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

/*
 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
 *                      David Goulet <dgoulet@efficios.com>
 *               2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License, version 2 only, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _LGPL_SOURCE
#include <common/common.h>
#include <common/index/index.h>
#include <common/compat/string.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_received_seqcount == 0) {
		vstream->index_file = NULL;
	} else {
		const uint32_t connection_major = stream->trace->session->major;
		const uint32_t connection_minor = stream->trace->session->minor;

		vstream->index_file = 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));
		if (!vstream->index_file) {
			goto error_unlock;
		}
	}

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

		lseek_ret = lseek(vstream->index_file->fd, 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.fd) {
		stream_fd_put(vstream->stream_file.fd);
		vstream->stream_file.fd = 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();
}

/*
 * Rotate a stream to the next tracefile.
 *
 * Must be called with the rstream lock held.
 * Returns 0 on success, 1 on EOF, a negative value on error.
 */
int viewer_stream_rotate(struct relay_viewer_stream *vstream)
{
	int ret;
	uint64_t new_id;
	const struct relay_stream *stream = vstream->stream;
	const uint32_t connection_major = stream->trace->session->major;
	const uint32_t connection_minor = stream->trace->session->minor;

	/* 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;
	}

	if (vstream->index_file) {
		lttng_index_file_put(vstream->index_file);
		vstream->index_file = NULL;
	}
	if (vstream->stream_file.fd) {
		stream_fd_put(vstream->stream_file.fd);
		vstream->stream_file.fd = NULL;
	}
	vstream->index_file =
			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));
	if (!vstream->index_file) {
		ret = -1;
		goto end;
	} else {
		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
	1	/*
	2	* Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
	3	* David Goulet <dgoulet@efficios.com>
	4	* 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License, version 2 only, as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	* You should have received a copy of the GNU General Public License along with
	16	* this program; if not, write to the Free Software Foundation, Inc., 51
	17	* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	18	*/
	19
	20	#define _LGPL_SOURCE
	21	#include <common/common.h>
	22	#include <common/index/index.h>
	23	#include <common/compat/string.h>
	24
	25	#include "lttng-relayd.h"
	26	#include "viewer-stream.h"
	27
	28	static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
	29	{
	30	free(vstream->path_name);
	31	free(vstream->channel_name);
	32	free(vstream);
	33	}
	34
	35	static void viewer_stream_destroy_rcu(struct rcu_head *head)
	36	{
	37	struct relay_viewer_stream *vstream =
	38	caa_container_of(head, struct relay_viewer_stream, rcu_node);
	39
	40	viewer_stream_destroy(vstream);
	41	}
	42
	43	struct relay_viewer_stream viewer_stream_create(struct relay_stream stream,
	44	struct lttng_trace_chunk *viewer_trace_chunk,
	45	enum lttng_viewer_seek seek_t)
	46	{
	47	struct relay_viewer_stream *vstream = NULL;
	48	const bool acquired_reference = lttng_trace_chunk_get(
	49	viewer_trace_chunk);
	50
	51	if (!acquired_reference) {
	52	goto error;
	53	}
	54
	55	vstream = zmalloc(sizeof(*vstream));
	56	if (!vstream) {
	57	PERROR("relay viewer stream zmalloc");
	58	goto error;
	59	}
	60
	61	vstream->stream_file.trace_chunk = viewer_trace_chunk;
	62	viewer_trace_chunk = NULL;
	63	vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
	64	if (vstream->path_name == NULL) {
	65	PERROR("relay viewer path_name alloc");
	66	goto error;
	67	}
	68	vstream->channel_name = lttng_strndup(stream->channel_name,
	69	LTTNG_VIEWER_NAME_MAX);
	70	if (vstream->channel_name == NULL) {
	71	PERROR("relay viewer channel_name alloc");
	72	goto error;
	73	}
	74
	75	if (!stream_get(stream)) {
	76	ERR("Cannot get stream");
