[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 _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
 * overlapping updates, but they need to be contiguous. Send the
 * contiguous metadata in cache 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);
	if (offset + len > cache->max_offset) {
		char dummy = 'c';

		cache->max_offset = offset + len;
		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
6c1c0768	19	#define _LGPL_SOURCE
331744e3 JD	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;
53efb85a	49	unsigned int new_size, old_size;
331744e3 JD	50
	51	assert(channel);
	52	assert(channel->metadata_cache);
	53
53efb85a MD	54	old_size = channel->metadata_cache->cache_alloc_size;
53efb85a MD	55	new_size = max_t(unsigned int, old_size + size, old_size << 1);
331744e3 JD	56	DBG("Extending metadata cache to %u", new_size);
	57	tmp_data_ptr = realloc(channel->metadata_cache->data, new_size);
	58	if (!tmp_data_ptr) {
	59	ERR("Reallocating metadata cache");
	60	free(channel->metadata_cache->data);
	61	ret = -1;
	62	goto end;
	63	}
53efb85a MD	64	/* Zero newly allocated memory */
53efb85a MD	65	memset(tmp_data_ptr + old_size, 0, new_size - old_size);
331744e3 JD	66	channel->metadata_cache->data = tmp_data_ptr;
	67	channel->metadata_cache->cache_alloc_size = new_size;
	68
	69	end:
	70	return ret;
	71	}
	72
	73	/*
	74	* Write metadata to the cache, extend the cache if necessary. We support
c585821b MD	75	* overlapping updates, but they need to be contiguous. Send the
c585821b MD	76	* contiguous metadata in cache to the ring buffer. The metadata cache
331744e3 JD	77	* lock MUST be acquired to write in the cache.
	78	*
	79	* Return 0 on success, a negative value on error.
	80	*/
	81	int consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
	82	unsigned int offset, unsigned int len, char *data)
	83	{
	84	int ret = 0;
6cd525e8	85	int size_ret;
331744e3 JD	86	struct consumer_metadata_cache *cache;
	87
	88	assert(channel);
	89	assert(channel->metadata_cache);
	90
	91	cache = channel->metadata_cache;
	92	DBG("Writing %u bytes from offset %u in metadata cache", len, offset);
	93
	94	if (offset + len > cache->cache_alloc_size) {
	95	ret = extend_metadata_cache(channel,
	96	len - cache->cache_alloc_size + offset);
	97	if (ret < 0) {
	98	ERR("Extending metadata cache");
	99	goto end;
	100	}
	101	}
	102
	103	memcpy(cache->data + offset, data, len);
331744e3	104	if (offset + len > cache->max_offset) {
04ef1097 MD	105	char dummy = 'c';
04ef1097 MD	106
c585821b	107	cache->max_offset = offset + len;
04ef1097	108	if (channel->monitor) {
6cd525e8	109	size_ret = lttng_write(channel->metadata_stream->ust_metadata_poll_pipe[1],
04ef1097	110	&dummy, 1);
6cd525e8	111	if (size_ret < 1) {
04ef1097	112	ERR("Wakeup UST metadata pipe");
6cd525e8	113	ret = -1;
04ef1097 MD	114	goto end;
04ef1097 MD	115	}
331744e3	116	}
331744e3 JD	117	}
	118
	119	end:
	120	return ret;
	121	}
	122
	123	/*
	124	* Create the metadata cache, original allocated size: max_sb_size
	125	*
	126	* Return 0 on success, a negative value on error.
