2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #include <sys/socket.h>
28 #include <sys/types.h>
30 #include <lttng/ust-ctl.h>
32 #include <common/common.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34 #include <common/compat/fcntl.h>
36 #include "ust-consumer.h"
38 extern struct lttng_consumer_global_data consumer_data
;
39 extern int consumer_poll_timeout
;
40 extern volatile int consumer_quit
;
43 * Mmap the ring buffer, read it and write the data to the tracefile.
45 * Returns the number of bytes written, else negative value on error.
47 ssize_t
lttng_ustconsumer_on_read_subbuffer_mmap(
48 struct lttng_consumer_local_data
*ctx
,
49 struct lttng_consumer_stream
*stream
, unsigned long len
)
51 unsigned long mmap_offset
;
52 long ret
= 0, written
= 0;
53 off_t orig_offset
= stream
->out_fd_offset
;
54 int outfd
= stream
->out_fd
;
56 /* get the offset inside the fd to mmap */
57 ret
= ustctl_get_mmap_read_offset(stream
->chan
->handle
,
58 stream
->buf
, &mmap_offset
);
61 PERROR("ustctl_get_mmap_read_offset");
66 ret
= write(outfd
, stream
->mmap_base
+ mmap_offset
, len
);
69 /* restart the interrupted system call */
72 PERROR("Error in file write");
78 } else if (ret
> len
) {
79 PERROR("Error in file write");
86 /* This won't block, but will start writeout asynchronously */
87 lttng_sync_file_range(outfd
, stream
->out_fd_offset
, ret
,
88 SYNC_FILE_RANGE_WRITE
);
89 stream
->out_fd_offset
+= ret
;
92 lttng_consumer_sync_trace_file(stream
, orig_offset
);
98 * Splice the data from the ring buffer to the tracefile.
100 * Returns the number of bytes spliced.
102 ssize_t
lttng_ustconsumer_on_read_subbuffer_splice(
103 struct lttng_consumer_local_data
*ctx
,
104 struct lttng_consumer_stream
*stream
, unsigned long len
)
110 * Take a snapshot for a specific fd
112 * Returns 0 on success, < 0 on error
114 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_local_data
*ctx
,
115 struct lttng_consumer_stream
*stream
)
119 ret
= ustctl_snapshot(stream
->chan
->handle
, stream
->buf
);
122 PERROR("Getting sub-buffer snapshot.");
129 * Get the produced position
131 * Returns 0 on success, < 0 on error
133 int lttng_ustconsumer_get_produced_snapshot(
134 struct lttng_consumer_local_data
*ctx
,
135 struct lttng_consumer_stream
*stream
,
140 ret
= ustctl_snapshot_get_produced(stream
->chan
->handle
,
144 PERROR("kernctl_snapshot_get_produced");
150 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
151 int sock
, struct pollfd
*consumer_sockpoll
)
154 struct lttcomm_consumer_msg msg
;
156 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
157 if (ret
!= sizeof(msg
)) {
158 lttng_consumer_send_error(ctx
, CONSUMERD_ERROR_RECV_FD
);
161 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
165 switch (msg
.cmd_type
) {
166 case LTTNG_CONSUMER_ADD_CHANNEL
:
168 struct lttng_consumer_channel
*new_channel
;
173 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
176 ret
= lttcomm_recv_fds_unix_sock(sock
, fds
, nb_fd
);
177 if (ret
!= sizeof(fds
)) {
178 lttng_consumer_send_error(ctx
, CONSUMERD_ERROR_RECV_FD
);
182 DBG("consumer_add_channel %d", msg
.u
.channel
.channel_key
);
184 new_channel
= consumer_allocate_channel(msg
.u
.channel
.channel_key
,
186 msg
.u
.channel
.mmap_len
,
187 msg
.u
.channel
.max_sb_size
);
188 if (new_channel
== NULL
) {
189 lttng_consumer_send_error(ctx
, CONSUMERD_OUTFD_ERROR
);
192 if (ctx
->on_recv_channel
!= NULL
) {
193 ret
= ctx
->on_recv_channel(new_channel
);
195 consumer_add_channel(new_channel
);
196 } else if (ret
< 0) {
200 consumer_add_channel(new_channel
);
204 case LTTNG_CONSUMER_ADD_STREAM
:
206 struct lttng_consumer_stream
*new_stream
;
211 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
214 ret
= lttcomm_recv_fds_unix_sock(sock
, fds
, nb_fd
);
215 if (ret
!= sizeof(fds
)) {
216 lttng_consumer_send_error(ctx
, CONSUMERD_ERROR_RECV_FD
);
220 DBG("consumer_add_stream %s (%d,%d)", msg
.u
.stream
.path_name
,
222 assert(msg
.u
.stream
.output
== LTTNG_EVENT_MMAP
);
223 new_stream
= consumer_allocate_stream(msg
.u
.channel
.channel_key
,
224 msg
.u
.stream
.stream_key
,
227 msg
.u
.stream
.mmap_len
,
229 msg
.u
.stream
.path_name
,
232 if (new_stream
== NULL
) {
233 lttng_consumer_send_error(ctx
, CONSUMERD_OUTFD_ERROR
);
236 if (ctx
->on_recv_stream
!= NULL
) {
237 ret
= ctx
->on_recv_stream(new_stream
);
239 consumer_add_stream(new_stream
);
240 } else if (ret
< 0) {
244 consumer_add_stream(new_stream
);
248 case LTTNG_CONSUMER_UPDATE_STREAM
:
252 if (ctx
->on_update_stream
!= NULL
) {
253 ret
= ctx
->on_update_stream(msg
.u
.stream
.stream_key
, msg
.u
.stream
.state
);
255 consumer_change_stream_state(msg
.u
.stream
.stream_key
, msg
.u
.stream
.state
);
256 } else if (ret
< 0) {
260 consumer_change_stream_state(msg
.u
.stream
.stream_key
,
271 * Wake-up the other end by writing a null byte in the pipe
272 * (non-blocking). Important note: Because writing into the
273 * pipe is non-blocking (and therefore we allow dropping wakeup
274 * data, as long as there is wakeup data present in the pipe
275 * buffer to wake up the other end), the other end should
276 * perform the following sequence for waiting:
277 * 1) empty the pipe (reads).