	77	goto error;
	78	}
	79	vstream->stream = stream;
	80
	81	pthread_mutex_lock(&stream->lock);
	82
	83	if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
	84	ERR("Cannot attach viewer metadata stream to trace (busy).");
	85	goto error_unlock;
	86	}
	87
	88	switch (seek_t) {
	89	case LTTNG_VIEWER_SEEK_BEGINNING:
	90	{
	91	uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	92
	93	if (seq_tail == -1ULL) {
	94	/*
	95	* Tail may not be initialized yet. Nonetheless, we know
	96	* we want to send the first index once it becomes
	97	* available.
	98	*/
	99	seq_tail = 0;
	100	}
	101	vstream->current_tracefile_id =
	102	tracefile_array_get_file_index_tail(stream->tfa);
	103	vstream->index_sent_seqcount = seq_tail;
	104	break;
	105	}
	106	case LTTNG_VIEWER_SEEK_LAST:
	107	vstream->current_tracefile_id =
	108	tracefile_array_get_read_file_index_head(stream->tfa);
	109	/*
	110	* We seek at the very end of each stream, awaiting for
	111	* a future packet to eventually come in.
	112	*
	113	* We don't need to check the head position for -1ULL since the
	114	* increment will set it to 0.
	115	*/
	116	vstream->index_sent_seqcount =
	117	tracefile_array_get_seq_head(stream->tfa) + 1;
	118	break;
	119	default:
	120	goto error_unlock;
	121	}
	122
	123	/*
	124	* If we never received an index for the current stream, delay
	125	* the opening of the index, otherwise open it right now.
	126	*/
	127	if (stream->index_received_seqcount == 0) {
	128	vstream->index_file = NULL;
	129	} else {
	130	const uint32_t connection_major = stream->trace->session->major;
	131	const uint32_t connection_minor = stream->trace->session->minor;
	132
	133	vstream->index_file = lttng_index_file_create_from_trace_chunk_read_only(
	134	vstream->stream_file.trace_chunk,
	135	stream->path_name,
	136	stream->channel_name, stream->tracefile_size,
	137	vstream->current_tracefile_id,
	138	lttng_to_index_major(connection_major,
	139	connection_minor),
	140	lttng_to_index_minor(connection_major,
	141	connection_minor));
	142	if (!vstream->index_file) {
	143	goto error_unlock;
	144	}
	145	}
	146
	147	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
	148	off_t lseek_ret;
	149
	150	lseek_ret = lseek(vstream->index_file->fd, 0, SEEK_END);
	151	if (lseek_ret < 0) {
	152	goto error_unlock;
	153	}
	154	}
	155	if (stream->is_metadata) {
	156	rcu_assign_pointer(stream->trace->viewer_metadata_stream,
	157	vstream);
	158	}
	159	pthread_mutex_unlock(&stream->lock);
	160
	161	/* Globally visible after the add unique. */
	162	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
	163	urcu_ref_init(&vstream->ref);
	164	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
	165
	166	return vstream;
	167
	168	error_unlock:
	169	pthread_mutex_unlock(&stream->lock);
	170	error:
	171	if (vstream) {
	172	viewer_stream_destroy(vstream);
	173	}
	174	if (viewer_trace_chunk && acquired_reference) {
	175	lttng_trace_chunk_put(viewer_trace_chunk);
	176	}
	177	return NULL;
	178	}
	179
	180	static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
	181	{
	182	int ret;
	183	struct lttng_ht_iter iter;
	184
	185	iter.iter.node = &vstream->stream_n.node;
	186	ret = lttng_ht_del(viewer_streams_ht, &iter);
	187	assert(!ret);
	188	}
	189
	190	static void viewer_stream_release(struct urcu_ref *ref)
	191	{
	192	struct relay_viewer_stream *vstream = caa_container_of(ref,
	193	struct relay_viewer_stream, ref);
	194
	195	if (vstream->stream->is_metadata) {
	196	rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
	197	}
	198
	199	viewer_stream_unpublish(vstream);
	200
	201	if (vstream->stream_file.fd) {
	202	stream_fd_put(vstream->stream_file.fd);
	203	vstream->stream_file.fd = NULL;
	204	}
	205	if (vstream->index_file) {
	206	lttng_index_file_put(vstream->index_file);
	207	vstream->index_file = NULL;
	208	}
	209	if (vstream->stream) {
	210	stream_put(vstream->stream);
	211	vstream->stream = NULL;
	212	}
	213	lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
	214	vstream->stream_file.trace_chunk = NULL;
	215	call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
	216	}
	217
