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d0b96690 DG |
1 | /* |
2 | * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU General Public License, version 2 only, as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
16 | */ | |
17 | #define _GNU_SOURCE | |
18 | #include <assert.h> | |
19 | ||
20 | #include <common/common.h> | |
21 | #include <common/utils.h> | |
22 | ||
23 | #include "fd-limit.h" | |
24 | #include "lttng-sessiond.h" | |
25 | #include "ust-thread.h" | |
8782cc74 | 26 | #include "health-sessiond.h" |
d0b96690 DG |
27 | |
28 | /* | |
29 | * This thread manage application notify communication. | |
30 | */ | |
31 | void *ust_thread_manage_notify(void *data) | |
32 | { | |
380e8d6f | 33 | int i, ret, pollfd, err = -1; |
6cd525e8 | 34 | ssize_t size_ret; |
d0b96690 DG |
35 | uint32_t revents, nb_fd; |
36 | struct lttng_poll_event events; | |
37 | ||
38 | DBG("[ust-thread] Manage application notify command"); | |
39 | ||
40 | rcu_register_thread(); | |
41 | rcu_thread_online(); | |
42 | ||
6c71277b MD |
43 | health_register(health_sessiond, |
44 | HEALTH_SESSIOND_TYPE_APP_MANAGE_NOTIFY); | |
380e8d6f MD |
45 | |
46 | health_code_update(); | |
47 | ||
d0b96690 DG |
48 | ret = sessiond_set_thread_pollset(&events, 2); |
49 | if (ret < 0) { | |
50 | goto error_poll_create; | |
51 | } | |
52 | ||
53 | /* Add notify pipe to the pollset. */ | |
54 | ret = lttng_poll_add(&events, apps_cmd_notify_pipe[0], LPOLLIN | LPOLLERR); | |
55 | if (ret < 0) { | |
56 | goto error; | |
57 | } | |
58 | ||
380e8d6f MD |
59 | health_code_update(); |
60 | ||
d0b96690 DG |
61 | while (1) { |
62 | DBG3("[ust-thread] Manage notify polling on %d fds", | |
63 | LTTNG_POLL_GETNB(&events)); | |
64 | ||
65 | /* Inifinite blocking call, waiting for transmission */ | |
66 | restart: | |
380e8d6f | 67 | health_poll_entry(); |
d0b96690 | 68 | ret = lttng_poll_wait(&events, -1); |
380e8d6f | 69 | health_poll_exit(); |
d0b96690 DG |
70 | if (ret < 0) { |
71 | /* | |
72 | * Restart interrupted system call. | |
73 | */ | |
74 | if (errno == EINTR) { | |
75 | goto restart; | |
76 | } | |
77 | goto error; | |
78 | } | |
79 | ||
80 | nb_fd = ret; | |
81 | ||
82 | for (i = 0; i < nb_fd; i++) { | |
380e8d6f MD |
83 | health_code_update(); |
84 | ||
d0b96690 DG |
85 | /* Fetch once the poll data */ |
86 | revents = LTTNG_POLL_GETEV(&events, i); | |
87 | pollfd = LTTNG_POLL_GETFD(&events, i); | |
88 | ||
89 | /* Thread quit pipe has been closed. Killing thread. */ | |
90 | ret = sessiond_check_thread_quit_pipe(pollfd, revents); | |
91 | if (ret) { | |
380e8d6f | 92 | err = 0; |
d0b96690 DG |
93 | goto exit; |
94 | } | |
95 | ||
96 | /* Inspect the apps cmd pipe */ | |
97 | if (pollfd == apps_cmd_notify_pipe[0]) { | |
98 | int sock; | |
99 | ||
100 | if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
101 | ERR("Apps notify command pipe error"); | |
102 | goto error; | |
103 | } else if (!(revents & LPOLLIN)) { | |
104 | /* No POLLIN and not a catched error, stop the thread. */ | |
105 | ERR("Notify command pipe failed. revent: %u", revents); | |
106 | goto error; | |
107 | } | |
108 | ||
6cd525e8 MD |
109 | /* Get socket from dispatch thread. */ |
110 | size_ret = lttng_read(apps_cmd_notify_pipe[0], | |
111 | &sock, sizeof(sock)); | |
112 | if (size_ret < sizeof(sock)) { | |
d0b96690 DG |
113 | PERROR("read apps notify pipe"); |
114 | goto error; | |
115 | } | |
380e8d6f | 116 | health_code_update(); |
d0b96690 DG |
117 | |
118 | ret = lttng_poll_add(&events, sock, | |
119 | LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP); | |
120 | if (ret < 0) { | |
121 | /* | |
122 | * It's possible we've reached the max poll fd allowed. | |
123 | * Let's close the socket but continue normal execution. | |
124 | */ | |
125 | ret = close(sock); | |
126 | if (ret) { | |
127 | PERROR("close notify socket %d", sock); | |
128 | } | |
129 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
130 | continue; | |
131 | } | |
132 | DBG3("UST thread notify added sock %d to pollset", sock); | |
133 | } else { | |
134 | /* | |
135 | * At this point, we know that a registered application | |
136 | * triggered the event. | |
137 | */ | |
138 | if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
139 | /* Removing from the poll set */ | |
140 | ret = lttng_poll_del(&events, pollfd); | |
141 | if (ret < 0) { | |
142 | goto error; | |
143 | } | |
144 | ||
d88aee68 DG |
145 | /* The socket is closed after a grace period here. */ |
146 | ust_app_notify_sock_unregister(pollfd); | |
d0b96690 DG |
147 | } else if (revents & (LPOLLIN | LPOLLPRI)) { |
148 | ret = ust_app_recv_notify(pollfd); | |
149 | if (ret < 0) { | |
d88aee68 DG |
150 | /* |
151 | * If the notification failed either the application is | |
152 | * dead or an internal error happened. In both cases, | |
153 | * we can only continue here. If the application is | |
154 | * dead, an unregistration will follow or else the | |
155 | * application will notice that we are not responding | |
156 | * on that socket and will close it. | |
157 | */ | |
158 | continue; | |
d0b96690 DG |
159 | } |
160 | } else { | |
161 | ERR("Unknown poll events %u for sock %d", revents, pollfd); | |
162 | continue; | |
163 | } | |
380e8d6f | 164 | health_code_update(); |
d0b96690 DG |
165 | } |
166 | } | |
167 | } | |
168 | ||
169 | exit: | |
170 | error: | |
171 | lttng_poll_clean(&events); | |
172 | error_poll_create: | |
173 | utils_close_pipe(apps_cmd_notify_pipe); | |
174 | apps_cmd_notify_pipe[0] = apps_cmd_notify_pipe[1] = -1; | |
175 | DBG("Application notify communication apps thread cleanup complete"); | |
380e8d6f MD |
176 | if (err) { |
177 | health_error(); | |
178 | ERR("Health error occurred in %s", __func__); | |
179 | } | |
8782cc74 | 180 | health_unregister(health_sessiond); |
d0b96690 DG |
181 | rcu_thread_offline(); |
182 | rcu_unregister_thread(); | |
183 | return NULL; | |
184 | } |