Commit | Line | Data |
---|---|---|
a7333da7 | 1 | /* |
ab5be9fa MJ |
2 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> |
3 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
a7333da7 | 5 | * |
ab5be9fa | 6 | * SPDX-License-Identifier: GPL-2.0-only |
a7333da7 | 7 | * |
a7333da7 JG |
8 | */ |
9 | ||
10 | #include "lttng-sessiond.h" | |
11 | #include "utils.h" | |
12 | #include <common/utils.h> | |
99d688f2 JG |
13 | #include <pthread.h> |
14 | ||
a7333da7 JG |
15 | /* |
16 | * Quit pipe for all threads. This permits a single cancellation point | |
17 | * for all threads when receiving an event on the pipe. | |
18 | */ | |
19 | static int thread_quit_pipe[2] = { -1, -1 }; | |
20 | ||
21 | /* | |
22 | * Init thread quit pipe. | |
23 | * | |
24 | * Return -1 on error or 0 if all pipes are created. | |
25 | */ | |
26 | static int __init_thread_quit_pipe(int *a_pipe) | |
27 | { | |
28 | int ret, i; | |
29 | ||
30 | ret = pipe(a_pipe); | |
31 | if (ret < 0) { | |
32 | PERROR("thread quit pipe"); | |
33 | goto error; | |
34 | } | |
35 | ||
36 | for (i = 0; i < 2; i++) { | |
37 | ret = fcntl(a_pipe[i], F_SETFD, FD_CLOEXEC); | |
38 | if (ret < 0) { | |
39 | PERROR("fcntl"); | |
40 | goto error; | |
41 | } | |
42 | } | |
43 | ||
44 | error: | |
45 | return ret; | |
46 | } | |
47 | ||
48 | int sessiond_init_thread_quit_pipe(void) | |
49 | { | |
50 | return __init_thread_quit_pipe(thread_quit_pipe); | |
51 | } | |
52 | ||
53 | int sessiond_check_thread_quit_pipe(int fd, uint32_t events) | |
54 | { | |
55 | return (fd == thread_quit_pipe[0] && (events & LPOLLIN)); | |
56 | } | |
57 | ||
58 | /* | |
59 | * Wait for a notification on the quit pipe (with a timeout). | |
60 | * | |
99d688f2 JG |
61 | * A timeout value of -1U means no timeout. |
62 | * | |
a7333da7 JG |
63 | * Returns 1 if the caller should quit, 0 if the timeout was reached, and |
64 | * -1 if an error was encountered. | |
65 | */ | |
2d54bfb6 | 66 | int sessiond_wait_for_quit_pipe(int timeout_ms) |
a7333da7 JG |
67 | { |
68 | int ret; | |
2d54bfb6 | 69 | struct lttng_poll_event events; |
a7333da7 | 70 | |
2d54bfb6 MD |
71 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
72 | if (ret < 0) { | |
73 | PERROR("Failed to initialize poll/epoll set"); | |
74 | ret = -1; | |
75 | goto end; | |
76 | } | |
77 | ret = lttng_poll_add(&events, thread_quit_pipe[0], LPOLLIN | LPOLLERR); | |
78 | if (ret < 0) { | |
79 | PERROR("Failed to add file descriptor to poll/epoll set"); | |
80 | ret = -1; | |
81 | goto end_clean_poll; | |
82 | } | |
83 | ret = lttng_poll_wait(&events, timeout_ms); | |
a7333da7 JG |
84 | if (ret > 0) { |
85 | /* Should quit. */ | |
86 | ret = 1; | |
87 | } else if (ret < 0 && errno != EINTR) { | |
88 | /* Unknown error. */ | |
2d54bfb6 | 89 | PERROR("Failed to epoll()/poll() thread quit pipe"); |
a7333da7 JG |
90 | ret = -1; |
91 | } else { | |
92 | /* Timeout reached. */ | |
93 | ret = 0; | |
94 | } | |
2d54bfb6 MD |
95 | end_clean_poll: |
96 | lttng_poll_clean(&events); | |
97 | end: | |
a7333da7 JG |
98 | return ret; |
99 | } | |
100 | ||
101 | int sessiond_notify_quit_pipe(void) | |
102 | { | |
103 | return notify_thread_pipe(thread_quit_pipe[1]); | |
104 | } | |
105 | ||
106 | void sessiond_close_quit_pipe(void) | |
107 | { | |
108 | utils_close_pipe(thread_quit_pipe); | |
109 | } | |
110 | ||
111 | static | |
112 | int __sessiond_set_thread_pollset(struct lttng_poll_event *events, size_t size, | |
113 | int *a_pipe) | |
114 | { | |
115 | int ret; | |
116 | ||
a0377dfe | 117 | LTTNG_ASSERT(events); |
a7333da7 JG |
118 | |
119 | ret = lttng_poll_create(events, size, LTTNG_CLOEXEC); | |
120 | if (ret < 0) { | |
121 | goto error; | |
122 | } | |
123 | ||
124 | /* Add quit pipe */ | |
125 | ret = lttng_poll_add(events, a_pipe[0], LPOLLIN | LPOLLERR); | |
126 | if (ret < 0) { | |
127 | goto error; | |
128 | } | |
129 | ||
130 | return 0; | |
131 | ||
132 | error: | |
133 | return ret; | |
134 | } | |
135 | ||
136 | /* | |
137 | * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set. | |
138 | */ | |
139 | int sessiond_set_thread_pollset(struct lttng_poll_event *events, size_t size) | |
140 | { | |
141 | return __sessiond_set_thread_pollset(events, size, thread_quit_pipe); | |
142 | } |