[lttng-tools.git] / src / bin / lttng-relayd / viewer-stream.cpp

/*
 * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
 * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#define _LGPL_SOURCE
#include <common/common.hpp>
#include <common/index/index.hpp>
#include <common/compat/string.hpp>
#include <common/utils.hpp>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <algorithm>

#include "lttng-relayd.hpp"
#include "viewer-stream.hpp"

static void viewer_stream_release_composite_objects(struct relay_viewer_stream *vstream)
{
	if (vstream->stream_file.handle) {
		fs_handle_close(vstream->stream_file.handle);
		vstream->stream_file.handle = NULL;
	}
	if (vstream->index_file) {
		lttng_index_file_put(vstream->index_file);
		vstream->index_file = NULL;
	}
	if (vstream->stream) {
		stream_put(vstream->stream);
		vstream->stream = NULL;
	}
	lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
	vstream->stream_file.trace_chunk = NULL;
}

static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
{
	free(vstream->path_name);
	free(vstream->channel_name);
	free(vstream);
}

static void viewer_stream_destroy_rcu(struct rcu_head *head)
{
	struct relay_viewer_stream *vstream =
		caa_container_of(head, struct relay_viewer_stream, rcu_node);

	viewer_stream_destroy(vstream);
}

/* Relay stream's lock must be held by the caller. */
struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
		struct lttng_trace_chunk *trace_chunk,
		enum lttng_viewer_seek seek_t)
{
	struct relay_viewer_stream *vstream = NULL;

	ASSERT_LOCKED(stream->lock);

	vstream = (relay_viewer_stream *) zmalloc(sizeof(*vstream));
	if (!vstream) {
		PERROR("relay viewer stream zmalloc");
		goto error;
	}

	if (trace_chunk) {
		const bool acquired_reference = lttng_trace_chunk_get(
				trace_chunk);

		LTTNG_ASSERT(acquired_reference);
	}

	vstream->stream_file.trace_chunk = trace_chunk;
	vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
	if (vstream->path_name == NULL) {
		PERROR("relay viewer path_name alloc");
		goto error;
	}
	vstream->channel_name = lttng_strndup(stream->channel_name,
			LTTNG_VIEWER_NAME_MAX);
	if (vstream->channel_name == NULL) {
		PERROR("relay viewer channel_name alloc");
		goto error;
	}

	if (!stream_get(stream)) {
		ERR("Cannot get stream");
		goto error;
	}
	vstream->stream = stream;

	if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
		ERR("Cannot attach viewer metadata stream to trace (busy).");
		goto error;
	}

	switch (seek_t) {
	case LTTNG_VIEWER_SEEK_BEGINNING:
	{
		uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);

		if (seq_tail == -1ULL) {
			/*
			 * Tail may not be initialized yet. Nonetheless, we know
			 * we want to send the first index once it becomes
			 * available.
			 */
			seq_tail = 0;
		}
		vstream->current_tracefile_id =
			tracefile_array_get_file_index_tail(stream->tfa);
		vstream->index_sent_seqcount = seq_tail;
		break;
	}
	case LTTNG_VIEWER_SEEK_LAST:
		vstream->current_tracefile_id =
			tracefile_array_get_read_file_index_head(stream->tfa);
		/*
		 * We seek at the very end of each stream, awaiting for
		 * a future packet to eventually come in.
		 *
		 * We don't need to check the head position for -1ULL since the
		 * increment will set it to 0.
		 */
		vstream->index_sent_seqcount =
				tracefile_array_get_seq_head(stream->tfa) + 1;
		break;
	default:
		goto error;
	}

