X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fconsumer.c;h=8d1a34025687da37b7c3c1555d80441c93d8761d;hp=80dedd5c6cfd057397eef3706ec62ef9717889e7;hb=ca22feea083301934d1c8511851c86fb008c0697;hpb=fbb2c21aac1386b7752f6254b2bd0bf001fa0ac1 diff --git a/src/common/consumer.c b/src/common/consumer.c index 80dedd5c6..8d1a34025 100644 --- a/src/common/consumer.c +++ b/src/common/consumer.c @@ -1,20 +1,20 @@ /* * Copyright (C) 2011 - Julien Desfossez * Mathieu Desnoyers + * 2012 - David Goulet * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; only version 2 - * of the License. + * 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. + * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * 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 @@ -27,11 +27,16 @@ #include #include #include +#include #include +#include +#include #include +#include #include #include +#include #include #include "consumer.h" @@ -53,24 +58,38 @@ int consumer_poll_timeout = -1; */ volatile int consumer_quit = 0; +/* + * The following two hash tables are visible by all threads which are separated + * in different source files. + * + * Global hash table containing respectively metadata and data streams. The + * stream element in this ht should only be updated by the metadata poll thread + * for the metadata and the data poll thread for the data. + */ +struct lttng_ht *metadata_ht = NULL; +struct lttng_ht *data_ht = NULL; + /* * Find a stream. The consumer_data.lock must be locked during this * call. */ -static struct lttng_consumer_stream *consumer_find_stream(int key) +static struct lttng_consumer_stream *consumer_find_stream(int key, + struct lttng_ht *ht) { struct lttng_ht_iter iter; struct lttng_ht_node_ulong *node; struct lttng_consumer_stream *stream = NULL; + assert(ht); + /* Negative keys are lookup failures */ - if (key < 0) + if (key < 0) { return NULL; + } rcu_read_lock(); - lttng_ht_lookup(consumer_data.stream_ht, (void *)((unsigned long) key), - &iter); + lttng_ht_lookup(ht, (void *)((unsigned long) key), &iter); node = lttng_ht_iter_get_node_ulong(&iter); if (node != NULL) { stream = caa_container_of(node, struct lttng_consumer_stream, node); @@ -81,13 +100,22 @@ static struct lttng_consumer_stream *consumer_find_stream(int key) return stream; } -static void consumer_steal_stream_key(int key) +void consumer_steal_stream_key(int key, struct lttng_ht *ht) { struct lttng_consumer_stream *stream; - stream = consumer_find_stream(key); - if (stream) + rcu_read_lock(); + stream = consumer_find_stream(key, ht); + if (stream) { stream->key = -1; + /* + * We don't want the lookup to match, but we still need + * to iterate on this stream when iterating over the hash table. Just + * change the node key. + */ + stream->node.key = -1; + } + rcu_read_unlock(); } static struct lttng_consumer_channel *consumer_find_channel(int key) @@ -97,8 +125,9 @@ static struct lttng_consumer_channel *consumer_find_channel(int key) struct lttng_consumer_channel *channel = NULL; /* Negative keys are lookup failures */ - if (key < 0) + if (key < 0) { return NULL; + } rcu_read_lock(); @@ -118,20 +147,114 @@ static void consumer_steal_channel_key(int key) { struct lttng_consumer_channel *channel; + rcu_read_lock(); channel = consumer_find_channel(key); - if (channel) + if (channel) { channel->key = -1; + /* + * We don't want the lookup to match, but we still need + * to iterate on this channel when iterating over the hash table. Just + * change the node key. + */ + channel->node.key = -1; + } + rcu_read_unlock(); +} + +static +void consumer_free_stream(struct rcu_head *head) +{ + struct lttng_ht_node_ulong *node = + caa_container_of(head, struct lttng_ht_node_ulong, head); + struct lttng_consumer_stream *stream = + caa_container_of(node, struct lttng_consumer_stream, node); + + free(stream); +} + +/* + * RCU protected relayd socket pair free. + */ +static void consumer_rcu_free_relayd(struct rcu_head *head) +{ + struct lttng_ht_node_ulong *node = + caa_container_of(head, struct lttng_ht_node_ulong, head); + struct consumer_relayd_sock_pair *relayd = + caa_container_of(node, struct consumer_relayd_sock_pair, node); + + free(relayd); +} + +/* + * Destroy and free relayd socket pair object. + * + * This function MUST be called with the consumer_data lock acquired. + */ +static void destroy_relayd(struct consumer_relayd_sock_pair *relayd) +{ + int ret; + struct lttng_ht_iter iter; + + if (relayd == NULL) { + return; + } + + DBG("Consumer destroy and close relayd socket pair"); + + iter.iter.node = &relayd->node.node; + ret = lttng_ht_del(consumer_data.relayd_ht, &iter); + if (ret != 0) { + /* We assume the relayd was already destroyed */ + return; + } + + /* Close all sockets */ + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + (void) relayd_close(&relayd->control_sock); + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + (void) relayd_close(&relayd->data_sock); + + /* RCU free() call */ + call_rcu(&relayd->node.head, consumer_rcu_free_relayd); +} + +/* + * Flag a relayd socket pair for destruction. Destroy it if the refcount + * reaches zero. + * + * RCU read side lock MUST be aquired before calling this function. + */ +void consumer_flag_relayd_for_destroy(struct consumer_relayd_sock_pair *relayd) +{ + assert(relayd); + + /* Set destroy flag for this object */ + uatomic_set(&relayd->destroy_flag, 1); + + /* Destroy the relayd if refcount is 0 */ + if (uatomic_read(&relayd->refcount) == 0) { + destroy_relayd(relayd); + } } /* * Remove a stream from the global list protected by a mutex. This * function is also responsible for freeing its data structures. */ -void consumer_del_stream(struct lttng_consumer_stream *stream) +void consumer_del_stream(struct lttng_consumer_stream *stream, + struct lttng_ht *ht) { int ret; struct