2 * Copyright (C) 2011 Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
6 * SPDX-License-Identifier: GPL-2.0-only
17 #include <sys/socket.h>
18 #include <sys/types.h>
24 #include <bin/lttng-consumerd/health-consumerd.h>
25 #include <common/common.h>
26 #include <common/kernel-ctl/kernel-ctl.h>
27 #include <common/sessiond-comm/sessiond-comm.h>
28 #include <common/sessiond-comm/relayd.h>
29 #include <common/compat/fcntl.h>
30 #include <common/compat/endian.h>
31 #include <common/pipe.h>
32 #include <common/relayd/relayd.h>
33 #include <common/utils.h>
34 #include <common/consumer/consumer-stream.h>
35 #include <common/index/index.h>
36 #include <common/consumer/consumer-timer.h>
37 #include <common/optional.h>
38 #include <common/buffer-view.h>
39 #include <common/consumer/consumer.h>
40 #include <common/consumer/metadata-bucket.h>
42 #include "kernel-consumer.h"
44 extern struct lttng_consumer_global_data consumer_data
;
45 extern int consumer_poll_timeout
;
48 * Take a snapshot for a specific fd
50 * Returns 0 on success, < 0 on error
52 int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
55 int infd
= stream
->wait_fd
;
57 ret
= kernctl_snapshot(infd
);
59 * -EAGAIN is not an error, it just means that there is no data to
62 if (ret
!= 0 && ret
!= -EAGAIN
) {
63 PERROR("Getting sub-buffer snapshot.");
70 * Sample consumed and produced positions for a specific fd.
72 * Returns 0 on success, < 0 on error.
74 int lttng_kconsumer_sample_snapshot_positions(
75 struct lttng_consumer_stream
*stream
)
79 return kernctl_snapshot_sample_positions(stream
->wait_fd
);
83 * Get the produced position
85 * Returns 0 on success, < 0 on error
87 int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream
*stream
,
91 int infd
= stream
->wait_fd
;
93 ret
= kernctl_snapshot_get_produced(infd
, pos
);
95 PERROR("kernctl_snapshot_get_produced");
102 * Get the consumerd position
104 * Returns 0 on success, < 0 on error
106 int lttng_kconsumer_get_consumed_snapshot(struct lttng_consumer_stream
*stream
,
110 int infd
= stream
->wait_fd
;
112 ret
= kernctl_snapshot_get_consumed(infd
, pos
);
114 PERROR("kernctl_snapshot_get_consumed");
121 int get_current_subbuf_addr(struct lttng_consumer_stream
*stream
,
125 unsigned long mmap_offset
;
126 const char *mmap_base
= stream
->mmap_base
;
128 ret
= kernctl_get_mmap_read_offset(stream
->wait_fd
, &mmap_offset
);
130 PERROR("Failed to get mmap read offset");
134 *addr
= mmap_base
+ mmap_offset
;
140 * Take a snapshot of all the stream of a channel
141 * RCU read-side lock must be held across this function to ensure existence of
142 * channel. The channel lock must be held by the caller.
144 * Returns 0 on success, < 0 on error
146 static int lttng_kconsumer_snapshot_channel(
147 struct lttng_consumer_channel
*channel
,
148 uint64_t key
, char *path
, uint64_t relayd_id
,
149 uint64_t nb_packets_per_stream
,
150 struct lttng_consumer_local_data
*ctx
)
153 struct lttng_consumer_stream
*stream
;
155 DBG("Kernel consumer snapshot channel %" PRIu64
, key
);
159 /* Splice is not supported yet for channel snapshot. */
160 if (channel
->output
!= CONSUMER_CHANNEL_MMAP
) {
161 ERR("Unsupported output type for channel \"%s\": mmap output is required to record a snapshot",
167 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
168 unsigned long consumed_pos
, produced_pos
;
170 health_code_update();
173 * Lock stream because we are about to change its state.
175 pthread_mutex_lock(&stream
->lock
);
177 assert(channel
->trace_chunk
);
178 if (!lttng_trace_chunk_get(channel
->trace_chunk
)) {
180 * Can't happen barring an internal error as the channel
181 * holds a reference to the trace chunk.
183 ERR("Failed to acquire reference to channel's trace chunk");
187 assert(!stream
->trace_chunk
);
188 stream
->trace_chunk
= channel
->trace_chunk
;
191 * Assign the received relayd ID so we can use it for streaming. The streams
192 * are not visible to anyone so this is OK to change it.
194 stream
->net_seq_idx
= relayd_id
;
195 channel
->relayd_id
= relayd_id
;
196 if (relayd_id
!= (uint64_t) -1ULL) {
197 ret
= consumer_send_relayd_stream(stream
, path
);
199 ERR("sending stream to relayd");
203 ret
= consumer_stream_create_output_files(stream
,
208 DBG("Kernel consumer snapshot stream (%" PRIu64
")",
212 ret
= kernctl_buffer_flush_empty(stream
->wait_fd
);
215 * Doing a buffer flush which does not take into
216 * account empty packets. This is not perfect
217 * for stream intersection, but required as a
218 * fall-back when "flush_empty" is not
219 * implemented by lttng-modules.