	/*
	 * If we never received an index for the current stream, delay
	 * the opening of the index, otherwise open it right now.
	 */
	if (stream->index_file == NULL) {
		vstream->index_file = NULL;
	} else if (vstream->stream_file.trace_chunk) {
		const uint32_t connection_major = stream->trace->session->major;
		const uint32_t connection_minor = stream->trace->session->minor;
		enum lttng_trace_chunk_status chunk_status;

		chunk_status = lttng_index_file_create_from_trace_chunk_read_only(
				vstream->stream_file.trace_chunk,
				stream->path_name,
				stream->channel_name, stream->tracefile_size,
				vstream->current_tracefile_id,
				lttng_to_index_major(connection_major,
						connection_minor),
				lttng_to_index_minor(connection_major,
						connection_minor),
				true, &vstream->index_file);
		if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
			if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_NO_FILE) {
				vstream->index_file = NULL;
			} else {
				goto error;
			}
		}
	}

	/*
	 * If we never received a data file for the current stream, delay the
	 * opening, otherwise open it right now.
	 */
	if (stream->file && vstream->stream_file.trace_chunk) {
		int ret;
		char file_path[LTTNG_PATH_MAX];
		enum lttng_trace_chunk_status status;

		ret = utils_stream_file_path(stream->path_name,
				stream->channel_name, stream->tracefile_size,
				vstream->current_tracefile_id, NULL, file_path,
				sizeof(file_path));
		if (ret < 0) {
			goto error;
		}

		status = lttng_trace_chunk_open_fs_handle(
				vstream->stream_file.trace_chunk, file_path,
				O_RDONLY, 0, &vstream->stream_file.handle,
				true);
		if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
			goto error;
		}
	}

	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
		off_t lseek_ret;

		lseek_ret = fs_handle_seek(
				vstream->index_file->file, 0, SEEK_END);
		if (lseek_ret < 0) {
			goto error;
		}
	}
	if (stream->is_metadata) {
		rcu_assign_pointer(stream->trace->viewer_metadata_stream,
				vstream);
	}

	vstream->last_seen_rotation_count = stream->completed_rotation_count;

	/* Globally visible after the add unique. */
	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
	urcu_ref_init(&vstream->ref);
	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);

	return vstream;

error:
	if (vstream) {
		/* Not using `put` since vstream is assumed to be published. */
		viewer_stream_release_composite_objects(vstream);
		viewer_stream_destroy(vstream);
	}
	return NULL;
}

static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
{
	int ret;
	struct lttng_ht_iter iter;

	iter.iter.node = &vstream->stream_n.node;
	ret = lttng_ht_del(viewer_streams_ht, &iter);
	LTTNG_ASSERT(!ret);
}

static void viewer_stream_release(struct urcu_ref *ref)
{
	struct relay_viewer_stream *vstream = caa_container_of(ref,
			struct relay_viewer_stream, ref);

	if (vstream->stream->is_metadata) {
		rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
	}
	viewer_stream_unpublish(vstream);
	viewer_stream_release_composite_objects(vstream);
	call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
}

/* Must be called with RCU read-side lock held. */
bool viewer_stream_get(struct relay_viewer_stream *vstream)
{
	return urcu_ref_get_unless_zero(&vstream->ref);
}

/*
 * Get viewer stream by id.
 *
 * Return viewer stream if found else NULL.
 */
struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
{
	struct lttng_ht_node_u64 *node;
	struct lttng_ht_iter iter;
	struct relay_viewer_stream *vstream = NULL;

	rcu_read_lock();
	lttng_ht_lookup(viewer_streams_ht, &id, &iter);
	node = lttng_ht_iter_get_node_u64(&iter);
	if (!node) {
		DBG("Relay viewer stream %" PRIu64 " not found", id);
		goto end;
	}
	vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
	if (!viewer_stream_get(vstream)) {
		vstream = NULL;
	}
end:
	rcu_read_unlock();
	return vstream;
}

void viewer_stream_put(struct relay_viewer_stream *vstream)
{
	rcu_read_lock();
	urcu_ref_put(&vstream->ref, viewer_stream_release);
	rcu_read_unlock();
}

void viewer_stream_close_files(struct relay_viewer_stream *vstream)
{
	if (vstream->index_file) {
		lttng_index_file_put(vstream->index_file);
		vstream->index_file = NULL;
	}
	if (vstream->stream_file.handle) {
	        fs_handle_close(vstream->stream_file.handle);
		vstream->stream_file.handle = NULL;
	}
}

void viewer_stream_sync_tracefile_array_tail(struct relay_viewer_stream *vstream)
{
	const struct relay_stream *stream = vstream->stream;
	uint64_t seq_tail;

	vstream->current_tracefile_id = tracefile_array_get_file_index_tail(stream->tfa);
	seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	if (seq_tail == -1ULL) {
		seq_tail = 0;
	}

