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
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; only version 2
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.
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.
28 #include <sys/socket.h>
29 #include <sys/types.h>
32 #include <common/common.h>
33 #include <common/kernel-ctl/kernel-ctl.h>
34 #include <common/sessiond-comm/sessiond-comm.h>
35 #include <common/kernel-consumer/kernel-consumer.h>
36 #include <common/ust-consumer/ust-consumer.h>
40 struct lttng_consumer_global_data consumer_data
= {
43 .type
= LTTNG_CONSUMER_UNKNOWN
,
46 /* timeout parameter, to control the polling thread grace period. */
47 int consumer_poll_timeout
= -1;
50 * Flag to inform the polling thread to quit when all fd hung up. Updated by
51 * the consumer_thread_receive_fds when it notices that all fds has hung up.
52 * Also updated by the signal handler (consumer_should_exit()). Read by the
55 volatile int consumer_quit
= 0;
58 * Find a stream. The consumer_data.lock must be locked during this
61 static struct lttng_consumer_stream
*consumer_find_stream(int key
)
63 struct lttng_ht_iter iter
;
64 struct lttng_ht_node_ulong
*node
;
65 struct lttng_consumer_stream
*stream
= NULL
;
67 /* Negative keys are lookup failures */
73 lttng_ht_lookup(consumer_data
.stream_ht
, (void *)((unsigned long) key
),
75 node
= lttng_ht_iter_get_node_ulong(&iter
);
77 stream
= caa_container_of(node
, struct lttng_consumer_stream
, node
);
85 static void consumer_steal_stream_key(int key
)
87 struct lttng_consumer_stream
*stream
;
89 stream
= consumer_find_stream(key
);
94 static struct lttng_consumer_channel
*consumer_find_channel(int key
)
96 struct lttng_ht_iter iter
;
97 struct lttng_ht_node_ulong
*node
;
98 struct lttng_consumer_channel
*channel
= NULL
;
100 /* Negative keys are lookup failures */
106 lttng_ht_lookup(consumer_data
.channel_ht
, (void *)((unsigned long) key
),
108 node
= lttng_ht_iter_get_node_ulong(&iter
);
110 channel
= caa_container_of(node
, struct lttng_consumer_channel
, node
);
118 static void consumer_steal_channel_key(int key
)
120 struct lttng_consumer_channel
*channel
;
122 channel
= consumer_find_channel(key
);
128 void consumer_free_stream(struct rcu_head
*head
)
130 struct lttng_ht_node_ulong
*node
=
131 caa_container_of(head
, struct lttng_ht_node_ulong
, head
);
132 struct lttng_consumer_stream
*stream
=
133 caa_container_of(node
, struct lttng_consumer_stream
, node
);
139 * Remove a stream from the global list protected by a mutex. This
140 * function is also responsible for freeing its data structures.
142 void consumer_del_stream(struct lttng_consumer_stream
*stream
)
145 struct lttng_ht_iter iter
;
146 struct lttng_consumer_channel
*free_chan
= NULL
;
148 pthread_mutex_lock(&consumer_data
.lock
);
150 switch (consumer_data
.type
) {
151 case LTTNG_CONSUMER_KERNEL
:
152 if (stream
->mmap_base
!= NULL
) {
153 ret
= munmap(stream
->mmap_base
, stream
->mmap_len
);
159 case LTTNG_CONSUMER32_UST
:
160 case LTTNG_CONSUMER64_UST
:
161 lttng_ustconsumer_del_stream(stream
);
164 ERR("Unknown consumer_data type");
171 /* Get stream node from hash table */
172 lttng_ht_lookup(consumer_data
.stream_ht
,
173 (void *)((unsigned long) stream
->key
), &iter
);
175 * Remove stream node from hash table. It can fail if it's been
176 * replaced due to key reuse.
