[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 _GNU_SOURCE
#define _LGPL_SOURCE
#include <common/common.h>
#include <common/index/index.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,
		enum lttng_viewer_seek seek_t)
{
	struct relay_viewer_stream *vstream;

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

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

	switch (seek_t) {
	case LTTNG_VIEWER_SEEK_BEGINNING:
		vstream->current_tracefile_id = stream->oldest_tracefile_id;
		break;
	case LTTNG_VIEWER_SEEK_LAST:
		vstream->current_tracefile_id = stream->current_tracefile_id;
		break;
	default:
		goto error;
	}
	if (!stream_get(stream)) {
		ERR("Cannot get stream");
		goto error;
	}
	vstream->stream = stream;

	pthread_mutex_lock(&stream->lock);
	/*
	 * If we never received an index for the current stream, delay the opening
	 * of the index, otherwise open it right now.
	 */
	if (vstream->current_tracefile_id == stream->current_tracefile_id
			&& stream->total_index_received == 0) {
		vstream->index_fd = NULL;
	} else {
		int read_fd;

		read_fd = index_open(vstream->path_name, vstream->channel_name,
				stream->tracefile_count,
				vstream->current_tracefile_id);
		if (read_fd < 0) {
			goto error_unlock;
		}
		vstream->index_fd = stream_fd_create(read_fd);
		if (!vstream->index_fd) {
			if (close(read_fd)) {
				PERROR("close");
			}
			goto error_unlock;
		}
	}

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

		lseek_ret = lseek(vstream->index_fd->fd, 0, SEEK_END);
		if (lseek_ret < 0) {
			goto error_unlock;
		}
		vstream->last_sent_index = stream->total_index_received;
	}
	pthread_mutex_unlock(&stream->lock);

	if (stream->is_metadata) {
		rcu_assign_pointer(stream->trace->viewer_metadata_stream,
				vstream);
	}

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

	pthread_mutex_init(&vstream->reflock, NULL);
	urcu_ref_init(&vstream->ref);

	return vstream;

error_unlock:
	pthread_mutex_unlock(&stream->lock);
error:
	if (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);
	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_fd) {
		stream_fd_put(vstream->stream_fd);
		vstream->stream_fd = NULL;
	}
	if (vstream->index_fd) {
		stream_fd_put(vstream->index_fd);
		vstream->index_fd = NULL;
	}
	if (vstream->stream) {
		stream_put(vstream->stream);
		vstream->stream = 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)
{
	bool has_ref = false;

	pthread_mutex_lock(&vstream->reflock);
	if (vstream->ref.refcount != 0) {
		has_ref = true;
		urcu_ref_get(&vstream->ref);
	}
	pthread_mutex_unlock(&vstream->reflock);

	return has_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();
	pthread_mutex_lock(&vstream->reflock);
	urcu_ref_put(&vstream->ref, viewer_stream_release);
	pthread_mutex_unlock(&vstream->reflock);
	rcu_read_unlock();
}

/*
 * Returns whether the current tracefile is readable. If not, it has
 * been overwritten.
 * Must be called with rstream lock held.
 */
bool viewer_stream_is_tracefile_seq_readable(struct relay_viewer_stream *vstream,
		 uint64_t seq)
{
	struct relay_stream *stream = vstream->stream;

	if (seq >= stream->oldest_tracefile_seq
			&& seq <= stream->current_tracefile_seq) {
		/* seq is a readable file. */
		return true;
	} else {
		/* seq is not readable. */
		return false;
	}
}

/*
 * 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;
	struct relay_stream *stream = vstream->stream;

	/* Detect the last tracefile to open. */
	if (stream->total_index_received == vstream->last_sent_index
			&& 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;
	}

	if (!viewer_stream_is_tracefile_seq_readable(vstream,
			vstream->current_tracefile_seq + 1)) {
		vstream->current_tracefile_id =
				stream->oldest_tracefile_id;
		vstream->current_tracefile_seq =
				stream->oldest_tracefile_seq;
	} else {
		vstream->current_tracefile_id =
				(vstream->current_tracefile_id + 1)
					% stream->tracefile_count;
		vstream->current_tracefile_seq++;
	}

	if (vstream->index_fd) {
		stream_fd_put(vstream->index_fd);
		vstream->index_fd = NULL;
	}
	if (vstream->stream_fd) {
		stream_fd_put(vstream->stream_fd);
		vstream->stream_fd = NULL;
	}

	ret = index_open(vstream->path_name, vstream->channel_name,
			stream->tracefile_count,
			vstream->current_tracefile_id);
	if (ret < 0) {
		goto end;
	}
	vstream->index_fd = stream_fd_create(ret);
	if (vstream->index_fd) {
		ret = 0;
	} else {
		if (close(ret)) {
			PERROR("close");
		}
		ret = -1;
	}
end:
	return ret;
}

