+++ /dev/null
-/*
- * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
- * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- * Copyright (C) 2013 - 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 <inttypes.h>
-#include <sys/mman.h>
-#include <unistd.h>
-
-#include <common/common.h>
-#include <common/index/index.h>
-#include <common/kernel-consumer/kernel-consumer.h>
-#include <common/relayd/relayd.h>
-#include <common/ust-consumer/ust-consumer.h>
-#include <common/utils.h>
-
-#include "consumer-stream.h"
-
-/*
- * RCU call to free stream. MUST only be used with call_rcu().
- */
-static void free_stream_rcu(struct rcu_head *head)
-{
- struct lttng_ht_node_u64 *node =
- caa_container_of(head, struct lttng_ht_node_u64, head);
- struct lttng_consumer_stream *stream =
- caa_container_of(node, struct lttng_consumer_stream, node);
-
- pthread_mutex_destroy(&stream->lock);
- free(stream);
-}
-
-/*
- * Close stream on the relayd side. This call can destroy a relayd if the
- * conditions are met.
- *
- * A RCU read side lock MUST be acquired if the relayd object was looked up in
- * a hash table before calling this.
- */
-void consumer_stream_relayd_close(struct lttng_consumer_stream *stream,
- struct consumer_relayd_sock_pair *relayd)
-{
- int ret;
-
- assert(stream);
- assert(relayd);
-
- if (stream->sent_to_relayd) {
- uatomic_dec(&relayd->refcount);
- assert(uatomic_read(&relayd->refcount) >= 0);
- }
-
- /* Closing streams requires to lock the control socket. */
- pthread_mutex_lock(&relayd->ctrl_sock_mutex);
- ret = relayd_send_close_stream(&relayd->control_sock,
- stream->relayd_stream_id,
- stream->next_net_seq_num - 1);
- pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
- if (ret < 0) {
- DBG("Unable to close stream on the relayd. Continuing");
- /*
- * Continue here. There is nothing we can do for the relayd.
- * Chances are that the relayd has closed the socket so we just
- * continue cleaning up.
- */
- }
-
- /* Both conditions are met, we destroy the relayd. */
- if (uatomic_read(&relayd->refcount) == 0 &&
- uatomic_read(&relayd->destroy_flag)) {
- consumer_destroy_relayd(relayd);
- }
- stream->net_seq_idx = (uint64_t) -1ULL;
- stream->sent_to_relayd = 0;
-}
-
-/*
- * Close stream's file descriptors and, if needed, close stream also on the
- * relayd side.
- *
- * The consumer data lock MUST be acquired.
- * The stream lock MUST be acquired.
- */
-void consumer_stream_close(struct lttng_consumer_stream *stream)
-{
- int ret;
- struct consumer_relayd_sock_pair *relayd;
-
- assert(stream);
-
- switch (consumer_data.type) {
- case LTTNG_CONSUMER_KERNEL:
- if (stream->mmap_base != NULL) {
- ret = munmap(stream->mmap_base, stream->mmap_len);
- if (ret != 0) {
- PERROR("munmap");
- }
- }
-
- if (stream->wait_fd >= 0) {
- ret = close(stream->wait_fd);
- if (ret) {
- PERROR("close");
- }
- stream->wait_fd = -1;
- }
- if (stream->chan->output == CONSUMER_CHANNEL_SPLICE) {
- utils_close_pipe(stream->splice_pipe);
- }
- break;
- case LTTNG_CONSUMER32_UST:
- case LTTNG_CONSUMER64_UST:
- {
- /*
- * Special case for the metadata since the wait fd is an internal pipe
- * polled in the metadata thread.
- */
- if (stream->metadata_flag && stream->chan->monitor) {
- int rpipe = stream->ust_metadata_poll_pipe[0];
-
- /*
- * This will stop the channel timer if one and close the write side
- * of the metadata poll pipe.