178 (void) lttng_ht_del(consumer_data
.stream_ht
, &iter
);
182 if (consumer_data
.stream_count
<= 0) {
185 consumer_data
.stream_count
--;
189 if (stream
->out_fd
>= 0) {
190 ret
= close(stream
->out_fd
);
195 if (stream
->wait_fd
>= 0 && !stream
->wait_fd_is_copy
) {
196 ret
= close(stream
->wait_fd
);
201 if (stream
->shm_fd
>= 0 && stream
->wait_fd
!= stream
->shm_fd
) {
202 ret
= close(stream
->shm_fd
);
207 if (!--stream
->chan
->refcount
)
208 free_chan
= stream
->chan
;
210 call_rcu(&stream
->node
.head
, consumer_free_stream
);
212 consumer_data
.need_update
= 1;
213 pthread_mutex_unlock(&consumer_data
.lock
);
216 consumer_del_channel(free_chan
);
219 struct lttng_consumer_stream
*consumer_allocate_stream(
220 int channel_key
, int stream_key
,
221 int shm_fd
, int wait_fd
,
222 enum lttng_consumer_stream_state state
,
224 enum lttng_event_output output
,
225 const char *path_name
,
229 struct lttng_consumer_stream
*stream
;
232 stream
= zmalloc(sizeof(*stream
));
233 if (stream
== NULL
) {
234 perror("malloc struct lttng_consumer_stream");
237 stream
->chan
= consumer_find_channel(channel_key
);
239 perror("Unable to find channel key");
242 stream
->chan
->refcount
++;
243 stream
->key
= stream_key
;
244 stream
->shm_fd
= shm_fd
;
245 stream
->wait_fd
= wait_fd
;
247 stream
->out_fd_offset
= 0;
248 stream
->state
= state
;
249 stream
->mmap_len
= mmap_len
;
250 stream
->mmap_base
= NULL
;
251 stream
->output
= output
;
254 strncpy(stream
->path_name
, path_name
, PATH_MAX
- 1);
255 stream
->path_name
[PATH_MAX
- 1] = '\0';
256 lttng_ht_node_init_ulong(&stream
->node
, stream
->key
);
258 switch (consumer_data
.type
) {
259 case LTTNG_CONSUMER_KERNEL
:
261 case LTTNG_CONSUMER32_UST
:
262 case LTTNG_CONSUMER64_UST
:
263 stream
->cpu
= stream
->chan
->cpucount
++;
264 ret
= lttng_ustconsumer_allocate_stream(stream
);
271 ERR("Unknown consumer_data type");
275 DBG("Allocated stream %s (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, out_fd %d)",
276 stream
->path_name
, stream
->key
,
279 (unsigned long long) stream
->mmap_len
,
286 * Add a stream to the global list protected by a mutex.
288 int consumer_add_stream(struct lttng_consumer_stream
*stream
)
292 pthread_mutex_lock(&consumer_data
.lock
);
293 /* Steal stream identifier, for UST */
294 consumer_steal_stream_key(stream
->key
);
297 * We simply remove the old channel from the hash table. It's
298 * ok, since we know for sure the sessiond wants to replace it
299 * with the new version, because the key has been reused.
301 (void) lttng_ht_add_replace_ulong(consumer_data
.stream_ht
, &stream
->node
);
303 consumer_data
.stream_count
++;
304 consumer_data
.need_update
= 1;
306 switch (consumer_data
.type
) {
307 case LTTNG_CONSUMER_KERNEL
:
309 case LTTNG_CONSUMER32_UST
:
310 case LTTNG_CONSUMER64_UST
:
311 /* Streams are in CPU number order (we rely on this) */
312 stream
->cpu
= stream
->chan
->nr_streams
++;
315 ERR("Unknown consumer_data type");
321 pthread_mutex_unlock(&consumer_data
.lock
);
327 * Update a stream according to what we just received.
329 void consumer_change_stream_state(int stream_key
,
330 enum lttng_consumer_stream_state state
)
332 struct lttng_consumer_stream
*stream
;
334 pthread_mutex_lock(&consumer_data
.lock
);
335 stream
= consumer_find_stream(stream_key
);
337 stream
->state
= state
;
339 consumer_data
.need_update
= 1;
340 pthread_mutex_unlock(&consumer_data
.lock
);
344 void consumer_free_channel(struct rcu_head
*head
)
346 struct lttng_ht_node_ulong
*node
=
347 caa_container_of(head
, struct lttng_ht_node_ulong
, head
);
348 struct lttng_consumer_channel
*channel
=
349 caa_container_of(node
, struct lttng_consumer_channel
, node
);
355 * Remove a channel from the global list protected by a mutex. This
356 * function is also responsible for freeing its data structures.
