[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, 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
	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
	75	* non-contiguous updates but not overlapping ones. If there is contiguous
	76	* metadata in the cache, we send it to the ring buffer. The metadata cache
	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);
	104	cache->total_bytes_written += len;
	105	if (offset + len > cache->max_offset) {
	106	cache->max_offset = offset + len;
	107	}
	108
	109	if (cache->max_offset == cache->total_bytes_written) {
04ef1097 MD	110	char dummy = 'c';
	111
	112	cache->contiguous = cache->max_offset;
	113	if (channel->monitor) {
6cd525e8	114	size_ret = lttng_write(channel->metadata_stream->ust_metadata_poll_pipe[1],
04ef1097	115	&dummy, 1);
6cd525e8	116	if (size_ret < 1) {
04ef1097	117	ERR("Wakeup UST metadata pipe");
6cd525e8	118	ret = -1;
04ef1097 MD	119	goto end;
04ef1097 MD	120	}
331744e3	121	}
331744e3 JD	122	}
	123
	124	end:
	125	return ret;
	126	}
	127
	128	/*
	129	* Create the metadata cache, original allocated size: max_sb_size
	130	*
	131	* Return 0 on success, a negative value on error.
	132	*/
	133	int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel)
	134	{
	135	int ret;
	136
	137	assert(channel);
	138
	139	channel->metadata_cache = zmalloc(
	140	sizeof(struct consumer_metadata_cache));
	141	if (!channel->metadata_cache) {
	142	PERROR("zmalloc metadata cache struct");
	143	ret = -1;
	144	goto end;
	145	}
	146	ret = pthread_mutex_init(&channel->metadata_cache->lock, NULL);
	147	if (ret != 0) {
	148	PERROR("mutex init");
	149	goto end_free_cache;
	150	}
	151
	152	channel->metadata_cache->cache_alloc_size = DEFAULT_METADATA_CACHE_SIZE;
	153	channel->metadata_cache->data = zmalloc(
	154	channel->metadata_cache->cache_alloc_size * sizeof(char));
	155	if (!channel->metadata_cache->data) {
	156	PERROR("zmalloc metadata cache data");
	157	ret = -1;
	158	goto end_free_mutex;
	159	}
	160	DBG("Allocated metadata cache of %" PRIu64 " bytes",
	161	channel->metadata_cache->cache_alloc_size);
	162
	163	ret = 0;
	164	goto end;
	165
	166	end_free_mutex:
	167	pthread_mutex_destroy(&channel->metadata_cache->lock);
	168	end_free_cache:
	169	free(channel->metadata_cache);
	170	end:
	171	return ret;
	172	}
	173
	174	/*
	175	* Destroy and free the metadata cache
	176	*/
	177	void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel)
	178	{
	179	if (!channel \|\| !channel->metadata_cache) {
	180	return;
	181	}
	182
	183	DBG("Destroying metadata cache");
	184
331744e3 JD	185	pthread_mutex_destroy(&channel->metadata_cache->lock);
	186	free(channel->metadata_cache->data);
	187	free(channel->metadata_cache);
	188	}
	189
	190	/*
	191	* Check if the cache is flushed up to the offset passed in parameter.
	192	*
	193	* Return 0 if everything has been flushed, 1 if there is data not flushed.
	194	*/
	195	int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
5e41ebe1	196	uint64_t offset, int timer)
331744e3	197	{
04ef1097 MD	198	int ret = 0;
04ef1097 MD	199	struct lttng_consumer_stream *metadata_stream;
331744e3 JD	200
	201	assert(channel);
	202	assert(channel->metadata_cache);
	203
7f725ec5	204	/*
5e41ebe1 MD	205	* If not called from a timer handler, we have to take the
	206	* channel lock to be mutually exclusive with channel teardown.
	207	* Timer handler does not need to take this lock because it is
	208	* already synchronized by timer stop (and, more importantly,
	209	* taking this lock in a timer handler would cause a deadlock).
7f725ec5	210	*/
5e41ebe1 MD	211	if (!timer) {
	212	pthread_mutex_lock(&channel->lock);
	213	}
ec6ea7d0	214	pthread_mutex_lock(&channel->timer_lock);
331744e3	215	pthread_mutex_lock(&channel->metadata_cache->lock);
fe81e5c9	216
04ef1097 MD	217	metadata_stream = channel->metadata_stream;
	218
	219	if (!metadata_stream) {
fe81e5c9 DG	220	/*
	221	* Having no metadata stream means the channel is being destroyed so there
	222	* is no cache to flush anymore.
	223	*/
	224	ret = 0;
04ef1097 MD	225	} else if (metadata_stream->ust_metadata_pushed >= offset) {
04ef1097 MD	226	ret = 0;
fe81e5c9 DG	227	} else if (channel->metadata_stream->endpoint_status !=
	228	CONSUMER_ENDPOINT_ACTIVE) {
	229	/* An inactive endpoint means we don't have to flush anymore. */
	230	ret = 0;
331744e3	231	} else {
fe81e5c9	232	/* Still not completely flushed. */
331744e3 JD	233	ret = 1;
331744e3 JD	234	}
fe81e5c9	235
331744e3	236	pthread_mutex_unlock(&channel->metadata_cache->lock);
ec6ea7d0	237	pthread_mutex_unlock(&channel->timer_lock);
5e41ebe1 MD	238	if (!timer) {
	239	pthread_mutex_unlock(&channel->lock);
	240	}
331744e3 JD	241
	242	return ret;
	243	}