[lttng-tools.git] / src / common / consumer-metadata-cache.c

/*
 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
 *                      David Goulet <dgoulet@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
#include <assert.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <inttypes.h>

#include <common/common.h>
#include <common/utils.h>
#include <common/sessiond-comm/sessiond-comm.h>
#include <common/ust-consumer/ust-consumer.h>
#include <common/consumer.h>

#include "consumer-metadata-cache.h"

extern struct lttng_consumer_global_data consumer_data;

/*
 * Extend the allocated size of the metadata cache. Called only from
 * lttng_ustconsumer_write_metadata_cache.
 *
 * Return 0 on success, a negative value on error.
 */
static int extend_metadata_cache(struct lttng_consumer_channel *channel,
		unsigned int size)
{
	int ret = 0;
	char *tmp_data_ptr;
	unsigned int new_size;

	assert(channel);
	assert(channel->metadata_cache);

	new_size = max_t(unsigned int,
			channel->metadata_cache->cache_alloc_size + size,
			channel->metadata_cache->cache_alloc_size << 1);
	DBG("Extending metadata cache to %u", new_size);
	tmp_data_ptr = realloc(channel->metadata_cache->data, new_size);
	if (!tmp_data_ptr) {
		ERR("Reallocating metadata cache");
		free(channel->metadata_cache->data);
		ret = -1;
		goto end;
	}
	channel->metadata_cache->data = tmp_data_ptr;
	channel->metadata_cache->cache_alloc_size = new_size;

end:
	return ret;
}

/*
 * Write metadata to the cache, extend the cache if necessary. We support
 * non-contiguous updates but not overlapping ones. If there is contiguous
 * metadata in the cache, we send it to the ring buffer. The metadata cache
 * lock MUST be acquired to write in the cache.
 *
 * Return 0 on success, a negative value on error.
 */
int consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
		unsigned int offset, unsigned int len, char *data)
{
	int ret = 0;
	struct consumer_metadata_cache *cache;

	assert(channel);
	assert(channel->metadata_cache);

	cache = channel->metadata_cache;
	DBG("Writing %u bytes from offset %u in metadata cache", len, offset);

	if (offset + len > cache->cache_alloc_size) {
		ret = extend_metadata_cache(channel,
				len - cache->cache_alloc_size + offset);
		if (ret < 0) {
			ERR("Extending metadata cache");
			goto end;
		}
	}

	memcpy(cache->data + offset, data, len);
	cache->total_bytes_written += len;
	if (offset + len > cache->max_offset) {
		cache->max_offset = offset + len;
	}

	if (cache->max_offset == cache->total_bytes_written) {
		char dummy = 'c';

		cache->contiguous = cache->max_offset;
		if (channel->monitor) {
			ret = write(channel->metadata_stream->ust_metadata_poll_pipe[1],
					&dummy, 1);
			if (ret < 1) {
				ERR("Wakeup UST metadata pipe");
				goto end;
			}
		}
	}

end:
	return ret;
}

/*
 * Create the metadata cache, original allocated size: max_sb_size
 *
 * Return 0 on success, a negative value on error.
 */
int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel)
{
	int ret;

	assert(channel);

	channel->metadata_cache = zmalloc(
			sizeof(struct consumer_metadata_cache));
	if (!channel->metadata_cache) {
		PERROR("zmalloc metadata cache struct");
		ret = -1;
		goto end;
	}
	ret = pthread_mutex_init(&channel->metadata_cache->lock, NULL);
	if (ret != 0) {
		PERROR("mutex init");
		goto end_free_cache;
	}

	channel->metadata_cache->cache_alloc_size = DEFAULT_METADATA_CACHE_SIZE;
	channel->metadata_cache->data = zmalloc(
			channel->metadata_cache->cache_alloc_size * sizeof(char));
	if (!channel->metadata_cache->data) {
		PERROR("zmalloc metadata cache data");
		ret = -1;
		goto end_free_mutex;
	}
	DBG("Allocated metadata cache of %" PRIu64 " bytes",
			channel->metadata_cache->cache_alloc_size);

	ret = 0;
	goto end;

end_free_mutex:
	pthread_mutex_destroy(&channel->metadata_cache->lock);
end_free_cache:
	free(channel->metadata_cache);
end:
	return ret;
}

/*
 * Destroy and free the metadata cache
 */
void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel)
{
	if (!channel || !channel->metadata_cache) {
		return;
	}

	DBG("Destroying metadata cache");

	pthread_mutex_destroy(&channel->metadata_cache->lock);
	free(channel->metadata_cache->data);
	free(channel->metadata_cache);
}

/*
 * Check if the cache is flushed up to the offset passed in parameter.
 *
 * Return 0 if everything has been flushed, 1 if there is data not flushed.
 */
int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
		uint64_t offset, int timer)
{
	int ret = 0;
	struct lttng_consumer_stream *metadata_stream;

	assert(channel);
	assert(channel->metadata_cache);