	/*
	 * Move the index sent seqcount forward if it was lagging behind
	 * the new tail of the tracefile array. If the current
	 * index_sent_seqcount is already further than the tracefile
	 * array tail position, keep its current position.
	 */
	vstream->index_sent_seqcount =
			std::max(seq_tail, vstream->index_sent_seqcount);
}

/*
 * Rotate a stream to the next tracefile.
 *
 * Must be called with the rstream lock held.
 * Returns 0 on success, 1 on EOF.
 */
int viewer_stream_rotate(struct relay_viewer_stream *vstream)
{
	int ret;
	uint64_t new_id;
	const struct relay_stream *stream = vstream->stream;

	/* Detect the last tracefile to open. */
	if (stream->index_received_seqcount
			== vstream->index_sent_seqcount
			&& stream->trace->session->connection_closed) {
		ret = 1;
		goto end;
	}

	if (stream->tracefile_count == 0) {
		/* Ignore rotation, there is none to do. */
		ret = 0;
		goto end;
	}

	/*
	 * Try to move to the next file.
	 */
	new_id = (vstream->current_tracefile_id + 1)
			% stream->tracefile_count;
	if (tracefile_array_seq_in_file(stream->tfa, new_id,
			vstream->index_sent_seqcount)) {
		vstream->current_tracefile_id = new_id;
	} else {
		uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);

		/*
		 * This can only be reached on overwrite, which implies there
		 * has been data written at some point, which will have set the
		 * tail.
		 */
		LTTNG_ASSERT(seq_tail != -1ULL);
		/*
		 * We need to resync because we lag behind tail.
		 */
		vstream->current_tracefile_id =
			tracefile_array_get_file_index_tail(stream->tfa);
		vstream->index_sent_seqcount = seq_tail;
	}
	viewer_stream_close_files(vstream);
	ret = 0;
end:
	return ret;
}

void print_viewer_streams(void)
{
	struct lttng_ht_iter iter;
	struct relay_viewer_stream *vstream;