358 void consumer_del_channel(struct lttng_consumer_channel
*channel
)
361 struct lttng_ht_iter iter
;
363 pthread_mutex_lock(&consumer_data
.lock
);
365 switch (consumer_data
.type
) {
366 case LTTNG_CONSUMER_KERNEL
:
368 case LTTNG_CONSUMER32_UST
:
369 case LTTNG_CONSUMER64_UST
:
370 lttng_ustconsumer_del_channel(channel
);
373 ERR("Unknown consumer_data type");
380 lttng_ht_lookup(consumer_data
.channel_ht
,
381 (void *)((unsigned long) channel
->key
), &iter
);
384 * Remove channel node from hash table. It can fail if it's been
385 * replaced due to key reuse.
387 (void) lttng_ht_del(consumer_data
.channel_ht
, &iter
);
391 if (channel
->mmap_base
!= NULL
) {
392 ret
= munmap(channel
->mmap_base
, channel
->mmap_len
);
397 if (channel
->wait_fd
>= 0 && !channel
->wait_fd_is_copy
) {
398 ret
= close(channel
->wait_fd
);
403 if (channel
->shm_fd
>= 0 && channel
->wait_fd
!= channel
->shm_fd
) {
404 ret
= close(channel
->shm_fd
);
410 call_rcu(&channel
->node
.head
, consumer_free_channel
);
412 pthread_mutex_unlock(&consumer_data
.lock
);
415 struct lttng_consumer_channel
*consumer_allocate_channel(
417 int shm_fd
, int wait_fd
,
419 uint64_t max_sb_size
)
421 struct lttng_consumer_channel
*channel
;
424 channel
= zmalloc(sizeof(*channel
));
425 if (channel
== NULL
) {
426 perror("malloc struct lttng_consumer_channel");
429 channel
->key
= channel_key
;
430 channel
->shm_fd
= shm_fd
;
431 channel
->wait_fd
= wait_fd
;
432 channel
->mmap_len
= mmap_len
;
433 channel
->max_sb_size
= max_sb_size
;
434 channel
->refcount
= 0;
435 channel
->nr_streams
= 0;
436 lttng_ht_node_init_ulong(&channel
->node
, channel
->key
);
438 switch (consumer_data
.type
) {
439 case LTTNG_CONSUMER_KERNEL
:
440 channel
->mmap_base
= NULL
;
441 channel
->mmap_len
= 0;
443 case LTTNG_CONSUMER32_UST
:
444 case LTTNG_CONSUMER64_UST
:
445 ret
= lttng_ustconsumer_allocate_channel(channel
);
452 ERR("Unknown consumer_data type");
456 DBG("Allocated channel (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, max_sb_size %llu)",
460 (unsigned long long) channel
->mmap_len
,
461 (unsigned long long) channel
->max_sb_size
);
467 * Add a channel to the global list protected by a mutex.
469 int consumer_add_channel(struct lttng_consumer_channel
*channel
)
471 pthread_mutex_lock(&consumer_data
.lock
);
472 /* Steal channel identifier, for UST */
473 consumer_steal_channel_key(channel
->key
);
476 * We simply remove the old channel from the hash table. It's
477 * ok, since we know for sure the sessiond wants to replace it
478 * with the new version, because the key has been reused.
480 (void) lttng_ht_add_replace_ulong(consumer_data
.channel_ht
, &channel
->node
);
482 pthread_mutex_unlock(&consumer_data
.lock
);
488 * Allocate the pollfd structure and the local view of the out fds to avoid
489 * doing a lookup in the linked list and concurrency issues when writing is
490 * needed. Called with consumer_data.lock held.
492 * Returns the number of fds in the structures.
494 int consumer_update_poll_array(
495 struct lttng_consumer_local_data
*ctx
, struct pollfd
**pollfd
,
496 struct lttng_consumer_stream
**local_stream
)
499 struct lttng_ht_iter iter
;
500 struct lttng_consumer_stream
*stream
;
502 DBG("Updating poll fd array");
504 cds_lfht_for_each_entry(consumer_data
.stream_ht
->ht
, &iter
.iter
, stream
,
506 if (stream
->state
!= LTTNG_CONSUMER_ACTIVE_STREAM
) {
509 DBG("Active FD %d", stream
->wait_fd
);
510 (*pollfd
)[i
].fd
= stream
->wait_fd
;
511 (*pollfd
)[i
].events
= POLLIN
| POLLPRI
;
512 local_stream
[i
] = stream
;
518 * Insert the consumer_poll_pipe at the end of the array and don't
519 * increment i so nb_fd is the number of real FD.
