2 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2013 Raphaƫl Beamonte <raphael.beamonte@gmail.com>
5 * SPDX-License-Identifier: GPL-2.0-only
9 #ifndef _LTT_SESSIOND_H
10 #define _LTT_SESSIOND_H
13 #include <urcu/wfcqueue.h>
15 #include <common/sessiond-comm/sessiond-comm.h>
16 #include <common/payload.h>
17 #include <common/compat/poll.h>
18 #include <common/compat/socket.h>
19 #include <common/uuid.h>
23 #include "notification-thread.h"
24 #include "sessiond-config.h"
27 * Consumer daemon state which is changed when spawning it, killing it or in
28 * case of a fatal error.
30 enum consumerd_state
{
36 /* Unique identifier of a session daemon instance. */
37 extern lttng_uuid sessiond_uuid
;
40 * This consumer daemon state is used to validate if a client command will be
41 * able to reach the consumer. If not, the client is informed. For instance,
42 * doing a "lttng start" when the consumer state is set to ERROR will return an
43 * error to the client.
45 * The following example shows a possible race condition of this scheme:
47 * consumer thread error happens
49 * client cmd checks state -> still OK
50 * consumer thread exit, sets error
51 * client cmd try to talk to consumer
54 * However, since the consumer is a different daemon, we have no way of making
55 * sure the command will reach it safely even with this state flag. This is why
56 * we consider that up to the state validation during command processing, the
57 * command is safe. After that, we can not guarantee the correctness of the
58 * client request vis-a-vis the consumer.
60 extern enum consumerd_state ust_consumerd_state
;
61 extern enum consumerd_state kernel_consumerd_state
;
63 extern const char default_home_dir
[],
64 default_tracing_group
[],
65 default_ust_sock_dir
[],
66 default_global_apps_pipe
[];
68 /* Set in main.c at boot time of the daemon */
69 extern struct lttng_kernel_tracer_version kernel_tracer_version
;
70 extern struct lttng_kernel_tracer_abi_version kernel_tracer_abi_version
;
72 /* Notification thread handle. */
73 extern struct notification_thread_handle
*notification_thread_handle
;
76 * This contains extra data needed for processing a command received by the
77 * session daemon from the lttng client.
80 unsigned int lttng_msg_size
;
81 struct ltt_session
*session
;
83 struct lttcomm_session_msg lsm
;
84 /* Reply content, starts with an lttcomm_lttng_msg header. */
85 struct lttng_payload reply_payload
;
86 lttng_sock_cred creds
;
91 struct ust_register_msg reg_msg
;
92 struct cds_wfcq_node node
;
96 * Queue used to enqueue UST registration request (ust_command) and synchronized
97 * by a futex with a scheme N wakers / 1 waiters. See futex.c/.h
99 struct ust_cmd_queue
{
101 struct cds_wfcq_head head
;
102 struct cds_wfcq_tail tail
;
106 * This is the wait queue containing wait nodes during the application
107 * registration process.
109 struct ust_reg_wait_queue
{
111 struct cds_list_head head
;
115 * Use by the dispatch registration to queue UST command socket to wait for the
118 struct ust_reg_wait_node
{
120 struct cds_list_head head
;
124 * Used to notify that a hash table needs to be destroyed by dedicated
125 * thread. Required by design because we don't want to move destroy
126 * paths outside of large RCU read-side lock paths, and destroy cannot
127 * be called by call_rcu thread, because it may hang (waiting for
128 * call_rcu completion).
130 extern int ht_cleanup_pipe
[2];
132 extern int kernel_poll_pipe
[2];
135 * Populated when the daemon starts with the current page size of the system.
136 * Set in main() with the current page size.
138 extern long page_size
;
140 /* Application health monitoring */
141 extern struct health_app
*health_sessiond
;
143 extern struct sessiond_config config
;
145 extern int ust_consumerd64_fd
, ust_consumerd32_fd
;
147 /* Parent PID for --sig-parent option */
149 /* Internal parent PID use with daemonize. */
150 extern pid_t child_ppid
;
152 /* Consumer daemon specific control data. */
153 extern struct consumer_data ustconsumer32_data
;
154 extern struct consumer_data ustconsumer64_data
;
155 extern struct consumer_data kconsumer_data
;
157 int sessiond_init_thread_quit_pipe(void);
158 int sessiond_check_thread_quit_pipe(int fd
, uint32_t events
);
159 int sessiond_wait_for_quit_pipe(int timeout_ms
);
160 int sessiond_notify_quit_pipe(void);
161 void sessiond_close_quit_pipe(void);
163 int sessiond_set_thread_pollset(struct lttng_poll_event
*events
, size_t size
);
164 void sessiond_signal_parents(void);
166 void sessiond_set_client_thread_state(bool running
);
167 void sessiond_wait_client_thread_stopped(void);
169 void *thread_manage_consumer(void *data
);
171 #endif /* _LTT_SESSIOND_H */