221 ret
= kernctl_buffer_flush(stream
->wait_fd
);
223 ERR("Failed to flush kernel stream");
229 ret
= lttng_kconsumer_take_snapshot(stream
);
231 ERR("Taking kernel snapshot");
235 ret
= lttng_kconsumer_get_produced_snapshot(stream
, &produced_pos
);
237 ERR("Produced kernel snapshot position");
241 ret
= lttng_kconsumer_get_consumed_snapshot(stream
, &consumed_pos
);
243 ERR("Consumerd kernel snapshot position");
247 consumed_pos
= consumer_get_consume_start_pos(consumed_pos
,
248 produced_pos
, nb_packets_per_stream
,
249 stream
->max_sb_size
);
251 while ((long) (consumed_pos
- produced_pos
) < 0) {
253 unsigned long len
, padded_len
;
254 const char *subbuf_addr
;
255 struct lttng_buffer_view subbuf_view
;
257 health_code_update();
258 DBG("Kernel consumer taking snapshot at pos %lu", consumed_pos
);
260 ret
= kernctl_get_subbuf(stream
->wait_fd
, &consumed_pos
);
262 if (ret
!= -EAGAIN
) {
263 PERROR("kernctl_get_subbuf snapshot");
266 DBG("Kernel consumer get subbuf failed. Skipping it.");
267 consumed_pos
+= stream
->max_sb_size
;
268 stream
->chan
->lost_packets
++;
272 ret
= kernctl_get_subbuf_size(stream
->wait_fd
, &len
);
274 ERR("Snapshot kernctl_get_subbuf_size");
275 goto error_put_subbuf
;
278 ret
= kernctl_get_padded_subbuf_size(stream
->wait_fd
, &padded_len
);
280 ERR("Snapshot kernctl_get_padded_subbuf_size");
281 goto error_put_subbuf
;
284 ret
= get_current_subbuf_addr(stream
, &subbuf_addr
);
286 goto error_put_subbuf
;
289 subbuf_view
= lttng_buffer_view_init(
290 subbuf_addr
, 0, padded_len
);
291 read_len
= lttng_consumer_on_read_subbuffer_mmap(
292 stream
, &subbuf_view
,
295 * We write the padded len in local tracefiles but the data len
296 * when using a relay. Display the error but continue processing
297 * to try to release the subbuffer.
299 if (relayd_id
!= (uint64_t) -1ULL) {
300 if (read_len
!= len
) {
301 ERR("Error sending to the relay (ret: %zd != len: %lu)",
305 if (read_len
!= padded_len
) {
306 ERR("Error writing to tracefile (ret: %zd != len: %lu)",
307 read_len
, padded_len
);
311 ret
= kernctl_put_subbuf(stream
->wait_fd
);
313 ERR("Snapshot kernctl_put_subbuf");
316 consumed_pos
+= stream
->max_sb_size
;
319 if (relayd_id
== (uint64_t) -1ULL) {
320 if (stream
->out_fd
>= 0) {
321 ret
= close(stream
->out_fd
);
323 PERROR("Kernel consumer snapshot close out_fd");
329 close_relayd_stream(stream
);
330 stream
->net_seq_idx
= (uint64_t) -1ULL;
332 lttng_trace_chunk_put(stream
->trace_chunk
);
333 stream
->trace_chunk
= NULL
;
334 pthread_mutex_unlock(&stream
->lock
);
342 ret
= kernctl_put_subbuf(stream
->wait_fd
);
344 ERR("Snapshot kernctl_put_subbuf error path");
347 pthread_mutex_unlock(&stream
->lock
);
354 * Read the whole metadata available for a snapshot.
355 * RCU read-side lock must be held across this function to ensure existence of
356 * metadata_channel. The channel lock must be held by the caller.
358 * Returns 0 on success, < 0 on error
360 static int lttng_kconsumer_snapshot_metadata(
361 struct lttng_consumer_channel
*metadata_channel
,
362 uint64_t key
, char *path
, uint64_t relayd_id
,
363 struct lttng_consumer_local_data
*ctx
)
365 int ret
, use_relayd
= 0;
367 struct lttng_consumer_stream
*metadata_stream
;
371 DBG("Kernel consumer snapshot metadata with key %" PRIu64
" at path %s",
376 metadata_stream
= metadata_channel
->metadata_stream
;
377 assert(metadata_stream
);
379 pthread_mutex_lock(&metadata_stream
->lock
);
380 assert(metadata_channel
->trace_chunk
);
381 assert(metadata_stream
->trace_chunk
);
383 /* Flag once that we have a valid relayd for the stream. */
384 if (relayd_id
!= (uint64_t) -1ULL) {
389 ret
= consumer_send_relayd_stream(metadata_stream
, path
);
394 ret
= consumer_stream_create_output_files(metadata_stream
,
402 health_code_update();
404 ret_read
= lttng_consumer_read_subbuffer(metadata_stream
, ctx
, true);
406 if (ret_read
!= -EAGAIN
) {
407 ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)",
412 /* ret_read is negative at this point so we will exit the loop. */
415 } while (ret_read
>= 0);
418 close_relayd_stream(metadata_stream
);
419 metadata_stream
->net_seq_idx
= (uint64_t) -1ULL;
421 if (metadata_stream
->out_fd
>= 0) {
422 ret
= close(metadata_stream
->out_fd
);
424 PERROR("Kernel consumer snapshot metadata close out_fd");
426 * Don't go on error here since the snapshot was successful at this
427 * point but somehow the close failed.
430 metadata_stream
->out_fd
= -1;
431 lttng_trace_chunk_put(metadata_stream
->trace_chunk
);
432 metadata_stream
->trace_chunk
= NULL
;
438 pthread_mutex_unlock(&metadata_stream
->lock
);
439 cds_list_del(&metadata_stream
->send_node
);
440 consumer_stream_destroy(metadata_stream
, NULL
);
441 metadata_channel
->metadata_stream
= NULL
;
447 * Receive command from session daemon and process it.
449 * Return 1 on success else a negative value or 0.
451 int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
452 int sock
, struct pollfd
*consumer_sockpoll
)
455 enum lttcomm_return_code ret_code
= LTTCOMM_CONSUMERD_SUCCESS
;
456 struct lttcomm_consumer_msg msg
;
458 health_code_update();
460 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
461 if (ret
!= sizeof(msg
)) {
463 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
469 health_code_update();
471 /* Deprecated command */
472 assert(msg
.cmd_type
!= LTTNG_CONSUMER_STOP
);
474 health_code_update();
476 /* relayd needs RCU read-side protection */
479 switch (msg
.cmd_type
) {
480 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
482 /* Session daemon status message are handled in the following call. */
483 consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
484 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
485 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
,
486 msg
.u
.relayd_sock
.relayd_session_id
);
489 case LTTNG_CONSUMER_ADD_CHANNEL
:
491 struct lttng_consumer_channel
*new_channel
;
493 const uint64_t chunk_id
= msg
.u
.channel
.chunk_id
.value
;
495 health_code_update();
497 /* First send a status message before receiving the fds. */
498 ret
= consumer_send_status_msg(sock
, ret_code
);
500 /* Somehow, the session daemon is not responding anymore. */
504 health_code_update();
506 DBG("consumer_add_channel %" PRIu64
, msg
.u
.channel
.channel_key
);
507 new_channel
= consumer_allocate_channel(msg
.u
.channel
.channel_key
,
508 msg
.u
.channel
.session_id
,
509 msg
.u
.channel
.chunk_id
.is_set
?
