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 | ||
28ab034a | 10 | #include "health-sessiond.hpp" |
c9e313bc SM |
11 | #include "manage-apps.hpp" |
12 | #include "testpoint.hpp" | |
c9e313bc | 13 | #include "thread.hpp" |
28ab034a | 14 | #include "utils.hpp" |
7649924e | 15 | |
671e39d7 MJ |
16 | #include <fcntl.h> |
17 | ||
f1494934 | 18 | namespace { |
7649924e JG |
19 | struct thread_notifiers { |
20 | struct lttng_pipe *quit_pipe; | |
21 | int apps_cmd_pipe_read_fd; | |
22 | }; | |
f1494934 | 23 | } /* namespace */ |
7649924e JG |
24 | |
25 | static void cleanup_application_management_thread(void *data) | |
26 | { | |
7966af57 | 27 | struct thread_notifiers *notifiers = (thread_notifiers *) data; |
7649924e JG |
28 | |
29 | lttng_pipe_destroy(notifiers->quit_pipe); | |
30 | free(notifiers); | |
31 | } | |
32 | ||
33 | /* | |
34 | * This thread receives application command sockets (FDs) on the | |
35 | * apps_cmd_pipe and waits (polls) on them until they are closed | |
36 | * or an error occurs. | |
37 | * | |
38 | * At that point, it flushes the data (tracing and metadata) associated | |
39 | * with this application and tears down ust app sessions and other | |
a7db814e | 40 | * associated data structures through ust_app_unregister_by_socket(). |
7649924e JG |
41 | * |
42 | * Note that this thread never sends commands to the applications | |
43 | * through the command sockets; it merely listens for hang-ups | |
44 | * and errors on those sockets and cleans-up as they occur. | |
45 | */ | |
46 | static void *thread_application_management(void *data) | |
47 | { | |
8a00688e | 48 | int i, ret, err = -1; |
7649924e | 49 | ssize_t size_ret; |
8a00688e | 50 | uint32_t nb_fd; |
7649924e | 51 | struct lttng_poll_event events; |
7966af57 | 52 | struct thread_notifiers *notifiers = (thread_notifiers *) data; |
28ab034a | 53 | const auto thread_quit_pipe_fd = lttng_pipe_get_readfd(notifiers->quit_pipe); |
7649924e JG |
54 | |
55 | DBG("[thread] Manage application started"); | |
56 | ||
57 | rcu_register_thread(); | |
58 | rcu_thread_online(); | |
59 | ||
412d7227 | 60 | health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_APP_MANAGE); |
7649924e JG |
61 | |
62 | if (testpoint(sessiond_thread_manage_apps)) { | |
63 | goto error_testpoint; | |
64 | } | |
65 | ||
66 | health_code_update(); | |
67 | ||
68 | ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC); | |
69 | if (ret < 0) { | |
70 | goto error_poll_create; | |
71 | } | |
72 | ||
28ab034a | 73 | ret = lttng_poll_add(&events, notifiers->apps_cmd_pipe_read_fd, LPOLLIN | LPOLLRDHUP); |
7649924e JG |
74 | if (ret < 0) { |
75 | goto error; | |
76 | } | |
77 | ||
1524f98c | 78 | ret = lttng_poll_add(&events, thread_quit_pipe_fd, LPOLLIN); |
7649924e JG |
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 | ||
cd9adb8b | 89 | while (true) { |
7649924e JG |
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); | |
28ab034a | 96 | DBG("Apps thread return from poll on %d fds", LTTNG_POLL_GETNB(&events)); |
7649924e JG |
97 | health_poll_exit(); |
98 | if (ret < 0) { | |
99 | /* | |
100 | * Restart interrupted system call. | |
101 | */ | |
102 | if (errno == EINTR) { | |
103 | goto restart; | |
104 | } | |
105 | goto error; | |
106 | } | |
107 | ||
108 | nb_fd = ret; | |
109 | ||
110 | for (i = 0; i < nb_fd; i++) { | |
111 | /* Fetch once the poll data */ | |
8a00688e MJ |
112 | const auto revents = LTTNG_POLL_GETEV(&events, i); |
113 | const auto pollfd = LTTNG_POLL_GETFD(&events, i); | |
7649924e JG |
114 | |
115 | health_code_update(); | |
116 | ||
8a00688e MJ |
117 | /* Activity on thread quit pipe, exiting. */ |
118 | if (pollfd == thread_quit_pipe_fd) { | |
119 | DBG("Activity on thread quit pipe"); | |
7649924e JG |
120 | err = 0; |
121 | goto exit; | |
8a00688e MJ |
122 | } |
123 | ||
124 | if (pollfd == notifiers->apps_cmd_pipe_read_fd) { | |
7649924e JG |
125 | /* Inspect the apps cmd pipe */ |
126 | if (revents & LPOLLIN) { | |
127 | int sock; | |