lttng_ht_iter iter; struct lttng_consumer_channel *free_chan = NULL; + struct consumer_relayd_sock_pair *relayd; + + assert(stream); + + if (ht == NULL) { + /* Means the stream was allocated but not successfully added */ + goto free_stream; + } pthread_mutex_lock(&consumer_data.lock); @@ -140,7 +263,7 @@ void consumer_del_stream(struct lttng_consumer_stream *stream) if (stream->mmap_base != NULL) { ret = munmap(stream->mmap_base, stream->mmap_len); if (ret != 0) { - perror("munmap"); + PERROR("munmap"); } } break; @@ -155,51 +278,84 @@ void consumer_del_stream(struct lttng_consumer_stream *stream) } rcu_read_lock(); - - /* Get stream node from hash table */ - lttng_ht_lookup(consumer_data.stream_ht, - (void *)((unsigned long) stream->key), &iter); - /* Remove stream node from hash table */ - ret = lttng_ht_del(consumer_data.stream_ht, &iter); + iter.iter.node = &stream->node.node; + ret = lttng_ht_del(ht, &iter); assert(!ret); + /* Remove node session id from the consumer_data stream ht */ + iter.iter.node = &stream->node_session_id.node; + ret = lttng_ht_del(consumer_data.stream_list_ht, &iter); + assert(!ret); rcu_read_unlock(); - if (consumer_data.stream_count <= 0) { - goto end; - } + assert(consumer_data.stream_count > 0); consumer_data.stream_count--; - if (!stream) { - goto end; - } + if (stream->out_fd >= 0) { - close(stream->out_fd); + ret = close(stream->out_fd); + if (ret) { + PERROR("close"); + } } if (stream->wait_fd >= 0 && !stream->wait_fd_is_copy) { - close(stream->wait_fd); + ret = close(stream->wait_fd); + if (ret) { + PERROR("close"); + } } if (stream->shm_fd >= 0 && stream->wait_fd != stream->shm_fd) { - close(stream->shm_fd); + ret = close(stream->shm_fd); + if (ret) { + PERROR("close"); + } + } + + /* Check and cleanup relayd */ + rcu_read_lock(); + relayd = consumer_find_relayd(stream->net_seq_idx); + if (relayd != NULL) { + 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)) { + destroy_relayd(relayd); + } } - if (!--stream->chan->refcount) + rcu_read_unlock(); + + uatomic_dec(&stream->chan->refcount); + if (!uatomic_read(&stream->chan->refcount) + && !uatomic_read(&stream->chan->nb_init_streams)) { free_chan = stream->chan; - free(stream); + } + end: consumer_data.need_update = 1; pthread_mutex_unlock(&consumer_data.lock); - if (free_chan) + if (free_chan) { consumer_del_channel(free_chan); -} - -static void consumer_del_stream_rcu(struct rcu_head *head) -{ - struct lttng_ht_node_ulong *node = - caa_container_of(head, struct lttng_ht_node_ulong, head); - struct lttng_consumer_stream *stream = - caa_container_of(node, struct lttng_consumer_stream, node); + } - consumer_del_stream(stream); +free_stream: + call_rcu(&stream->node.head, consumer_free_stream); } struct lttng_consumer_stream *consumer_allocate_stream( @@ -210,22 +366,32 @@ struct lttng_consumer_stream *consumer_allocate_stream( enum lttng_event_output output, const char *path_name, uid_t uid, - gid_t gid) + gid_t gid, + int net_index, + int metadata_flag, + uint64_t session_id, + int *alloc_ret) { struct lttng_consumer_stream *stream; - int ret; stream = zmalloc(sizeof(*stream)); if (stream == NULL) { - perror("malloc struct lttng_consumer_stream"); + PERROR("malloc struct lttng_consumer_stream"); + *alloc_ret = -ENOMEM; goto end; } + + /* + * Get stream's channel reference. Needed when adding the stream to the + * global hash table. + */ stream->chan = consumer_find_channel(channel_key); if (!stream->chan) { - perror("Unable to find channel key"); - goto end; + *alloc_ret = -ENOENT; + ERR("Unable to find channel for stream %d", stream_key); + goto error; } - stream->chan->refcount++; + stream->key = stream_key; stream->shm_fd = shm_fd; stream->wait_fd = wait_fd; @@ -237,87 +403,253 @@ struct lttng_consumer_stream *consumer_allocate_stream( stream->output = output; stream->uid = uid; stream->gid = gid; - strncpy(stream->path_name, path_name, PATH_MAX - 1); - stream->path_name[PATH_MAX - 1] = '\0'; - lttng_ht_node_init_ulong(&stream->node, stream->key); + stream->net_seq_idx = net_index; + stream->metadata_flag = metadata_flag; + stream->session_id = session_id; + strncpy(stream->path_name, path_name, sizeof(stream->path_name)); + stream->path_name[sizeof(stream->path_name) - 1] = '\0'; + pthread_mutex_init(&stream->lock, NULL); - switch (consumer_data.type) { - case LTTNG_CONSUMER_KERNEL: - break; - case LTTNG_CONSUMER32_UST: - case LTTNG_CONSUMER64_UST: - stream->cpu = stream->chan->cpucount++; - ret = lttng_ustconsumer_allocate_stream(stream); - if (ret) { - free(stream); - return NULL; - } - break; - default: - ERR("Unknown consumer_data type"); - assert(0); - goto end; + /* + * Index differently the metadata node because the thread is using an + * internal hash table to match streams in the metadata_ht to the epoll set + * file descriptor. + */ + if (metadata_flag) { + lttng_ht_node_init_ulong(&stream->node, stream->wait_fd); + } else { + lttng_ht_node_init_ulong(&stream->node, stream->key); } - DBG("Allocated stream %s (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, out_fd %d)", - stream->path_name, stream->key, - stream->shm_fd, - stream->wait_fd, - (unsigned long long) stream->mmap_len, - stream->out_fd); -end: + + /* Init session id node with the stream session id */ + lttng_ht_node_init_ulong(&stream->node_session_id, stream->session_id); + + /* + * The cpu number is needed before using any ustctl_* actions. Ignored for + * the kernel so the value does not matter. + */ + pthread_mutex_lock(&consumer_data.lock); + stream->cpu = stream->chan->cpucount++; + pthread_mutex_unlock(&consumer_data.lock); + + DBG3("Allocated stream %s (key %d, shm_fd %d, wait_fd %d, mmap_len %llu," + " out_fd %d, net_seq_idx %d, session_id %" PRIu64, + stream->path_name, stream->key, stream->shm_fd, stream->wait_fd, + (unsigned