521 (*pollfd
)[i
].fd
= ctx
->consumer_poll_pipe
[0];
522 (*pollfd
)[i
].events
= POLLIN
;
527 * Poll on the should_quit pipe and the command socket return -1 on error and
528 * should exit, 0 if data is available on the command socket
530 int lttng_consumer_poll_socket(struct pollfd
*consumer_sockpoll
)
535 num_rdy
= poll(consumer_sockpoll
, 2, -1);
538 * Restart interrupted system call.
540 if (errno
== EINTR
) {
543 perror("Poll error");
546 if (consumer_sockpoll
[0].revents
== POLLIN
) {
547 DBG("consumer_should_quit wake up");
557 * Set the error socket.
559 void lttng_consumer_set_error_sock(
560 struct lttng_consumer_local_data
*ctx
, int sock
)
562 ctx
->consumer_error_socket
= sock
;
566 * Set the command socket path.
569 void lttng_consumer_set_command_sock_path(
570 struct lttng_consumer_local_data
*ctx
, char *sock
)
572 ctx
->consumer_command_sock_path
= sock
;
576 * Send return code to the session daemon.
577 * If the socket is not defined, we return 0, it is not a fatal error
579 int lttng_consumer_send_error(
580 struct lttng_consumer_local_data
*ctx
, int cmd
)
582 if (ctx
->consumer_error_socket
> 0) {
583 return lttcomm_send_unix_sock(ctx
->consumer_error_socket
, &cmd
,
584 sizeof(enum lttcomm_sessiond_command
));
591 * Close all the tracefiles and stream fds, should be called when all instances
594 void lttng_consumer_cleanup(void)
596 struct lttng_ht_iter iter
;
597 struct lttng_ht_node_ulong
*node
;
602 * close all outfd. Called when there are no more threads running (after
603 * joining on the threads), no need to protect list iteration with mutex.
605 cds_lfht_for_each_entry(consumer_data
.stream_ht
->ht
, &iter
.iter
, node
,
607 struct lttng_consumer_stream
*stream
=
608 caa_container_of(node
, struct lttng_consumer_stream
, node
);
609 consumer_del_stream(stream
);
612 cds_lfht_for_each_entry(consumer_data
.channel_ht
->ht
, &iter
.iter
, node
,
614 struct lttng_consumer_channel
*channel
=
615 caa_container_of(node
, struct lttng_consumer_channel
, node
);
616 consumer_del_channel(channel
);
623 * Called from signal handler.
625 void lttng_consumer_should_exit(struct lttng_consumer_local_data
*ctx
)
629 ret
= write(ctx
->consumer_should_quit
[1], "4", 1);
631 perror("write consumer quit");
635 void lttng_consumer_sync_trace_file(
636 struct lttng_consumer_stream
*stream
, off_t orig_offset
)
638 int outfd
= stream
->out_fd
;
641 * This does a blocking write-and-wait on any page that belongs to the
642 * subbuffer prior to the one we just wrote.
643 * Don't care about error values, as these are just hints and ways to
644 * limit the amount of page cache used.
646 if (orig_offset
< stream
->chan
->max_sb_size
) {
649 sync_file_range(outfd
, orig_offset
- stream
->chan
->max_sb_size
,
650 stream
->chan
->max_sb_size
,
651 SYNC_FILE_RANGE_WAIT_BEFORE
652 | SYNC_FILE_RANGE_WRITE
653 | SYNC_FILE_RANGE_WAIT_AFTER
);
655 * Give hints to the kernel about how we access the file:
656 * POSIX_FADV_DONTNEED : we won't re-access data in a near future after
659 * We need to call fadvise again after the file grows because the
660 * kernel does not seem to apply fadvise to non-existing parts of the
663 * Call fadvise _after_ having waited for the page writeback to
664 * complete because the dirty page writeback semantic is not well
665 * defined. So it can be expected to lead to lower throughput in
668 posix_fadvise(outfd
, orig_offset
- stream
->chan
->max_sb_size
,
669 stream
->chan
->max_sb_size
, POSIX_FADV_DONTNEED
);
673 * Initialise the necessary environnement :
674 * - create a new context
675 * - create the poll_pipe
676 * - create the should_quit pipe (for signal handler)
677 * - create the thread pipe (for splice)
679 * Takes a function pointer as argument, this function is called when data is
680 * available on a buffer. This function is responsible to do the
681 * kernctl_get_next_subbuf, read the data with mmap or splice depending on the
682 * buffer configuration and then kernctl_put_next_subbuf at the end.