511 msg
.u
.channel
.pathname
,
513 msg
.u
.channel
.relayd_id
, msg
.u
.channel
.output
,
514 msg
.u
.channel
.tracefile_size
,
515 msg
.u
.channel
.tracefile_count
, 0,
516 msg
.u
.channel
.monitor
,
517 msg
.u
.channel
.live_timer_interval
,
518 msg
.u
.channel
.is_live
,
520 if (new_channel
== NULL
) {
521 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
524 new_channel
->nb_init_stream_left
= msg
.u
.channel
.nb_init_streams
;
525 switch (msg
.u
.channel
.output
) {
526 case LTTNG_EVENT_SPLICE
:
527 new_channel
->output
= CONSUMER_CHANNEL_SPLICE
;
529 case LTTNG_EVENT_MMAP
:
530 new_channel
->output
= CONSUMER_CHANNEL_MMAP
;
533 ERR("Channel output unknown %d", msg
.u
.channel
.output
);
537 /* Translate and save channel type. */
538 switch (msg
.u
.channel
.type
) {
539 case CONSUMER_CHANNEL_TYPE_DATA
:
540 case CONSUMER_CHANNEL_TYPE_METADATA
:
541 new_channel
->type
= msg
.u
.channel
.type
;
548 health_code_update();
550 if (ctx
->on_recv_channel
!= NULL
) {
551 ret_recv
= ctx
->on_recv_channel(new_channel
);
553 ret
= consumer_add_channel(new_channel
, ctx
);
554 } else if (ret_recv
< 0) {
558 ret
= consumer_add_channel(new_channel
, ctx
);
560 if (msg
.u
.channel
.type
== CONSUMER_CHANNEL_TYPE_DATA
&& !ret
) {
561 int monitor_start_ret
;
563 DBG("Consumer starting monitor timer");
564 consumer_timer_live_start(new_channel
,
565 msg
.u
.channel
.live_timer_interval
);
566 monitor_start_ret
= consumer_timer_monitor_start(
568 msg
.u
.channel
.monitor_timer_interval
);
569 if (monitor_start_ret
< 0) {
570 ERR("Starting channel monitoring timer failed");
576 health_code_update();
578 /* If we received an error in add_channel, we need to report it. */
580 ret
= consumer_send_status_msg(sock
, ret
);
589 case LTTNG_CONSUMER_ADD_STREAM
:
592 struct lttng_pipe
*stream_pipe
;
593 struct lttng_consumer_stream
*new_stream
;
594 struct lttng_consumer_channel
*channel
;
598 * Get stream's channel reference. Needed when adding the stream to the
601 channel
= consumer_find_channel(msg
.u
.stream
.channel_key
);
604 * We could not find the channel. Can happen if cpu hotplug
605 * happens while tearing down.
607 ERR("Unable to find channel key %" PRIu64
, msg
.u
.stream
.channel_key
);
608 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
611 health_code_update();
613 /* First send a status message before receiving the fds. */
614 ret
= consumer_send_status_msg(sock
, ret_code
);
616 /* Somehow, the session daemon is not responding anymore. */
617 goto error_add_stream_fatal
;
620 health_code_update();
622 if (ret_code
!= LTTCOMM_CONSUMERD_SUCCESS
) {
623 /* Channel was not found. */
624 goto error_add_stream_nosignal
;
629 ret
= lttng_consumer_poll_socket(consumer_sockpoll
);
632 goto error_add_stream_fatal
;
635 health_code_update();
637 /* Get stream file descriptor from socket */
638 ret
= lttcomm_recv_fds_unix_sock(sock
, &fd
, 1);
639 if (ret
!= sizeof(fd
)) {
640 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_FD
);
644 health_code_update();
647 * Send status code to session daemon only if the recv works. If the
648 * above recv() failed, the session daemon is notified through the
649 * error socket and the teardown is eventually done.
651 ret
= consumer_send_status_msg(sock
, ret_code
);
653 /* Somehow, the session daemon is not responding anymore. */
654 goto error_add_stream_nosignal
;
657 health_code_update();
659 pthread_mutex_lock(&channel
->lock
);
660 new_stream
= consumer_stream_create(
667 channel
->trace_chunk
,
672 if (new_stream
== NULL
) {
677 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
680 pthread_mutex_unlock(&channel
->lock
);
681 goto error_add_stream_nosignal
;
684 new_stream
->wait_fd
= fd
;
685 ret
= kernctl_get_max_subbuf_size(new_stream
->wait_fd
,
686 &new_stream
->max_sb_size
);
688 pthread_mutex_unlock(&channel
->lock
);
689 ERR("Failed to get kernel maximal subbuffer size");
690 goto error_add_stream_nosignal
;
693 consumer_stream_update_channel_attributes(new_stream
,
697 * We've just assigned the channel to the stream so increment the
698 * refcount right now. We don't need to increment the refcount for
699 * streams in no monitor because we handle manually the cleanup of
700 * those. It is very important to make sure there is NO prior
701 * consumer_del_stream() calls or else the refcount will be unbalanced.
703 if (channel
->monitor
) {
704 uatomic_inc(&new_stream
->chan
->refcount
);
708 * The buffer flush is done on the session daemon side for the kernel
709 * so no need for the stream "hangup_flush_done" variable to be
710 * tracked. This is important for a kernel stream since we don't rely
711 * on the flush state of the stream to read data. It's not the case for
712 * user space tracing.