long long) stream->mmap_len, stream->out_fd, + stream->net_seq_idx, stream->session_id); return stream; + +error: + free(stream); +end: + return NULL; } /* * Add a stream to the global list protected by a mutex. */ -int consumer_add_stream(struct lttng_consumer_stream *stream) +static int consumer_add_stream(struct lttng_consumer_stream *stream, + struct lttng_ht *ht) { int ret = 0; + struct consumer_relayd_sock_pair *relayd; + + assert(stream); + assert(ht); + + DBG3("Adding consumer stream %d", stream->key); pthread_mutex_lock(&consumer_data.lock); - /* Steal stream identifier, for UST */ - consumer_steal_stream_key(stream->key); rcu_read_lock(); - lttng_ht_add_unique_ulong(consumer_data.stream_ht, &stream->node); - rcu_read_unlock(); + + /* Steal stream identifier to avoid having streams with the same key */ + consumer_steal_stream_key(stream->key, ht); + + lttng_ht_add_unique_ulong(ht, &stream->node); + + /* + * Add stream to the stream_list_ht of the consumer data. No need to steal + * the key since the HT does not use it and we allow to add redundant keys + * into this table. + */ + lttng_ht_add_ulong(consumer_data.stream_list_ht, &stream->node_session_id); + + /* Check and cleanup relayd */ + relayd = consumer_find_relayd(stream->net_seq_idx); + if (relayd != NULL) { + uatomic_inc(&relayd->refcount); + } + + /* Update channel refcount once added without error(s). */ + uatomic_inc(&stream->chan->refcount); + + /* + * When nb_init_streams reaches 0, we don't need to trigger any action in + * terms of destroying the associated channel, because the action that + * causes the count to become 0 also causes a stream to be added. The + * channel deletion will thus be triggered by the following removal of this + * stream. + */ + if (uatomic_read(&stream->chan->nb_init_streams) > 0) { + uatomic_dec(&stream->chan->nb_init_streams); + } + + /* Update consumer data once the node is inserted. */ consumer_data.stream_count++; consumer_data.need_update = 1; - switch (consumer_data.type) { - case LTTNG_CONSUMER_KERNEL: - break; - case LTTNG_CONSUMER32_UST: - case LTTNG_CONSUMER64_UST: - /* Streams are in CPU number order (we rely on this) */ - stream->cpu = stream->chan->nr_streams++; - break; - default: - ERR("Unknown consumer_data type"); - assert(0); + rcu_read_unlock(); + pthread_mutex_unlock(&consumer_data.lock); + + return ret; +} + +/* + * Add relayd socket to global consumer data hashtable. RCU read side lock MUST + * be acquired before calling this. + */ +static int add_relayd(struct consumer_relayd_sock_pair *relayd) +{ + int ret = 0; + struct lttng_ht_node_ulong *node; + struct lttng_ht_iter iter; + + if (relayd == NULL) { + ret = -1; + goto end; + } + + lttng_ht_lookup(consumer_data.relayd_ht, + (void *)((unsigned long) relayd->net_seq_idx), &iter); + node = lttng_ht_iter_get_node_ulong(&iter); + if (node != NULL) { + /* Relayd already exist. Ignore the insertion */ goto end; } + lttng_ht_add_unique_ulong(consumer_data.relayd_ht, &relayd->node); end: - pthread_mutex_unlock(&consumer_data.lock); return ret; } /* - * Update a stream according to what we just received. + * Allocate and return a consumer relayd socket. */ -void consumer_change_stream_state(int stream_key, - enum lttng_consumer_stream_state state) +struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair( + int net_seq_idx) { - struct lttng_consumer_stream *stream; + struct consumer_relayd_sock_pair *obj = NULL; - pthread_mutex_lock(&consumer_data.lock); - stream = consumer_find_stream(stream_key); - if (stream) { - stream->state = state; + /* Negative net sequence index is a failure */ + if (net_seq_idx < 0) { + goto error; } - consumer_data.need_update = 1; - pthread_mutex_unlock(&consumer_data.lock); + + obj = zmalloc(sizeof(struct consumer_relayd_sock_pair)); + if (obj == NULL) { + PERROR("zmalloc relayd sock"); + goto error; + } + + obj->net_seq_idx = net_seq_idx; + obj->refcount = 0; + obj->destroy_flag = 0; + lttng_ht_node_init_ulong(&obj->node, obj->net_seq_idx); + pthread_mutex_init(&obj->ctrl_sock_mutex, NULL); + +error: + return obj; +} + +/* + * Find a relayd socket pair in the global consumer data. + * + * Return the object if found else NULL. + * RCU read-side lock must be held across this call and while using the + * returned object. + */ +struct consumer_relayd_sock_pair *consumer_find_relayd(int key) +{ + struct lttng_ht_iter iter; + struct lttng_ht_node_ulong *node; + struct consumer_relayd_sock_pair *relayd = NULL; + + /* Negative keys are lookup failures */ + if (key < 0) { + goto error; + } + + lttng_ht_lookup(consumer_data.relayd_ht, (void *)((unsigned long) key), + &iter); + node = lttng_ht_iter_get_node_ulong(&iter); + if (node != NULL) { + relayd = caa_container_of(node, struct consumer_relayd_sock_pair, node); + } + +error: + return relayd; +} + +/* + * Handle stream for relayd transmission if the stream applies for network + * streaming where the net sequence index is set. + * + * Return destination file descriptor or negative value on error. + */ +static int write_relayd_stream_header(struct lttng_consumer_stream *stream, + size_t data_size, unsigned long padding, + struct consumer_relayd_sock_pair *relayd) +{ + int outfd = -1, ret; + struct lttcomm_relayd_data_hdr data_hdr; + + /* Safety net */ + assert(stream); + assert(relayd); + + /* Reset data header */ + memset(&data_hdr, 0, sizeof(data_hdr)); + + if (stream->metadata_flag) { + /* Caller MUST acquire the relayd control socket lock */ + ret = relayd_send_metadata(&relayd->control_sock, data_size); + if (ret < 0) { + goto error; + } + + /* Metadata are always sent on the control socket. */ + outfd = relayd->control_sock.fd; + } else { + /* Set header with stream information */ + data_hdr.stream_id = htobe64(stream->relayd_stream_id); + data_hdr.data_size = htobe32(data_size); + data_hdr.padding_size = htobe32(padding); + data_hdr.net_seq_num = htobe64(stream->next_net_seq_num++); + /* Other fields are zeroed previously */ + + ret = relayd_send_data_hdr(&relayd->data_sock, &data_hdr, + sizeof(data_hdr)); + if (ret < 0) { + goto error; + } + + /* Set to go on data socket */ + outfd = relayd->data_sock.fd; + } + +error: + return outfd; +} + +static +void consumer_free_channel(struct rcu_head *head) +{ + struct lttng_ht_node_ulong *node = + caa_container_of(head, struct lttng_ht_node_ulong, head); + struct lttng_consumer_channel *channel = + caa_container_of(node, struct lttng_consumer_channel, node); + + free(channel); } /* @@ -345,53 +677,48 @@ void consumer_del_channel(struct lttng_consumer_channel *channel) } rcu_read_lock(); - - lttng_ht_lookup(consumer_data.channel_ht, - (void *)((unsigned long) channel->key), &iter); + iter.iter.node = &channel->node.node; ret = lttng_ht_del(consumer_data.channel_ht, &iter); assert(!ret); - rcu_read_unlock(); if (channel->mmap_base != NULL) { ret = munmap(channel->mmap_base, channel->mmap_len); if (ret != 0) { - perror("munmap"); + PERROR("munmap"); } } if (channel->wait_fd >= 0 && !channel->wait_fd_is_copy) { - close(channel->wait_fd); + ret = close(channel->wait_fd); + if (ret) { + PERROR("close"); + } } if (channel->shm_fd >= 0 && channel->wait_fd != channel->shm_fd) { - close(channel->shm_fd); + ret = close(channel->shm_fd); + if (ret) { + PERROR("close"); + } } - free(channel); + + call_rcu(&channel->node.head, consumer_free_channel); end: pthread_mutex_unlock(&consumer_data.lock); } -static void consumer_del_channel_rcu(struct rcu_head *head) -{ - struct lttng_ht_node_ulong *node = - caa_container_of(head, struct lttng_ht_node_ulong, head); - struct lttng_consumer_channel *channel= - caa_container_of(node, struct lttng_consumer_channel, node); - - consumer_del_channel(channel); -} - struct lttng_consumer_channel *consumer_allocate_channel( int channel_key, int shm_fd, int wait_fd, uint64_t mmap_len, - uint64_t max_sb_size) + uint64_t max_sb_size, + unsigned int nb_init_streams) { struct lttng_consumer_channel *channel; int ret; channel = zmalloc(sizeof(*channel)); if (channel == NULL) { - perror("malloc struct lttng_consumer_channel"); + PERROR("malloc struct lttng_consumer_channel"); goto end; } channel->key = channel_key; @@ -400,7 +727,7 @@ struct lttng_consumer_channel *consumer_allocate_channel( channel->mmap_len = mmap_len; channel->max_sb_size = max_sb_size; channel->refcount = 0; - channel->nr_streams = 0; + channel->nb_init_streams = nb_init_streams; lttng_ht_node_init_ulong(&channel->node, channel->key); switch (consumer_data.type) { @@ -422,9 +749,7 @@ struct lttng_consumer_channel *consumer_allocate_channel( goto end; } DBG("Allocated channel (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, max_sb_size %llu)", - channel->key, - channel->shm_fd, - channel->wait_fd, + channel->key, channel->shm_fd, channel->wait_fd, (unsigned long long) channel->mmap_len, (unsigned long long) channel->max_sb_size); end: @@ -436,13 +761,28 @@ end: */ int consumer_add_channel(struct lttng_consumer_channel *channel) { + struct lttng_ht_node_ulong *node; + struct lttng_ht_iter iter; + pthread_mutex_lock(&consumer_data.lock); /* Steal channel identifier, for UST */ consumer_steal_channel_key(channel->key); rcu_read_lock(); - lttng_ht_add_unique_ulong(consumer_data.channel_ht, &channel->node); - rcu_read_unlock(); + + lttng_ht_lookup(consumer_data.channel_ht, + (void *)((unsigned long) channel->key), &iter); + node = lttng_ht_iter_get_node_ulong(&iter); + if (node != NULL) { + /* Channel already exist. Ignore the insertion */ + goto end; + } + + lttng_ht_add_unique_ulong(consumer_data.channel_ht, &channel->node); + +end: + rcu_read_unlock(); pthread_mutex_unlock(&consumer_data.lock); + return 0; } @@ -453,17 +793,17 @@ int consumer_add_channel(struct lttng_consumer_channel *channel) * * Returns the number of fds in the structures. */ -int consumer_update_poll_array( +static int consumer_update_poll_array( struct lttng_consumer_local_data *ctx, struct pollfd **pollfd, - struct lttng_consumer_stream **local_stream) + struct lttng_consumer_stream **local_stream, struct lttng_ht *ht) { int i = 0; struct lttng_ht_iter iter; struct lttng_consumer_stream *stream; DBG("Updating poll fd array"); - cds_lfht_for_each_entry(consumer_data.stream_ht->ht, &iter.iter, stream, - node.node) { + rcu_read_lock(); + cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) { if (stream->state != LTTNG_CONSUMER_ACTIVE_STREAM) { continue; } @@ -473,13 +813,14 @@ int consumer_update_poll_array( local_stream[i] = stream; i++; } + rcu_read_unlock(); /* - * Insert the consumer_poll_pipe at the end of the array and don't + * Insert the consumer_data_pipe at the end of the array and don't * increment i so nb_fd is the number of real FD. */ - (*pollfd)[i].fd = ctx->consumer_poll_pipe[0]; - (*pollfd)[i].events = POLLIN; + (*pollfd)[i].fd = ctx->consumer_data_pipe[0]; + (*pollfd)[i].events = POLLIN | POLLPRI; return i; } @@ -491,12 +832,19 @@ int lttng_consumer_poll_socket(struct pollfd *consumer_sockpoll) { int num_rdy; +restart: num_rdy = poll(consumer_sockpoll, 2, -1); if (num_rdy == -1) { - perror("Poll error"); + /* + * Restart interrupted system call. + */ + if (errno == EINTR) { + goto restart; + } + PERROR("Poll error"); goto exit; } - if (consumer_sockpoll[0].revents == POLLIN) { + if (consumer_sockpoll[0].revents & (POLLIN | POLLPRI)) { DBG("consumer_should_quit wake up"); goto exit; } @@ -518,7 +866,6 @@ void lttng_consumer_set_error_sock( /* * Set the command socket path. */ - void lttng_consumer_set_command_sock_path( struct lttng_consumer_local_data *ctx, char *sock) { @@ -546,31 +893,21 @@ int