684 * Returns a pointer to the new context or NULL on error.
686 struct lttng_consumer_local_data
*lttng_consumer_create(
687 enum lttng_consumer_type type
,
688 ssize_t (*buffer_ready
)(struct lttng_consumer_stream
*stream
,
689 struct lttng_consumer_local_data
*ctx
),
690 int (*recv_channel
)(struct lttng_consumer_channel
*channel
),
691 int (*recv_stream
)(struct lttng_consumer_stream
*stream
),
692 int (*update_stream
)(int stream_key
, uint32_t state
))
695 struct lttng_consumer_local_data
*ctx
;
697 assert(consumer_data
.type
== LTTNG_CONSUMER_UNKNOWN
||
698 consumer_data
.type
== type
);
699 consumer_data
.type
= type
;
701 ctx
= zmalloc(sizeof(struct lttng_consumer_local_data
));
703 perror("allocating context");
707 ctx
->consumer_error_socket
= -1;
708 /* assign the callbacks */
709 ctx
->on_buffer_ready
= buffer_ready
;
710 ctx
->on_recv_channel
= recv_channel
;
711 ctx
->on_recv_stream
= recv_stream
;
712 ctx
->on_update_stream
= update_stream
;
714 ret
= pipe(ctx
->consumer_poll_pipe
);
716 perror("Error creating poll pipe");
717 goto error_poll_pipe
;
720 ret
= pipe(ctx
->consumer_should_quit
);
722 perror("Error creating recv pipe");
723 goto error_quit_pipe
;
726 ret
= pipe(ctx
->consumer_thread_pipe
);
728 perror("Error creating thread pipe");
729 goto error_thread_pipe
;
736 for (i
= 0; i
< 2; i
++) {
739 err
= close(ctx
->consumer_should_quit
[i
]);
745 for (i
= 0; i
< 2; i
++) {
748 err
= close(ctx
->consumer_poll_pipe
[i
]);
760 * Close all fds associated with the instance and free the context.
762 void lttng_consumer_destroy(struct lttng_consumer_local_data
*ctx
)
766 ret
= close(ctx
->consumer_error_socket
);
770 ret
= close(ctx
->consumer_thread_pipe
[0]);
774 ret
= close(ctx
->consumer_thread_pipe
[1]);
778 ret
= close(ctx
->consumer_poll_pipe
[0]);
782 ret
= close(ctx
->consumer_poll_pipe
[1]);
786 ret
= close(ctx
->consumer_should_quit
[0]);
790 ret
= close(ctx
->consumer_should_quit
[1]);
794 unlink(ctx
->consumer_command_sock_path
);
799 * Mmap the ring buffer, read it and write the data to the tracefile.
801 * Returns the number of bytes written
803 ssize_t
lttng_consumer_on_read_subbuffer_mmap(
804 struct lttng_consumer_local_data
*ctx
,
805 struct lttng_consumer_stream
*stream
, unsigned long len
)
807 switch (consumer_data
.type
) {
808 case LTTNG_CONSUMER_KERNEL
:
809 return lttng_kconsumer_on_read_subbuffer_mmap(ctx
, stream
, len
);
810 case LTTNG_CONSUMER32_UST
:
811 case LTTNG_CONSUMER64_UST
:
812 return lttng_ustconsumer_on_read_subbuffer_mmap(ctx
, stream
, len
);
814 ERR("Unknown consumer_data type");
820 * Splice the data from the ring buffer to the tracefile.
822 * Returns the number of bytes spliced.
