[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
#define _LGPL_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, old_size;

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

	old_size = channel->metadata_cache->cache_alloc_size;
	new_size = max_t(unsigned int, old_size + size, old_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;
	}
	/* Zero newly allocated memory */
	memset(tmp_data_ptr + old_size, 0, new_size - old_size);
	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;
	int size_ret;
	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) {
			size_ret = lttng_write(channel->metadata_stream->ust_metadata_poll_pipe[1],
					&dummy, 1);
			if (size_ret < 1) {
				ERR("Wakeup UST metadata pipe");
				ret = -1;
				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
6c1c0768	20	#define _LGPL_SOURCE
331744e3 JD	21	#include <assert.h>
	22	#include <pthread.h>
	23	#include <stdlib.h>
	24	#include <string.h>
	25	#include <sys/types.h>
	26	#include <unistd.h>
	27	#include <inttypes.h>
	28
	29	#include <common/common.h>
	30	#include <common/utils.h>
	31	#include <common/sessiond-comm/sessiond-comm.h>
	32	#include <common/ust-consumer/ust-consumer.h>
	33	#include <common/consumer.h>
	34
	35	#include "consumer-metadata-cache.h"
	36
fe81e5c9 DG	37	extern struct lttng_consumer_global_data consumer_data;
fe81e5c9 DG	38
331744e3 JD	39	/*
	40	* Extend the allocated size of the metadata cache. Called only from
	41	* lttng_ustconsumer_write_metadata_cache.
	42	*
	43	* Return 0 on success, a negative value on error.
	44	*/
	45	static int extend_metadata_cache(struct lttng_consumer_channel *channel,
	46	unsigned int size)
	47	{
	48	int ret = 0;
	49	char *tmp_data_ptr;
53efb85a	50	unsigned int new_size, old_size;
331744e3 JD	51
	52	assert(channel);
	53	assert(channel->metadata_cache);
	54
53efb85a MD	55	old_size = channel->metadata_cache->cache_alloc_size;
53efb85a MD	56	new_size = max_t(unsigned int, old_size + size, old_size << 1);
331744e3 JD	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	}
53efb85a MD	65	/* Zero newly allocated memory */
53efb85a MD	66	memset(tmp_data_ptr + old_size, 0, new_size - old_size);
331744e3 JD	67	channel->metadata_cache->data = tmp_data_ptr;
	68	channel->metadata_cache->cache_alloc_size = new_size;
	69
	70	end:
	71	return ret;
	72	}
	73
	74	/*
	75	* Write metadata to the cache, extend the cache if necessary. We support
	76	* non-contiguous updates but not overlapping ones. If there is contiguous
	77	* metadata in the cache, we send it to the ring buffer. The metadata cache
	78	* lock MUST be acquired to write in the cache.
	79	*
	80	* Return 0 on success, a negative value on error.
	81	*/
	82	int consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
	83	unsigned int offset, unsigned int len, char *data)
	84	{
	85	int ret = 0;
6cd525e8	86	int size_ret;
331744e3 JD	87	struct consumer_metadata_cache *cache;
	88
	89	assert(channel);
	90	assert(channel->metadata_cache);
	91
	92	cache = channel->metadata_cache;
	93	DBG("Writing %u bytes from offset %u in metadata cache", len, offset);
	94
	95	if (offset + len > cache->cache_alloc_size) {
	96	ret = extend_metadata_cache(channel,
	97	len - cache->cache_alloc_size + offset);
	98	if (ret < 0) {
	99	ERR("Extending metadata cache");
	100	goto end;
	101	}
	102	}
	103
	104	memcpy(cache->data + offset, data, len);
	105	cache->total_bytes_written += len;
	106	if (offset + len > cache->max_offset) {
	107	cache->max_offset = offset + len;
	108	}
	109
	110	if (cache->max_offset == cache->total_bytes_written) {
04ef1097 MD	111	char dummy = 'c';
	112
	113	cache->contiguous = cache->max_offset;
	114	if (channel->monitor) {
6cd525e8	115	size_ret = lttng_write(channel->metadata_stream->ust_metadata_poll_pipe[1],
04ef1097	116	&dummy, 1);
6cd525e8	117	if (size_ret < 1) {
04ef1097	118	ERR("Wakeup UST metadata pipe");
6cd525e8	119	ret = -1;
04ef1097 MD	120	goto end;
04ef1097 MD	121	}
331744e3	122	}
331744e3 JD	123	}
	124
	125	end:
	126	return ret;
	127	}
	128
	129	/*
	130	* Create the metadata cache, original allocated size: max_sb_size
	131	*
	132	* Return 0 on success, a negative value on error.
