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/compat/poll.h>
17 #include <common/compat/socket.h>
18 #include <common/uuid.h>
22 #include "notification-thread.h"
23 #include "sessiond-config.h"
26 * Consumer daemon state which is changed when spawning it, killing it or in
27 * case of a fatal error.
29 enum consumerd_state
{
35 /* Unique identifier of a session daemon instance. */
36 extern lttng_uuid sessiond_uuid
;
39 * This consumer daemon state is used to validate if a client command will be
40 * able to reach the consumer. If not, the client is informed. For instance,
41 * doing a "lttng start" when the consumer state is set to ERROR will return an
42 * error to the client.
44 * The following example shows a possible race condition of this scheme:
46 * consumer thread error happens
48 * client cmd checks state -> still OK
49 * consumer thread exit, sets error
50 * client cmd try to talk to consumer
53 * However, since the consumer is a different daemon, we have no way of making
54 * sure the command will reach it safely even with this state flag. This is why
55 * we consider that up to the state validation during command processing, the
56 * command is safe. After that, we can not guarantee the correctness of the
57 * client request vis-a-vis the consumer.
59 extern enum consumerd_state ust_consumerd_state
;
60 extern enum consumerd_state kernel_consumerd_state
;
62 extern const char default_home_dir
[],
63 default_tracing_group
[],
64 default_ust_sock_dir
[],
65 default_global_apps_pipe
[];
67 /* Set in main.c at boot time of the daemon */
68 extern struct lttng_kernel_tracer_version kernel_tracer_version
;
69 extern struct lttng_kernel_tracer_abi_version kernel_tracer_abi_version
;
71 /* Notification thread handle. */
72 extern struct notification_thread_handle
*notification_thread_handle
;
73 extern pthread_mutex_t notification_trigger_tokens_ht_lock
;
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
;
82 struct lttcomm_lttng_msg
*llm
;
83 struct lttcomm_session_msg
*lsm
;
84 lttng_sock_cred creds
;
89 struct ust_register_msg reg_msg
;
90 struct cds_wfcq_node node
;
94 * Queue used to enqueue UST registration request (ust_command) and synchronized
95 * by a futex with a scheme N wakers / 1 waiters. See futex.c/.h
97 struct ust_cmd_queue
{
99 struct cds_wfcq_head head
;
100 struct cds_wfcq_tail tail
;
104 * This is the wait queue containing wait nodes during the application
105 * registration process.
107 struct ust_reg_wait_queue
{
109 struct cds_list_head head
;
113 * Use by the dispatch registration to queue UST command socket to wait for the
116 struct ust_reg_wait_node
{
118 struct cds_list_head head
;
122 * Used to notify that a hash table needs to be destroyed by dedicated
123 * thread. Required by design because we don't want to move destroy
124 * paths outside of large RCU read-side lock paths, and destroy cannot
125 * be called by call_rcu thread, because it may hang (waiting for
126 * call_rcu completion).
128 extern int ht_cleanup_pipe
[2];
130 extern int kernel_poll_pipe
[2];
133 * Populated when the daemon starts with the current page size of the system.
134 * Set in main() with the current page size.
136 extern long page_size
;
138 /* Application health monitoring */
139 extern struct health_app
*health_sessiond
;
141 extern struct sessiond_config config
;
143 extern int ust_consumerd64_fd
, ust_consumerd32_fd
;
145 /* Parent PID for --sig-parent option */
147 /* Internal parent PID use with daemonize. */
148 extern pid_t child_ppid
;
150 /* Consumer daemon specific control data. */
151 extern struct consumer_data ustconsumer32_data
;
152 extern struct consumer_data ustconsumer64_data
;
153 extern struct consumer_data kconsumer_data
;
155 int sessiond_init_thread_quit_pipe(void);
156 int sessiond_check_thread_quit_pipe(int fd
, uint32_t events
);
157 int sessiond_wait_for_quit_pipe(int timeout_ms
);
158 int sessiond_notify_quit_pipe(void);
159 void sessiond_close_quit_pipe(void);
161 int sessiond_set_thread_pollset(struct lttng_poll_event
*events
, size_t size
);
162 void sessiond_signal_parents(void);
164 void sessiond_set_client_thread_state(bool running
);
165 void sessiond_wait_client_thread_stopped(void);
167 void *thread_manage_consumer(void *data
);
169 #endif /* _LTT_SESSIOND_H */