Fix: include stdlib.h in compat/string.h
[lttng-tools.git] / tests / regression / tools / notification / consumer_testpoints.c
1 /*
2 * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@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
18 #include <common/compat/getenv.h>
19 #include <common/consumer/consumer.h>
20 #include <common/pipe.h>
21 #include <common/error.h>
22 #include <unistd.h>
23 #include <stdbool.h>
24 #include <lttng/constant.h>
25 #include <fcntl.h>
26 #include <dlfcn.h>
27 #include <assert.h>
28 #include <stdio.h>
29
30 static char *pause_pipe_path;
31 static struct lttng_pipe *pause_pipe;
32 static int *data_consumption_state;
33 static enum lttng_consumer_type (*lttng_consumer_get_type)(void);
34
35 int lttng_opt_verbose;
36 int lttng_opt_mi;
37 int lttng_opt_quiet;
38
39 static
40 void __attribute__((destructor)) pause_pipe_fini(void)
41 {
42 int ret;
43
44 if (pause_pipe_path) {
45 ret = unlink(pause_pipe_path);
46 if (ret) {
47 PERROR("unlink pause pipe");
48 }
49 }
50
51 free(pause_pipe_path);
52 lttng_pipe_destroy(pause_pipe);
53 }
54
55 /*
56 * We use this testpoint, invoked at the start of the consumerd's data handling
57 * thread to create a named pipe/FIFO which a test application can use to either
58 * pause or resume the consumption of data.
59 */
60 int __testpoint_consumerd_thread_data(void)
61 {
62 int ret = 0;
63 const char *pause_pipe_path_prefix, *domain;
64
65 pause_pipe_path_prefix = lttng_secure_getenv(
66 "CONSUMER_PAUSE_PIPE_PATH");
67 if (!pause_pipe_path_prefix) {
68 ret = -1;
69 goto end;
70 }
71
72 /*
73 * These symbols are exclusive to the consumerd process, hence we can't
74 * rely on their presence in the sessiond. Not looking-up these symbols
75 * dynamically would not allow this shared object to be LD_PRELOAD-ed
76 * when launching the session daemon.
77 */
78 data_consumption_state = dlsym(NULL, "data_consumption_paused");
79 assert(data_consumption_state);
80 lttng_consumer_get_type = dlsym(NULL, "lttng_consumer_get_type");
81 assert(lttng_consumer_get_type);
82
83 switch (lttng_consumer_get_type()) {
84 case LTTNG_CONSUMER_KERNEL:
85 domain = "kernel";
86 break;
87 case LTTNG_CONSUMER32_UST:
88 domain = "ust32";
89 break;
90 case LTTNG_CONSUMER64_UST:
91 domain = "ust64";
92 break;
93 default:
94 abort();
95 }
96
97 ret = asprintf(&pause_pipe_path, "%s-%s", pause_pipe_path_prefix,
98 domain);
99 if (ret < 1) {
100 ERR("Failed to allocate pause pipe path");
101 goto end;
102 }
103
104 DBG("Creating pause pipe at %s", pause_pipe_path);
105 pause_pipe = lttng_pipe_named_open(pause_pipe_path,
106 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP, O_NONBLOCK);
107 if (!pause_pipe) {
108 ERR("Failed to create pause pipe at %s", pause_pipe_path);
109 ret = -1;
110 goto end;
111 }
112
113 /* Only the read end of the pipe is useful to us. */
114 ret = lttng_pipe_write_close(pause_pipe);
115 end:
116 return ret;
117 }
118
119 int __testpoint_consumerd_thread_data_poll(void)
120 {
121 int ret = 0;
122 uint8_t value;
123 bool value_read = false;
124
125 if (!pause_pipe) {
126 ret = -1;
127 goto end;
128 }
129
130 /* Purge pipe and only consider the freshest value. */
131 do {
132 ret = lttng_pipe_read(pause_pipe, &value, sizeof(value));
133 if (ret == sizeof(value)) {
134 value_read = true;
135 }
136 } while (ret == sizeof(value));
137
138 ret = (errno == EAGAIN) ? 0 : -errno;
139
140 if (value_read) {
141 *data_consumption_state = !!value;
142 DBG("Message received on pause pipe: %s data consumption",
143 *data_consumption_state ? "paused" : "resumed");
144 }
145 end:
146 return ret;
147 }
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