	if (!viewer_streams_ht) {
		return;
	}

	rcu_read_lock();
	cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
			stream_n.node) {
		if (!viewer_stream_get(vstream)) {
			continue;
		}
		DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
			" session %" PRIu64,
			vstream,
			vstream->ref.refcount,
			vstream->stream->stream_handle,
			vstream->stream->trace->id,
			vstream->stream->trace->session->id);
		viewer_stream_put(vstream);
	}
	rcu_read_unlock();
}
Commit	Line	Data
2f8f53af	1	/*
ab5be9fa MJ	2	* Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
	3	* Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
	4	* Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2f8f53af	5	*
ab5be9fa	6	* SPDX-License-Identifier: GPL-2.0-only
2f8f53af	7	*
2f8f53af DG	8	*/
2f8f53af DG	9
6c1c0768	10	#define _LGPL_SOURCE
c9e313bc SM	11	#include <common/common.hpp>
	12	#include <common/index/index.hpp>
	13	#include <common/compat/string.hpp>
	14	#include <common/utils.hpp>
b0d240a2 MD	15	#include <sys/types.h>
	16	#include <sys/stat.h>
	17	#include <fcntl.h>
7fb6d478	18	#include <algorithm>
2f8f53af	19
c9e313bc SM	20	#include "lttng-relayd.hpp"
c9e313bc SM	21	#include "viewer-stream.hpp"
2f8f53af	22
b9973dea	23	static void viewer_stream_release_composite_objects(struct relay_viewer_stream *vstream)
2f8f53af	24	{
b9973dea MD	25	if (vstream->stream_file.handle) {
	26	fs_handle_close(vstream->stream_file.handle);
	27	vstream->stream_file.handle = NULL;
	28	}
	29	if (vstream->index_file) {
	30	lttng_index_file_put(vstream->index_file);
	31	vstream->index_file = NULL;
	32	}
	33	if (vstream->stream) {
	34	stream_put(vstream->stream);
	35	vstream->stream = NULL;
	36	}
80516611	37	lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
b9973dea MD	38	vstream->stream_file.trace_chunk = NULL;
	39	}
	40
	41	static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
	42	{
7591bab1 MD	43	free(vstream->path_name);
	44	free(vstream->channel_name);
	45	free(vstream);
2f8f53af DG	46	}
2f8f53af DG	47
7591bab1	48	static void viewer_stream_destroy_rcu(struct rcu_head *head)
2f8f53af	49	{
7591bab1	50	struct relay_viewer_stream *vstream =
2f8f53af DG	51	caa_container_of(head, struct relay_viewer_stream, rcu_node);
2f8f53af DG	52
7591bab1	53	viewer_stream_destroy(vstream);
2f8f53af DG	54	}
2f8f53af DG	55
9edaf114	56	/* Relay stream's lock must be held by the caller. */
2f8f53af	57	struct relay_viewer_stream viewer_stream_create(struct relay_stream stream,
9edaf114	58	struct lttng_trace_chunk *trace_chunk,
7591bab1	59	enum lttng_viewer_seek seek_t)
2f8f53af	60	{
ebb29c10	61	struct relay_viewer_stream *vstream = NULL;
ebb29c10	62
9edaf114	63	ASSERT_LOCKED(stream->lock);
2f8f53af	64
ac497a37	65	vstream = (relay_viewer_stream ) zmalloc(sizeof(vstream));
2f8f53af DG	66	if (!vstream) {
	67	PERROR("relay viewer stream zmalloc");
	68	goto error;
	69	}
	70
80516611 JG	71	if (trace_chunk) {
	72	const bool acquired_reference = lttng_trace_chunk_get(
	73	trace_chunk);
	74
a0377dfe	75	LTTNG_ASSERT(acquired_reference);
80516611 JG	76	}
80516611 JG	77
9edaf114	78	vstream->stream_file.trace_chunk = trace_chunk;
f5436bfc	79	vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
b272577e MD	80	if (vstream->path_name == NULL) {
	81	PERROR("relay viewer path_name alloc");
	82	goto error;
	83	}
f5436bfc	84	vstream->channel_name = lttng_strndup(stream->channel_name,
2f8f53af	85	LTTNG_VIEWER_NAME_MAX);
b272577e MD	86	if (vstream->channel_name == NULL) {
	87	PERROR("relay viewer channel_name alloc");
	88	goto error;
	89	}
2f8f53af	90