	133	*/
	134	int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel)
	135	{
	136	int ret;
	137
	138	assert(channel);
	139
	140	channel->metadata_cache = zmalloc(
	141	sizeof(struct consumer_metadata_cache));
	142	if (!channel->metadata_cache) {
	143	PERROR("zmalloc metadata cache struct");
	144	ret = -1;
	145	goto end;
	146	}
	147	ret = pthread_mutex_init(&channel->metadata_cache->lock, NULL);
	148	if (ret != 0) {
	149	PERROR("mutex init");
	150	goto end_free_cache;
	151	}
	152
	153	channel->metadata_cache->cache_alloc_size = DEFAULT_METADATA_CACHE_SIZE;
	154	channel->metadata_cache->data = zmalloc(
	155	channel->metadata_cache->cache_alloc_size * sizeof(char));
	156	if (!channel->metadata_cache->data) {
	157	PERROR("zmalloc metadata cache data");
	158	ret = -1;
	159	goto end_free_mutex;
	160	}
	161	DBG("Allocated metadata cache of %" PRIu64 " bytes",
	162	channel->metadata_cache->cache_alloc_size);
	163
	164	ret = 0;
	165	goto end;
	166
	167	end_free_mutex:
	168	pthread_mutex_destroy(&channel->metadata_cache->lock);
	169	end_free_cache:
	170	free(channel->metadata_cache);
	171	end:
	172	return ret;
	173	}
	174
	175	/*
	176	* Destroy and free the metadata cache
	177	*/
	178	void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel)
	179	{
	180	if (!channel \|\| !channel->metadata_cache) {
	181	return;
	182	}
	183
	184	DBG("Destroying metadata cache");
	185
331744e3 JD	186	pthread_mutex_destroy(&channel->metadata_cache->lock);
	187	free(channel->metadata_cache->data);
	188	free(channel->metadata_cache);
	189	}
	190
	191	/*
	192	* Check if the cache is flushed up to the offset passed in parameter.
	193	*
	194	* Return 0 if everything has been flushed, 1 if there is data not flushed.
	195	*/
	196	int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
5e41ebe1	197	uint64_t offset, int timer)
331744e3	198	{
04ef1097 MD	199	int ret = 0;
04ef1097 MD	200	struct lttng_consumer_stream *metadata_stream;
331744e3 JD	201
	202	assert(channel);
	203	assert(channel->metadata_cache);
	204
7f725ec5	205	/*
5e41ebe1 MD	206	* If not called from a timer handler, we have to take the
	207	* channel lock to be mutually exclusive with channel teardown.
	208	* Timer handler does not need to take this lock because it is
	209	* already synchronized by timer stop (and, more importantly,
	210	* taking this lock in a timer handler would cause a deadlock).
7f725ec5	211	*/
5e41ebe1 MD	212	if (!timer) {
	213	pthread_mutex_lock(&channel->lock);
	214	}
ec6ea7d0	215	pthread_mutex_lock(&channel->timer_lock);
331744e3	216	pthread_mutex_lock(&channel->metadata_cache->lock);
fe81e5c9	217
04ef1097 MD	218	metadata_stream = channel->metadata_stream;
	219
	220	if (!metadata_stream) {
fe81e5c9 DG	221	/*
	222	* Having no metadata stream means the channel is being destroyed so there
	223	* is no cache to flush anymore.
	224	*/
	225	ret = 0;
04ef1097 MD	226	} else if (metadata_stream->ust_metadata_pushed >= offset) {
04ef1097 MD	227	ret = 0;
fe81e5c9 DG	228	} else if (channel->metadata_stream->endpoint_status !=
	229	CONSUMER_ENDPOINT_ACTIVE) {
	230	/* An inactive endpoint means we don't have to flush anymore. */
	231	ret = 0;
331744e3	232	} else {
fe81e5c9	233	/* Still not completely flushed. */
331744e3 JD	234	ret = 1;
331744e3 JD	235	}
fe81e5c9	236
331744e3	237	pthread_mutex_unlock(&channel->metadata_cache->lock);
ec6ea7d0	238	pthread_mutex_unlock(&channel->timer_lock);
5e41ebe1 MD	239	if (!timer) {
	240	pthread_mutex_unlock(&channel->lock);
	241	}
331744e3 JD	242
	243	return ret;
	244	}