714 new_stream
->hangup_flush_done
= 0;
716 health_code_update();
718 pthread_mutex_lock(&new_stream
->lock
);
719 if (ctx
->on_recv_stream
) {
720 ret
= ctx
->on_recv_stream(new_stream
);
722 pthread_mutex_unlock(&new_stream
->lock
);
723 pthread_mutex_unlock(&channel
->lock
);
724 consumer_stream_free(new_stream
);
725 goto error_add_stream_nosignal
;
728 health_code_update();
730 if (new_stream
->metadata_flag
) {
731 channel
->metadata_stream
= new_stream
;
734 /* Do not monitor this stream. */
735 if (!channel
->monitor
) {
736 DBG("Kernel consumer add stream %s in no monitor mode with "
737 "relayd id %" PRIu64
, new_stream
->name
,
738 new_stream
->net_seq_idx
);
739 cds_list_add(&new_stream
->send_node
, &channel
->streams
.head
);
740 pthread_mutex_unlock(&new_stream
->lock
);
741 pthread_mutex_unlock(&channel
->lock
);
745 /* Send stream to relayd if the stream has an ID. */
746 if (new_stream
->net_seq_idx
!= (uint64_t) -1ULL) {
747 ret
= consumer_send_relayd_stream(new_stream
,
748 new_stream
->chan
->pathname
);
750 pthread_mutex_unlock(&new_stream
->lock
);
751 pthread_mutex_unlock(&channel
->lock
);
752 consumer_stream_free(new_stream
);
753 goto error_add_stream_nosignal
;
757 * If adding an extra stream to an already
758 * existing channel (e.g. cpu hotplug), we need
759 * to send the "streams_sent" command to relayd.
761 if (channel
->streams_sent_to_relayd
) {
762 ret
= consumer_send_relayd_streams_sent(
763 new_stream
->net_seq_idx
);
765 pthread_mutex_unlock(&new_stream
->lock
);
766 pthread_mutex_unlock(&channel
->lock
);
767 goto error_add_stream_nosignal
;
771 pthread_mutex_unlock(&new_stream
->lock
);
772 pthread_mutex_unlock(&channel
->lock
);
774 /* Get the right pipe where the stream will be sent. */
775 if (new_stream
->metadata_flag
) {
776 consumer_add_metadata_stream(new_stream
);
777 stream_pipe
= ctx
->consumer_metadata_pipe
;
779 consumer_add_data_stream(new_stream
);
780 stream_pipe
= ctx
->consumer_data_pipe
;
783 /* Visible to other threads */
784 new_stream
->globally_visible
= 1;
786 health_code_update();
788 ret
= lttng_pipe_write(stream_pipe
, &new_stream
, sizeof(new_stream
));
790 ERR("Consumer write %s stream to pipe %d",
791 new_stream
->metadata_flag
? "metadata" : "data",
792 lttng_pipe_get_writefd(stream_pipe
));
793 if (new_stream
->metadata_flag
) {
794 consumer_del_stream_for_metadata(new_stream
);
796 consumer_del_stream_for_data(new_stream
);
798 goto error_add_stream_nosignal
;
801 DBG("Kernel consumer ADD_STREAM %s (fd: %d) %s with relayd id %" PRIu64
,
802 new_stream
->name
, fd
, new_stream
->chan
->pathname
, new_stream
->relayd_stream_id
);
805 error_add_stream_nosignal
:
807 error_add_stream_fatal
:
810 case LTTNG_CONSUMER_STREAMS_SENT
:
812 struct lttng_consumer_channel
*channel
;
815 * Get stream's channel reference. Needed when adding the stream to the
818 channel
= consumer_find_channel(msg
.u
.sent_streams
.channel_key
);
821 * We could not find the channel. Can happen if cpu hotplug
822 * happens while tearing down.
824 ERR("Unable to find channel key %" PRIu64
,
825 msg
.u
.sent_streams
.channel_key
);
826 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
829 health_code_update();
832 * Send status code to session daemon.
834 ret
= consumer_send_status_msg(sock
, ret_code
);
835 if (ret
< 0 || ret_code
!= LTTCOMM_CONSUMERD_SUCCESS
) {
836 /* Somehow, the session daemon is not responding anymore. */
837 goto error_streams_sent_nosignal
;
840 health_code_update();
843 * We should not send this message if we don't monitor the
844 * streams in this channel.
846 if (!channel
->monitor
) {
847 goto end_error_streams_sent
;
850 health_code_update();
851 /* Send stream to relayd if the stream has an ID. */
852 if (msg
.u
.sent_streams
.net_seq_idx
!= (uint64_t) -1ULL) {
853 ret
= consumer_send_relayd_streams_sent(
854 msg
.u
.sent_streams
.net_seq_idx
);
856 goto error_streams_sent_nosignal
;
858 channel
->streams_sent_to_relayd
= true;
860 end_error_streams_sent
:
862 error_streams_sent_nosignal
:
865 case LTTNG_CONSUMER_UPDATE_STREAM
:
870 case LTTNG_CONSUMER_DESTROY_RELAYD
:
872 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
873 struct consumer_relayd_sock_pair
*relayd
;
875 DBG("Kernel consumer destroying relayd %" PRIu64
, index
);
877 /* Get relayd reference if exists. */
878 relayd
= consumer_find_relayd(index
);
879 if (relayd
== NULL
) {
880 DBG("Unable to find relayd %" PRIu64
, index
);
881 ret_code
= LTTCOMM_CONSUMERD_RELAYD_FAIL
;
885 * Each relayd socket pair has a refcount of stream attached to it
886 * which tells if the relayd is still active or not depending on the
889 * This will set the destroy flag of the relayd object and destroy it
890 * if the refcount reaches zero when called.
892 * The destroy can happen either here or when a stream fd hangs up.
895 consumer_flag_relayd_for_destroy(relayd
);
898 health_code_update();
900 ret
= consumer_send_status_msg(sock
, ret_code
);
902 /* Somehow, the session daemon is not responding anymore. */
908 case LTTNG_CONSUMER_DATA_PENDING
:
911 uint64_t id
= msg
.u
.data_pending
.session_id
;
913 DBG("Kernel consumer data pending command for id %" PRIu64
, id
);
915 ret
= consumer_data_pending(id
);
917 health_code_update();
919 /* Send back returned value to session daemon */
920 ret
= lttcomm_send_unix_sock(sock
, &ret
, sizeof(ret
));
922 PERROR("send data pending ret code");
927 * No need to send back a status message since the data pending
928 * returned value is the response.