824 ssize_t
lttng_consumer_on_read_subbuffer_splice(
825 struct lttng_consumer_local_data
*ctx
,
826 struct lttng_consumer_stream
*stream
, unsigned long len
)
828 switch (consumer_data
.type
) {
829 case LTTNG_CONSUMER_KERNEL
:
830 return lttng_kconsumer_on_read_subbuffer_splice(ctx
, stream
, len
);
831 case LTTNG_CONSUMER32_UST
:
832 case LTTNG_CONSUMER64_UST
:
835 ERR("Unknown consumer_data type");
843 * Take a snapshot for a specific fd
845 * Returns 0 on success, < 0 on error
847 int lttng_consumer_take_snapshot(struct lttng_consumer_local_data
*ctx
,
848 struct lttng_consumer_stream
*stream
)
850 switch (consumer_data
.type
) {
851 case LTTNG_CONSUMER_KERNEL
:
852 return lttng_kconsumer_take_snapshot(ctx
, stream
);
853 case LTTNG_CONSUMER32_UST
:
854 case LTTNG_CONSUMER64_UST
:
855 return lttng_ustconsumer_take_snapshot(ctx
, stream
);
857 ERR("Unknown consumer_data type");
865 * Get the produced position
867 * Returns 0 on success, < 0 on error
869 int lttng_consumer_get_produced_snapshot(
870 struct lttng_consumer_local_data
*ctx
,
871 struct lttng_consumer_stream
*stream
,
874 switch (consumer_data
.type
) {
875 case LTTNG_CONSUMER_KERNEL
:
876 return lttng_kconsumer_get_produced_snapshot(ctx
, stream
, pos
);
877 case LTTNG_CONSUMER32_UST
:
878 case LTTNG_CONSUMER64_UST
:
879 return lttng_ustconsumer_get_produced_snapshot(ctx
, stream
, pos
);
881 ERR("Unknown consumer_data type");
887 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
888 int sock
, struct pollfd
*consumer_sockpoll
)
890 switch (consumer_data
.type
) {
891 case LTTNG_CONSUMER_KERNEL
:
892 return lttng_kconsumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
893 case LTTNG_CONSUMER32_UST
:
894 case LTTNG_CONSUMER64_UST
:
895 return lttng_ustconsumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
897 ERR("Unknown consumer_data type");
904 * This thread polls the fds in the set to consume the data and write
905 * it to tracefile if necessary.
907 void *lttng_consumer_thread_poll_fds(void *data
)
909 int num_rdy
, num_hup
, high_prio
, ret
, i
;
910 struct pollfd
*pollfd
= NULL
;
911 /* local view of the streams */
912 struct lttng_consumer_stream
**local_stream
= NULL
;
913 /* local view of consumer_data.fds_count */
917 struct lttng_consumer_local_data
*ctx
= data
;
919 rcu_register_thread();
921 local_stream
= zmalloc(sizeof(struct lttng_consumer_stream
));
928 * the fds set has been updated, we need to update our
929 * local array as well
931 pthread_mutex_lock(&consumer_data
.lock
);
932 if (consumer_data
.need_update
) {
933 if (pollfd
!= NULL
) {
937 if (local_stream
!= NULL
) {
942 /* allocate for all fds + 1 for the consumer_poll_pipe */
943 pollfd
= zmalloc((consumer_data
.stream_count
+ 1) * sizeof(struct pollfd
));
944 if (pollfd
== NULL
) {
945 perror("pollfd malloc");
946 pthread_mutex_unlock(&consumer_data
.lock
);
950 /* allocate for all fds + 1 for the consumer_poll_pipe */
951 local_stream
= zmalloc((consumer_data
.stream_count
+ 1) *
952 sizeof(struct lttng_consumer_stream
));
953 if (local_stream
== NULL
) {
954 perror("local_stream malloc");
955 pthread_mutex_unlock(&consumer_data
.lock
);
958 ret
= consumer_update_poll_array(ctx
, &pollfd
, local_stream
);
960 ERR("Error in allocating pollfd or local_outfds");
961 lttng_consumer_send_error(ctx
, CONSUMERD_POLL_ERROR
);
962 pthread_mutex_unlock(&consumer_data
.lock
);
966 consumer_data
.need_update
= 0;
968 pthread_mutex_unlock(&consumer_data
.lock
);
970 /* No FDs and consumer_quit, consumer_cleanup the thread */
971 if (nb_fd
== 0 && consumer_quit
== 1) {
974 /* poll on the array of fds */
976 DBG("polling on %d fd", nb_fd
+ 1);
977 num_rdy
= poll(pollfd
, nb_fd
+ 1, consumer_poll_timeout
);
978 DBG("poll num_rdy : %d", num_rdy
);
981 * Restart interrupted system call.