- */
- lttng_ustconsumer_close_metadata(stream->chan);
- if (rpipe >= 0) {
- ret = close(rpipe);
- if (ret < 0) {
- PERROR("closing metadata pipe read side");
- }
- stream->ust_metadata_poll_pipe[0] = -1;
- }
- }
- break;
- }
- default:
- ERR("Unknown consumer_data type");
- assert(0);
- }
-
- /* Close output fd. Could be a socket or local file at this point. */
- if (stream->out_fd >= 0) {
- ret = close(stream->out_fd);
- if (ret) {
- PERROR("close");
- }
- stream->out_fd = -1;
- }
-
- if (stream->index_fd >= 0) {
- ret = close(stream->index_fd);
- if (ret) {
- PERROR("close stream index_fd");
- }
- stream->index_fd = -1;
- }
-
- /* Check and cleanup relayd if needed. */
- rcu_read_lock();
- relayd = consumer_find_relayd(stream->net_seq_idx);
- if (relayd != NULL) {
- consumer_stream_relayd_close(stream, relayd);
- }
- rcu_read_unlock();
-}
-
-/*
- * Delete the stream from all possible hash tables.
- *
- * The consumer data lock MUST be acquired.
- * The stream lock MUST be acquired.
- */
-void consumer_stream_delete(struct lttng_consumer_stream *stream,
- struct lttng_ht *ht)
-{
- int ret;
- struct lttng_ht_iter iter;
-
- assert(stream);
- /* Should NEVER be called not in monitor mode. */
- assert(stream->chan->monitor);
-
- rcu_read_lock();
-
- if (ht) {
- iter.iter.node = &stream->node.node;
- ret = lttng_ht_del(ht, &iter);
- assert(!ret);
- }
-
- /* Delete from stream per channel ID hash table. */
- iter.iter.node = &stream->node_channel_id.node;
- /*
- * The returned value is of no importance. Even if the node is NOT in the
- * hash table, we continue since we may have been called by a code path
- * that did not add the stream to a (all) hash table. Same goes for the
- * next call ht del call.
- */
- (void) lttng_ht_del(consumer_data.stream_per_chan_id_ht, &iter);
-
- /* Delete from the global stream list. */
- iter.iter.node = &stream->node_session_id.node;
- /* See the previous ht del on why we ignore the returned value. */
- (void) lttng_ht_del(consumer_data.stream_list_ht, &iter);
-
- rcu_read_unlock();
-
- if (!stream->metadata_flag) {
- /* Decrement the stream count of the global consumer data. */
- assert(consumer_data.stream_count > 0);
- consumer_data.stream_count--;
- }
-}
-
-/*
- * Free the given stream within a RCU call.
- */
-void consumer_stream_free(struct lttng_consumer_stream *stream)
-{
- assert(stream);
-
- call_rcu(&stream->node.head, free_stream_rcu);
-}
-
-/*
- * Destroy the stream's buffers of the tracer.
- */
-void consumer_stream_destroy_buffers(struct lttng_consumer_stream *stream)
-{
- assert(stream);
-
- switch (consumer_data.type) {
- case LTTNG_CONSUMER_KERNEL:
- break;
- case LTTNG_CONSUMER32_UST:
- case LTTNG_CONSUMER64_UST:
- lttng_ustconsumer_del_stream(stream);
- break;
- default:
- ERR("Unknown consumer_data type");
- assert(0);
- }
-}
-
-/*
- * Destroy and close a already created stream.
- */
-static void destroy_close_stream(struct lttng_consumer_stream *stream)
-{
- assert(stream);
-
- DBG("Consumer stream destroy monitored key: %" PRIu64, stream->key);
-
- /* Destroy tracer buffers of the stream. */
- consumer_stream_destroy_buffers(stream);
- /* Close down everything including the relayd if one. */
- consumer_stream_close(stream);
-}
-
-/*
- * Decrement the stream's channel refcount and if down to 0, return the channel
- * pointer so it can be destroyed by the caller or NULL if not.