932 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL
:
934 struct lttng_consumer_channel
*channel
;
935 uint64_t key
= msg
.u
.snapshot_channel
.key
;
937 channel
= consumer_find_channel(key
);
939 ERR("Channel %" PRIu64
" not found", key
);
940 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
942 pthread_mutex_lock(&channel
->lock
);
943 if (msg
.u
.snapshot_channel
.metadata
== 1) {
944 ret
= lttng_kconsumer_snapshot_metadata(channel
, key
,
945 msg
.u
.snapshot_channel
.pathname
,
946 msg
.u
.snapshot_channel
.relayd_id
, ctx
);
948 ERR("Snapshot metadata failed");
949 ret_code
= LTTCOMM_CONSUMERD_SNAPSHOT_FAILED
;
952 ret
= lttng_kconsumer_snapshot_channel(channel
, key
,
953 msg
.u
.snapshot_channel
.pathname
,
954 msg
.u
.snapshot_channel
.relayd_id
,
955 msg
.u
.snapshot_channel
.nb_packets_per_stream
,
958 ERR("Snapshot channel failed");
959 ret_code
= LTTCOMM_CONSUMERD_SNAPSHOT_FAILED
;
962 pthread_mutex_unlock(&channel
->lock
);
964 health_code_update();
966 ret
= consumer_send_status_msg(sock
, ret_code
);
968 /* Somehow, the session daemon is not responding anymore. */
973 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
975 uint64_t key
= msg
.u
.destroy_channel
.key
;
976 struct lttng_consumer_channel
*channel
;
978 channel
= consumer_find_channel(key
);
980 ERR("Kernel consumer destroy channel %" PRIu64
" not found", key
);
981 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
984 health_code_update();
986 ret
= consumer_send_status_msg(sock
, ret_code
);
988 /* Somehow, the session daemon is not responding anymore. */
989 goto end_destroy_channel
;
992 health_code_update();
994 /* Stop right now if no channel was found. */
996 goto end_destroy_channel
;
1000 * This command should ONLY be issued for channel with streams set in
1003 assert(!channel
->monitor
);
1006 * The refcount should ALWAYS be 0 in the case of a channel in no
1009 assert(!uatomic_sub_return(&channel
->refcount
, 1));
1011 consumer_del_channel(channel
);
1012 end_destroy_channel
:
1015 case LTTNG_CONSUMER_DISCARDED_EVENTS
:
1019 struct lttng_consumer_channel
*channel
;
1020 uint64_t id
= msg
.u
.discarded_events
.session_id
;
1021 uint64_t key
= msg
.u
.discarded_events
.channel_key
;
1023 DBG("Kernel consumer discarded events command for session id %"
1024 PRIu64
", channel key %" PRIu64
, id
, key
);
1026 channel
= consumer_find_channel(key
);
1028 ERR("Kernel consumer discarded events channel %"
1029 PRIu64
" not found", key
);
1032 count
= channel
->discarded_events
;
1035 health_code_update();
1037 /* Send back returned value to session daemon */
1038 ret
= lttcomm_send_unix_sock(sock
, &count
, sizeof(count
));
1040 PERROR("send discarded events");
1046 case LTTNG_CONSUMER_LOST_PACKETS
:
1050 struct lttng_consumer_channel
*channel
;
1051 uint64_t id
= msg
.u
.lost_packets
.session_id
;
1052 uint64_t key
= msg
.u
.lost_packets
.channel_key
;
1054 DBG("Kernel consumer lost packets command for session id %"
1055 PRIu64
", channel key %" PRIu64
, id
, key
);
1057 channel
= consumer_find_channel(key
);
1059 ERR("Kernel consumer lost packets channel %"
1060 PRIu64
" not found", key
);
1063 count
= channel
->lost_packets
;
1066 health_code_update();
1068 /* Send back returned value to session daemon */
1069 ret
= lttcomm_send_unix_sock(sock
, &count
, sizeof(count
));
1071 PERROR("send lost packets");
1077 case LTTNG_CONSUMER_SET_CHANNEL_MONITOR_PIPE
:
1079 int channel_monitor_pipe
;
1081 ret_code
= LTTCOMM_CONSUMERD_SUCCESS
;
1082 /* Successfully received the command's type. */
1083 ret
= consumer_send_status_msg(sock
, ret_code
);
1088 ret
= lttcomm_recv_fds_unix_sock(sock
, &channel_monitor_pipe
,
1090 if (ret
!= sizeof(channel_monitor_pipe
)) {
1091 ERR("Failed to receive channel monitor pipe");
1095 DBG("Received channel monitor pipe (%d)", channel_monitor_pipe
);
1096 ret
= consumer_timer_thread_set_channel_monitor_pipe(
1097 channel_monitor_pipe
);
1101 ret_code
= LTTCOMM_CONSUMERD_SUCCESS
;
1102 /* Set the pipe as non-blocking. */
1103 ret
= fcntl(channel_monitor_pipe
, F_GETFL
, 0);
1105 PERROR("fcntl get flags of the channel monitoring pipe");
1110 ret
= fcntl(channel_monitor_pipe
, F_SETFL
,
1111 flags
| O_NONBLOCK
);
1113 PERROR("fcntl set O_NONBLOCK flag of the channel monitoring pipe");
1116 DBG("Channel monitor pipe set as non-blocking");
1118 ret_code
= LTTCOMM_CONSUMERD_ALREADY_SET
;
1120 ret
= consumer_send_status_msg(sock
, ret_code
);
1126 case LTTNG_CONSUMER_ROTATE_CHANNEL
:
1128 struct lttng_consumer_channel
*channel
;
1129 uint64_t key
= msg
.u
.rotate_channel
.key
;
1131 DBG("Consumer rotate channel %" PRIu64
, key
);
1133 channel
= consumer_find_channel(key
);
1135 ERR("Channel %" PRIu64
" not found", key
);
1136 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
1139 * Sample the rotate position of all the streams in this channel.