lttng_consumer_send_error( */ void lttng_consumer_cleanup(void) { - int ret; struct lttng_ht_iter iter; struct lttng_ht_node_ulong *node; rcu_read_lock(); - /* - * close all outfd. Called when there are no more threads running (after - * joining on the threads), no need to protect list iteration with mutex. - */ - cds_lfht_for_each_entry(consumer_data.stream_ht->ht, &iter.iter, node, - node) { - ret = lttng_ht_del(consumer_data.stream_ht, &iter); - assert(!ret); - call_rcu(&node->head, consumer_del_stream_rcu); - } - cds_lfht_for_each_entry(consumer_data.channel_ht->ht, &iter.iter, node, node) { - ret = lttng_ht_del(consumer_data.channel_ht, &iter); - assert(!ret); - call_rcu(&node->head, consumer_del_channel_rcu); + struct lttng_consumer_channel *channel = + caa_container_of(node, struct lttng_consumer_channel, node); + consumer_del_channel(channel); } rcu_read_unlock(); + + lttng_ht_destroy(consumer_data.channel_ht); } /* @@ -580,14 +917,16 @@ void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx) { int ret; consumer_quit = 1; - ret = write(ctx->consumer_should_quit[1], "4", 1); + do { + ret = write(ctx->consumer_should_quit[1], "4", 1); + } while (ret < 0 && errno == EINTR); if (ret < 0) { - perror("write consumer quit"); + PERROR("write consumer quit"); } } -void lttng_consumer_sync_trace_file( - struct lttng_consumer_stream *stream, off_t orig_offset) +void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream, + off_t orig_offset) { int outfd = stream->out_fd; @@ -639,7 +978,7 @@ void lttng_consumer_sync_trace_file( */ struct lttng_consumer_local_data *lttng_consumer_create( enum lttng_consumer_type type, - int (*buffer_ready)(struct lttng_consumer_stream *stream, + ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream, struct lttng_consumer_local_data *ctx), int (*recv_channel)(struct lttng_consumer_channel *channel), int (*recv_stream)(struct lttng_consumer_stream *stream), @@ -654,7 +993,7 @@ struct lttng_consumer_local_data *lttng_consumer_create( ctx = zmalloc(sizeof(struct lttng_consumer_local_data)); if (ctx == NULL) { - perror("allocating context"); + PERROR("allocating context"); goto error; } @@ -665,40 +1004,72 @@ struct lttng_consumer_local_data *lttng_consumer_create( ctx->on_recv_stream = recv_stream; ctx->on_update_stream = update_stream; - ret = pipe(ctx->consumer_poll_pipe); + ret = pipe(ctx->consumer_data_pipe); if (ret < 0) { - perror("Error creating poll pipe"); + PERROR("Error creating poll pipe"); goto error_poll_pipe; } + /* set read end of the pipe to non-blocking */ + ret = fcntl(ctx->consumer_data_pipe[0], F_SETFL, O_NONBLOCK); + if (ret < 0) { + PERROR("fcntl O_NONBLOCK"); + goto error_poll_fcntl; + } + + /* set write end of the pipe to non-blocking */ + ret = fcntl(ctx->consumer_data_pipe[1], F_SETFL, O_NONBLOCK); + if (ret < 0) { + PERROR("fcntl O_NONBLOCK"); + goto error_poll_fcntl; + } + ret = pipe(ctx->consumer_should_quit); if (ret < 0) { - perror("Error creating recv pipe"); + PERROR("Error creating recv pipe"); goto error_quit_pipe; } ret = pipe(ctx->consumer_thread_pipe); if (ret < 0) { - perror("Error creating thread pipe"); + PERROR("Error creating thread pipe"); goto error_thread_pipe; } - return ctx; + ret = utils_create_pipe(ctx->consumer_metadata_pipe); + if (ret < 0) { + goto error_metadata_pipe; + } + ret = utils_create_pipe(ctx->consumer_splice_metadata_pipe); + if (ret < 0) { + goto error_splice_pipe; + } + return ctx; + +error_splice_pipe: + utils_close_pipe(ctx->consumer_metadata_pipe); +error_metadata_pipe: + utils_close_pipe(ctx->consumer_thread_pipe); error_thread_pipe: for (i = 0; i < 2; i++) { int err; err = close(ctx->consumer_should_quit[i]); - assert(!err); + if (err) { + PERROR("close"); + } } +error_poll_fcntl: error_quit_pipe: for (i = 0; i < 2; i++) { int err; - err = close(ctx->consumer_poll_pipe[i]); - assert(!err); + err = close(ctx->consumer_data_pipe[i]); + if (err) { + PERROR("close"); + } } error_poll_pipe: free(ctx); @@ -711,38 +1082,195 @@ error: */ void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx) { - close(ctx->consumer_error_socket); - close(ctx->consumer_thread_pipe[0]); - close(ctx->consumer_thread_pipe[1]); - close(ctx->consumer_poll_pipe[0]); - close(ctx->consumer_poll_pipe[1]); - close(ctx->consumer_should_quit[0]); - close(ctx->consumer_should_quit[1]); + int ret; + + ret = close(ctx->consumer_error_socket); + if (ret) { + PERROR("close"); + } + ret = close(ctx->consumer_thread_pipe[0]); + if (ret) { + PERROR("close"); + } + ret = close(ctx->consumer_thread_pipe[1]); + if (ret) { + PERROR("close"); + } + ret = close(ctx->consumer_data_pipe[0]); + if (ret) { + PERROR("close"); + } + ret = close(ctx->consumer_data_pipe[1]); + if (ret) { + PERROR("close"); + } + ret = close(ctx->consumer_should_quit[0]); + if (ret) { + PERROR("close"); + } + ret = close(ctx->consumer_should_quit[1]); + if (ret) { + PERROR("close"); + } + utils_close_pipe(ctx->consumer_splice_metadata_pipe); + unlink(ctx->consumer_command_sock_path); free(ctx); } /* - * Mmap the ring buffer, read it and write the data to the tracefile. + * Write the metadata stream id on the specified file descriptor. + */ +static int write_relayd_metadata_id(int fd, + struct lttng_consumer_stream *stream, + struct consumer_relayd_sock_pair *relayd, + unsigned long padding) +{ + int ret; + struct lttcomm_relayd_metadata_payload hdr; + + hdr.stream_id = htobe64(stream->relayd_stream_id); + hdr.padding_size = htobe32(padding); + do { + ret = write(fd, (void *) &hdr, sizeof(hdr)); + } while (ret < 0 && errno == EINTR); + if (ret < 0) { + PERROR("write metadata stream id"); + goto end; + } + DBG("Metadata stream id %" PRIu64 " with padding %lu written before data", + stream->relayd_stream_id, padding); + +end: + return ret; +} + +/* + * Mmap the ring