128 | ||
129 | /* Empty pipe */ | |
28ab034a JG |
130 | size_ret = lttng_read(notifiers->apps_cmd_pipe_read_fd, |
131 | &sock, | |
132 | sizeof(sock)); | |
7649924e JG |
133 | if (size_ret < sizeof(sock)) { |
134 | PERROR("read apps cmd pipe"); | |
135 | goto error; | |
136 | } | |
137 | ||
138 | health_code_update(); | |
139 | ||
140 | /* | |
141 | * Since this is a command socket (write then read), | |
142 | * we only monitor the error events of the socket. | |
143 | */ | |
1524f98c | 144 | ret = lttng_poll_add(&events, sock, LPOLLRDHUP); |
7649924e JG |
145 | if (ret < 0) { |
146 | goto error; | |
147 | } | |
148 | ||
149 | DBG("Apps with sock %d added to poll set", sock); | |
150 | } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
151 | ERR("Apps command pipe error"); | |
152 | goto error; | |
153 | } else { | |
154 | ERR("Unknown poll events %u for sock %d", revents, pollfd); | |
155 | goto error; | |
156 | } | |
157 | } else { | |
158 | /* | |
159 | * At this point, we know that a registered application made | |
160 | * the event at poll_wait. | |
161 | */ | |
162 | if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
163 | /* Removing from the poll set */ | |
164 | ret = lttng_poll_del(&events, pollfd); | |
165 | if (ret < 0) { | |
166 | goto error; | |
167 | } | |
168 | ||
169 | /* Socket closed on remote end. */ | |
a7db814e | 170 | ust_app_unregister_by_socket(pollfd); |
7649924e | 171 | } else { |
28ab034a JG |
172 | ERR("Unexpected poll events %u for sock %d", |
173 | revents, | |
174 | pollfd); | |
7649924e JG |
175 | goto error; |
176 | } | |
177 | } | |
178 | ||
179 | health_code_update(); | |
180 | } | |
181 | } | |
182 | ||
183 | exit: | |
184 | error: | |
185 | lttng_poll_clean(&events); | |
186 | error_poll_create: | |
187 | error_testpoint: | |
188 | ||
189 | /* | |
190 | * We don't clean the UST app hash table here since already registered | |
191 | * applications can still be controlled so let them be until the session | |
192 | * daemon dies or the applications stop. | |
193 | */ | |
194 | ||
195 | if (err) { | |
196 | health_error(); | |
197 | ERR("Health error occurred in %s", __func__); | |
198 | } | |
412d7227 | 199 | health_unregister(the_health_sessiond); |
7649924e JG |
200 | DBG("Application communication apps thread cleanup complete"); |
201 | rcu_thread_offline(); | |
202 | rcu_unregister_thread(); | |
cd9adb8b | 203 | return nullptr; |
7649924e JG |
204 | } |
205 | ||
206 | static bool shutdown_application_management_thread(void *data) | |
207 | { | |
7966af57 | 208 | struct thread_notifiers *notifiers = (thread_notifiers *) data; |
7649924e JG |
209 | const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe); |
210 | ||
211 | return notify_thread_pipe(write_fd) == 1; | |
212 | } | |
213 | ||
214 | bool launch_application_management_thread(int apps_cmd_pipe_read_fd) | |
215 | { | |
216 | struct lttng_pipe *quit_pipe; | |
cd9adb8b | 217 | struct thread_notifiers *notifiers = nullptr; |
7649924e JG |
218 | struct lttng_thread *thread; |
219 | ||
64803277 | 220 | notifiers = zmalloc<thread_notifiers>(); |
7649924e | 221 | if (!notifiers) { |
21fa020e JG |
222 | goto error_alloc; |
223 | } | |
224 | quit_pipe = lttng_pipe_open(FD_CLOEXEC); | |
225 | if (!quit_pipe) { | |
7649924e JG |
226 | goto error; |
227 | } | |
228 | notifiers->quit_pipe = quit_pipe; | |
229 | notifiers->apps_cmd_pipe_read_fd = apps_cmd_pipe_read_fd; | |
230 | ||
231 | thread = lttng_thread_create("UST application management", | |
28ab034a JG |
232 | thread_application_management, |
233 | shutdown_application_management_thread, | |
234 | cleanup_application_management_thread, | |
235 | notifiers); | |
7649924e JG |
236 | if (!thread) { |
237 | goto error; | |
238 | } | |
239 | ||
240 | lttng_thread_put(thread); | |
241 | return true; | |
242 | error: | |
243 | cleanup_application_management_thread(notifiers); | |
21fa020e | 244 | error_alloc: |
7649924e JG |
245 | return false; |
246 | } |