a44ca2ca MD	91	if (!stream_get(stream)) {
	92	ERR("Cannot get stream");
	93	goto error;
	94	}
	95	vstream->stream = stream;
	96
a44ca2ca MD	97	if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
a44ca2ca MD	98	ERR("Cannot attach viewer metadata stream to trace (busy).");
71381736	99	goto error;
a44ca2ca MD	100	}
a44ca2ca MD	101
2f8f53af	102	switch (seek_t) {
c4e361a4	103	case LTTNG_VIEWER_SEEK_BEGINNING:
a44ca2ca MD	104	{
	105	uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	106
	107	if (seq_tail == -1ULL) {
	108	/*
	109	* Tail may not be initialized yet. Nonetheless, we know
	110	* we want to send the first index once it becomes
	111	* available.
	112	*/
	113	seq_tail = 0;
	114	}
	115	vstream->current_tracefile_id =
	116	tracefile_array_get_file_index_tail(stream->tfa);
	117	vstream->index_sent_seqcount = seq_tail;
2f8f53af	118	break;
a44ca2ca	119	}
c4e361a4	120	case LTTNG_VIEWER_SEEK_LAST:
a44ca2ca	121	vstream->current_tracefile_id =
78118e3b	122	tracefile_array_get_read_file_index_head(stream->tfa);
a44ca2ca MD	123	/*
	124	* We seek at the very end of each stream, awaiting for
	125	* a future packet to eventually come in.
	126	*
	127	* We don't need to check the head position for -1ULL since the
	128	* increment will set it to 0.
	129	*/
	130	vstream->index_sent_seqcount =
	131	tracefile_array_get_seq_head(stream->tfa) + 1;
2f8f53af DG	132	break;
2f8f53af DG	133	default:
71381736	134	goto error;
2f8f53af	135	}
2f8f53af	136
2f8f53af	137	/*
a44ca2ca MD	138	* If we never received an index for the current stream, delay
a44ca2ca MD	139	* the opening of the index, otherwise open it right now.
2f8f53af	140	*/
b0d240a2	141	if (stream->index_file == NULL) {
f8f3885c	142	vstream->index_file = NULL;
0eafad74	143	} else if (vstream->stream_file.trace_chunk) {
ebb29c10 JG	144	const uint32_t connection_major = stream->trace->session->major;
ebb29c10 JG	145	const uint32_t connection_minor = stream->trace->session->minor;
3ff5c5db	146	enum lttng_trace_chunk_status chunk_status;
ebb29c10	147
3ff5c5db	148	chunk_status = lttng_index_file_create_from_trace_chunk_read_only(
b66a15d1 JG	149	vstream->stream_file.trace_chunk,
b66a15d1 JG	150	stream->path_name,
ebb29c10 JG	151	stream->channel_name, stream->tracefile_size,
	152	vstream->current_tracefile_id,
	153	lttng_to_index_major(connection_major,
	154	connection_minor),
	155	lttng_to_index_minor(connection_major,
3ff5c5db MD	156	connection_minor),
	157	true, &vstream->index_file);
	158	if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
	159	if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_NO_FILE) {
	160	vstream->index_file = NULL;
	161	} else {
71381736	162	goto error;
3ff5c5db	163	}
2f8f53af	164	}
2f8f53af DG	165	}
2f8f53af DG	166
b0d240a2 MD	167	/*
	168	* If we never received a data file for the current stream, delay the
	169	* opening, otherwise open it right now.
	170	*/
0eafad74	171	if (stream->file && vstream->stream_file.trace_chunk) {
8bb66c3c	172	int ret;
b0d240a2 MD	173	char file_path[LTTNG_PATH_MAX];
	174	enum lttng_trace_chunk_status status;
	175
	176	ret = utils_stream_file_path(stream->path_name,
	177	stream->channel_name, stream->tracefile_size,
	178	vstream->current_tracefile_id, NULL, file_path,
	179	sizeof(file_path));
	180	if (ret < 0) {
71381736	181	goto error;
b0d240a2 MD	182	}
b0d240a2 MD	183
8bb66c3c JG	184	status = lttng_trace_chunk_open_fs_handle(
	185	vstream->stream_file.trace_chunk, file_path,
	186	O_RDONLY, 0, &vstream->stream_file.handle,
	187	true);
b0d240a2	188	if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
