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, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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>
27 #include <sys/types.h>
30 #include <common/common.h>
31 #include <common/kernel-ctl/kernel-ctl.h>
32 #include <common/sessiond-comm/sessiond-comm.h>
33 #include <common/kernel-consumer/kernel-consumer.h>
34 #include <common/ust-consumer/ust-consumer.h>
38 struct lttng_consumer_global_data consumer_data
= {
41 .type
= LTTNG_CONSUMER_UNKNOWN
,
44 /* timeout parameter, to control the polling thread grace period. */
45 int consumer_poll_timeout
= -1;
48 * Flag to inform the polling thread to quit when all fd hung up. Updated by
49 * the consumer_thread_receive_fds when it notices that all fds has hung up.
50 * Also updated by the signal handler (consumer_should_exit()). Read by the
53 volatile int consumer_quit
= 0;
56 * Find a stream. The consumer_data.lock must be locked during this
59 static struct lttng_consumer_stream
*consumer_find_stream(int key
)
61 struct lttng_ht_iter iter
;
62 struct lttng_ht_node_ulong
*node
;
63 struct lttng_consumer_stream
*stream
= NULL
;
65 /* Negative keys are lookup failures */
71 lttng_ht_lookup(consumer_data
.stream_ht
, (void *)((unsigned long) key
),
73 node
= lttng_ht_iter_get_node_ulong(&iter
);
75 stream
= caa_container_of(node
, struct lttng_consumer_stream
, node
);
83 static void consumer_steal_stream_key(int key
)
85 struct lttng_consumer_stream
*stream
;
88 stream
= consumer_find_stream(key
);
92 * We don't want the lookup to match, but we still need
93 * to iterate on this stream when iterating over the hash table. Just
94 * change the node key.
96 stream
->node
.key
= -1;
101 static struct lttng_consumer_channel
*consumer_find_channel(int key
)
103 struct lttng_ht_iter iter
;
104 struct lttng_ht_node_ulong
*node
;
105 struct lttng_consumer_channel
*channel
= NULL
;
107 /* Negative keys are lookup failures */
113 lttng_ht_lookup(consumer_data
.channel_ht
, (void *)((unsigned long) key
),
115 node
= lttng_ht_iter_get_node_ulong(&iter
);
117 channel
= caa_container_of(node
, struct lttng_consumer_channel
, node
);
125 static void consumer_steal_channel_key(int key
)
127 struct lttng_consumer_channel
*channel
;
130 channel
= consumer_find_channel(key
);
134 * We don't want the lookup to match, but we still need
135 * to iterate on this channel when iterating over the hash table. Just
136 * change the node key.
138 channel
->node
.key
= -1;
144 void consumer_free_stream(struct rcu_head
*head
)
146 struct lttng_ht_node_ulong
*node
=
147 caa_container_of(head
, struct lttng_ht_node_ulong
, head
);
148 struct lttng_consumer_stream
*stream
=
149 caa_container_of(node
, struct lttng_consumer_stream
, node
);
155 * Remove a stream from the global list protected by a mutex. This
156 * function is also responsible for freeing its data structures.
158 void consumer_del_stream(struct lttng_consumer_stream
*stream
)
161 struct lttng_ht_iter iter
;
162 struct lttng_consumer_channel
*free_chan
= NULL
;
164 pthread_mutex_lock(&consumer_data
.lock
);
166 switch (consumer_data
.type
) {
167 case LTTNG_CONSUMER_KERNEL
:
168 if (stream
->mmap_base
!= NULL
) {
169 ret
= munmap(stream
->mmap_base
, stream
->mmap_len
);
175 case LTTNG_CONSUMER32_UST
:
176 case LTTNG_CONSUMER64_UST
:
177 lttng_ustconsumer_del_stream(stream
);
180 ERR("Unknown consumer_data type");
186 iter
.iter
.node
= &stream
->node
.node
;
187 ret
= lttng_ht_del(consumer_data
.stream_ht
, &iter
);
192 if (consumer_data
.stream_count
<= 0) {
195 consumer_data
.stream_count
--;
199 if (stream
->out_fd
>= 0) {
200 ret
= close(stream
->out_fd
);
205 if (stream
->wait_fd