buffer, read it and write the data to the tracefile. This is a + * core function for writing trace buffers to either the local filesystem or + * the network. + * + * Careful review MUST be put if any changes occur! * * Returns the number of bytes written */ -int lttng_consumer_on_read_subbuffer_mmap( +ssize_t lttng_consumer_on_read_subbuffer_mmap( struct lttng_consumer_local_data *ctx, - struct lttng_consumer_stream *stream, unsigned long len) + struct lttng_consumer_stream *stream, unsigned long len, + unsigned long padding) { + unsigned long mmap_offset; + ssize_t ret = 0, written = 0; + off_t orig_offset = stream->out_fd_offset; + /* Default is on the disk */ + int outfd = stream->out_fd; + struct consumer_relayd_sock_pair *relayd = NULL; + + /* RCU lock for the relayd pointer */ + rcu_read_lock(); + + /* Flag that the current stream if set for network streaming. */ + if (stream->net_seq_idx != -1) { + relayd = consumer_find_relayd(stream->net_seq_idx); + if (relayd == NULL) { + goto end; + } + } + + /* get the offset inside the fd to mmap */ switch (consumer_data.type) { case LTTNG_CONSUMER_KERNEL: - return lttng_kconsumer_on_read_subbuffer_mmap(ctx, stream, len); + ret = kernctl_get_mmap_read_offset(stream->wait_fd, &mmap_offset); + break; case LTTNG_CONSUMER32_UST: case LTTNG_CONSUMER64_UST: - return lttng_ustconsumer_on_read_subbuffer_mmap(ctx, stream, len); + ret = lttng_ustctl_get_mmap_read_offset(stream->chan->handle, + stream->buf, &mmap_offset); + break; default: ERR("Unknown consumer_data type"); assert(0); } + if (ret != 0) { + errno = -ret; + PERROR("tracer ctl get_mmap_read_offset"); + written = ret; + goto end; + } - return 0; + /* Handle stream on the relayd if the output is on the network */ + if (relayd) { + unsigned long netlen = len; + + /* + * Lock the control socket for the complete duration of the function + * since from this point on we will use the socket. + */ + if (stream->metadata_flag) { + /* Metadata requires the control socket. */ + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + netlen += sizeof(struct lttcomm_relayd_metadata_payload); + } + + ret = write_relayd_stream_header(stream, netlen, padding, relayd); + if (ret >= 0) { + /* Use the returned socket. */ + outfd = ret; + + /* Write metadata stream id before payload */ + if (stream->metadata_flag) { + ret = write_relayd_metadata_id(outfd, stream, relayd, padding); + if (ret < 0) { + written = ret; + goto end; + } + } + } + /* Else, use the default set before which is the filesystem. */ + } else { + /* No streaming, we have to set the len with the full padding */ + len += padding; + } + + while (len > 0) { + do { + ret = write(outfd, stream->mmap_base + mmap_offset, len); + } while (ret < 0 && errno == EINTR); + DBG("Consumer mmap write() ret %zd (len %lu)", ret, len); + if (ret < 0) { + PERROR("Error in file write"); + if (written == 0) { + written = ret; + } + goto end; + } else if (ret > len) { + PERROR("Error in file write (ret %zd > len %lu)", ret, len); + written += ret; + goto end; + } else { + len -= ret; + mmap_offset += ret; + } + + /* This call is useless on a socket so better save a syscall. */ + if (!relayd) { + /* This won't block, but will start writeout asynchronously */ + lttng_sync_file_range(outfd, stream->out_fd_offset, ret, + SYNC_FILE_RANGE_WRITE); + stream->out_fd_offset += ret; + } + written += ret; + } + lttng_consumer_sync_trace_file(stream, orig_offset); + +end: + /* Unlock only if ctrl socket used */ + if (relayd && stream->metadata_flag) { + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + } + + rcu_read_unlock(); + return written; } /* @@ -750,103 +1278,685 @@ int lttng_consumer_on_read_subbuffer_mmap( * * Returns the number of bytes spliced. */ -int lttng_consumer_on_read_subbuffer_splice( +ssize_t lttng_consumer_on_read_subbuffer_splice( + struct lttng_consumer_local_data *ctx, + struct lttng_consumer_stream *stream, unsigned long len, + unsigned long padding) +{ + ssize_t ret = 0, written = 0, ret_splice = 0; + loff_t offset = 0; + off_t orig_offset = stream->out_fd_offset; + int fd = stream->wait_fd; + /* Default is on the disk */ + int outfd = stream->out_fd; + struct consumer_relayd_sock_pair *relayd = NULL; + int *splice_pipe; + + switch (consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + /* Not supported for user space tracing */ + return -ENOSYS; + default: + ERR("Unknown consumer_data type"); + assert(0); + } + + /* RCU lock for the relayd pointer */ + rcu_read_lock(); + + /* Flag that the current stream if set for network streaming. */ + if (stream->net_seq_idx != -1) { + relayd = consumer_find_relayd(stream->net_seq_idx); + if (relayd == NULL) { + goto end; + } + } + + /* + * Choose right pipe for splice. Metadata and trace data are handled by + * different threads hence the use of two pipes in order not to race or + * corrupt the written data. + */ + if (stream->metadata_flag) { + splice_pipe = ctx->consumer_splice_metadata_pipe; + } else { + splice_pipe = ctx->consumer_thread_pipe; + } + + /* Write metadata stream id before payload */ + if (relayd) { + int total_len = len; + + if (stream->metadata_flag) { + /* + * Lock the control socket for the complete duration of the function + * since from this point on we will use the socket. + */ + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + + ret = write_relayd_metadata_id(splice_pipe[1], stream, relayd, + padding); + if (ret < 0) { + written = ret; + goto end; + } + + total_len += sizeof(struct lttcomm_relayd_metadata_payload); + } + + ret = write_relayd_stream_header(stream, total_len, padding, relayd); + if (ret >= 0) { + /* Use the returned socket. */ + outfd = ret; + } else { + ERR("Remote relayd disconnected. Stopping"); + goto end; + } + } else { + /* No streaming, we have to set the len