | ||
32 | enum lttng_notification_channel_message_type { | |
33 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN = -1, | |
34 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE = 0, | |
35 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE = 1, | |
36 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE = 2, | |
37 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY = 3, | |
38 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION = 4, | |
39 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED = 5, | |
40 | }; | |
41 | ||
42 | struct lttng_notification_channel_message { | |
43 | /* enum lttng_notification_channel_message_type */ | |
44 | int8_t type; | |
45 | /* Size of the payload following this field. */ | |
46 | uint32_t size; | |
47 | char payload[]; | |
48 | } LTTNG_PACKED; | |
49 | ||
50 | struct lttng_notification_channel_command_handshake { | |
51 | uint8_t major; | |
52 | uint8_t minor; | |
53 | } LTTNG_PACKED; | |
54 | ||
55 | struct lttng_notification_channel_command_reply { | |
56 | /* enum lttng_notification_channel_status */ | |
57 | int8_t status; | |
58 | } LTTNG_PACKED; | |
59 | ||
60 | struct pending_notification { | |
61 | /* NULL means "notification dropped". */ | |
62 | struct lttng_notification *notification; | |
63 | struct cds_list_head node; | |
64 | }; | |
65 | ||
66 | /* | |
67 | * The notification channel protocol is bidirectional and accomodates | |
68 | * synchronous and asynchronous communication modes: | |
69 | * | |
70 | * - Synchronous: commands emitted by the client to which a reply is expected | |
71 | * (e.g. subscribing/unsubscribing to conditions), | |
72 | * - Asynchronous: notifications which are sent by the lttng_endpoint to the | |
73 | * client as one of the subscribed condition has occured. | |
74 | * | |
75 | * The nature of this hybrid communication mode means that asynchronous messages | |
76 | * (e.g. notifications) may be interleaved between synchronous messages (e.g. a | |
77 | * command and its reply). | |
78 | * | |
79 | * Notifications that are received between a command and its reply and enqueued | |
80 | * in the pending_notifications list. | |
81 | */ | |
82 | struct lttng_notification_channel { | |
83 | pthread_mutex_t lock; | |
84 | int socket; | |
85 | struct { | |
86 | /* Count of pending notifications. */ | |
87 | unsigned int count; | |
88 | /* List of struct pending_notification. */ | |
89 | struct cds_list_head list; | |
90 | } pending_notifications; | |
91 | struct lttng_dynamic_buffer reception_buffer; | |
92 | /* Sessiond notification protocol version. */ | |
93 | struct { | |
94 | bool set; | |
95 | int8_t major, minor; | |
96 | } version; | |
97 | }; | |
98 | ||
99 | #endif /* LTTNG_NOTIFICATION_CHANNEL_INTERNAL_H */ |