>= 0 && !stream
->wait_fd_is_copy
) {
206 ret
= close(stream
->wait_fd
);
211 if (stream
->shm_fd
>= 0 && stream
->wait_fd
!= stream
->shm_fd
) {
212 ret
= close(stream
->shm_fd
);
217 if (!--stream
->chan
->refcount
)
218 free_chan
= stream
->chan
;
220 call_rcu(&stream
->node
.head
, consumer_free_stream
);
222 consumer_data
.need_update
= 1;
223 pthread_mutex_unlock(&consumer_data
.lock
);
226 consumer_del_channel(free_chan
);
229 struct lttng_consumer_stream
*consumer_allocate_stream(
230 int channel_key
, int stream_key
,
231 int shm_fd
, int wait_fd
,
232 enum lttng_consumer_stream_state state
,
234 enum lttng_event_output output
,
235 const char *path_name
,
239 struct lttng_consumer_stream
*stream
;
242 stream
= zmalloc(sizeof(*stream
));
243 if (stream
== NULL
) {
244 perror("malloc struct lttng_consumer_stream");
247 stream
->chan
= consumer_find_channel(channel_key
);
249 perror("Unable to find channel key");
252 stream
->chan
->refcount
++;
253 stream
->key
= stream_key
;
254 stream
->shm_fd
= shm_fd
;
255 stream
->wait_fd
= wait_fd
;
257 stream
->out_fd_offset
= 0;
258 stream
->state
= state
;
259 stream
->mmap_len
= mmap_len
;
260 stream
->mmap_base
= NULL
;
261 stream
->output
= output
;
264 strncpy(stream
->path_name
, path_name
, PATH_MAX
- 1);
265 stream
->path_name
[PATH_MAX
- 1] = '\0';
266 lttng_ht_node_init_ulong(&stream
->node
, stream
->key
);
268 switch (consumer_data
.type
) {
269 case LTTNG_CONSUMER_KERNEL
:
271 case LTTNG_CONSUMER32_UST
:
272 case LTTNG_CONSUMER64_UST
:
273 stream
->cpu
= stream
->chan
->cpucount
++;
274 ret
= lttng_ustconsumer_allocate_stream(stream
);
281 ERR("Unknown consumer_data type");
285 DBG("Allocated stream %s (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, out_fd %d)",
286 stream
->path_name
, stream
->key
,
289 (unsigned long long) stream
->mmap_len
,
296 * Add a stream to the global list protected by a mutex.
298 int consumer_add_stream(struct lttng_consumer_stream
*stream
)
301 struct lttng_ht_node_ulong
*node
;
302 struct lttng_ht_iter iter
;
304 pthread_mutex_lock(&consumer_data
.lock
);
305 /* Steal stream identifier, for UST */
306 consumer_steal_stream_key(stream
->key
);
309 lttng_ht_lookup(consumer_data
.stream_ht
,
310 (void *)((unsigned long) stream
->key
), &iter
);
311 node
= lttng_ht_iter_get_node_ulong(&iter
);
314 /* Stream already exist. Ignore the insertion */
318 lttng_ht_add_unique_ulong(consumer_data
.stream_ht
, &stream
->node
);
320 consumer_data
.stream_count
++;
321 consumer_data
.need_update
= 1;
323 switch (consumer_data
.type
) {
324 case LTTNG_CONSUMER_KERNEL
:
326 case LTTNG_CONSUMER32_UST
:
327 case LTTNG_CONSUMER64_UST
:
328 /* Streams are in CPU number order (we rely on this) */
329 stream
->cpu
= stream
->chan
->nr_streams
++;
332 ERR("Unknown consumer_data type");
338 pthread_mutex_unlock(&consumer_data
.lock
);
344 * Update a stream according to what we just received.
346 void consumer_change_stream_state(int stream_key
,
347 enum lttng_consumer_stream_state state
)
349 struct lttng_consumer_stream
*stream
;
351 pthread_mutex_lock(&consumer_data
.lock
);
352 stream
= consumer_find_stream(stream_key
);
354 stream
->state
= state
;
356 consumer_data
.need_update
= 1;
357 pthread_mutex_unlock(&consumer_data
.lock
);
361 void consumer_free_channel(struct rcu_head
*head
)
363 struct lttng_ht_node_ulong
*node
=
364 caa_container_of(head
, struct lttng_ht_node_ulong
, head
);
365 struct lttng_consumer_channel
*channel
=
366 caa_container_of(node
, struct lttng_consumer_channel
, node
);
372 * Remove a channel from the global list protected by a mutex. This
373 * function is also responsible for freeing its data structures.