1141 ret
= lttng_consumer_rotate_channel(channel
, key
,
1142 msg
.u
.rotate_channel
.relayd_id
,
1143 msg
.u
.rotate_channel
.metadata
,
1146 ERR("Rotate channel failed");
1147 ret_code
= LTTCOMM_CONSUMERD_ROTATION_FAIL
;
1150 health_code_update();
1152 ret
= consumer_send_status_msg(sock
, ret_code
);
1154 /* Somehow, the session daemon is not responding anymore. */
1155 goto error_rotate_channel
;
1158 /* Rotate the streams that are ready right now. */
1159 ret
= lttng_consumer_rotate_ready_streams(
1162 ERR("Rotate ready streams failed");
1166 error_rotate_channel
:
1169 case LTTNG_CONSUMER_CLEAR_CHANNEL
:
1171 struct lttng_consumer_channel
*channel
;
1172 uint64_t key
= msg
.u
.clear_channel
.key
;
1174 channel
= consumer_find_channel(key
);
1176 DBG("Channel %" PRIu64
" not found", key
);
1177 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
1179 ret
= lttng_consumer_clear_channel(channel
);
1181 ERR("Clear channel failed");
1185 health_code_update();
1187 ret
= consumer_send_status_msg(sock
, ret_code
);
1189 /* Somehow, the session daemon is not responding anymore. */
1195 case LTTNG_CONSUMER_INIT
:
1197 ret_code
= lttng_consumer_init_command(ctx
,
1198 msg
.u
.init
.sessiond_uuid
);
1199 health_code_update();
1200 ret
= consumer_send_status_msg(sock
, ret_code
);
1202 /* Somehow, the session daemon is not responding anymore. */
1207 case LTTNG_CONSUMER_CREATE_TRACE_CHUNK
:
1209 const struct lttng_credentials credentials
= {
1210 .uid
= LTTNG_OPTIONAL_INIT_VALUE(msg
.u
.create_trace_chunk
.credentials
.value
.uid
),
1211 .gid
= LTTNG_OPTIONAL_INIT_VALUE(msg
.u
.create_trace_chunk
.credentials
.value
.gid
),
1213 const bool is_local_trace
=
1214 !msg
.u
.create_trace_chunk
.relayd_id
.is_set
;
1215 const uint64_t relayd_id
=
1216 msg
.u
.create_trace_chunk
.relayd_id
.value
;
1217 const char *chunk_override_name
=
1218 *msg
.u
.create_trace_chunk
.override_name
?
1219 msg
.u
.create_trace_chunk
.override_name
:
1221 struct lttng_directory_handle
*chunk_directory_handle
= NULL
;
1224 * The session daemon will only provide a chunk directory file
1225 * descriptor for local traces.
1227 if (is_local_trace
) {
1230 /* Acnowledge the reception of the command. */
1231 ret
= consumer_send_status_msg(sock
,
1232 LTTCOMM_CONSUMERD_SUCCESS
);
1234 /* Somehow, the session daemon is not responding anymore. */
1238 ret
= lttcomm_recv_fds_unix_sock(sock
, &chunk_dirfd
, 1);
1239 if (ret
!= sizeof(chunk_dirfd
)) {
1240 ERR("Failed to receive trace chunk directory file descriptor");
1244 DBG("Received trace chunk directory fd (%d)",
1246 chunk_directory_handle
= lttng_directory_handle_create_from_dirfd(
1248 if (!chunk_directory_handle
) {
1249 ERR("Failed to initialize chunk directory handle from directory file descriptor");
1250 if (close(chunk_dirfd
)) {
1251 PERROR("Failed to close chunk directory file descriptor");
1257 ret_code
= lttng_consumer_create_trace_chunk(
1258 !is_local_trace
? &relayd_id
: NULL
,
1259 msg
.u
.create_trace_chunk
.session_id
,
1260 msg
.u
.create_trace_chunk
.chunk_id
,
1261 (time_t) msg
.u
.create_trace_chunk
1262 .creation_timestamp
,
1263 chunk_override_name
,
1264 msg
.u
.create_trace_chunk
.credentials
.is_set
?
1267 chunk_directory_handle
);
1268 lttng_directory_handle_put(chunk_directory_handle
);
1269 goto end_msg_sessiond
;
1271 case LTTNG_CONSUMER_CLOSE_TRACE_CHUNK
:
1273 enum lttng_trace_chunk_command_type close_command
=
1274 msg
.u
.close_trace_chunk
.close_command
.value
;
1275 const uint64_t relayd_id
=
1276 msg
.u
.close_trace_chunk
.relayd_id
.value
;
1277 struct lttcomm_consumer_close_trace_chunk_reply reply
;
1278 char path
[LTTNG_PATH_MAX
];
1280 ret_code
= lttng_consumer_close_trace_chunk(
1281 msg
.u
.close_trace_chunk
.relayd_id
.is_set
?
1284 msg
.u
.close_trace_chunk
.session_id
,
1285 msg
.u
.close_trace_chunk
.chunk_id
,
1286 (time_t) msg
.u
.close_trace_chunk
.close_timestamp
,
1287 msg
.u
.close_trace_chunk
.close_command
.is_set
?
1290 reply
.ret_code
= ret_code
;
1291 reply
.path_length
= strlen(path
) + 1;
1292 ret
= lttcomm_send_unix_sock(sock
, &reply
, sizeof(reply
));
1293 if (ret
!= sizeof(reply
)) {
1296 ret
= lttcomm_send_unix_sock(sock
, path
, reply
.path_length
);
1297 if (ret
!= reply
.path_length
) {
1302 case LTTNG_CONSUMER_TRACE_CHUNK_EXISTS
:
1304 const uint64_t relayd_id
=
1305 msg
.u
.trace_chunk_exists
.relayd_id
.value
;
1307 ret_code
= lttng_consumer_trace_chunk_exists(
1308 msg
.u
.trace_chunk_exists
.relayd_id
.is_set
?