71381736	189	goto error;
b0d240a2	190	}
b0d240a2 MD	191	}
b0d240a2 MD	192
f8f3885c	193	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
2f8f53af DG	194	off_t lseek_ret;
2f8f53af DG	195
8bb66c3c JG	196	lseek_ret = fs_handle_seek(
8bb66c3c JG	197	vstream->index_file->file, 0, SEEK_END);
2f8f53af	198	if (lseek_ret < 0) {
71381736	199	goto error;
2f8f53af	200	}
7591bab1	201	}
7591bab1 MD	202	if (stream->is_metadata) {
	203	rcu_assign_pointer(stream->trace->viewer_metadata_stream,
	204	vstream);
2f8f53af DG	205	}
2f8f53af DG	206
80516611 JG	207	vstream->last_seen_rotation_count = stream->completed_rotation_count;
80516611 JG	208
7591bab1 MD	209	/* Globally visible after the add unique. */
7591bab1 MD	210	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
7591bab1	211	urcu_ref_init(&vstream->ref);
c51b2177	212	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
7591bab1	213
2f8f53af DG	214	return vstream;
	215
	216	error:
	217	if (vstream) {
b9973dea MD	218	/* Not using `put` since vstream is assumed to be published. */
b9973dea MD	219	viewer_stream_release_composite_objects(vstream);
7591bab1	220	viewer_stream_destroy(vstream);
2f8f53af DG	221	}
	222	return NULL;
	223	}
	224
7591bab1	225	static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
2f8f53af DG	226	{
	227	int ret;
	228	struct lttng_ht_iter iter;
	229
7591bab1	230	iter.iter.node = &vstream->stream_n.node;
2f8f53af	231	ret = lttng_ht_del(viewer_streams_ht, &iter);
a0377dfe	232	LTTNG_ASSERT(!ret);
2f8f53af DG	233	}
2f8f53af DG	234
7591bab1	235	static void viewer_stream_release(struct urcu_ref *ref)
2f8f53af	236	{
7591bab1 MD	237	struct relay_viewer_stream *vstream = caa_container_of(ref,
7591bab1 MD	238	struct relay_viewer_stream, ref);
2a174661	239
7591bab1 MD	240	if (vstream->stream->is_metadata) {
7591bab1 MD	241	rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
2a174661	242	}
7591bab1	243	viewer_stream_unpublish(vstream);
b9973dea	244	viewer_stream_release_composite_objects(vstream);
7591bab1 MD	245	call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
	246	}
	247
	248	/* Must be called with RCU read-side lock held. */
	249	bool viewer_stream_get(struct relay_viewer_stream *vstream)
	250	{
ce4d4083	251	return urcu_ref_get_unless_zero(&vstream->ref);
2f8f53af DG	252	}
	253
	254	/*
7591bab1	255	* Get viewer stream by id.
2f8f53af	256	*
7591bab1	257	* Return viewer stream if found else NULL.
2f8f53af	258	*/
7591bab1	259	struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
2f8f53af DG	260	{
	261	struct lttng_ht_node_u64 *node;
	262	struct lttng_ht_iter iter;
7591bab1	263	struct relay_viewer_stream *vstream = NULL;
2f8f53af	264
7591bab1	265	rcu_read_lock();
2f8f53af DG	266	lttng_ht_lookup(viewer_streams_ht, &id, &iter);
	267	node = lttng_ht_iter_get_node_u64(&iter);
	268	if (!node) {
	269	DBG("Relay viewer stream %" PRIu64 " not found", id);
	270	goto end;
	271	}
7591bab1 MD	272	vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
	273	if (!viewer_stream_get(vstream)) {
	274	vstream = NULL;
	275	}
2f8f53af	276	end:
7591bab1 MD	277	rcu_read_unlock();
	278	return vstream;
	279	}
	280
	281	void viewer_stream_put(struct relay_viewer_stream *vstream)
	282	{
	283	rcu_read_lock();
7591bab1	284	urcu_ref_put(&vstream->ref, viewer_stream_release);
7591bab1 MD	285	rcu_read_unlock();
	286	}
	287
3087b021 MD	288	void viewer_stream_close_files(struct relay_viewer_stream *vstream)
	289	{
	290	if (vstream->index_file) {
	291	lttng_index_file_put(vstream->index_file);
	292	vstream->index_file = NULL;