375 void consumer_del_channel(struct lttng_consumer_channel
*channel
)
378 struct lttng_ht_iter iter
;
380 pthread_mutex_lock(&consumer_data
.lock
);
382 switch (consumer_data
.type
) {
383 case LTTNG_CONSUMER_KERNEL
:
385 case LTTNG_CONSUMER32_UST
:
386 case LTTNG_CONSUMER64_UST
:
387 lttng_ustconsumer_del_channel(channel
);
390 ERR("Unknown consumer_data type");
396 iter
.iter
.node
= &channel
->node
.node
;
397 ret
= lttng_ht_del(consumer_data
.channel_ht
, &iter
);
401 if (channel
->mmap_base
!= NULL
) {
402 ret
= munmap(channel
->mmap_base
, channel
->mmap_len
);
407 if (channel
->wait_fd
>= 0 && !channel
->wait_fd_is_copy
) {
408 ret
= close(channel
->wait_fd
);
413 if (channel
->shm_fd
>= 0 && channel
->wait_fd
!= channel
->shm_fd
) {
414 ret
= close(channel
->shm_fd
);
420 call_rcu(&channel
->node
.head
, consumer_free_channel
);
422 pthread_mutex_unlock(&consumer_data
.lock
);
425 struct lttng_consumer_channel
*consumer_allocate_channel(
427 int shm_fd
, int wait_fd
,
429 uint64_t max_sb_size
)
431 struct lttng_consumer_channel
*channel
;
434 channel
= zmalloc(sizeof(*channel
));
435 if (channel
== NULL
) {
436 perror("malloc struct lttng_consumer_channel");
439 channel
->key
= channel_key
;
440 channel
->shm_fd
= shm_fd
;
441 channel
->wait_fd
= wait_fd
;
442 channel
->mmap_len
= mmap_len
;
443 channel
->max_sb_size
= max_sb_size
;
444 channel
->refcount
= 0;
445 channel
->nr_streams
= 0;
446 lttng_ht_node_init_ulong(&channel
->node
, channel
->key
);
448 switch (consumer_data
.type
) {
449 case LTTNG_CONSUMER_KERNEL
:
450 channel
->mmap_base
= NULL
;
451 channel
->mmap_len
= 0;
453 case LTTNG_CONSUMER32_UST
:
454 case LTTNG_CONSUMER64_UST
:
455 ret
= lttng_ustconsumer_allocate_channel(channel
);
462 ERR("Unknown consumer_data type");
466 DBG("Allocated channel (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, max_sb_size %llu)",
470 (unsigned long long) channel
->mmap_len
,
471 (unsigned long long) channel
->max_sb_size
);
477 * Add a channel to the global list protected by a mutex.
479 int consumer_add_channel(struct lttng_consumer_channel
*channel
)
481 struct lttng_ht_node_ulong
*node
;
482 struct lttng_ht_iter iter
;
484 pthread_mutex_lock(&consumer_data
.lock
);
485 /* Steal channel identifier, for UST */
486 consumer_steal_channel_key(channel
->key
);
489 lttng_ht_lookup(consumer_data
.channel_ht
,
490 (void *)((unsigned long) channel
->key
), &iter
);
491 node
= lttng_ht_iter_get_node_ulong(&iter
);
493 /* Channel already exist. Ignore the insertion */
497 lttng_ht_add_unique_ulong(consumer_data
.channel_ht
, &channel
->node
);
501 pthread_mutex_unlock(&consumer_data
.lock
);
507 * Allocate the pollfd structure and the local view of the out fds to avoid
508 * doing a lookup in the linked list and concurrency issues when writing is
509 * needed. Called with consumer_data.lock held.
511 * Returns the number of fds in the structures.
513 int consumer_update_poll_array(
514 struct lttng_consumer_local_data
*ctx
, struct pollfd
**pollfd
,
515 struct lttng_consumer_stream
**local_stream
)
518 struct lttng_ht_iter iter
;
519 struct lttng_consumer_stream
*stream
;
521 DBG("Updating poll fd array");
523 cds_lfht_for_each_entry(consumer_data
.stream_ht
->ht
, &iter
.iter
, stream
,
525 if (stream
->state
!= LTTNG_CONSUMER_ACTIVE_STREAM
) {
528 DBG("Active FD %d", stream
->wait_fd
);
529 (*pollfd
)[i
].fd
= stream
->wait_fd
;
530 (*pollfd
)[i
].events
= POLLIN
| POLLPRI
;
531 local_stream
[i
] = stream
;
537 * Insert the consumer_poll_pipe at the end of the array and don't
538 * increment i so nb_fd is the number of real FD.
