1e0bf55ec70727578bbff92fe921ba8af74b55ca
[lttng-tools.git] / liblttng-ustconsumer / lttng-ustconsumer.c
1 /*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; only version 2
8 * of the License.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 */
19
20 #define _GNU_SOURCE
21 #include <assert.h>
22 #include <fcntl.h>
23 #include <poll.h>
24 #include <pthread.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sys/mman.h>
28 #include <sys/socket.h>
29 #include <sys/types.h>
30 #include <unistd.h>
31
32 #include <ust/lttng-ust-ctl.h>
33 #include <lttng-sessiond-comm.h>
34 #include <lttng/lttng-ustconsumer.h>
35 #include <lttngerr.h>
36
37 extern struct lttng_consumer_global_data consumer_data;
38 extern int consumer_poll_timeout;
39 extern volatile int consumer_quit;
40
41 /*
42 * Mmap the ring buffer, read it and write the data to the tracefile.
43 *
44 * Returns the number of bytes written
45 */
46 int lttng_ustconsumer_on_read_subbuffer_mmap(
47 struct lttng_consumer_local_data *ctx,
48 struct lttng_consumer_stream *stream, unsigned long len)
49 {
50 unsigned long mmap_offset;
51 long ret = 0;
52 off_t orig_offset = stream->out_fd_offset;
53 int outfd = stream->out_fd;
54
55 /* get the offset inside the fd to mmap */
56 ret = ustctl_get_mmap_read_offset(stream->chan->handle,
57 stream->buf, &mmap_offset);
58 if (ret != 0) {
59 ret = -errno;
60 perror("ustctl_get_mmap_read_offset");
61 goto end;
62 }
63 while (len > 0) {
64 ret = write(outfd, stream->mmap_base + mmap_offset, len);
65 if (ret >= len) {
66 len = 0;
67 } else if (ret < 0) {
68 ret = -errno;
69 perror("Error in file write");
70 goto end;
71 }
72 /* This won't block, but will start writeout asynchronously */
73 sync_file_range(outfd, stream->out_fd_offset, ret,
74 SYNC_FILE_RANGE_WRITE);
75 stream->out_fd_offset += ret;
76 }
77
78 lttng_consumer_sync_trace_file(stream, orig_offset);
79
80 goto end;
81
82 end:
83 return ret;
84 }
85
86 /*
87 * Splice the data from the ring buffer to the tracefile.
88 *
89 * Returns the number of bytes spliced.
90 */
91 int lttng_ustconsumer_on_read_subbuffer_splice(
92 struct lttng_consumer_local_data *ctx,
93 struct lttng_consumer_stream *stream, unsigned long len)
94 {
95 return -ENOSYS;
96 }
97
98 /*
99 * Take a snapshot for a specific fd
100 *
101 * Returns 0 on success, < 0 on error
102 */
103 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_local_data *ctx,
104 struct lttng_consumer_stream *stream)
105 {
106 int ret = 0;
107
108 ret = ustctl_snapshot(stream->chan->handle, stream->buf);
109 if (ret != 0) {
110 ret = errno;
111 perror("Getting sub-buffer snapshot.");
112 }
113
114 return ret;
115 }
116
117 /*
118 * Get the produced position
119 *
120 * Returns 0 on success, < 0 on error
121 */
122 int lttng_ustconsumer_get_produced_snapshot(
123 struct lttng_consumer_local_data *ctx,
124 struct lttng_consumer_stream *stream,
125 unsigned long *pos)
126 {
127 int ret;
128
129 ret = ustctl_snapshot_get_produced(stream->chan->handle,
130 stream->buf, pos);
131 if (ret != 0) {
132 ret = errno;
133 perror("kernctl_snapshot_get_produced");
134 }
135
136 return ret;
137 }
138
139 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
140 int sock, struct pollfd *consumer_sockpoll)
141 {
142 ssize_t ret;
143 struct lttcomm_consumer_msg msg;
144
145 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
146 if (ret != sizeof(msg)) {
147 lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
148 return ret;
149 }
150 if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
151 return -ENOENT;
152 }
153
154 switch (msg.cmd_type) {
155 case LTTNG_CONSUMER_ADD_CHANNEL:
156 {
157 struct lttng_consumer_channel *new_channel;
158 int fds[1];
159 size_t nb_fd = 1;
160
161 /* block */
162 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