983 if (errno
== EINTR
) {
986 perror("Poll error");
987 lttng_consumer_send_error(ctx
, CONSUMERD_POLL_ERROR
);
989 } else if (num_rdy
== 0) {
990 DBG("Polling thread timed out");
995 * If the consumer_poll_pipe triggered poll go
996 * directly to the beginning of the loop to update the
997 * array. We want to prioritize array update over
998 * low-priority reads.
1000 if (pollfd
[nb_fd
].revents
& POLLIN
) {
1001 DBG("consumer_poll_pipe wake up");
1002 tmp2
= read(ctx
->consumer_poll_pipe
[0], &tmp
, 1);
1004 perror("read consumer poll");
1009 /* Take care of high priority channels first. */
1010 for (i
= 0; i
< nb_fd
; i
++) {
1011 if (pollfd
[i
].revents
& POLLPRI
) {
1014 DBG("Urgent read on fd %d", pollfd
[i
].fd
);
1016 len
= ctx
->on_buffer_ready(local_stream
[i
], ctx
);
1017 /* it's ok to have an unavailable sub-buffer */
1018 if (len
< 0 && len
!= -EAGAIN
) {
1020 } else if (len
> 0) {
1021 local_stream
[i
]->data_read
= 1;
1027 * If we read high prio channel in this loop, try again
1028 * for more high prio data.
1034 /* Take care of low priority channels. */
1035 for (i
= 0; i
< nb_fd
; i
++) {
1036 if ((pollfd
[i
].revents
& POLLIN
) ||
1037 local_stream
[i
]->hangup_flush_done
) {
1040 assert(!(pollfd
[i
].revents
& POLLERR
));
1041 assert(!(pollfd
[i
].revents
& POLLNVAL
));
1042 DBG("Normal read on fd %d", pollfd
[i
].fd
);
1043 len
= ctx
->on_buffer_ready(local_stream
[i
], ctx
);
1044 /* it's ok to have an unavailable sub-buffer */
1045 if (len
< 0 && len
!= -EAGAIN
) {
1047 } else if (len
> 0) {
1048 local_stream
[i
]->data_read
= 1;
1053 /* Handle hangup and errors */
1054 for (i
= 0; i
< nb_fd
; i
++) {
1055 if (!local_stream
[i
]->hangup_flush_done
1056 && (pollfd
[i
].revents
& (POLLHUP
| POLLERR
| POLLNVAL
))
1057 && (consumer_data
.type
== LTTNG_CONSUMER32_UST
1058 || consumer_data
.type
== LTTNG_CONSUMER64_UST
)) {
1059 DBG("fd %d is hup|err|nval. Attempting flush and read.",
1061 lttng_ustconsumer_on_stream_hangup(local_stream
[i
]);
1062 /* Attempt read again, for the data we just flushed. */
1063 local_stream
[i
]->data_read
= 1;
1066 * If the poll flag is HUP/ERR/NVAL and we have
1067 * read no data in this pass, we can remove the
1068 * stream from its hash table.
1070 if ((pollfd
[i
].revents
& POLLHUP
)) {
1071 DBG("Polling fd %d tells it has hung up.", pollfd
[i
].fd
);
1072 if (!local_stream
[i
]->data_read
) {
1073 consumer_del_stream(local_stream
[i
]);
1076 } else if (pollfd
[i
].revents
& POLLERR
) {
1077 ERR("Error returned in polling fd %d.", pollfd
[i
].fd
);
1078 if (!local_stream
[i
]->data_read
) {
1079 consumer_del_stream(local_stream
[i
]);
1082 } else if (pollfd
[i
].revents
& POLLNVAL
) {
1083 ERR("Polling fd %d tells fd is not open.", pollfd
[i
].fd
);
1084 if (!local_stream
[i
]->data_read
) {
1085 consumer_del_stream(local_stream
[i
]);
1089 local_stream
[i
]->data_read
= 0;
1093 DBG("polling thread exiting");
1094 if (pollfd
!= NULL
) {
1098 if (local_stream
!= NULL
) {
1100 local_stream
= NULL
;
1102 rcu_unregister_thread();
1107 * This thread listens on the consumerd socket and receives the file
1108 * descriptors from the session daemon.
