Commit | Line | Data |
---|---|---|
7649924e | 1 | /* |
21cf9b6b | 2 | * Copyright (C) 2011 EfficiOS Inc. |
ab5be9fa MJ |
3 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
4 | * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
7649924e | 5 | * |
ab5be9fa | 6 | * SPDX-License-Identifier: GPL-2.0-only |
7649924e | 7 | * |
7649924e JG |
8 | */ |
9 | ||
c9e313bc SM |
10 | #include "manage-apps.hpp" |
11 | #include "testpoint.hpp" | |
12 | #include "health-sessiond.hpp" | |
13 | #include "utils.hpp" | |
14 | #include "thread.hpp" | |
7649924e | 15 | |
f1494934 | 16 | namespace { |
7649924e JG |
17 | struct thread_notifiers { |
18 | struct lttng_pipe *quit_pipe; | |
19 | int apps_cmd_pipe_read_fd; | |
20 | }; | |
f1494934 | 21 | } /* namespace */ |
7649924e JG |
22 | |
23 | static void cleanup_application_management_thread(void *data) | |
24 | { | |
7966af57 | 25 | struct thread_notifiers *notifiers = (thread_notifiers *) data; |
7649924e JG |
26 | |
27 | lttng_pipe_destroy(notifiers->quit_pipe); | |
28 | free(notifiers); | |
29 | } | |
30 | ||
31 | /* | |
32 | * This thread receives application command sockets (FDs) on the | |
33 | * apps_cmd_pipe and waits (polls) on them until they are closed | |
34 | * or an error occurs. | |
35 | * | |
36 | * At that point, it flushes the data (tracing and metadata) associated | |
37 | * with this application and tears down ust app sessions and other | |
38 | * associated data structures through ust_app_unregister(). | |
39 | * | |
40 | * Note that this thread never sends commands to the applications | |
41 | * through the command sockets; it merely listens for hang-ups | |
42 | * and errors on those sockets and cleans-up as they occur. | |
43 | */ | |
44 | static void *thread_application_management(void *data) | |
45 | { | |
46 | int i, ret, pollfd, err = -1; | |
47 | ssize_t size_ret; | |
48 | uint32_t revents, nb_fd; | |
49 | struct lttng_poll_event events; | |
7966af57 | 50 | struct thread_notifiers *notifiers = (thread_notifiers *) data; |
7649924e JG |
51 | const int quit_pipe_read_fd = lttng_pipe_get_readfd( |
52 | notifiers->quit_pipe); | |
53 | ||
54 | DBG("[thread] Manage application started"); | |
55 | ||
56 | rcu_register_thread(); | |
57 | rcu_thread_online(); | |
58 | ||
412d7227 | 59 | health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_APP_MANAGE); |
7649924e JG |
60 | |
61 | if (testpoint(sessiond_thread_manage_apps)) { | |
62 | goto error_testpoint; | |
63 | } | |
64 | ||
65 | health_code_update(); | |
66 | ||
67 | ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC); | |
68 | if (ret < 0) { | |
69 | goto error_poll_create; | |
70 | } | |
71 | ||
72 | ret = lttng_poll_add(&events, notifiers->apps_cmd_pipe_read_fd, | |
73 | LPOLLIN | LPOLLRDHUP); | |
74 | if (ret < 0) { | |
75 | goto error; | |
76 | } | |
77 | ||
78 | ret = lttng_poll_add(&events, quit_pipe_read_fd, LPOLLIN | LPOLLERR); | |
79 | if (ret < 0) { | |
80 | goto error; | |
81 | } | |
82 | ||
83 | if (testpoint(sessiond_thread_manage_apps_before_loop)) { | |
84 | goto error; | |
85 | } | |
86 | ||
87 | health_code_update(); | |
88 | ||
89 | while (1) { | |
90 | DBG("Apps thread polling"); | |
91 | ||
92 | /* Inifinite blocking call, waiting for transmission */ | |
93 | restart: | |
94 | health_poll_entry(); | |
95 | ret = lttng_poll_wait(&events, -1); | |
96 | DBG("Apps thread return from poll on %d fds", | |
97 | LTTNG_POLL_GETNB(&events)); | |
98 | health_poll_exit(); | |
99 | if (ret < 0) { | |
100 | /* | |
101 | * Restart interrupted system call. | |
102 | */ | |
103 | if (errno == EINTR) { | |
104 | goto restart; | |
105 | } | |
106 | goto error; | |
107 | } | |
108 | ||
109 | nb_fd = ret; | |
110 | ||
111 | for (i = 0; i < nb_fd; i++) { | |
112 | /* Fetch once the poll data */ | |
113 | revents = LTTNG_POLL_GETEV(&events, i); | |
114 | pollfd = LTTNG_POLL_GETFD(&events, i); | |
115 | ||
116 | health_code_update(); | |
117 | ||
7649924e JG |
118 | if (pollfd == quit_pipe_read_fd) { |
119 | err = 0; | |
