clang-tidy: add a subset of cppcoreguidelines and other style checks
[lttng-tools.git] / src / bin / lttng-sessiond / thread-utils.cpp
1 /*
2 * Copyright (C) 2011 EfficiOS Inc.
3 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
5 *
6 * SPDX-License-Identifier: GPL-2.0-only
7 *
8 */
9
10 #include "lttng-sessiond.hpp"
11 #include "utils.hpp"
12
13 #include <common/utils.hpp>
14
15 #include <pthread.h>
16
17 /*
18 * Quit pipe for the main thread. This is used by signal handlers to start the
19 * shutdown sequence of the main thread which will tear down the other threads
20 * in the appropriate order.
21 */
22 static int main_quit_pipe[2] = { -1, -1 };
23
24 /*
25 * Init main quit pipe.
26 *
27 * Return -1 on error or 0 if all pipes are created.
28 */
29 int sessiond_init_main_quit_pipe()
30 {
31 int ret, i;
32
33 ret = pipe(main_quit_pipe);
34 if (ret < 0) {
35 PERROR("main quit pipe");
36 goto error;
37 }
38
39 for (i = 0; i < 2; i++) {
40 ret = fcntl(main_quit_pipe[i], F_SETFD, FD_CLOEXEC);
41 if (ret < 0) {
42 PERROR("fcntl main_quit_pipe");
43 goto error;
44 }
45 }
46
47 error:
48 return ret;
49 }
50
51 /*
52 * Wait for a notification on the main quit pipe (with a timeout).
53 *
54 * A timeout value of -1U means no timeout.
55 *
56 * Returns 1 if the caller should quit, 0 if the timeout was reached, and
57 * -1 if an error was encountered.
58 */
59 int sessiond_wait_for_main_quit_pipe(int timeout_ms)
60 {
61 int ret;
62 struct lttng_poll_event events;
63
64 ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC);
65 if (ret < 0) {
66 PERROR("Failed to initialize poll/epoll set");
67 ret = -1;
68 goto end;
69 }
70 ret = lttng_poll_add(&events, main_quit_pipe[0], LPOLLIN);
71 if (ret < 0) {
72 PERROR("Failed to add file descriptor to poll/epoll set");
73 ret = -1;
74 goto end_clean_poll;
75 }
76 ret = lttng_poll_wait(&events, timeout_ms);
77 if (ret > 0) {
78 /* Should quit. */
79 ret = 1;
80 } else if (ret < 0 && errno != EINTR) {
81 /* Unknown error. */
82 PERROR("Failed to epoll()/poll() main quit pipe");
83 ret = -1;
84 } else {
85 /* Timeout reached. */
86 ret = 0;
87 }
88 end_clean_poll:
89 lttng_poll_clean(&events);
90 end:
91 return ret;
92 }
93
94 int sessiond_notify_main_quit_pipe()
95 {
96 return notify_thread_pipe(main_quit_pipe[1]);
97 }
98
99 void sessiond_close_main_quit_pipe()
100 {
101 utils_close_pipe(main_quit_pipe);
102 }
103
104 /*
105 * Create a poll set with O_CLOEXEC and add the main quit pipe to the set.
106 */
107 int sessiond_set_thread_pollset(struct lttng_poll_event *events, size_t size)
108 {
109 int ret;
110
111 LTTNG_ASSERT(events);
112
113 ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
114 if (ret < 0) {
115 goto error;
116 }
117
118 /* Add main quit pipe */
119 ret = lttng_poll_add(events, main_quit_pipe[0], LPOLLIN);
120 if (ret < 0) {
121 goto error;
122 }
123
124 return 0;
125
126 error:
127 return ret;
128 }
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