1310 msg
.u
.trace_chunk_exists
.session_id
,
1311 msg
.u
.trace_chunk_exists
.chunk_id
);
1312 goto end_msg_sessiond
;
1314 case LTTNG_CONSUMER_OPEN_CHANNEL_PACKETS
:
1316 const uint64_t key
= msg
.u
.open_channel_packets
.key
;
1317 struct lttng_consumer_channel
*channel
=
1318 consumer_find_channel(key
);
1321 pthread_mutex_lock(&channel
->lock
);
1322 ret_code
= lttng_consumer_open_channel_packets(channel
);
1323 pthread_mutex_unlock(&channel
->lock
);
1325 WARN("Channel %" PRIu64
" not found", key
);
1326 ret_code
= LTTCOMM_CONSUMERD_CHAN_NOT_FOUND
;
1329 health_code_update();
1330 goto end_msg_sessiond
;
1338 * Return 1 to indicate success since the 0 value can be a socket
1339 * shutdown during the recv() or send() call.
1344 /* This will issue a consumer stop. */
1349 * The returned value here is not useful since either way we'll return 1 to
1350 * the caller because the session daemon socket management is done
1351 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1353 ret
= consumer_send_status_msg(sock
, ret_code
);
1359 health_code_update();
1365 * Sync metadata meaning request them to the session daemon and snapshot to the
1366 * metadata thread can consumer them.
1368 * Metadata stream lock MUST be acquired.
1370 enum sync_metadata_status
lttng_kconsumer_sync_metadata(
1371 struct lttng_consumer_stream
*metadata
)
1374 enum sync_metadata_status status
;
1378 ret
= kernctl_buffer_flush(metadata
->wait_fd
);
1380 ERR("Failed to flush kernel stream");
1381 status
= SYNC_METADATA_STATUS_ERROR
;
1385 ret
= kernctl_snapshot(metadata
->wait_fd
);
1387 if (errno
== EAGAIN
) {
1388 /* No new metadata, exit. */
1389 DBG("Sync metadata, no new kernel metadata");
1390 status
= SYNC_METADATA_STATUS_NO_DATA
;
1392 ERR("Sync metadata, taking kernel snapshot failed.");
1393 status
= SYNC_METADATA_STATUS_ERROR
;
1396 status
= SYNC_METADATA_STATUS_NEW_DATA
;
1404 int extract_common_subbuffer_info(struct lttng_consumer_stream
*stream
,
1405 struct stream_subbuffer
*subbuf
)
1409 ret
= kernctl_get_subbuf_size(
1410 stream
->wait_fd
, &subbuf
->info
.data
.subbuf_size
);
1415 ret
= kernctl_get_padded_subbuf_size(
1416 stream
->wait_fd
, &subbuf
->info
.data
.padded_subbuf_size
);
1426 int extract_metadata_subbuffer_info(struct lttng_consumer_stream
*stream
,
1427 struct stream_subbuffer
*subbuf
)
1431 ret
= extract_common_subbuffer_info(stream
, subbuf
);
1436 ret
= kernctl_get_metadata_version(
1437 stream
->wait_fd
, &subbuf
->info
.metadata
.version
);
1447 int extract_data_subbuffer_info(struct lttng_consumer_stream
*stream
,
1448 struct stream_subbuffer
*subbuf
)
1452 ret
= extract_common_subbuffer_info(stream
, subbuf
);
1457 ret
= kernctl_get_packet_size(
1458 stream
->wait_fd
, &subbuf
->info
.data
.packet_size
);
1460 PERROR("Failed to get sub-buffer packet size");
1464 ret
= kernctl_get_content_size(
1465 stream
->wait_fd
, &subbuf
->info
.data
.content_size
);
1467 PERROR("Failed to get sub-buffer content size");
1471 ret
= kernctl_get_timestamp_begin(
1472 stream
->wait_fd
, &subbuf
->info
.data
.timestamp_begin
);
1474 PERROR("Failed to get sub-buffer begin timestamp");
1478 ret
= kernctl_get_timestamp_end(
1479 stream
->wait_fd
, &subbuf
->info
.data
.timestamp_end
);
1481 PERROR("Failed to get sub-buffer end timestamp");
1485 ret
= kernctl_get_events_discarded(
1486 stream
->wait_fd
, &subbuf
->info
.data
.events_discarded
);
1488 PERROR("Failed to get sub-buffer events discarded count");
1492 ret
= kernctl_get_sequence_number(stream
->wait_fd
,
1493 &subbuf
->info
.data
.sequence_number
.value
);
1495 /* May not be supported by older LTTng-modules. */
1496 if (ret
!= -ENOTTY
) {
1497 PERROR("Failed to get sub-buffer sequence number");
1501 subbuf
->info
.data
.sequence_number
.is_set
= true;
1504 ret
= kernctl_get_stream_id(
1505 stream
->wait_fd
, &subbuf
->info
.data
.stream_id
);
1507 PERROR("Failed to get stream id");
1511 ret
= kernctl_get_instance_id(stream
->wait_fd
,
1512 &subbuf
->info
.data
.stream_instance_id
.value
);
1514 /* May not be supported by older LTTng-modules. */
1515 if (ret
!= -ENOTTY
) {
1516 PERROR("Failed to get stream instance id");
1520 subbuf
->info
.data
.stream_instance_id
.is_set
= true;
1527 int get_subbuffer_common(struct lttng_consumer_stream
*stream
,
1528 struct stream_subbuffer
*subbuffer
)
1532 ret
= kernctl_get_next_subbuf(stream
->wait_fd
);
1537 ret
= stream
->read_subbuffer_ops
.extract_subbuffer_info(
1544 int get_next_subbuffer_splice(struct lttng_consumer_stream
*stream
,
1545 struct stream_subbuffer
*subbuffer
)
1549 ret
= get_subbuffer_common(stream
, subbuffer
);
1554 subbuffer
->buffer
.fd
= stream
->wait_fd
;
1560 int get_next_subbuffer_mmap(struct lttng_consumer_stream
*stream
,
1561 struct stream_subbuffer
*subbuffer
)
1566 ret
= get_subbuffer_common(stream
, subbuffer
);
1571 ret
= get_current_subbuf_addr(stream
, &addr
);
1576 subbuffer
->buffer
.buffer
= lttng_buffer_view_init(
