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

/*
 * 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.h>
#include <common/index/index.h>
#include <common/compat/string.h>
#include <common/utils.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

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

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);
}

struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
		struct lttng_trace_chunk *viewer_trace_chunk,
		enum lttng_viewer_seek seek_t)
{
	struct relay_viewer_stream *vstream = NULL;
	const bool acquired_reference = lttng_trace_chunk_get(
			viewer_trace_chunk);

	if (!acquired_reference) {
		goto error;
	}

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

	vstream->stream_file.trace_chunk = viewer_trace_chunk;
	viewer_trace_chunk = NULL;
	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;

	pthread_mutex_lock(&stream->lock);

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

	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_unlock;
	}

	/*
	 * 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 {
		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_unlock;
			}
		}
	}

	/*
	 * If we never received a data file for the current stream, delay the
	 * opening, otherwise open it right now.
	 */
	if (stream->file) {
		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_unlock;
		}

		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_unlock;
		}
	}

	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_unlock;
		}
	}
	if (stream->is_metadata) {
		rcu_assign_pointer(stream->trace->viewer_metadata_stream,
				vstream);
	}
	pthread_mutex_unlock(&stream->lock);

	/* 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_unlock:
	pthread_mutex_unlock(&stream->lock);
error:
	if (vstream) {
		viewer_stream_destroy(vstream);
	}
	if (viewer_trace_chunk && acquired_reference) {
		lttng_trace_chunk_put(viewer_trace_chunk);
	}
	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);
	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);

	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;
	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;
	}
	vstream->index_sent_seqcount = seq_tail;
}