540 (*pollfd
)[i
].fd
= ctx
->consumer_poll_pipe
[0];
541 (*pollfd
)[i
].events
= POLLIN
| POLLPRI
;
546 * Poll on the should_quit pipe and the command socket return -1 on error and
547 * should exit, 0 if data is available on the command socket
549 int lttng_consumer_poll_socket(struct pollfd
*consumer_sockpoll
)
554 num_rdy
= poll(consumer_sockpoll
, 2, -1);
557 * Restart interrupted system call.
559 if (errno
== EINTR
) {
562 perror("Poll error");
565 if (consumer_sockpoll
[0].revents
& (POLLIN
| POLLPRI
)) {
566 DBG("consumer_should_quit wake up");
576 * Set the error socket.
578 void lttng_consumer_set_error_sock(
579 struct lttng_consumer_local_data
*ctx
, int sock
)
581 ctx
->consumer_error_socket
= sock
;
585 * Set the command socket path.
588 void lttng_consumer_set_command_sock_path(
589 struct lttng_consumer_local_data
*ctx
, char *sock
)
591 ctx
->consumer_command_sock_path
= sock
;
595 * Send return code to the session daemon.
596 * If the socket is not defined, we return 0, it is not a fatal error
598 int lttng_consumer_send_error(
599 struct lttng_consumer_local_data
*ctx
, int cmd
)
601 if (ctx
->consumer_error_socket
> 0) {
602 return lttcomm_send_unix_sock(ctx
->consumer_error_socket
, &cmd
,
603 sizeof(enum lttcomm_sessiond_command
));
610 * Close all the tracefiles and stream fds, should be called when all instances
613 void lttng_consumer_cleanup(void)
615 struct lttng_ht_iter iter
;
616 struct lttng_ht_node_ulong
*node
;
621 * close all outfd. Called when there are no more threads running (after
622 * joining on the threads), no need to protect list iteration with mutex.
624 cds_lfht_for_each_entry(consumer_data
.stream_ht
->ht
, &iter
.iter
, node
,
626 struct lttng_consumer_stream
*stream
=
627 caa_container_of(node
, struct lttng_consumer_stream
, node
);
628 consumer_del_stream(stream
);
631 cds_lfht_for_each_entry(consumer_data
.channel_ht
->ht
, &iter
.iter
, node
,
633 struct lttng_consumer_channel
*channel
=
634 caa_container_of(node
, struct lttng_consumer_channel
, node
);
635 consumer_del_channel(channel
);
640 lttng_ht_destroy(consumer_data
.stream_ht
);
641 lttng_ht_destroy(consumer_data
.channel_ht
);
645 * Called from signal handler.
647 void lttng_consumer_should_exit(struct lttng_consumer_local_data
*ctx
)
651 ret
= write(ctx
->consumer_should_quit
[1], "4", 1);
653 perror("write consumer quit");
657 void lttng_consumer_sync_trace_file(
658 struct lttng_consumer_stream
*stream
, off_t orig_offset
)
660 int outfd
= stream
->out_fd
;
663 * This does a blocking write-and-wait on any page that belongs to the
664 * subbuffer prior to the one we just wrote.
665 * Don't care about error values, as these are just hints and ways to
666 * limit the amount of page cache used.
668 if (orig_offset
< stream
->chan
->max_sb_size
) {
671 lttng_sync_file_range(outfd
, orig_offset
- stream
->chan
->max_sb_size
,
672 stream
->chan
->max_sb_size
,
673 SYNC_FILE_RANGE_WAIT_BEFORE
674 | SYNC_FILE_RANGE_WRITE
675 | SYNC_FILE_RANGE_WAIT_AFTER
);
677 * Give hints to the kernel about how we access the file:
678 * POSIX_FADV_DONTNEED : we won't re-access data in a near future after
681 * We need to call fadvise again after the file grows because the
682 * kernel does not seem to apply fadvise to non-existing parts of the
685 * Call fadvise _after_ having waited for the page writeback to
686 * complete because the dirty page writeback semantic is not well
687 * defined. So it can be expected to lead to lower throughput in
690 posix_fadvise(outfd
, orig_offset
- stream
->chan
->max_sb_size
,
691 stream
->chan
->max_sb_size
, POSIX_FADV_DONTNEED
);
695 * Initialise the necessary environnement :
696 * - create a new context
697 * - create the poll_pipe
698 * - create the should_quit pipe (for signal handler)
699 * - create the thread pipe (for splice)
701 * Takes a function pointer as argument, this function is called when data is
702 * available on a buffer. This function is responsible to do the
703 * kernctl_get_next_subbuf, read the data with mmap or splice depending on the
704 * buffer configuration and then kernctl_put_next_subbuf at the end.