	/*
	 * If not called from a timer handler, we have to take the
	 * channel lock to be mutually exclusive with channel teardown.
	 * Timer handler does not need to take this lock because it is
	 * already synchronized by timer stop (and, more importantly,
	 * taking this lock in a timer handler would cause a deadlock).
	 */
	if (!timer) {
		pthread_mutex_lock(&channel->lock);
	}
	pthread_mutex_lock(&channel->timer_lock);
	pthread_mutex_lock(&channel->metadata_cache->lock);

	metadata_stream = channel->metadata_stream;

	if (!metadata_stream) {
		/*
		 * Having no metadata stream means the channel is being destroyed so there
		 * is no cache to flush anymore.
		 */
		ret = 0;
	} else if (metadata_stream->ust_metadata_pushed >= offset) {
		ret = 0;
	} else if (channel->metadata_stream->endpoint_status !=
			CONSUMER_ENDPOINT_ACTIVE) {
		/* An inactive endpoint means we don't have to flush anymore. */
		ret = 0;
	} else {
		/* Still not completely flushed. */
		ret = 1;
	}

	pthread_mutex_unlock(&channel->metadata_cache->lock);
	pthread_mutex_unlock(&channel->timer_lock);
	if (!timer) {
		pthread_mutex_unlock(&channel->lock);
	}

