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