706 * Returns a pointer to the new context or NULL on error.
708 struct lttng_consumer_local_data
*lttng_consumer_create(
709 enum lttng_consumer_type type
,
710 ssize_t (*buffer_ready
)(struct lttng_consumer_stream
*stream
,
711 struct lttng_consumer_local_data
*ctx
),
712 int (*recv_channel
)(struct lttng_consumer_channel
*channel
),
713 int (*recv_stream
)(struct lttng_consumer_stream
*stream
),
714 int (*update_stream
)(int stream_key
, uint32_t state
))
717 struct lttng_consumer_local_data
*ctx
;
719 assert(consumer_data
.type
== LTTNG_CONSUMER_UNKNOWN
||
720 consumer_data
.type
== type
);
721 consumer_data
.type
= type
;
723 ctx
= zmalloc(sizeof(struct lttng_consumer_local_data
));
725 perror("allocating context");
729 ctx
->consumer_error_socket
= -1;
730 /* assign the callbacks */
731 ctx
->on_buffer_ready
= buffer_ready
;
732 ctx
->on_recv_channel
= recv_channel
;
733 ctx
->on_recv_stream
= recv_stream
;
734 ctx
->on_update_stream
= update_stream
;
736 ret
= pipe(ctx
->consumer_poll_pipe
);
738 perror("Error creating poll pipe");
739 goto error_poll_pipe
;
742 /* set read end of the pipe to non-blocking */
743 ret
= fcntl(ctx
->consumer_poll_pipe
[0], F_SETFL
, O_NONBLOCK
);
745 perror("fcntl O_NONBLOCK");
746 goto error_poll_fcntl
;
749 /* set write end of the pipe to non-blocking */
750 ret
= fcntl(ctx
->consumer_poll_pipe
[1], F_SETFL
, O_NONBLOCK
);
752 perror("fcntl O_NONBLOCK");
753 goto error_poll_fcntl
;
756 ret
= pipe(ctx
->consumer_should_quit
);
758 perror("Error creating recv pipe");
759 goto error_quit_pipe
;
762 ret
= pipe(ctx
->consumer_thread_pipe
);
764 perror("Error creating thread pipe");
765 goto error_thread_pipe
;
772 for (i
= 0; i
< 2; i
++) {
775 err
= close(ctx
->consumer_should_quit
[i
]);
782 for (i
= 0; i
< 2; i
++) {
785 err
= close(ctx
->consumer_poll_pipe
[i
]);
797 * Close all fds associated with the instance and free the context.
799 void lttng_consumer_destroy(struct lttng_consumer_local_data
*ctx
)
803 ret
= close(ctx
->consumer_error_socket
);
807 ret
= close(ctx
->consumer_thread_pipe
[0]);
811 ret
= close(ctx
->consumer_thread_pipe
[1]);
815 ret
= close(ctx
->consumer_poll_pipe
[0]);
819 ret
= close(ctx
->consumer_poll_pipe
[1]);
823 ret
= close(ctx
->consumer_should_quit
[0]);
827 ret
= close(ctx
->consumer_should_quit
[1]);
831 unlink(ctx
->consumer_command_sock_path
);
836 * Mmap the ring buffer, read it and write the data to the tracefile.
838 * Returns the number of bytes written
840 ssize_t
lttng_consumer_on_read_subbuffer_mmap(
841 struct lttng_consumer_local_data
*ctx
,
842 struct lttng_consumer_stream
*stream
, unsigned long len
)
844 switch (consumer_data
.type
) {
845 case LTTNG_CONSUMER_KERNEL
:
846 return lttng_kconsumer_on_read_subbuffer_mmap(ctx
, stream
, len
);
847 case LTTNG_CONSUMER32_UST
:
848 case LTTNG_CONSUMER64_UST
:
849 return lttng_ustconsumer_on_read_subbuffer_mmap(ctx
, stream
, len
);
851 ERR("Unknown consumer_data type");
859 * Splice the data from the ring buffer to the tracefile.
861 * Returns the number of bytes spliced.