278 * 2) perform update operation.
279 * 3) wait on the pipe (poll).
282 ret
= write(ctx
->consumer_poll_pipe
[1], "", 1);
283 } while (ret
== -1UL && errno
== EINTR
);
288 int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel
*chan
)
290 struct lttng_ust_object_data obj
;
293 obj
.shm_fd
= chan
->shm_fd
;
294 obj
.wait_fd
= chan
->wait_fd
;
295 obj
.memory_map_size
= chan
->mmap_len
;
296 chan
->handle
= ustctl_map_channel(&obj
);
300 chan
->wait_fd_is_copy
= 1;
306 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream
*stream
)
308 ustctl_flush_buffer(stream
->chan
->handle
, stream
->buf
, 0);
309 stream
->hangup_flush_done
= 1;
312 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel
*chan
)
314 ustctl_unmap_channel(chan
->handle
);
317 int lttng_ustconsumer_allocate_stream(struct lttng_consumer_stream
*stream
)
319 struct lttng_ust_object_data obj
;
323 obj
.shm_fd
= stream
->shm_fd
;
324 obj
.wait_fd
= stream
->wait_fd
;
325 obj
.memory_map_size
= stream
->mmap_len
;
326 ret
= ustctl_add_stream(stream
->chan
->handle
, &obj
);
329 stream
->buf
= ustctl_open_stream_read(stream
->chan
->handle
, stream
->cpu
);
332 /* ustctl_open_stream_read has closed the shm fd. */
333 stream
->wait_fd_is_copy
= 1;
336 stream
->mmap_base
= ustctl_get_mmap_base(stream
->chan
->handle
, stream
->buf
);
337 if (!stream
->mmap_base
) {
344 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream
*stream
)
346 ustctl_close_stream_read(stream
->chan
->handle
, stream
->buf
);
350 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
351 struct lttng_consumer_local_data
*ctx
)
356 struct lttng_ust_shm_handle
*handle
;
357 struct lttng_ust_lib_ring_buffer
*buf
;
361 DBG("In read_subbuffer (wait_fd: %d, stream key: %d)",
362 stream
->wait_fd
, stream
->key
);
364 /* We can consume the 1 byte written into the wait_fd by UST */
365 if (!stream
->hangup_flush_done
) {
367 readlen
= read(stream
->wait_fd
, &dummy
, 1);
368 } while (readlen
== -1 && errno
== EINTR
);
376 handle
= stream
->chan
->handle
;
377 /* Get the next subbuffer */
378 err
= ustctl_get_next_subbuf(handle
, buf
);
380 ret
= -ret
; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
382 * This is a debug message even for single-threaded consumer,
383 * because poll() have more relaxed criterions than get subbuf,
384 * so get_subbuf may fail for short race windows where poll()
385 * would issue wakeups.
387 DBG("Reserving sub buffer failed (everything is normal, "
388 "it is due to concurrency)");
391 assert(stream
->output
== LTTNG_EVENT_MMAP
);
392 /* read the used subbuffer size */
393 err
= ustctl_get_padded_subbuf_size(handle
, buf
, &len
);
395 /* write the subbuffer to the tracefile */
396 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, len
);
399 * display the error but continue processing to try
400 * to release the subbuffer
402 ERR("Error writing to tracefile");
404 err
= ustctl_put_next_subbuf(handle
, buf
);
410 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
414 /* Opening the tracefile in write mode */
415 if (stream
->path_name
!= NULL
) {
416 ret
= run_as_open(stream
->path_name
,
417 O_WRONLY
|O_CREAT
|O_TRUNC
,
418 S_IRWXU
|S_IRWXG
|S_IRWXO
,
419 stream
->uid
, stream
->gid
);
421 ERR("Opening %s", stream
->path_name
);
425 stream
->out_fd
= ret
;
428 /* we return 0 to let the library handle the FD internally */