	218	/* Must be called with RCU read-side lock held. */
	219	bool viewer_stream_get(struct relay_viewer_stream *vstream)
	220	{
	221	return urcu_ref_get_unless_zero(&vstream->ref);
	222	}
	223
	224	/*
	225	* Get viewer stream by id.
	226	*
	227	* Return viewer stream if found else NULL.
	228	*/
	229	struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
	230	{
	231	struct lttng_ht_node_u64 *node;
	232	struct lttng_ht_iter iter;
	233	struct relay_viewer_stream *vstream = NULL;
	234
	235	rcu_read_lock();
	236	lttng_ht_lookup(viewer_streams_ht, &id, &iter);
	237	node = lttng_ht_iter_get_node_u64(&iter);
	238	if (!node) {
	239	DBG("Relay viewer stream %" PRIu64 " not found", id);
	240	goto end;
	241	}
	242	vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
	243	if (!viewer_stream_get(vstream)) {
	244	vstream = NULL;
	245	}
	246	end:
	247	rcu_read_unlock();
	248	return vstream;
	249	}
	250
	251	void viewer_stream_put(struct relay_viewer_stream *vstream)
	252	{
	253	rcu_read_lock();
	254	urcu_ref_put(&vstream->ref, viewer_stream_release);
	255	rcu_read_unlock();
	256	}
	257
	258	/*
	259	* Rotate a stream to the next tracefile.
	260	*
	261	* Must be called with the rstream lock held.
	262	* Returns 0 on success, 1 on EOF, a negative value on error.
	263	*/
	264	int viewer_stream_rotate(struct relay_viewer_stream *vstream)
	265	{
	266	int ret;
	267	uint64_t new_id;
	268	const struct relay_stream *stream = vstream->stream;
	269	const uint32_t connection_major = stream->trace->session->major;
	270	const uint32_t connection_minor = stream->trace->session->minor;
	271
	272	/* Detect the last tracefile to open. */
	273	if (stream->index_received_seqcount
	274	== vstream->index_sent_seqcount
	275	&& stream->trace->session->connection_closed) {
	276	ret = 1;
	277	goto end;
	278	}
	279
	280	if (stream->tracefile_count == 0) {
	281	/* Ignore rotation, there is none to do. */
	282	ret = 0;
	283	goto end;
	284	}
	285
	286	/*
	287	* Try to move to the next file.
	288	*/
	289	new_id = (vstream->current_tracefile_id + 1)
	290	% stream->tracefile_count;
	291	if (tracefile_array_seq_in_file(stream->tfa, new_id,
	292	vstream->index_sent_seqcount)) {
	293	vstream->current_tracefile_id = new_id;
	294	} else {
	295	uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	296
	297	/*
	298	* This can only be reached on overwrite, which implies there
	299	* has been data written at some point, which will have set the
	300	* tail.
	301	*/
	302	assert(seq_tail != -1ULL);
	303	/*
	304	* We need to resync because we lag behind tail.
	305	*/
	306	vstream->current_tracefile_id =
	307	tracefile_array_get_file_index_tail(stream->tfa);
	308	vstream->index_sent_seqcount = seq_tail;
	309	}
	310
	311	if (vstream->index_file) {
	312	lttng_index_file_put(vstream->index_file);
	313	vstream->index_file = NULL;
	314	}
	315	if (vstream->stream_file.fd) {
	316	stream_fd_put(vstream->stream_file.fd);
	317	vstream->stream_file.fd = NULL;
	318	}
	319	vstream->index_file =
	320	lttng_index_file_create_from_trace_chunk_read_only(
	321	vstream->stream_file.trace_chunk,
	322	stream->path_name,
	323	stream->channel_name,
	324	stream->tracefile_size,
	325	vstream->current_tracefile_id,
	326	lttng_to_index_major(connection_major,
	327	connection_minor),
	328	lttng_to_index_minor(connection_major,
	329	connection_minor));
	330	if (!vstream->index_file) {
	331	ret = -1;
	332	goto end;
	333	} else {
	334	ret = 0;
	335	}
	336	end:
	337	return ret;
	338	}
	339
	340	void print_viewer_streams(void)
	341	{
	342	struct lttng_ht_iter iter;
	343	struct relay_viewer_stream *vstream;
	344
	345	if (!viewer_streams_ht) {
	346	return;
	347	}
	348
	349	rcu_read_lock();
	350	cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
	351	stream_n.node) {
	352	if (!viewer_stream_get(vstream)) {
	353	continue;
	354	}
	355	DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
	356	" session %" PRIu64,
	357	vstream,
	358	vstream->ref.refcount,
	359	vstream->stream->stream_handle,
	360	vstream->stream->trace->id,
	361	vstream->stream->trace->session->id);
	362	viewer_stream_put(vstream);
	363	}
	364	rcu_read_unlock();
	365	}