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

	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 DG	1	/*
	2	* Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
	3	* David Goulet <dgoulet@efficios.com>
7591bab1	4	* 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2f8f53af DG	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 _GNU_SOURCE
6c1c0768	21	#define _LGPL_SOURCE
2f8f53af DG	22	#include <common/common.h>
	23	#include <common/index/index.h>
	24
	25	#include "lttng-relayd.h"
	26	#include "viewer-stream.h"
	27
7591bab1	28	static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
2f8f53af	29	{
7591bab1 MD	30	free(vstream->path_name);
	31	free(vstream->channel_name);
	32	free(vstream);
2f8f53af DG	33	}
2f8f53af DG	34
7591bab1	35	static void viewer_stream_destroy_rcu(struct rcu_head *head)
2f8f53af	36	{
7591bab1	37	struct relay_viewer_stream *vstream =
2f8f53af DG	38	caa_container_of(head, struct relay_viewer_stream, rcu_node);
2f8f53af DG	39
7591bab1	40	viewer_stream_destroy(vstream);
2f8f53af DG	41	}
	42
	43	struct relay_viewer_stream viewer_stream_create(struct relay_stream stream,
7591bab1	44	enum lttng_viewer_seek seek_t)
2f8f53af DG	45	{
	46	struct relay_viewer_stream *vstream;
	47
2f8f53af DG	48	vstream = zmalloc(sizeof(*vstream));
	49	if (!vstream) {
	50	PERROR("relay viewer stream zmalloc");
	51	goto error;
	52	}
	53
2f8f53af	54	vstream->path_name = strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
b272577e MD	55	if (vstream->path_name == NULL) {
	56	PERROR("relay viewer path_name alloc");
	57	goto error;
	58	}
2f8f53af DG	59	vstream->channel_name = strndup(stream->channel_name,
2f8f53af DG	60	LTTNG_VIEWER_NAME_MAX);
b272577e MD	61	if (vstream->channel_name == NULL) {
	62	PERROR("relay viewer channel_name alloc");
	63	goto error;
	64	}
2f8f53af DG	65
2f8f53af DG	66	switch (seek_t) {
c4e361a4	67	case LTTNG_VIEWER_SEEK_BEGINNING:
7591bab1	68	vstream->current_tracefile_id = stream->oldest_tracefile_id;
2f8f53af	69	break;
c4e361a4	70	case LTTNG_VIEWER_SEEK_LAST:
7591bab1	71	vstream->current_tracefile_id = stream->current_tracefile_id;
2f8f53af DG	72	break;
2f8f53af DG	73	default:
2f8f53af DG	74	goto error;
2f8f53af DG	75	}
7591bab1 MD	76	if (!stream_get(stream)) {
	77	ERR("Cannot get stream");
	78	goto error;
2f8f53af	79	}
7591bab1	80	vstream->stream = stream;
2f8f53af	81
7591bab1	82	pthread_mutex_lock(&stream->lock);
2f8f53af DG	83	/*
	84	* If we never received an index for the current stream, delay the opening
	85	* of the index, otherwise open it right now.
	86	*/
7591bab1 MD	87	if (vstream->current_tracefile_id == stream->current_tracefile_id
	88	&& stream->total_index_received == 0) {
	89	vstream->index_fd = NULL;
2f8f53af DG	90	} else {
	91	int read_fd;
	92
	93	read_fd = index_open(vstream->path_name, vstream->channel_name,
7591bab1 MD	94	stream->tracefile_count,
7591bab1 MD	95	vstream->current_tracefile_id);
2f8f53af	96	if (read_fd < 0) {
7591bab1 MD	97	goto error_unlock;
	98	}
	99	vstream->index_fd = stream_fd_create(read_fd);
	100	if (!vstream->index_fd) {
	101	if (close(read_fd)) {
	102	PERROR("close");
	103	}
	104	goto error_unlock;
2f8f53af	105	}
2f8f53af DG	106	}
2f8f53af DG	107
7591bab1	108	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_fd) {
2f8f53af DG	109	off_t lseek_ret;
2f8f53af DG	110
7591bab1	111	lseek_ret = lseek(vstream->index_fd->fd, 0, SEEK_END);