863 ssize_t
lttng_consumer_on_read_subbuffer_splice(
864 struct lttng_consumer_local_data
*ctx
,
865 struct lttng_consumer_stream
*stream
, unsigned long len
)
867 switch (consumer_data
.type
) {
868 case LTTNG_CONSUMER_KERNEL
:
869 return lttng_kconsumer_on_read_subbuffer_splice(ctx
, stream
, len
);
870 case LTTNG_CONSUMER32_UST
:
871 case LTTNG_CONSUMER64_UST
:
874 ERR("Unknown consumer_data type");
882 * Take a snapshot for a specific fd
884 * Returns 0 on success, < 0 on error
886 int lttng_consumer_take_snapshot(struct lttng_consumer_local_data
*ctx
,
887 struct lttng_consumer_stream
*stream
)
889 switch (consumer_data
.type
) {
890 case LTTNG_CONSUMER_KERNEL
:
891 return lttng_kconsumer_take_snapshot(ctx
, stream
);
892 case LTTNG_CONSUMER32_UST
:
893 case LTTNG_CONSUMER64_UST
:
894 return lttng_ustconsumer_take_snapshot(ctx
, stream
);
896 ERR("Unknown consumer_data type");
904 * Get the produced position
906 * Returns 0 on success, < 0 on error
908 int lttng_consumer_get_produced_snapshot(
909 struct lttng_consumer_local_data
*ctx
,
910 struct lttng_consumer_stream
*stream
,
913 switch (consumer_data
.type
) {
914 case LTTNG_CONSUMER_KERNEL
:
915 return lttng_kconsumer_get_produced_snapshot(ctx
, stream
, pos
);
916 case LTTNG_CONSUMER32_UST
:
917 case LTTNG_CONSUMER64_UST
:
918 return lttng_ustconsumer_get_produced_snapshot(ctx
, stream
, pos
);
920 ERR("Unknown consumer_data type");
926 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
927 int sock
, struct pollfd
*consumer_sockpoll
)
929 switch (consumer_data
.type
) {
930 case LTTNG_CONSUMER_KERNEL
:
931 return lttng_kconsumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
932 case LTTNG_CONSUMER32_UST
:
933 case LTTNG_CONSUMER64_UST
:
934 return lttng_ustconsumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
936 ERR("Unknown consumer_data type");
943 * This thread polls the fds in the set to consume the data and write
944 * it to tracefile if necessary.
946 void *lttng_consumer_thread_poll_fds(void *data
)
948 int num_rdy
, num_hup
, high_prio
, ret
, i
;
949 struct pollfd
*pollfd
= NULL
;
950 /* local view of the streams */
951 struct lttng_consumer_stream
**local_stream
= NULL
;
952 /* local view of consumer_data.fds_count */
954 struct lttng_consumer_local_data
*ctx
= data
;
956 rcu_register_thread();
958 local_stream
= zmalloc(sizeof(struct lttng_consumer_stream
));
965 * the fds set has been updated, we need to update our
966 * local array as well
968 pthread_mutex_lock(&consumer_data
.lock
);
969 if (consumer_data
.need_update
) {
970 if (pollfd
!= NULL
) {
974 if (local_stream
!= NULL
) {
979 /* allocate for all fds + 1 for the consumer_poll_pipe */
980 pollfd
= zmalloc((consumer_data
.stream_count
+ 1) * sizeof(struct pollfd
));
981 if (pollfd
== NULL
) {
982 perror("pollfd malloc");
983 pthread_mutex_unlock(&consumer_data
.lock
);
987 /* allocate for all fds + 1 for the consumer_poll_pipe */
988 local_stream
= zmalloc((consumer_data
.stream_count
+ 1) *
989 sizeof(struct lttng_consumer_stream
));
990 if (local_stream
== NULL
) {
991 perror("local_stream malloc");
992 pthread_mutex_unlock(&consumer_data
.lock
);
995 ret
= consumer_update_poll_array(ctx
, &pollfd
, local_stream
);
997 ERR("Error in allocating pollfd or local_outfds");
998 lttng_consumer_send_error(ctx
, CONSUMERD_POLL_ERROR
);
999 pthread_mutex_unlock(&consumer_data
.lock
);
1003 consumer_data
.need_update
= 0;
1005 pthread_mutex_unlock(&consumer_data
.lock
);
1007 /* No FDs and consumer_quit, consumer_cleanup the thread */
1008 if (nb_fd
== 0 && consumer_quit
== 1) {
1011 /* poll on the array of fds */
1013 DBG("polling on %d fd", nb_fd
+ 1);
1014 num_rdy
= poll(pollfd
, nb_fd
+ 1, consumer_poll_timeout
);
1015 DBG("poll num_rdy : %d", num_rdy
);
1016 if (num_rdy
== -1) {
1018 * Restart interrupted system call.