	return ret;
}
Commit	Line	Data
331744e3 JD	1	/*
	2	* Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
	3	* David Goulet <dgoulet@efficios.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License, version 2 only,
	7	* as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along
	15	* with this program; if not, write to the Free Software Foundation, Inc.,
	16	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	17	*/
	18
	19	#define _GNU_SOURCE
	20	#include <assert.h>
	21	#include <pthread.h>
	22	#include <stdlib.h>
	23	#include <string.h>
	24	#include <sys/types.h>
	25	#include <unistd.h>
	26	#include <inttypes.h>
	27
	28	#include <common/common.h>
	29	#include <common/utils.h>
	30	#include <common/sessiond-comm/sessiond-comm.h>
	31	#include <common/ust-consumer/ust-consumer.h>
	32	#include <common/consumer.h>
	33
	34	#include "consumer-metadata-cache.h"
	35
fe81e5c9 DG	36	extern struct lttng_consumer_global_data consumer_data;
fe81e5c9 DG	37
331744e3 JD	38	/*
	39	* Extend the allocated size of the metadata cache. Called only from
	40	* lttng_ustconsumer_write_metadata_cache.
	41	*
	42	* Return 0 on success, a negative value on error.
	43	*/
	44	static int extend_metadata_cache(struct lttng_consumer_channel *channel,
	45	unsigned int size)
	46	{
	47	int ret = 0;
	48	char *tmp_data_ptr;
	49	unsigned int new_size;
	50
	51	assert(channel);
	52	assert(channel->metadata_cache);
	53
	54	new_size = max_t(unsigned int,
	55	channel->metadata_cache->cache_alloc_size + size,
	56	channel->metadata_cache->cache_alloc_size << 1);
	57	DBG("Extending metadata cache to %u", new_size);
	58	tmp_data_ptr = realloc(channel->metadata_cache->data, new_size);
	59	if (!tmp_data_ptr) {
	60	ERR("Reallocating metadata cache");
	61	free(channel->metadata_cache->data);
	62	ret = -1;
	63	goto end;
	64	}
	65	channel->metadata_cache->data = tmp_data_ptr;
	66	channel->metadata_cache->cache_alloc_size = new_size;
	67
	68	end:
	69	return ret;
	70	}
	71
	72	/*
	73	* Write metadata to the cache, extend the cache if necessary. We support
	74	* non-contiguous updates but not overlapping ones. If there is contiguous
	75	* metadata in the cache, we send it to the ring buffer. The metadata cache
	76	* lock MUST be acquired to write in the cache.
	77	*
	78	* Return 0 on success, a negative value on error.
	79	*/
	80	int consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
	81	unsigned int offset, unsigned int len, char *data)
	82	{
	83	int ret = 0;
	84	struct consumer_metadata_cache *cache;
	85
	86	assert(channel);
	87	assert(channel->metadata_cache);
	88
	89	cache = channel->metadata_cache;
	90	DBG("Writing %u bytes from offset %u in metadata cache", len, offset);
	91
	92	if (offset + len > cache->cache_alloc_size) {
	93	ret = extend_metadata_cache(channel,
	94	len - cache->cache_alloc_size + offset);
	95	if (ret < 0) {
	96	ERR("Extending metadata cache");
	97	goto end;
	98	}
	99	}
	100
	101	memcpy(cache->data + offset, data, len);
102	cache->total_bytes_written += len;
103	if (offset + len > cache->max_offset) {
104	cache->max_offset = offset + len;
105	}
106
107	if (cache->max_offset == cache->total_bytes_written) {
04ef1097 MD	108	char dummy = 'c';
	109
	110	cache->contiguous = cache->max_offset;
	111	if (channel->monitor) {
	112	ret = write(channel->metadata_stream->ust_metadata_poll_pipe[1],
	113	&dummy, 1);
	114	if (ret < 1) {
	115	ERR("Wakeup UST metadata pipe");
	116	goto end;
	117	}
331744e3	118	}
331744e3 JD	119	}
	120
	121	end:
	122	return ret;
	123	}
	124
	125	/*
	126	* Create the metadata cache, original allocated size: max_sb_size
	127	*
	128	* Return 0 on success, a negative value on error.
	129	*/
	130	int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel)
	131	{
	132	int ret;
	133
	134	assert(channel);
	135
	136	channel->metadata_cache = zmalloc(
	137	sizeof(struct consumer_metadata_cache));
	138	if (!channel->metadata_cache) {
	139	PERROR("zmalloc metadata cache struct");
	140	ret = -1;
	141	goto end;
	142	}
	143	ret = pthread_mutex_init(&channel->metadata_cache->lock, NULL);
	144	if (ret != 0) {
	145	PERROR("mutex init");
	146	goto end_free_cache;
	147	}
	148
	149	channel->metadata_cache->cache_alloc_size = DEFAULT_METADATA_CACHE_SIZE;
	150	channel->metadata_cache->data = zmalloc(
	151	channel->metadata_cache->cache_alloc_size * sizeof(char));
	152	if (!channel->metadata_cache->data) {
	153	PERROR("zmalloc metadata cache data");
	154	ret = -1;
	155	goto end_free_mutex;
	156	}
	157	DBG("Allocated metadata cache of %" PRIu64 " bytes",
	158	channel->metadata_cache->cache_alloc_size);
	159
	160	ret = 0;
	161	goto end;
	162
	163	end_free_mutex:
	164	pthread_mutex_destroy(&channel->metadata_cache->lock);
	165	end_free_cache:
	166	free(channel->metadata_cache);
	167	end:
	168	return ret;
	169	}
	170
	171	/*
	172	* Destroy and free the metadata cache
	173	*/
	174	void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel)
	175	{
	176	if (!channel \|\| !channel->metadata_cache) {
	177	return;
	178	}
	179
	180	DBG("Destroying metadata cache");
	181
331744e3 JD	182	pthread_mutex_destroy(&channel->metadata_cache->lock);
	183	free(channel->metadata_cache->data);
	184	free(channel->metadata_cache);
	185	}
	186
	187	/*
	188	* Check if the cache is flushed up to the offset passed in parameter.
	189	*
	190	* Return 0 if everything has been flushed, 1 if there is data not flushed.
	191	*/
	192	int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
5e41ebe1	193	uint64_t offset, int timer)
331744e3	194	{
04ef1097 MD	195	int ret = 0;
04ef1097 MD	196	struct lttng_consumer_stream *metadata_stream;
331744e3 JD	197
	198	assert(channel);
	199	assert(channel->metadata_cache);
	200
7f725ec5	201	/*
5e41ebe1 MD	202	* If not called from a timer handler, we have to take the
	203	* channel lock to be mutually exclusive with channel teardown.
	204	* Timer handler does not need to take this lock because it is
	205	* already synchronized by timer stop (and, more importantly,
	206	* taking this lock in a timer handler would cause a deadlock).
7f725ec5	207	*/
5e41ebe1 MD	208	if (!timer) {
	209	pthread_mutex_lock(&channel->lock);
	210	}
ec6ea7d0	211	pthread_mutex_lock(&channel->timer_lock);
331744e3	212	pthread_mutex_lock(&channel->metadata_cache->lock);
fe81e5c9	213
04ef1097 MD	214	metadata_stream = channel->metadata_stream;
	215
	216	if (!metadata_stream) {
fe81e5c9 DG	217	/*
	218	* Having no metadata stream means the channel is being destroyed so there
	219	* is no cache to flush anymore.
	220	*/
	221	ret = 0;
04ef1097 MD	222	} else if (metadata_stream->ust_metadata_pushed >= offset) {
04ef1097 MD	223	ret = 0;
fe81e5c9 DG	224	} else if (channel->metadata_stream->endpoint_status !=
	225	CONSUMER_ENDPOINT_ACTIVE) {
	226	/* An inactive endpoint means we don't have to flush anymore. */
	227	ret = 0;
331744e3	228	} else {
fe81e5c9	229	/* Still not completely flushed. */
331744e3 JD	230	ret = 1;
331744e3 JD	231	}
fe81e5c9	232
331744e3	233	pthread_mutex_unlock(&channel->metadata_cache->lock);
ec6ea7d0	234	pthread_mutex_unlock(&channel->timer_lock);
5e41ebe1 MD	235	if (!timer) {
	236	pthread_mutex_unlock(&channel->lock);
	237	}
331744e3 JD	238
	239	return ret;
	240	}