1110 void *lttng_consumer_thread_receive_fds(void *data
)
1112 int sock
, client_socket
, ret
;
1114 * structure to poll for incoming data on communication socket avoids
1115 * making blocking sockets.
1117 struct pollfd consumer_sockpoll
[2];
1118 struct lttng_consumer_local_data
*ctx
= data
;
1120 rcu_register_thread();
1122 DBG("Creating command socket %s", ctx
->consumer_command_sock_path
);
1123 unlink(ctx
->consumer_command_sock_path
);
1124 client_socket
= lttcomm_create_unix_sock(ctx
->consumer_command_sock_path
);
1125 if (client_socket
< 0) {
1126 ERR("Cannot create command socket");
1130 ret
= lttcomm_listen_unix_sock(client_socket
);
1135 DBG("Sending ready command to lttng-sessiond");
1136 ret
= lttng_consumer_send_error(ctx
, CONSUMERD_COMMAND_SOCK_READY
);
1137 /* return < 0 on error, but == 0 is not fatal */
1139 ERR("Error sending ready command to lttng-sessiond");
1143 ret
= fcntl(client_socket
, F_SETFL
, O_NONBLOCK
);
1145 perror("fcntl O_NONBLOCK");
1149 /* prepare the FDs to poll : to client socket and the should_quit pipe */
1150 consumer_sockpoll
[0].fd
= ctx
->consumer_should_quit
[0];
1151 consumer_sockpoll
[0].events
= POLLIN
| POLLPRI
;
1152 consumer_sockpoll
[1].fd
= client_socket
;
1153 consumer_sockpoll
[1].events
= POLLIN
| POLLPRI
;
1155 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
1158 DBG("Connection on client_socket");
1160 /* Blocking call, waiting for transmission */
1161 sock
= lttcomm_accept_unix_sock(client_socket
);
1166 ret
= fcntl(sock
, F_SETFL
, O_NONBLOCK
);
1168 perror("fcntl O_NONBLOCK");
1172 /* update the polling structure to poll on the established socket */
1173 consumer_sockpoll
[1].fd
= sock
;
1174 consumer_sockpoll
[1].events
= POLLIN
| POLLPRI
;
1177 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
1180 DBG("Incoming command on sock");
1181 ret
= lttng_consumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
1182 if (ret
== -ENOENT
) {
1183 DBG("Received STOP command");
1187 ERR("Communication interrupted on command socket");
1190 if (consumer_quit
) {
1191 DBG("consumer_thread_receive_fds received quit from signal");
1194 DBG("received fds on sock");
1197 DBG("consumer_thread_receive_fds exiting");
1200 * when all fds have hung up, the polling thread
1206 * 2s of grace period, if no polling events occur during
1207 * this period, the polling thread will exit even if there
1208 * are still open FDs (should not happen, but safety mechanism).
1210 consumer_poll_timeout
= LTTNG_CONSUMER_POLL_TIMEOUT
;
1212 /* wake up the polling thread */
1213 ret
= write(ctx
->consumer_poll_pipe
[1], "4", 1);
1215 perror("poll pipe write");
1217 rcu_unregister_thread();
1221 ssize_t
lttng_consumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
1222 struct lttng_consumer_local_data
*ctx
)
1224 switch (consumer_data
.type
) {
1225 case LTTNG_CONSUMER_KERNEL
:
1226 return lttng_kconsumer_read_subbuffer(stream
, ctx
);
1227 case LTTNG_CONSUMER32_UST
:
1228 case LTTNG_CONSUMER64_UST
:
1229 return lttng_ustconsumer_read_subbuffer(stream
, ctx
);
1231 ERR("Unknown consumer_data type");
1237 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1239 switch (consumer_data
.type
) {
1240 case LTTNG_CONSUMER_KERNEL
:
1241 return lttng_kconsumer_on_recv_stream(stream
);
1242 case LTTNG_CONSUMER32_UST
:
1243 case LTTNG_CONSUMER64_UST
:
1244 return lttng_ustconsumer_on_recv_stream(stream
);
1246 ERR("Unknown consumer_data type");
1253 * Allocate and set consumer data hash tables.
1255 void lttng_consumer_init(void)
1257 consumer_data
.stream_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);
1258 consumer_data
.channel_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);