1020 if (errno
== EINTR
) {
1023 perror("Poll error");
1024 lttng_consumer_send_error(ctx
, CONSUMERD_POLL_ERROR
);
1026 } else if (num_rdy
== 0) {
1027 DBG("Polling thread timed out");
1032 * If the consumer_poll_pipe triggered poll go
1033 * directly to the beginning of the loop to update the
1034 * array. We want to prioritize array update over
1035 * low-priority reads.
1037 if (pollfd
[nb_fd
].revents
& (POLLIN
| POLLPRI
)) {
1038 size_t pipe_readlen
;
1041 DBG("consumer_poll_pipe wake up");
1042 /* Consume 1 byte of pipe data */
1044 pipe_readlen
= read(ctx
->consumer_poll_pipe
[0], &tmp
, 1);
1045 } while (pipe_readlen
== -1 && errno
== EINTR
);
1049 /* Take care of high priority channels first. */
1050 for (i
= 0; i
< nb_fd
; i
++) {
1051 if (pollfd
[i
].revents
& POLLPRI
) {
1054 DBG("Urgent read on fd %d", pollfd
[i
].fd
);
1056 len
= ctx
->on_buffer_ready(local_stream
[i
], ctx
);
1057 /* it's ok to have an unavailable sub-buffer */
1058 if (len
< 0 && len
!= -EAGAIN
) {
1060 } else if (len
> 0) {
1061 local_stream
[i
]->data_read
= 1;
1067 * If we read high prio channel in this loop, try again
1068 * for more high prio data.
1074 /* Take care of low priority channels. */
1075 for (i
= 0; i
< nb_fd
; i
++) {
1076 if ((pollfd
[i
].revents
& POLLIN
) ||
1077 local_stream
[i
]->hangup_flush_done
) {
1080 DBG("Normal read on fd %d", pollfd
[i
].fd
);
1081 len
= ctx
->on_buffer_ready(local_stream
[i
], ctx
);
1082 /* it's ok to have an unavailable sub-buffer */
1083 if (len
< 0 && len
!= -EAGAIN
) {
1085 } else if (len
> 0) {
1086 local_stream
[i
]->data_read
= 1;
1091 /* Handle hangup and errors */
1092 for (i
= 0; i
< nb_fd
; i
++) {
1093 if (!local_stream
[i
]->hangup_flush_done
1094 && (pollfd
[i
].revents
& (POLLHUP
| POLLERR
| POLLNVAL
))
1095 && (consumer_data
.type
== LTTNG_CONSUMER32_UST
1096 || consumer_data
.type
== LTTNG_CONSUMER64_UST
)) {
1097 DBG("fd %d is hup|err|nval. Attempting flush and read.",
1099 lttng_ustconsumer_on_stream_hangup(local_stream
[i
]);
1100 /* Attempt read again, for the data we just flushed. */
1101 local_stream
[i
]->data_read
= 1;
1104 * If the poll flag is HUP/ERR/NVAL and we have
1105 * read no data in this pass, we can remove the
1106 * stream from its hash table.
1108 if ((pollfd
[i
].revents
& POLLHUP
)) {
1109 DBG("Polling fd %d tells it has hung up.", pollfd
[i
].fd
);
1110 if (!local_stream
[i
]->data_read
) {
1111 consumer_del_stream(local_stream
[i
]);
1114 } else if (pollfd
[i
].revents
& POLLERR
) {
1115 ERR("Error returned in polling fd %d.", pollfd
[i
].fd
);
1116 if (!local_stream
[i
]->data_read
) {
1117 consumer_del_stream(local_stream
[i
]);
1120 } else if (pollfd
[i
].revents
& POLLNVAL
) {
1121 ERR("Polling fd %d tells fd is not open.", pollfd
[i
].fd
);
1122 if (!local_stream
[i
]->data_read
) {
1123 consumer_del_stream(local_stream
[i
]);
1127 local_stream
[i
]->data_read
= 0;
1131 DBG("polling thread exiting");
1132 if (pollfd
!= NULL
) {
1136 if (local_stream
!= NULL
) {
1138 local_stream
= NULL
;
1140 rcu_unregister_thread();
1145 * This thread listens on the consumerd socket and receives the file
1146 * descriptors from the session daemon.
1148 void *lttng_consumer_thread_receive_fds(void *data
)
1150 int sock
, client_socket
, ret
;
1152 * structure to poll for incoming data on communication socket avoids
1153 * making blocking sockets.
