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 | ||
8 | #include <common/compat/getenv.h> | |
9 | #include <common/consumer/consumer.h> | |
10 | #include <common/pipe.h> | |
11 | #include <common/error.h> | |
12 | #include <unistd.h> | |
13 | #include <stdbool.h> | |
14 | #include <lttng/constant.h> | |
15 | #include <fcntl.h> | |
16 | #include <dlfcn.h> | |
17 | #include <assert.h> | |
18 | #include <stdio.h> | |
19 | ||
20 | static char *pause_pipe_path; | |
21 | static struct lttng_pipe *pause_pipe; | |
22 | static int *data_consumption_state; | |
23 | static enum lttng_consumer_type (*lttng_consumer_get_type)(void); | |
24 | ||
25 | int lttng_opt_verbose; | |
26 | int lttng_opt_mi; | |
27 | int lttng_opt_quiet; | |
28 | ||
29 | static | |
30 | void __attribute__((destructor)) pause_pipe_fini(void) | |
31 | { | |
32 | int ret; | |
33 | ||
34 | if (pause_pipe_path) { | |
35 | ret = unlink(pause_pipe_path); | |
36 | if (ret) { | |
37 | PERROR("unlink pause pipe"); | |
38 | } | |
39 | } | |
40 | ||
41 | free(pause_pipe_path); | |
42 | lttng_pipe_destroy(pause_pipe); | |
43 | } | |
44 | ||
45 | /* | |
46 | * We use this testpoint, invoked at the start of the consumerd's data handling | |
47 | * thread to create a named pipe/FIFO which a test application can use to either | |
48 | * pause or resume the consumption of data. | |
49 | */ | |
8abfcbd1 | 50 | int __testpoint_consumerd_thread_data(void); |
434f8068 JR |
51 | int __testpoint_consumerd_thread_data(void) |
52 | { | |
53 | int ret = 0; | |
54 | const char *pause_pipe_path_prefix, *domain; | |
55 | ||
56 | pause_pipe_path_prefix = lttng_secure_getenv( | |
57 | "CONSUMER_PAUSE_PIPE_PATH"); | |
58 | if (!pause_pipe_path_prefix) { | |
59 | ret = -1; | |
60 | goto end; | |
61 | } | |
62 | ||
63 | /* | |
64 | * These symbols are exclusive to the consumerd process, hence we can't | |
65 | * rely on their presence in the sessiond. Not looking-up these symbols | |
66 | * dynamically would not allow this shared object to be LD_PRELOAD-ed | |
67 | * when launching the session daemon. | |
68 | */ | |
69 | data_consumption_state = dlsym(NULL, "data_consumption_paused"); | |
70 | assert(data_consumption_state); | |
71 | lttng_consumer_get_type = dlsym(NULL, "lttng_consumer_get_type"); | |
72 | assert(lttng_consumer_get_type); | |
73 | ||
74 | switch (lttng_consumer_get_type()) { | |
75 | case LTTNG_CONSUMER_KERNEL: | |
76 | domain = "kernel"; | |
77 | break; | |
78 | case LTTNG_CONSUMER32_UST: | |
79 | domain = "ust32"; | |
80 | break; | |
81 | case LTTNG_CONSUMER64_UST: | |
82 | domain = "ust64"; | |
83 | break; | |
84 | default: | |
85 | abort(); | |
86 | } | |
87 | ||
88 | ret = asprintf(&pause_pipe_path, "%s-%s", pause_pipe_path_prefix, | |
89 | domain); | |
90 | if (ret < 1) { | |
91 | ERR("Failed to allocate pause pipe path"); | |
92 | goto end; | |
93 | } | |
94 | ||
95 | DBG("Creating pause pipe at %s", pause_pipe_path); | |
96 | pause_pipe = lttng_pipe_named_open(pause_pipe_path, | |
97 | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP, O_NONBLOCK); | |
98 | if (!pause_pipe) { | |
99 | ERR("Failed to create pause pipe at %s", pause_pipe_path); | |
100 | ret = -1; | |
101 | goto end; | |
102 | } | |
103 | ||
104 | /* Only the read end of the pipe is useful to us. */ | |
105 | ret = lttng_pipe_write_close(pause_pipe); | |
106 | end: | |
107 | return ret; | |
108 | } | |
109 | ||
8abfcbd1 | 110 | int __testpoint_consumerd_thread_data_poll(void); |
434f8068 JR |
111 | int __testpoint_consumerd_thread_data_poll(void) |
112 | { | |
113 | int ret = 0; | |
114 | uint8_t value; | |
115 | bool value_read = false; | |
116 | ||
117 | if (!pause_pipe) { | |
118 | ret = -1; | |
119 | goto end; | |
120 | } | |
121 | ||
122 | /* Purge pipe and only consider the freshest value. */ | |
123 | do { | |
124 | ret = lttng_pipe_read(pause_pipe, &value, sizeof(value)); | |
125 | if (ret == sizeof(value)) { | |
126 | value_read = true; | |
127 | } | |
128 | } while (ret == sizeof(value)); | |
129 | ||
130 | ret = (errno == EAGAIN) ? 0 : -errno; | |
131 | ||
132 | if (value_read) { | |
133 | *data_consumption_state = !!value; | |
134 | DBG("Message received on pause pipe: %s data consumption", | |
135 | *data_consumption_state ? "paused" : "resumed"); | |
136 | } | |
137 | end: | |
138 | return ret; | |
139 | } |