1577 addr
, 0, subbuffer
->info
.data
.padded_subbuf_size
);
1583 int get_next_subbuffer_metadata_check(struct lttng_consumer_stream
*stream
,
1584 struct stream_subbuffer
*subbuffer
)
1590 ret
= kernctl_get_next_subbuf_metadata_check(stream
->wait_fd
,
1596 ret
= stream
->read_subbuffer_ops
.extract_subbuffer_info(
1602 LTTNG_OPTIONAL_SET(&subbuffer
->info
.metadata
.coherent
, coherent
);
1604 ret
= get_current_subbuf_addr(stream
, &addr
);
1609 subbuffer
->buffer
.buffer
= lttng_buffer_view_init(
1610 addr
, 0, subbuffer
->info
.data
.padded_subbuf_size
);
1611 DBG("Got metadata packet with padded_subbuf_size = %lu, coherent = %s",
1612 subbuffer
->info
.metadata
.padded_subbuf_size
,
1613 coherent
? "true" : "false");
1619 int put_next_subbuffer(struct lttng_consumer_stream
*stream
,
1620 struct stream_subbuffer
*subbuffer
)
1622 const int ret
= kernctl_put_next_subbuf(stream
->wait_fd
);
1625 if (ret
== -EFAULT
) {
1626 PERROR("Error in unreserving sub buffer");
1627 } else if (ret
== -EIO
) {
1628 /* Should never happen with newer LTTng versions */
1629 PERROR("Reader has been pushed by the writer, last sub-buffer corrupted");
1637 bool is_get_next_check_metadata_available(int tracer_fd
)
1639 return kernctl_get_next_subbuf_metadata_check(tracer_fd
, NULL
) !=
1644 int lttng_kconsumer_set_stream_ops(
1645 struct lttng_consumer_stream
*stream
)
1649 if (stream
->metadata_flag
&& stream
->chan
->is_live
) {
1650 DBG("Attempting to enable metadata bucketization for live consumers");
1651 if (is_get_next_check_metadata_available(stream
->wait_fd
)) {
1652 DBG("Kernel tracer supports get_next_subbuffer_metadata_check, metadata will be accumulated until a coherent state is reached");
1653 stream
->read_subbuffer_ops
.get_next_subbuffer
=
1654 get_next_subbuffer_metadata_check
;
1655 ret
= consumer_stream_enable_metadata_bucketization(
1662 * The kernel tracer version is too old to indicate
1663 * when the metadata stream has reached a "coherent"
1664 * (parseable) point.
1666 * This means that a live viewer may see an incoherent
1667 * sequence of metadata and fail to parse it.
1669 WARN("Kernel tracer does not support get_next_subbuffer_metadata_check which may cause live clients to fail to parse the metadata stream");
1670 metadata_bucket_destroy(stream
->metadata_bucket
);
1671 stream
->metadata_bucket
= NULL
;
1675 if (!stream
->read_subbuffer_ops
.get_next_subbuffer
) {
1676 if (stream
->chan
->output
== CONSUMER_CHANNEL_MMAP
) {
1677 stream
->read_subbuffer_ops
.get_next_subbuffer
=
1678 get_next_subbuffer_mmap
;
1680 stream
->read_subbuffer_ops
.get_next_subbuffer
=
1681 get_next_subbuffer_splice
;
1685 if (stream
->metadata_flag
) {
1686 stream
->read_subbuffer_ops
.extract_subbuffer_info
=
1687 extract_metadata_subbuffer_info
;
1689 stream
->read_subbuffer_ops
.extract_subbuffer_info
=
1690 extract_data_subbuffer_info
;
1691 if (stream
->chan
->is_live
) {
1692 stream
->read_subbuffer_ops
.send_live_beacon
=
1693 consumer_flush_kernel_index
;
1697 stream
->read_subbuffer_ops
.put_next_subbuffer
= put_next_subbuffer
;
1702 int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1709 * Don't create anything if this is set for streaming or if there is
1710 * no current trace chunk on the parent channel.
1712 if (stream
->net_seq_idx
== (uint64_t) -1ULL && stream
->chan
->monitor
&&
1713 stream
->chan
->trace_chunk
) {
1714 ret
= consumer_stream_create_output_files(stream
, true);
1720 if (stream
->output
== LTTNG_EVENT_MMAP
) {
1721 /* get the len of the mmap region */
1722 unsigned long mmap_len
;
1724 ret
= kernctl_get_mmap_len(stream
->wait_fd
, &mmap_len
);
1726 PERROR("kernctl_get_mmap_len");
1727 goto error_close_fd
;
1729 stream
->mmap_len
= (size_t) mmap_len
;
1731 stream
->mmap_base
= mmap(NULL
, stream
->mmap_len
, PROT_READ
,
1732 MAP_PRIVATE
, stream
->wait_fd
, 0);
1733 if (stream
->mmap_base
== MAP_FAILED
) {
1734 PERROR("Error mmaping");
1736 goto error_close_fd
;
1740 ret
= lttng_kconsumer_set_stream_ops(stream
);
1742 goto error_close_fd
;
1745 /* we return 0 to let the library handle the FD internally */
1749 if (stream
->out_fd
>= 0) {
1752 err
= close(stream
->out_fd
);
1754 stream
->out_fd
= -1;
1761 * Check if data is still being extracted from the buffers for a specific
1762 * stream. Consumer data lock MUST be acquired before calling this function
1763 * and the stream lock.
1765 * Return 1 if the traced data are still getting read else 0 meaning that the
1766 * data is available for trace viewer reading.
1768 int lttng_kconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1774 if (stream
->endpoint_status
!= CONSUMER_ENDPOINT_ACTIVE
) {
1779 ret
= kernctl_get_next_subbuf(stream
->wait_fd
);
1781 /* There is still data so let's put back this subbuffer. */
1782 ret
= kernctl_put_subbuf(stream
->wait_fd
);
1784 ret
= 1; /* Data is pending */
1788 /* Data is NOT pending and ready to be read. */