Commit | Line | Data |
---|---|---|
434f8068 | 1 | /* |
9d16b343 | 2 | * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
434f8068 | 3 | * |
9d16b343 | 4 | * SPDX-License-Identifier: GPL-2.0-only |
434f8068 | 5 | * |
434f8068 JR |
6 | */ |
7 | ||
c9e313bc SM |
8 | #include <common/compat/getenv.hpp> |
9 | #include <common/consumer/consumer.hpp> | |
c9e313bc | 10 | #include <common/error.hpp> |
28ab034a JG |
11 | #include <common/pipe.hpp> |
12 | ||
434f8068 | 13 | #include <lttng/constant.h> |
4bd69c5f | 14 | #include <lttng/lttng-export.h> |
28ab034a | 15 | |
434f8068 | 16 | #include <dlfcn.h> |
28ab034a JG |
17 | #include <fcntl.h> |
18 | #include <stdbool.h> | |
434f8068 | 19 | #include <stdio.h> |
28ab034a | 20 | #include <unistd.h> |
434f8068 JR |
21 | |
22 | static char *pause_pipe_path; | |
23 | static struct lttng_pipe *pause_pipe; | |
24 | static int *data_consumption_state; | |
729c1fec SM |
25 | using lttng_consumer_get_type_func = enum lttng_consumer_type (*)(); |
26 | static lttng_consumer_get_type_func lttng_consumer_get_type; | |
434f8068 JR |
27 | |
28 | int lttng_opt_verbose; | |
29 | int lttng_opt_mi; | |
30 | int lttng_opt_quiet; | |
31 | ||
cd9adb8b | 32 | static void __attribute__((destructor)) pause_pipe_fini() |
434f8068 JR |
33 | { |
34 | int ret; | |
35 | ||
36 | if (pause_pipe_path) { | |
37 | ret = unlink(pause_pipe_path); | |
38 | if (ret) { | |
39 | PERROR("unlink pause pipe"); | |
40 | } | |
41 | } | |
42 | ||
43 | free(pause_pipe_path); | |
44 | lttng_pipe_destroy(pause_pipe); | |
45 | } | |
46 | ||
47 | /* | |
48 | * We use this testpoint, invoked at the start of the consumerd's data handling | |
49 | * thread to create a named pipe/FIFO which a test application can use to either | |
50 | * pause or resume the consumption of data. | |
51 | */ | |
97535efa | 52 | extern "C" LTTNG_EXPORT int __testpoint_consumerd_thread_data(void); |
434f8068 JR |
53 | int __testpoint_consumerd_thread_data(void) |
54 | { | |
55 | int ret = 0; | |
56 | const char *pause_pipe_path_prefix, *domain; | |
57 | ||
28ab034a | 58 | pause_pipe_path_prefix = lttng_secure_getenv("CONSUMER_PAUSE_PIPE_PATH"); |
434f8068 JR |
59 | if (!pause_pipe_path_prefix) { |
60 | ret = -1; | |
61 | goto end; | |
62 | } | |
63 | ||
64 | /* | |
65 | * These symbols are exclusive to the consumerd process, hence we can't | |
66 | * rely on their presence in the sessiond. Not looking-up these symbols | |
67 | * dynamically would not allow this shared object to be LD_PRELOAD-ed | |
68 | * when launching the session daemon. | |
69 | */ | |
cd9adb8b | 70 | data_consumption_state = (int *) dlsym(nullptr, "data_consumption_paused"); |
a0377dfe | 71 | LTTNG_ASSERT(data_consumption_state); |
cd9adb8b JG |
72 | lttng_consumer_get_type = |
73 | (lttng_consumer_type(*)()) dlsym(nullptr, "lttng_consumer_get_type"); | |
a0377dfe | 74 | LTTNG_ASSERT(lttng_consumer_get_type); |
434f8068 JR |
75 | |
76 | switch (lttng_consumer_get_type()) { | |
77 | case LTTNG_CONSUMER_KERNEL: | |
78 | domain = "kernel"; | |
79 | break; | |
80 | case LTTNG_CONSUMER32_UST: | |
81 | domain = "ust32"; | |
82 | break; | |
83 | case LTTNG_CONSUMER64_UST: | |
84 | domain = "ust64"; | |
85 | break; | |
86 | default: | |
87 | abort(); | |
88 | } | |
89 | ||
28ab034a | 90 | ret = asprintf(&pause_pipe_path, "%s-%s", pause_pipe_path_prefix, domain); |
434f8068 JR |
91 | if (ret < 1) { |
92 | ERR("Failed to allocate pause pipe path"); | |
93 | goto end; | |
94 | } | |
95 | ||
96 | DBG("Creating pause pipe at %s", pause_pipe_path); | |
28ab034a JG |
97 | pause_pipe = lttng_pipe_named_open( |
98 | pause_pipe_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP, O_NONBLOCK); | |
434f8068 JR |
99 | if (!pause_pipe) { |
100 | ERR("Failed to create pause pipe at %s", pause_pipe_path); | |
101 | ret = -1; | |
102 | goto end; | |
103 | } | |
104 | ||
105 | /* Only the read end of the pipe is useful to us. */ | |
106 | ret = lttng_pipe_write_close(pause_pipe); | |
107 | end: | |
108 | return ret; | |
109 | } | |
110 | ||
97535efa | 111 | extern "C" LTTNG_EXPORT int __testpoint_consumerd_thread_data_poll(void); |
434f8068 JR |
112 | int __testpoint_consumerd_thread_data_poll(void) |
113 | { | |
114 | int ret = 0; | |
115 | uint8_t value; | |
116 | bool value_read = false; | |
117 | ||
118 | if (!pause_pipe) { | |
119 | ret = -1; | |
120 | goto end; | |
121 | } | |
122 | ||
123 | /* Purge pipe and only consider the freshest value. */ | |
124 | do { | |
125 | ret = lttng_pipe_read(pause_pipe, &value, sizeof(value)); | |
126 | if (ret == sizeof(value)) { | |
127 | value_read = true; | |
128 | } | |
129 | } while (ret == sizeof(value)); | |
130 | ||
131 | ret = (errno == EAGAIN) ? 0 : -errno; | |
132 | ||
133 | if (value_read) { | |
134 | *data_consumption_state = !!value; | |
135 | DBG("Message received on pause pipe: %s data consumption", | |
28ab034a | 136 | *data_consumption_state ? "paused" : "resumed"); |
434f8068 JR |
137 | } |
138 | end: | |
139 | return ret; | |
140 | } |