with the full padding */ + len += padding; + } + + while (len > 0) { + DBG("splice chan to pipe offset %lu of len %lu (fd : %d, pipe: %d)", + (unsigned long)offset, len, fd, splice_pipe[1]); + ret_splice = splice(fd, &offset, splice_pipe[1], NULL, len, + SPLICE_F_MOVE | SPLICE_F_MORE); + DBG("splice chan to pipe, ret %zd", ret_splice); + if (ret_splice < 0) { + PERROR("Error in relay splice"); + if (written == 0) { + written = ret_splice; + } + ret = errno; + goto splice_error; + } + + /* Handle stream on the relayd if the output is on the network */ + if (relayd) { + if (stream->metadata_flag) { + size_t metadata_payload_size = + sizeof(struct lttcomm_relayd_metadata_payload); + + /* Update counter to fit the spliced data */ + ret_splice += metadata_payload_size; + len += metadata_payload_size; + /* + * We do this so the return value can match the len passed as + * argument to this function. + */ + written -= metadata_payload_size; + } + } + + /* Splice data out */ + ret_splice = splice(splice_pipe[0], NULL, outfd, NULL, + ret_splice, SPLICE_F_MOVE | SPLICE_F_MORE); + DBG("Consumer splice pipe to file, ret %zd", ret_splice); + if (ret_splice < 0) { + PERROR("Error in file splice"); + if (written == 0) { + written = ret_splice; + } + ret = errno; + goto splice_error; + } else if (ret_splice > len) { + errno = EINVAL; + PERROR("Wrote more data than requested %zd (len: %lu)", + ret_splice, len); + written += ret_splice; + ret = errno; + goto splice_error; + } + len -= ret_splice; + + /* This call is useless on a socket so better save a syscall. */ + if (!relayd) { + /* This won't block, but will start writeout asynchronously */ + lttng_sync_file_range(outfd, stream->out_fd_offset, ret_splice, + SYNC_FILE_RANGE_WRITE); + stream->out_fd_offset += ret_splice; + } + written += ret_splice; + } + lttng_consumer_sync_trace_file(stream, orig_offset); + + ret = ret_splice; + + goto end; + +splice_error: + /* send the appropriate error description to sessiond */ + switch (ret) { + case EBADF: + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_EBADF); + break; + case EINVAL: + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_EINVAL); + break; + case ENOMEM: + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_ENOMEM); + break; + case ESPIPE: + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_ESPIPE); + break; + } + +end: + if (relayd && stream->metadata_flag) { + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + } + + rcu_read_unlock(); + return written; +} + +/* + * Take a snapshot for a specific fd + * + * Returns 0 on success, < 0 on error + */ +int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx, + struct lttng_consumer_stream *stream) +{ + switch (consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + return lttng_kconsumer_take_snapshot(ctx, stream); + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + return lttng_ustconsumer_take_snapshot(ctx, stream); + default: + ERR("Unknown consumer_data type"); + assert(0); + return -ENOSYS; + } + +} + +/* + * Get the produced position + * + * Returns 0 on success, < 0 on error + */ +int lttng_consumer_get_produced_snapshot( struct lttng_consumer_local_data *ctx, - struct lttng_consumer_stream *stream, unsigned long len) + struct lttng_consumer_stream *stream, + unsigned long *pos) { switch (consumer_data.type) { case LTTNG_CONSUMER_KERNEL: - return lttng_kconsumer_on_read_subbuffer_splice(ctx, stream, len); + return lttng_kconsumer_get_produced_snapshot(ctx, stream, pos); case LTTNG_CONSUMER32_UST: case LTTNG_CONSUMER64_UST: + return lttng_ustconsumer_get_produced_snapshot(ctx, stream, pos); + default: + ERR("Unknown consumer_data type"); + assert(0); return -ENOSYS; + } +} + +int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx, + int sock, struct pollfd *consumer_sockpoll) +{ + switch (consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + return lttng_kconsumer_recv_cmd(ctx, sock, consumer_sockpoll); + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + return lttng_ustconsumer_recv_cmd(ctx, sock, consumer_sockpoll); default: ERR("Unknown consumer_data type"); assert(0); return -ENOSYS; } +} + +/* + * Iterate over all streams of the hashtable and free them properly. + * + * WARNING: *MUST* be used with data stream only. + */ +static void destroy_data_stream_ht(struct lttng_ht *ht) +{ + int ret; + struct lttng_ht_iter iter; + struct lttng_consumer_stream *stream; + + if (ht == NULL) { + return; + } + + rcu_read_lock(); + cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) { + ret = lttng_ht_del(ht, &iter); + assert(!ret); + + call_rcu(&stream->node.head, consumer_free_stream); + } + rcu_read_unlock(); + + lttng_ht_destroy(ht); +} + +/* + * Iterate over all streams of the hashtable and free them properly. + * + * XXX: Should not be only for metadata stream or else use an other name. + */ +static void destroy_stream_ht(struct lttng_ht *ht) +{ + int ret; + struct lttng_ht_iter iter; + struct lttng_consumer_stream *stream; + + if (ht == NULL) { + return; + } + + rcu_read_lock(); + cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) { + ret = lttng_ht_del(ht, &iter); + assert(!ret); + + call_rcu(&stream->node.head, consumer_free_stream); + } + rcu_read_unlock(); + + lttng_ht_destroy(ht); +} + +/* + * Clean up a metadata stream and free its memory. + */ +void consumer_del_metadata_stream(struct lttng_consumer_stream *stream, + struct lttng_ht *ht) +{ + int ret; + struct lttng_ht_iter iter; + struct lttng_consumer_channel *free_chan = NULL; + struct consumer_relayd_sock_pair *relayd; + + assert(stream); + /* + * This call should NEVER receive regular stream. It must always be + * metadata stream and this is crucial for data structure synchronization. + */ + assert(stream->metadata_flag); + + DBG3("Consumer delete