	293	}
8bb66c3c JG	294	if (vstream->stream_file.handle) {
	295	fs_handle_close(vstream->stream_file.handle);
	296	vstream->stream_file.handle = NULL;
3087b021 MD	297	}
	298	}
	299
	300	void viewer_stream_sync_tracefile_array_tail(struct relay_viewer_stream *vstream)
	301	{
	302	const struct relay_stream *stream = vstream->stream;
	303	uint64_t seq_tail;
	304
	305	vstream->current_tracefile_id = tracefile_array_get_file_index_tail(stream->tfa);
	306	seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	307	if (seq_tail == -1ULL) {
	308	seq_tail = 0;
	309	}
7fb6d478 MD	310
	311	/*
	312	* Move the index sent seqcount forward if it was lagging behind
	313	* the new tail of the tracefile array. If the current
	314	* index_sent_seqcount is already further than the tracefile
	315	* array tail position, keep its current position.
	316	*/
	317	vstream->index_sent_seqcount =
	318	std::max(seq_tail, vstream->index_sent_seqcount);
3087b021 MD	319	}
3087b021 MD	320
2f8f53af DG	321	/*
	322	* Rotate a stream to the next tracefile.
	323	*
7591bab1	324	* Must be called with the rstream lock held.
b0d240a2	325	* Returns 0 on success, 1 on EOF.
2f8f53af	326	*/
7591bab1	327	int viewer_stream_rotate(struct relay_viewer_stream *vstream)
2f8f53af DG	328	{
2f8f53af DG	329	int ret;
a44ca2ca	330	uint64_t new_id;
ebb29c10	331	const struct relay_stream *stream = vstream->stream;
2f8f53af	332
7591bab1	333	/* Detect the last tracefile to open. */
a44ca2ca MD	334	if (stream->index_received_seqcount
a44ca2ca MD	335	== vstream->index_sent_seqcount
7591bab1 MD	336	&& stream->trace->session->connection_closed) {
7591bab1 MD	337	ret = 1;
2a174661 DG	338	goto end;
2a174661 DG	339	}
2f8f53af	340
7591bab1 MD	341	if (stream->tracefile_count == 0) {
	342	/* Ignore rotation, there is none to do. */
	343	ret = 0;
2f8f53af DG	344	goto end;
	345	}
	346
a44ca2ca MD	347	/*
	348	* Try to move to the next file.
	349	*/
	350	new_id = (vstream->current_tracefile_id + 1)
	351	% stream->tracefile_count;
	352	if (tracefile_array_seq_in_file(stream->tfa, new_id,
	353	vstream->index_sent_seqcount)) {
	354	vstream->current_tracefile_id = new_id;
2f8f53af	355	} else {
a44ca2ca MD	356	uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	357
	358	/*
	359	* This can only be reached on overwrite, which implies there
	360	* has been data written at some point, which will have set the
	361	* tail.
	362	*/
a0377dfe	363	LTTNG_ASSERT(seq_tail != -1ULL);
a44ca2ca MD	364	/*
	365	* We need to resync because we lag behind tail.
	366	*/
7591bab1	367	vstream->current_tracefile_id =
a44ca2ca MD	368	tracefile_array_get_file_index_tail(stream->tfa);
a44ca2ca MD	369	vstream->index_sent_seqcount = seq_tail;
2f8f53af	370	}
b0d240a2 MD	371	viewer_stream_close_files(vstream);
b0d240a2 MD	372	ret = 0;
2f8f53af	373	end:
2f8f53af DG	374	return ret;
2f8f53af DG	375	}
7591bab1 MD	376
	377	void print_viewer_streams(void)
	378	{
	379	struct lttng_ht_iter iter;
	380	struct relay_viewer_stream *vstream;
	381
ce3f3ba3 JG	382	if (!viewer_streams_ht) {
	383	return;
	384	}
	385
7591bab1 MD	386	rcu_read_lock();
	387	cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
	388	stream_n.node) {
	389	if (!viewer_stream_get(vstream)) {
	390	continue;
	391	}
	392	DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
	393	" session %" PRIu64,
	394	vstream,
	395	vstream->ref.refcount,
	396	vstream->stream->stream_handle,
	397	vstream->stream->trace->id,
	398	vstream->stream->trace->session->id);
	399	viewer_stream_put(vstream);
	400	}
	401	rcu_read_unlock();
	402	}