/*
 * 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.
		 */
		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
2f8f53af DG	11	#include <common/common.h>
2f8f53af DG	12	#include <common/index/index.h>
f5436bfc	13	#include <common/compat/string.h>
b0d240a2 MD	14	#include <common/utils.h>
	15	#include <sys/types.h>
	16	#include <sys/stat.h>
	17	#include <fcntl.h>
2f8f53af DG	18
	19	#include "lttng-relayd.h"
	20	#include "viewer-stream.h"
	21
7591bab1	22	static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
2f8f53af	23	{
7591bab1 MD	24	free(vstream->path_name);
	25	free(vstream->channel_name);
	26	free(vstream);
2f8f53af DG	27	}
2f8f53af DG	28
7591bab1	29	static void viewer_stream_destroy_rcu(struct rcu_head *head)
2f8f53af	30	{
7591bab1	31	struct relay_viewer_stream *vstream =
2f8f53af DG	32	caa_container_of(head, struct relay_viewer_stream, rcu_node);
2f8f53af DG	33
7591bab1	34	viewer_stream_destroy(vstream);
2f8f53af DG	35	}
	36
	37	struct relay_viewer_stream viewer_stream_create(struct relay_stream stream,
b66a15d1	38	struct lttng_trace_chunk *viewer_trace_chunk,
7591bab1	39	enum lttng_viewer_seek seek_t)
2f8f53af	40	{
ebb29c10 JG	41	struct relay_viewer_stream *vstream = NULL;
ebb29c10 JG	42	const bool acquired_reference = lttng_trace_chunk_get(
b66a15d1	43	viewer_trace_chunk);
ebb29c10 JG	44
	45	if (!acquired_reference) {
	46	goto error;
	47	}
2f8f53af	48
2f8f53af DG	49	vstream = zmalloc(sizeof(*vstream));
	50	if (!vstream) {
	51	PERROR("relay viewer stream zmalloc");
	52	goto error;
	53	}
	54
b66a15d1 JG	55	vstream->stream_file.trace_chunk = viewer_trace_chunk;
b66a15d1 JG	56	viewer_trace_chunk = NULL;
f5436bfc	57	vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
b272577e MD	58	if (vstream->path_name == NULL) {
	59	PERROR("relay viewer path_name alloc");
	60	goto error;
	61	}
f5436bfc	62	vstream->channel_name = lttng_strndup(stream->channel_name,
2f8f53af	63	LTTNG_VIEWER_NAME_MAX);
b272577e MD	64	if (vstream->channel_name == NULL) {
	65	PERROR("relay viewer channel_name alloc");
	66	goto error;
	67	}
2f8f53af	68
a44ca2ca MD	69	if (!stream_get(stream)) {
	70	ERR("Cannot get stream");
	71	goto error;
	72	}
	73	vstream->stream = stream;
	74
	75	pthread_mutex_lock(&stream->lock);
	76
	77	if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
	78	ERR("Cannot attach viewer metadata stream to trace (busy).");
	79	goto error_unlock;
	80	}
	81
2f8f53af	82	switch (seek_t) {
c4e361a4	83	case LTTNG_VIEWER_SEEK_BEGINNING:
a44ca2ca MD	84	{
	85	uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	86
	87	if (seq_tail == -1ULL) {
	88	/*
	89	* Tail may not be initialized yet. Nonetheless, we know
	90	* we want to send the first index once it becomes
	91	* available.
	92	*/
	93	seq_tail = 0;
	94	}
	95	vstream->current_tracefile_id =
	96	tracefile_array_get_file_index_tail(stream->tfa);
	97	vstream->index_sent_seqcount = seq_tail;
2f8f53af	98	break;
a44ca2ca	99	}
c4e361a4	100	case LTTNG_VIEWER_SEEK_LAST:
a44ca2ca	101	vstream->current_tracefile_id =
78118e3b	102	tracefile_array_get_read_file_index_head(stream->tfa);
a44ca2ca MD	103	/*
	104	* We seek at the very end of each stream, awaiting for
	105	* a future packet to eventually come in.
	106	*
	107	* We don't need to check the head position for -1ULL since the
	108	* increment will set it to 0.
	109	*/
	110	vstream->index_sent_seqcount =
	111	tracefile_array_get_seq_head(stream->tfa) + 1;
2f8f53af DG	112	break;
2f8f53af DG	113	default:
a44ca2ca	114	goto error_unlock;
2f8f53af	115	}
2f8f53af	116
2f8f53af	117	/*
a44ca2ca MD	118	* If we never received an index for the current stream, delay
a44ca2ca MD	119	* the opening of the index, otherwise open it right now.
2f8f53af	120	*/
b0d240a2	121	if (stream->index_file == NULL) {
f8f3885c	122	vstream->index_file = NULL;
2f8f53af	123	} else {
ebb29c10 JG	124	const uint32_t connection_major = stream->trace->session->major;
ebb29c10 JG	125	const uint32_t connection_minor = stream->trace->session->minor;
3ff5c5db	126	enum lttng_trace_chunk_status chunk_status;
ebb29c10	127
3ff5c5db	128	chunk_status = lttng_index_file_create_from_trace_chunk_read_only(
b66a15d1 JG	129	vstream->stream_file.trace_chunk,
b66a15d1 JG	130	stream->path_name,
ebb29c10 JG	131	stream->channel_name, stream->tracefile_size,