2f8f53af	112	if (lseek_ret < 0) {
7591bab1	113	goto error_unlock;
2f8f53af	114	}
7591bab1 MD	115	vstream->last_sent_index = stream->total_index_received;
	116	}
	117	pthread_mutex_unlock(&stream->lock);
	118
	119	if (stream->is_metadata) {
	120	rcu_assign_pointer(stream->trace->viewer_metadata_stream,
	121	vstream);
2f8f53af DG	122	}
2f8f53af DG	123
7591bab1 MD	124	/* Globally visible after the add unique. */
	125	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
	126	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
	127
	128	pthread_mutex_init(&vstream->reflock, NULL);
	129	urcu_ref_init(&vstream->ref);
	130
2f8f53af DG	131	return vstream;
2f8f53af DG	132
7591bab1 MD	133	error_unlock:
7591bab1 MD	134	pthread_mutex_unlock(&stream->lock);
2f8f53af DG	135	error:
2f8f53af DG	136	if (vstream) {
7591bab1	137	viewer_stream_destroy(vstream);
2f8f53af DG	138	}
	139	return NULL;
	140	}
	141
7591bab1	142	static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
2f8f53af DG	143	{
	144	int ret;
	145	struct lttng_ht_iter iter;
	146
7591bab1	147	iter.iter.node = &vstream->stream_n.node;
2f8f53af DG	148	ret = lttng_ht_del(viewer_streams_ht, &iter);
	149	assert(!ret);
	150	}
	151
7591bab1	152	static void viewer_stream_release(struct urcu_ref *ref)
2f8f53af	153	{
7591bab1 MD	154	struct relay_viewer_stream *vstream = caa_container_of(ref,
7591bab1 MD	155	struct relay_viewer_stream, ref);
2a174661	156
7591bab1 MD	157	if (vstream->stream->is_metadata) {
7591bab1 MD	158	rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
2a174661	159	}
2f8f53af	160
7591bab1 MD	161	viewer_stream_unpublish(vstream);
	162
	163	if (vstream->stream_fd) {
	164	stream_fd_put(vstream->stream_fd);
	165	vstream->stream_fd = NULL;
2f8f53af	166	}
7591bab1 MD	167	if (vstream->index_fd) {
	168	stream_fd_put(vstream->index_fd);
	169	vstream->index_fd = NULL;
	170	}
	171	if (vstream->stream) {
	172	stream_put(vstream->stream);
	173	vstream->stream = NULL;
	174	}
	175	call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
	176	}
	177
	178	/* Must be called with RCU read-side lock held. */
	179	bool viewer_stream_get(struct relay_viewer_stream *vstream)
	180	{
	181	bool has_ref = false;
	182
	183	pthread_mutex_lock(&vstream->reflock);
	184	if (vstream->ref.refcount != 0) {
	185	has_ref = true;
	186	urcu_ref_get(&vstream->ref);
2f8f53af	187	}
7591bab1	188	pthread_mutex_unlock(&vstream->reflock);
2f8f53af	189
7591bab1	190	return has_ref;
2f8f53af DG	191	}
	192
	193	/*
7591bab1	194	* Get viewer stream by id.
2f8f53af	195	*
7591bab1	196	* Return viewer stream if found else NULL.
2f8f53af	197	*/
7591bab1	198	struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
2f8f53af DG	199	{
	200	struct lttng_ht_node_u64 *node;
	201	struct lttng_ht_iter iter;
7591bab1	202	struct relay_viewer_stream *vstream = NULL;
2f8f53af	203
7591bab1	204	rcu_read_lock();
2f8f53af DG	205	lttng_ht_lookup(viewer_streams_ht, &id, &iter);
	206	node = lttng_ht_iter_get_node_u64(&iter);
	207	if (!node) {
	208	DBG("Relay viewer stream %" PRIu64 " not found", id);
	209	goto end;
	210	}
7591bab1 MD	211	vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
	212	if (!viewer_stream_get(vstream)) {
	213	vstream = NULL;
	214	}
2f8f53af	215	end:
7591bab1 MD	216	rcu_read_unlock();
	217	return vstream;
	218	}
	219
	220	void viewer_stream_put(struct relay_viewer_stream *vstream)
	221	{
	222	rcu_read_lock();