- */
-static struct lttng_consumer_channel *unref_channel(
- struct lttng_consumer_stream *stream)
-{
- struct lttng_consumer_channel *free_chan = NULL;
-
- assert(stream);
- assert(stream->chan);
-
- /* Update refcount of channel and see if we need to destroy it. */
- if (!uatomic_sub_return(&stream->chan->refcount, 1)
- && !uatomic_read(&stream->chan->nb_init_stream_left)) {
- free_chan = stream->chan;
- }
-
- return free_chan;
-}
-
-/*
- * Destroy a stream completely. This will delete, close and free the stream.
- * Once return, the stream is NO longer usable. Its channel may get destroyed
- * if conditions are met for a monitored stream.
- *
- * This MUST be called WITHOUT the consumer data and stream lock acquired if
- * the stream is in _monitor_ mode else it does not matter.
- */
-void consumer_stream_destroy(struct lttng_consumer_stream *stream,
- struct lttng_ht *ht)
-{
- assert(stream);
-
- /* Stream is in monitor mode. */
- if (stream->monitor) {
- struct lttng_consumer_channel *free_chan = NULL;
-
- /*
- * This means that the stream was successfully removed from the streams
- * list of the channel and sent to the right thread managing this
- * stream thus being globally visible.
- */
- if (stream->globally_visible) {
- pthread_mutex_lock(&consumer_data.lock);
- pthread_mutex_lock(&stream->chan->lock);
- pthread_mutex_lock(&stream->lock);
- /* Remove every reference of the stream in the consumer. */
- consumer_stream_delete(stream, ht);
-
- destroy_close_stream(stream);
-
- /* Update channel's refcount of the stream. */
- free_chan = unref_channel(stream);
-
- /* Indicates that the consumer data state MUST be updated after this. */
- consumer_data.need_update = 1;
-
- pthread_mutex_unlock(&stream->lock);
- pthread_mutex_unlock(&stream->chan->lock);
- pthread_mutex_unlock(&consumer_data.lock);
- } else {
- /*
- * If the stream is not visible globally, this needs to be done
- * outside of the consumer data lock section.
- */
- free_chan = unref_channel(stream);
- }
-
- if (free_chan) {
- consumer_del_channel(free_chan);
- }
- } else {
- destroy_close_stream(stream);
- }
-
- /* Free stream within a RCU call. */
- consumer_stream_free(stream);
-}
-
-/*
- * Write index of a specific stream either on the relayd or local disk.
- *
- * Return 0 on success or else a negative value.
- */
-int consumer_stream_write_index(struct lttng_consumer_stream *stream,
- struct ctf_packet_index *index)
-{
- int ret;
- struct consumer_relayd_sock_pair *relayd;
-
- assert(stream);
- assert(index);
-
- rcu_read_lock();
- relayd = consumer_find_relayd(stream->net_seq_idx);
- if (relayd) {
- pthread_mutex_lock(&relayd->ctrl_sock_mutex);
- ret = relayd_send_index(&relayd->control_sock, index,
- stream->relayd_stream_id, stream->next_net_seq_num - 1);
- pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
- } else {
- ssize_t size_ret;
-
- size_ret = index_write(stream->index_fd, index,
- sizeof(struct ctf_packet_index));
- if (size_ret < sizeof(struct ctf_packet_index)) {
- ret = -1;
- } else {
- ret = 0;
- }
- }
- if (ret < 0) {
- goto error;
- }
-
-error:
- rcu_read_unlock();
- return ret;
-}
-
-/*
- * Actually do the metadata sync using the given metadata stream.
- *
- * Return 0 on success else a negative value. ENODATA can be returned also
- * indicating that there is no metadata available for that stream.
- */
-static int do_sync_metadata(struct lttng_consumer_stream *metadata,
- struct lttng_consumer_local_data *ctx)
-{
- int ret;
-
- assert(metadata);
- assert(metadata->metadata_flag);
- assert(ctx);
-
- /*
- * In UST, since we have to write the metadata from the cache packet
- * by packet, we might need to start this procedure multiple times
- * until all the metadata from the cache has been extracted.
- */
- do {
- /*
- * Steps :
- * - Lock the metadata stream
- * - Check if metadata stream node was deleted before locking.