	132	vstream->current_tracefile_id,
	133	lttng_to_index_major(connection_major,
	134	connection_minor),
	135	lttng_to_index_minor(connection_major,
3ff5c5db MD	136	connection_minor),
	137	true, &vstream->index_file);
	138	if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
	139	if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_NO_FILE) {
	140	vstream->index_file = NULL;
	141	} else {
	142	goto error_unlock;
	143	}
2f8f53af	144	}
2f8f53af DG	145	}
2f8f53af DG	146
b0d240a2 MD	147	/*
	148	* If we never received a data file for the current stream, delay the
	149	* opening, otherwise open it right now.
	150	*/
8bb66c3c JG	151	if (stream->file) {
8bb66c3c JG	152	int ret;
b0d240a2 MD	153	char file_path[LTTNG_PATH_MAX];
	154	enum lttng_trace_chunk_status status;
	155
	156	ret = utils_stream_file_path(stream->path_name,
	157	stream->channel_name, stream->tracefile_size,
	158	vstream->current_tracefile_id, NULL, file_path,
	159	sizeof(file_path));
	160	if (ret < 0) {
	161	goto error_unlock;
	162	}
	163
8bb66c3c JG	164	status = lttng_trace_chunk_open_fs_handle(
	165	vstream->stream_file.trace_chunk, file_path,
	166	O_RDONLY, 0, &vstream->stream_file.handle,
	167	true);
b0d240a2 MD	168	if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
	169	goto error_unlock;
	170	}
b0d240a2 MD	171	}
b0d240a2 MD	172
f8f3885c	173	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
2f8f53af DG	174	off_t lseek_ret;
2f8f53af DG	175
8bb66c3c JG	176	lseek_ret = fs_handle_seek(
8bb66c3c JG	177	vstream->index_file->file, 0, SEEK_END);
2f8f53af	178	if (lseek_ret < 0) {
7591bab1	179	goto error_unlock;
2f8f53af	180	}
7591bab1	181	}
7591bab1 MD	182	if (stream->is_metadata) {
	183	rcu_assign_pointer(stream->trace->viewer_metadata_stream,
	184	vstream);
2f8f53af	185	}
a44ca2ca	186	pthread_mutex_unlock(&stream->lock);
2f8f53af	187
7591bab1 MD	188	/* Globally visible after the add unique. */
7591bab1 MD	189	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
7591bab1	190	urcu_ref_init(&vstream->ref);
c51b2177	191	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
7591bab1	192
2f8f53af DG	193	return vstream;
2f8f53af DG	194
7591bab1 MD	195	error_unlock:
7591bab1 MD	196	pthread_mutex_unlock(&stream->lock);
2f8f53af DG	197	error:
2f8f53af DG	198	if (vstream) {
7591bab1	199	viewer_stream_destroy(vstream);
2f8f53af	200	}
e4650a96	201	if (viewer_trace_chunk && acquired_reference) {
b66a15d1 JG	202	lttng_trace_chunk_put(viewer_trace_chunk);
b66a15d1 JG	203	}
2f8f53af DG	204	return NULL;
	205	}
	206
7591bab1	207	static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
2f8f53af DG	208	{
	209	int ret;
	210	struct lttng_ht_iter iter;
	211
7591bab1	212	iter.iter.node = &vstream->stream_n.node;
2f8f53af DG	213	ret = lttng_ht_del(viewer_streams_ht, &iter);
	214	assert(!ret);
	215	}
	216
7591bab1	217	static void viewer_stream_release(struct urcu_ref *ref)
2f8f53af	218	{
7591bab1 MD	219	struct relay_viewer_stream *vstream = caa_container_of(ref,
7591bab1 MD	220	struct relay_viewer_stream, ref);
2a174661	221
7591bab1 MD	222	if (vstream->stream->is_metadata) {
7591bab1 MD	223	rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
2a174661	224	}
2f8f53af	225
7591bab1 MD	226	viewer_stream_unpublish(vstream);
7591bab1 MD	227
8bb66c3c JG	228	if (vstream->stream_file.handle) {
	229	fs_handle_close(vstream->stream_file.handle);
	230	vstream->stream_file.handle = NULL;
2f8f53af	231	}
f8f3885c MD	232	if (vstream->index_file) {
	233	lttng_index_file_put(vstream->index_file);
	234	vstream->index_file = NULL;
7591bab1 MD	235	}
	236	if (vstream->stream) {
	237	stream_put(vstream->stream);
	238	vstream->stream = NULL;
	239	}
4c2717fc JG	240	lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
4c2717fc JG	241	vstream->stream_file.trace_chunk = NULL;
7591bab1 MD	242	call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
	243	}
	244
	245	/* Must be called with RCU read-side lock held. */
	246	bool viewer_stream_get(struct relay_viewer_stream *vstream)
	247	{
ce4d4083	248	return urcu_ref_get_unless_zero(&vstream->ref);
2f8f53af DG	249	}
	250
	251	/*
7591bab1	252	* Get viewer stream by id.
2f8f53af	253	*
7591bab1	254	* Return viewer stream if found else NULL.
2f8f53af	255	*/