163 return -EINTR;
164 }
165 ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
166 if (ret != sizeof(fds)) {
167 lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
168 return ret;
169 }
170
171 DBG("consumer_add_channel %d", msg.u.channel.channel_key);
172
173 new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
174 fds[0], -1,
175 msg.u.channel.mmap_len,
176 msg.u.channel.max_sb_size);
177 if (new_channel == NULL) {
178 lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
179 goto end_nosignal;
180 }
181 if (ctx->on_recv_channel != NULL) {
182 ret = ctx->on_recv_channel(new_channel);
183 if (ret == 0) {
184 consumer_add_channel(new_channel);
185 } else if (ret < 0) {
186 goto end_nosignal;
187 }
188 } else {
189 consumer_add_channel(new_channel);
190 }
191 goto end_nosignal;
192 }
193 case LTTNG_CONSUMER_ADD_STREAM:
194 {
195 struct lttng_consumer_stream *new_stream;
196 int fds[2];
197 size_t nb_fd = 2;
198
199 /* block */
200 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
201 return -EINTR;
202 }
203 ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
204 if (ret != sizeof(fds)) {
205 lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
206 return ret;
207 }
208
209 DBG("consumer_add_stream %s (%d,%d)", msg.u.stream.path_name,
210 fds[0], fds[1]);
211 new_stream = consumer_allocate_stream(msg.u.stream.channel_key,
212 msg.u.stream.stream_key,
213 fds[0], fds[1],
214 msg.u.stream.state,
215 msg.u.stream.mmap_len,
216 msg.u.stream.output,
217 msg.u.stream.path_name);
218 if (new_stream == NULL) {
219 lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
220 goto end;
221 }
222 if (ctx->on_recv_stream != NULL) {
223 ret = ctx->on_recv_stream(new_stream);
224 if (ret == 0) {
225 consumer_add_stream(new_stream);
226 } else if (ret < 0) {
227 goto end;
228 }
229 } else {
230 consumer_add_stream(new_stream);
231 }
232 break;
233 }
234 case LTTNG_CONSUMER_UPDATE_STREAM:
235 {
236 if (ctx->on_update_stream != NULL) {
237 ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state);
238 if (ret == 0) {
239 consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state);
240 } else if (ret < 0) {
241 goto end;
242 }
243 } else {
244 consumer_change_stream_state(msg.u.stream.stream_key,
245 msg.u.stream.state);
246 }
247 break;
248 }
249 default:
250 break;
251 }
252 end:
253 /* signal the poll thread */
254 ret = write(ctx->consumer_poll_pipe[1], "4", 1);
255 if (ret < 0) {
256 perror("write consumer poll");
257 }
258 end_nosignal:
259 return 0;
260 }
261
262 int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan)
263 {
264 struct object_data obj;
265
266 obj.handle = -1;
267 obj.shm_fd = chan->shm_fd;
268 obj.wait_fd = chan->wait_fd;
269 obj.memory_map_size = chan->mmap_len;
270 chan->handle = ustctl_map_channel(&obj);
271 if (!chan->handle) {
272 return -ENOMEM;
273 }
274 return 0;
275 }
276
277 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
278 {
279 ustctl_unmap_channel(chan->handle);
280 }
281
282 int lttng_ustconsumer_allocate_stream(struct lttng_consumer_stream *stream)
283 {
284 struct object_data obj;
285 int ret;
286
287 obj.handle = -1;
288 obj.shm_fd = stream->shm_fd;
289 obj.wait_fd = stream->wait_fd;
290 obj.memory_map_size = stream->mmap_len;
291 ret = ustctl_add_stream(stream->chan->handle, &obj);
292 if (ret)
293 return ret;
294 stream->buf = ustctl_open_stream_read(stream->chan->handle, stream->cpu);
295 if (!stream->buf)
296 return -EBUSY;
297 stream->mmap_base = ustctl_get_mmap_base(stream->chan->handle, stream->buf);
298 if (!stream->mmap_base) {
299 return -EINVAL;
300 }
301 return 0;
302 }
303
304 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
305 {
306 ustctl_close_stream_read(stream->chan->handle, stream->buf);
307 }
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