	127	*/
	128	int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel)
	129	{
	130	int ret;
	131
	132	assert(channel);
	133
	134	channel->metadata_cache = zmalloc(
	135	sizeof(struct consumer_metadata_cache));
	136	if (!channel->metadata_cache) {
	137	PERROR("zmalloc metadata cache struct");
	138	ret = -1;
	139	goto end;
	140	}
	141	ret = pthread_mutex_init(&channel->metadata_cache->lock, NULL);
	142	if (ret != 0) {
	143	PERROR("mutex init");
	144	goto end_free_cache;
	145	}
	146
	147	channel->metadata_cache->cache_alloc_size = DEFAULT_METADATA_CACHE_SIZE;
	148	channel->metadata_cache->data = zmalloc(
	149	channel->metadata_cache->cache_alloc_size * sizeof(char));
	150	if (!channel->metadata_cache->data) {
	151	PERROR("zmalloc metadata cache data");
	152	ret = -1;
	153	goto end_free_mutex;
	154	}
	155	DBG("Allocated metadata cache of %" PRIu64 " bytes",
	156	channel->metadata_cache->cache_alloc_size);
	157
	158	ret = 0;
	159	goto end;
	160
	161	end_free_mutex:
	162	pthread_mutex_destroy(&channel->metadata_cache->lock);
	163	end_free_cache:
	164	free(channel->metadata_cache);
	165	end:
	166	return ret;
	167	}
	168
	169	/*
	170	* Destroy and free the metadata cache
	171	*/
	172	void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel)
	173	{
	174	if (!channel \|\| !channel->metadata_cache) {
	175	return;
	176	}
	177
	178	DBG("Destroying metadata cache");
	179
331744e3 JD	180	pthread_mutex_destroy(&channel->metadata_cache->lock);
	181	free(channel->metadata_cache->data);
	182	free(channel->metadata_cache);
	183	}
	184
	185	/*
	186	* Check if the cache is flushed up to the offset passed in parameter.
	187	*
	188	* Return 0 if everything has been flushed, 1 if there is data not flushed.
	189	*/
	190	int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
5e41ebe1	191	uint64_t offset, int timer)
331744e3	192	{
04ef1097 MD	193	int ret = 0;
04ef1097 MD	194	struct lttng_consumer_stream *metadata_stream;
331744e3 JD	195
	196	assert(channel);
	197	assert(channel->metadata_cache);
	198
7f725ec5	199	/*
5e41ebe1 MD	200	* If not called from a timer handler, we have to take the
	201	* channel lock to be mutually exclusive with channel teardown.
	202	* Timer handler does not need to take this lock because it is
	203	* already synchronized by timer stop (and, more importantly,
	204	* taking this lock in a timer handler would cause a deadlock).
7f725ec5	205	*/
5e41ebe1 MD	206	if (!timer) {
	207	pthread_mutex_lock(&channel->lock);
	208	}
ec6ea7d0	209	pthread_mutex_lock(&channel->timer_lock);
331744e3	210	pthread_mutex_lock(&channel->metadata_cache->lock);
fe81e5c9	211
04ef1097 MD	212	metadata_stream = channel->metadata_stream;
	213
	214	if (!metadata_stream) {
fe81e5c9 DG	215	/*
	216	* Having no metadata stream means the channel is being destroyed so there
	217	* is no cache to flush anymore.
	218	*/
	219	ret = 0;
04ef1097 MD	220	} else if (metadata_stream->ust_metadata_pushed >= offset) {
04ef1097 MD	221	ret = 0;
fe81e5c9 DG	222	} else if (channel->metadata_stream->endpoint_status !=
	223	CONSUMER_ENDPOINT_ACTIVE) {
	224	/* An inactive endpoint means we don't have to flush anymore. */
	225	ret = 0;
331744e3	226	} else {
fe81e5c9	227	/* Still not completely flushed. */
331744e3 JD	228	ret = 1;
331744e3 JD	229	}
fe81e5c9	230
331744e3	231	pthread_mutex_unlock(&channel->metadata_cache->lock);
ec6ea7d0	232	pthread_mutex_unlock(&channel->timer_lock);
5e41ebe1 MD	233	if (!timer) {
	234	pthread_mutex_unlock(&channel->lock);
	235	}
331744e3 JD	236
	237	return ret;
	238	}