7591bab1	256	struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
2f8f53af DG	257	{
	258	struct lttng_ht_node_u64 *node;
	259	struct lttng_ht_iter iter;
7591bab1	260	struct relay_viewer_stream *vstream = NULL;
2f8f53af	261
7591bab1	262	rcu_read_lock();
2f8f53af DG	263	lttng_ht_lookup(viewer_streams_ht, &id, &iter);
	264	node = lttng_ht_iter_get_node_u64(&iter);
	265	if (!node) {
	266	DBG("Relay viewer stream %" PRIu64 " not found", id);
	267	goto end;
	268	}
7591bab1 MD	269	vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
	270	if (!viewer_stream_get(vstream)) {
	271	vstream = NULL;
	272	}
2f8f53af	273	end:
7591bab1 MD	274	rcu_read_unlock();
	275	return vstream;
	276	}
	277
	278	void viewer_stream_put(struct relay_viewer_stream *vstream)
	279	{
	280	rcu_read_lock();
7591bab1	281	urcu_ref_put(&vstream->ref, viewer_stream_release);
7591bab1 MD	282	rcu_read_unlock();
	283	}
	284
3087b021 MD	285	void viewer_stream_close_files(struct relay_viewer_stream *vstream)
	286	{
	287	if (vstream->index_file) {
	288	lttng_index_file_put(vstream->index_file);
	289	vstream->index_file = NULL;
	290	}
8bb66c3c JG	291	if (vstream->stream_file.handle) {
	292	fs_handle_close(vstream->stream_file.handle);
	293	vstream->stream_file.handle = NULL;
3087b021 MD	294	}
	295	}
	296
	297	void viewer_stream_sync_tracefile_array_tail(struct relay_viewer_stream *vstream)
	298	{
	299	const struct relay_stream *stream = vstream->stream;
	300	uint64_t seq_tail;
	301
	302	vstream->current_tracefile_id = tracefile_array_get_file_index_tail(stream->tfa);
	303	seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	304	if (seq_tail == -1ULL) {
	305	seq_tail = 0;
	306	}
	307	vstream->index_sent_seqcount = seq_tail;
	308	}
	309
2f8f53af DG	310	/*
	311	* Rotate a stream to the next tracefile.
	312	*
7591bab1	313	* Must be called with the rstream lock held.
b0d240a2	314	* Returns 0 on success, 1 on EOF.
2f8f53af	315	*/
7591bab1	316	int viewer_stream_rotate(struct relay_viewer_stream *vstream)
2f8f53af DG	317	{
2f8f53af DG	318	int ret;
a44ca2ca	319	uint64_t new_id;
ebb29c10	320	const struct relay_stream *stream = vstream->stream;
2f8f53af	321
7591bab1	322	/* Detect the last tracefile to open. */
a44ca2ca MD	323	if (stream->index_received_seqcount
a44ca2ca MD	324	== vstream->index_sent_seqcount
7591bab1 MD	325	&& stream->trace->session->connection_closed) {
7591bab1 MD	326	ret = 1;
2a174661 DG	327	goto end;
2a174661 DG	328	}
2f8f53af	329
7591bab1 MD	330	if (stream->tracefile_count == 0) {
	331	/* Ignore rotation, there is none to do. */
	332	ret = 0;
2f8f53af DG	333	goto end;
	334	}
	335
a44ca2ca MD	336	/*
	337	* Try to move to the next file.
	338	*/
	339	new_id = (vstream->current_tracefile_id + 1)
	340	% stream->tracefile_count;
	341	if (tracefile_array_seq_in_file(stream->tfa, new_id,
	342	vstream->index_sent_seqcount)) {
	343	vstream->current_tracefile_id = new_id;
2f8f53af	344	} else {
a44ca2ca MD	345	uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	346
	347	/*
	348	* This can only be reached on overwrite, which implies there
	349	* has been data written at some point, which will have set the
	350	* tail.
	351	*/
	352	assert(seq_tail != -1ULL);
	353	/*
	354	* We need to resync because we lag behind tail.
	355	*/
7591bab1	356	vstream->current_tracefile_id =
a44ca2ca MD	357	tracefile_array_get_file_index_tail(stream->tfa);
a44ca2ca MD	358	vstream->index_sent_seqcount = seq_tail;
2f8f53af	359	}
b0d240a2 MD	360	viewer_stream_close_files(vstream);
b0d240a2 MD	361	ret = 0;
2f8f53af	362	end:
2f8f53af DG	363	return ret;
2f8f53af DG	364	}
7591bab1 MD	365
	366	void print_viewer_streams(void)
	367	{
	368	struct lttng_ht_iter iter;
	369	struct relay_viewer_stream *vstream;
	370
ce3f3ba3 JG	371	if (!viewer_streams_ht) {
	372	return;
	373	}
	374
7591bab1 MD	375	rcu_read_lock();
	376	cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
	377	stream_n.node) {
	378	if (!viewer_stream_get(vstream)) {
	379	continue;
	380	}
	381	DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
	382	" session %" PRIu64,
	383	vstream,
	384	vstream->ref.refcount,
	385	vstream->stream->stream_handle,
	386	vstream->stream->trace->id,
	387	vstream->stream->trace->session->id);
	388	viewer_stream_put(vstream);
	389	}
	390	rcu_read_unlock();
	391	}