1155 struct pollfd consumer_sockpoll
[2];
1156 struct lttng_consumer_local_data
*ctx
= data
;
1158 rcu_register_thread();
1160 DBG("Creating command socket %s", ctx
->consumer_command_sock_path
);
1161 unlink(ctx
->consumer_command_sock_path
);
1162 client_socket
= lttcomm_create_unix_sock(ctx
->consumer_command_sock_path
);
1163 if (client_socket
< 0) {
1164 ERR("Cannot create command socket");
1168 ret
= lttcomm_listen_unix_sock(client_socket
);
1173 DBG("Sending ready command to lttng-sessiond");
1174 ret
= lttng_consumer_send_error(ctx
, CONSUMERD_COMMAND_SOCK_READY
);
1175 /* return < 0 on error, but == 0 is not fatal */
1177 ERR("Error sending ready command to lttng-sessiond");
1181 ret
= fcntl(client_socket
, F_SETFL
, O_NONBLOCK
);
1183 perror("fcntl O_NONBLOCK");
1187 /* prepare the FDs to poll : to client socket and the should_quit pipe */
1188 consumer_sockpoll
[0].fd
= ctx
->consumer_should_quit
[0];
1189 consumer_sockpoll
[0].events
= POLLIN
| POLLPRI
;
1190 consumer_sockpoll
[1].fd
= client_socket
;
1191 consumer_sockpoll
[1].events
= POLLIN
| POLLPRI
;
1193 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
1196 DBG("Connection on client_socket");
1198 /* Blocking call, waiting for transmission */
1199 sock
= lttcomm_accept_unix_sock(client_socket
);
1204 ret
= fcntl(sock
, F_SETFL
, O_NONBLOCK
);
1206 perror("fcntl O_NONBLOCK");
1210 /* update the polling structure to poll on the established socket */
1211 consumer_sockpoll
[1].fd
= sock
;
1212 consumer_sockpoll
[1].events
= POLLIN
| POLLPRI
;
1215 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
1218 DBG("Incoming command on sock");
1219 ret
= lttng_consumer_recv_cmd(ctx
, sock
, consumer_sockpoll
);
1220 if (ret
== -ENOENT
) {
1221 DBG("Received STOP command");
1225 ERR("Communication interrupted on command socket");
1228 if (consumer_quit
) {
1229 DBG("consumer_thread_receive_fds received quit from signal");
1232 DBG("received fds on sock");
1235 DBG("consumer_thread_receive_fds exiting");
1238 * when all fds have hung up, the polling thread
1244 * 2s of grace period, if no polling events occur during
1245 * this period, the polling thread will exit even if there
1246 * are still open FDs (should not happen, but safety mechanism).
1248 consumer_poll_timeout
= LTTNG_CONSUMER_POLL_TIMEOUT
;
1251 * Wake-up the other end by writing a null byte in the pipe
1252 * (non-blocking). Important note: Because writing into the
1253 * pipe is non-blocking (and therefore we allow dropping wakeup
1254 * data, as long as there is wakeup data present in the pipe
1255 * buffer to wake up the other end), the other end should
1256 * perform the following sequence for waiting:
1257 * 1) empty the pipe (reads).
1258 * 2) perform update operation.
1259 * 3) wait on the pipe (poll).
1262 ret
= write(ctx
->consumer_poll_pipe
[1], "", 1);
1263 } while (ret
== -1UL && errno
== EINTR
);
1264 rcu_unregister_thread();
1268 ssize_t
lttng_consumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
1269 struct lttng_consumer_local_data
*ctx
)
1271 switch (consumer_data
.type
) {
1272 case LTTNG_CONSUMER_KERNEL
:
1273 return lttng_kconsumer_read_subbuffer(stream
, ctx
);
1274 case LTTNG_CONSUMER32_UST
:
1275 case LTTNG_CONSUMER64_UST
:
1276 return lttng_ustconsumer_read_subbuffer(stream
, ctx
);
1278 ERR("Unknown consumer_data type");
1284 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1286 switch (consumer_data
.type
) {
1287 case LTTNG_CONSUMER_KERNEL
:
1288 return lttng_kconsumer_on_recv_stream(stream
);
1289 case LTTNG_CONSUMER32_UST
:
1290 case LTTNG_CONSUMER64_UST
:
1291 return lttng_ustconsumer_on_recv_stream(stream
);
1293 ERR("Unknown consumer_data type");
1300 * Allocate and set consumer data hash tables.
1302 void lttng_consumer_init(void)
1304 consumer_data
.stream_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);
1305 consumer_data
.channel_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);