- * - if yes, release and return success
- * - Check if new metadata is ready (flush + snapshot pos)
- * - If nothing : release and return.
- * - Lock the metadata_rdv_lock
- * - Unlock the metadata stream
- * - cond_wait on metadata_rdv to wait the wakeup from the
- * metadata thread
- * - Unlock the metadata_rdv_lock
- */
- pthread_mutex_lock(&metadata->lock);
-
- /*
- * There is a possibility that we were able to acquire a reference on the
- * stream from the RCU hash table but between then and now, the node might
- * have been deleted just before the lock is acquired. Thus, after locking,
- * we make sure the metadata node has not been deleted which means that the
- * buffers are closed.
- *
- * In that case, there is no need to sync the metadata hence returning a
- * success return code.
- */
- ret = cds_lfht_is_node_deleted(&metadata->node.node);
- if (ret) {
- ret = 0;
- goto end_unlock_mutex;
- }
-
- switch (ctx->type) {
- case LTTNG_CONSUMER_KERNEL:
- /*
- * Empty the metadata cache and flush the current stream.
- */
- ret = lttng_kconsumer_sync_metadata(metadata);
- break;
- case LTTNG_CONSUMER32_UST:
- case LTTNG_CONSUMER64_UST:
- /*
- * Ask the sessiond if we have new metadata waiting and update the
- * consumer metadata cache.
- */
- ret = lttng_ustconsumer_sync_metadata(ctx, metadata);
- break;
- default:
- assert(0);
- ret = -1;
- break;
- }
- /*
- * Error or no new metadata, we exit here.
- */
- if (ret <= 0 || ret == ENODATA) {
- goto end_unlock_mutex;
- }
-
- /*
- * At this point, new metadata have been flushed, so we wait on the
- * rendez-vous point for the metadata thread to wake us up when it
- * finishes consuming the metadata and continue execution.
- */
-
- pthread_mutex_lock(&metadata->metadata_rdv_lock);
-
- /*
- * Release metadata stream lock so the metadata thread can process it.
- */
- pthread_mutex_unlock(&metadata->lock);
-
- /*
- * Wait on the rendez-vous point. Once woken up, it means the metadata was
- * consumed and thus synchronization is achieved.
- */
- pthread_cond_wait(&metadata->metadata_rdv, &metadata->metadata_rdv_lock);
- pthread_mutex_unlock(&metadata->metadata_rdv_lock);
- } while (ret == EAGAIN);
-
- /* Success */
- return 0;
-
-end_unlock_mutex:
- pthread_mutex_unlock(&metadata->lock);
- return ret;
-}
-
-/*
- * Synchronize the metadata using a given session ID. A successful acquisition
- * of a metadata stream will trigger a request to the session daemon and a
- * snapshot so the metadata thread can consume it.
- *
- * This function call is a rendez-vous point between the metadata thread and
- * the data thread.
- *
- * Return 0 on success or else a negative value.
- */
-int consumer_stream_sync_metadata(struct lttng_consumer_local_data *ctx,
- uint64_t session_id)
-{
- int ret;
- struct lttng_consumer_stream *stream = NULL;
- struct lttng_ht_iter iter;
- struct lttng_ht *ht;
-
- assert(ctx);
-
- /* Ease our life a bit. */
- ht = consumer_data.stream_list_ht;
-
- rcu_read_lock();
-
- /* Search the metadata associated with the session id of the given stream. */
-
- cds_lfht_for_each_entry_duplicate(ht->ht,
- ht->hash_fct(&session_id, lttng_ht_seed), ht->match_fct,
- &session_id, &iter.iter, stream, node_session_id.node) {
- if (!stream->metadata_flag) {
- continue;
- }
-
- ret = do_sync_metadata(stream, ctx);
- if (ret < 0) {
- goto end;
- }
- }
-
- /*
- * Force return code to 0 (success) since ret might be ENODATA for instance
- * which is not an error but rather that we should come back.
- */
- ret = 0;
-
-end:
- rcu_read_unlock();
- return ret;
-}
projects / lttng-tools.git / blobdiff