120 | goto exit; | |
121 | } else if (pollfd == notifiers->apps_cmd_pipe_read_fd) { | |
122 | /* Inspect the apps cmd pipe */ | |
123 | if (revents & LPOLLIN) { | |
124 | int sock; | |
125 | ||
126 | /* Empty pipe */ | |
127 | size_ret = lttng_read( | |
128 | notifiers->apps_cmd_pipe_read_fd, | |
129 | &sock, sizeof(sock)); | |
130 | if (size_ret < sizeof(sock)) { | |
131 | PERROR("read apps cmd pipe"); | |
132 | goto error; | |
133 | } | |
134 | ||
135 | health_code_update(); | |
136 | ||
137 | /* | |
138 | * Since this is a command socket (write then read), | |
139 | * we only monitor the error events of the socket. | |
140 | */ | |
141 | ret = lttng_poll_add(&events, sock, | |
142 | LPOLLERR | LPOLLHUP | LPOLLRDHUP); | |
143 | if (ret < 0) { | |
144 | goto error; | |
145 | } | |
146 | ||
147 | DBG("Apps with sock %d added to poll set", sock); | |
148 | } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
149 | ERR("Apps command pipe error"); | |
150 | goto error; | |
151 | } else { | |
152 | ERR("Unknown poll events %u for sock %d", revents, pollfd); | |
153 | goto error; | |
154 | } | |
155 | } else { | |
156 | /* | |
157 | * At this point, we know that a registered application made | |
158 | * the event at poll_wait. | |
159 | */ | |
160 | if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
161 | /* Removing from the poll set */ | |
162 | ret = lttng_poll_del(&events, pollfd); | |
163 | if (ret < 0) { | |
164 | goto error; | |
165 | } | |
166 | ||
167 | /* Socket closed on remote end. */ | |
168 | ust_app_unregister(pollfd); | |
169 | } else { | |
170 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); | |
171 | goto error; | |
172 | } | |
173 | } | |
174 | ||
175 | health_code_update(); | |
176 | } | |
177 | } | |
178 | ||
179 | exit: | |
180 | error: | |
181 | lttng_poll_clean(&events); | |
182 | error_poll_create: | |
183 | error_testpoint: | |
184 | ||
185 | /* | |
186 | * We don't clean the UST app hash table here since already registered | |
187 | * applications can still be controlled so let them be until the session | |
188 | * daemon dies or the applications stop. | |
189 | */ | |
190 | ||
191 | if (err) { | |
192 | health_error(); | |
193 | ERR("Health error occurred in %s", __func__); | |
194 | } | |
412d7227 | 195 | health_unregister(the_health_sessiond); |
7649924e JG |
196 | DBG("Application communication apps thread cleanup complete"); |
197 | rcu_thread_offline(); | |
198 | rcu_unregister_thread(); | |
199 | return NULL; | |
200 | } | |
201 | ||
202 | static bool shutdown_application_management_thread(void *data) | |
203 | { | |
7966af57 | 204 | struct thread_notifiers *notifiers = (thread_notifiers *) data; |
7649924e JG |
205 | const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe); |
206 | ||
207 | return notify_thread_pipe(write_fd) == 1; | |
208 | } | |
209 | ||
210 | bool launch_application_management_thread(int apps_cmd_pipe_read_fd) | |
211 | { | |
212 | struct lttng_pipe *quit_pipe; | |
213 | struct thread_notifiers *notifiers = NULL; | |
214 | struct lttng_thread *thread; | |
215 | ||
64803277 | 216 | notifiers = zmalloc<thread_notifiers>(); |
7649924e | 217 | if (!notifiers) { |
21fa020e JG |
218 | goto error_alloc; |
219 | } | |
220 | quit_pipe = lttng_pipe_open(FD_CLOEXEC); | |
221 | if (!quit_pipe) { | |
7649924e JG |
222 | goto error; |
223 | } | |
224 | notifiers->quit_pipe = quit_pipe; | |
225 | notifiers->apps_cmd_pipe_read_fd = apps_cmd_pipe_read_fd; | |
226 | ||
227 | thread = lttng_thread_create("UST application management", | |
228 | thread_application_management, | |
229 | shutdown_application_management_thread, | |
230 | cleanup_application_management_thread, | |
231 | notifiers); | |
232 | if (!thread) { | |
233 | goto error; | |
234 | } | |
235 | ||
236 | lttng_thread_put(thread); | |
237 | return true; | |
238 | error: | |
239 | cleanup_application_management_thread(notifiers); | |
21fa020e | 240 | error_alloc: |
7649924e JG |
241 | return false; |
242 | } |