	223	pthread_mutex_lock(&vstream->reflock);
	224	urcu_ref_put(&vstream->ref, viewer_stream_release);
	225	pthread_mutex_unlock(&vstream->reflock);
	226	rcu_read_unlock();
	227	}
	228
	229	/*
	230	* Returns whether the current tracefile is readable. If not, it has
	231	* been overwritten.
	232	* Must be called with rstream lock held.
	233	*/
	234	bool viewer_stream_is_tracefile_seq_readable(struct relay_viewer_stream *vstream,
	235	uint64_t seq)
	236	{
	237	struct relay_stream *stream = vstream->stream;
	238
	239	if (seq >= stream->oldest_tracefile_seq
	240	&& seq <= stream->current_tracefile_seq) {
	241	/* seq is a readable file. */
	242	return true;
	243	} else {
	244	/* seq is not readable. */
	245	return false;
	246	}
2f8f53af DG	247	}
	248
	249	/*
	250	* Rotate a stream to the next tracefile.
	251	*
7591bab1	252	* Must be called with the rstream lock held.
2f8f53af DG	253	* Returns 0 on success, 1 on EOF, a negative value on error.
2f8f53af DG	254	*/
7591bab1	255	int viewer_stream_rotate(struct relay_viewer_stream *vstream)
2f8f53af DG	256	{
2f8f53af DG	257	int ret;
7591bab1	258	struct relay_stream *stream = vstream->stream;
2f8f53af	259
7591bab1 MD	260	/* Detect the last tracefile to open. */
	261	if (stream->total_index_received == vstream->last_sent_index
	262	&& stream->trace->session->connection_closed) {
	263	ret = 1;
2a174661 DG	264	goto end;
2a174661 DG	265	}
2f8f53af	266
7591bab1 MD	267	if (stream->tracefile_count == 0) {
	268	/* Ignore rotation, there is none to do. */
	269	ret = 0;
2f8f53af DG	270	goto end;
	271	}
	272
7591bab1 MD	273	if (!viewer_stream_is_tracefile_seq_readable(vstream,
	274	vstream->current_tracefile_seq + 1)) {
	275	vstream->current_tracefile_id =
	276	stream->oldest_tracefile_id;
	277	vstream->current_tracefile_seq =
	278	stream->oldest_tracefile_seq;
2f8f53af	279	} else {
7591bab1 MD	280	vstream->current_tracefile_id =
	281	(vstream->current_tracefile_id + 1)
	282	% stream->tracefile_count;
	283	vstream->current_tracefile_seq++;
2f8f53af	284	}
2f8f53af	285
7591bab1 MD	286	if (vstream->index_fd) {
	287	stream_fd_put(vstream->index_fd);
	288	vstream->index_fd = NULL;
2f8f53af	289	}
7591bab1 MD	290	if (vstream->stream_fd) {
	291	stream_fd_put(vstream->stream_fd);
	292	vstream->stream_fd = NULL;
2f8f53af	293	}
2f8f53af	294
2f8f53af	295	ret = index_open(vstream->path_name, vstream->channel_name,
7591bab1 MD	296	stream->tracefile_count,
7591bab1 MD	297	vstream->current_tracefile_id);
2f8f53af	298	if (ret < 0) {
7591bab1 MD	299	goto end;
	300	}
	301	vstream->index_fd = stream_fd_create(ret);
	302	if (vstream->index_fd) {
	303	ret = 0;
	304	} else {
	305	if (close(ret)) {
	306	PERROR("close");
	307	}
	308	ret = -1;
2f8f53af	309	}
2f8f53af	310	end:
2f8f53af DG	311	return ret;
2f8f53af DG	312	}
7591bab1 MD	313
	314	void print_viewer_streams(void)
	315	{
	316	struct lttng_ht_iter iter;
	317	struct relay_viewer_stream *vstream;
	318
	319	rcu_read_lock();
	320	cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
	321	stream_n.node) {
	322	if (!viewer_stream_get(vstream)) {
	323	continue;
	324	}
	325	DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
	326	" session %" PRIu64,
	327	vstream,
	328	vstream->ref.refcount,
	329	vstream->stream->stream_handle,
	330	vstream->stream->trace->id,
	331	vstream->stream->trace->session->id);
	332	viewer_stream_put(vstream);
	333	}
	334	rcu_read_unlock();
	335	}