metadata stream %d", stream->wait_fd); + + if (ht == NULL) { + /* Means the stream was allocated but not successfully added */ + goto free_stream; + } + + pthread_mutex_lock(&consumer_data.lock); + 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 metadata stream"); + } + } + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + lttng_ustconsumer_del_stream(stream); + break; + default: + ERR("Unknown consumer_data type"); + assert(0); + goto end; + } + + rcu_read_lock(); + iter.iter.node = &stream->node.node; + ret = lttng_ht_del(ht, &iter); + assert(!ret); + + /* Remove node session id from the consumer_data stream ht */ + iter.iter.node = &stream->node_session_id.node; + ret = lttng_ht_del(consumer_data.stream_list_ht, &iter); + assert(!ret); + rcu_read_unlock(); + + if (stream->out_fd >= 0) { + ret = close(stream->out_fd); + if (ret) { + PERROR("close"); + } + } + + if (stream->wait_fd >= 0 && !stream->wait_fd_is_copy) { + ret = close(stream->wait_fd); + if (ret) { + PERROR("close"); + } + } + + if (stream->shm_fd >= 0 && stream->wait_fd != stream->shm_fd) { + ret = close(stream->shm_fd); + if (ret) { + PERROR("close"); + } + } + + /* Check and cleanup relayd */ + rcu_read_lock(); + relayd = consumer_find_relayd(stream->net_seq_idx); + if (relayd != NULL) { + 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)) { + destroy_relayd(relayd); + } + } + rcu_read_unlock(); + + /* Atomically decrement channel refcount since other threads can use it. */ + uatomic_dec(&stream->chan->refcount); + if (!uatomic_read(&stream->chan->refcount) + && !uatomic_read(&stream->chan->nb_init_streams)) { + /* Go for channel deletion! */ + free_chan = stream->chan; + } +end: + pthread_mutex_unlock(&consumer_data.lock); + + if (free_chan) { + consumer_del_channel(free_chan); + } + +free_stream: + call_rcu(&stream->node.head, consumer_free_stream); } /* - * Take a snapshot for a specific fd - * - * Returns 0 on success, < 0 on error + * Action done with the metadata stream when adding it to the consumer internal + * data structures to handle it. */ -int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx, - struct lttng_consumer_stream *stream) +static int consumer_add_metadata_stream(struct lttng_consumer_stream *stream, + struct lttng_ht *ht) { - switch (consumer_data.type) { - case LTTNG_CONSUMER_KERNEL: - return lttng_kconsumer_take_snapshot(ctx, stream); - case LTTNG_CONSUMER32_UST: - case LTTNG_CONSUMER64_UST: - return lttng_ustconsumer_take_snapshot(ctx, stream); - default: - ERR("Unknown consumer_data type"); - assert(0); - return -ENOSYS; + int ret = 0; + struct consumer_relayd_sock_pair *relayd; + + assert(stream); + assert(ht); + + DBG3("Adding metadata stream %d to hash table", stream->wait_fd); + + pthread_mutex_lock(&consumer_data.lock); + + /* + * From here, refcounts are updated so be _careful_ when returning an error + * after this point. + */ + + rcu_read_lock(); + /* Find relayd and, if one is found, increment refcount. */ + relayd = consumer_find_relayd(stream->net_seq_idx); + if (relayd != NULL) { + uatomic_inc(&relayd->refcount); + } + + /* Update channel refcount once added without error(s). */ + uatomic_inc(&stream->chan->refcount); + + /* + * When nb_init_streams reaches 0, we don't need to trigger any action in + * terms of destroying the associated channel, because the action that + * causes the count to become 0 also causes a stream to be added. The + * channel deletion will thus be triggered by the following removal of this + * stream. + */ + if (uatomic_read(&stream->chan->nb_init_streams) > 0) { + uatomic_dec(&stream->chan->nb_init_streams); } + /* Steal stream identifier to avoid having streams with the same key */ + consumer_steal_stream_key(stream->key, ht); + + lttng_ht_add_unique_ulong(ht, &stream->node); + + /* + * Add stream to the stream_list_ht of the consumer data. No need to steal + * the key since the HT does not use it and we allow to add redundant keys + * into this table. + */ + lttng_ht_add_ulong(consumer_data.stream_list_ht, &stream->node_session_id); + + rcu_read_unlock(); + + pthread_mutex_unlock(&consumer_data.lock); + return ret; } /* - * Get the produced position - * - * Returns 0 on success, < 0 on error + * Thread polls on metadata file descriptor and write them on disk or on the + * network. */ -int lttng_consumer_get_produced_snapshot( - struct lttng_consumer_local_data *ctx, - struct lttng_consumer_stream *stream, - unsigned long *pos) +void *consumer_thread_metadata_poll(void *data) { - switch (consumer_data.type) { - case LTTNG_CONSUMER_KERNEL: - return lttng_kconsumer_get_produced_snapshot(ctx, stream, pos); - case LTTNG_CONSUMER32_UST: - case LTTNG_CONSUMER64_UST: - return lttng_ustconsumer_get_produced_snapshot(ctx, stream, pos); - default: - ERR("Unknown consumer_data type"); - assert(0); - return -ENOSYS; + int ret, i, pollfd; + uint32_t revents, nb_fd; + struct lttng_consumer_stream *stream = NULL; + struct lttng_ht_iter iter; + struct lttng_ht_node_ulong *node; + struct lttng_poll_event events; + struct lttng_consumer_local_data *ctx = data; + ssize_t len; + + rcu_register_thread(); + + DBG("Thread metadata poll started"); + + /* Size is set to 1 for the consumer_metadata pipe */ + ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC); + if (ret < 0) { + ERR("Poll set creation failed"); + goto end; } -} -int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx, - int sock, struct pollfd *consumer_sockpoll) -{ - switch (consumer_data.type) { - case LTTNG_CONSUMER_KERNEL: - return lttng_kconsumer_recv_cmd(ctx, sock, consumer_sockpoll); - case LTTNG_CONSUMER32_UST: - case LTTNG_CONSUMER64_UST: - return lttng_ustconsumer_recv_cmd(ctx, sock, consumer_sockpoll); - default: - ERR("Unknown consumer_data type"); - assert(0); - return -ENOSYS; + ret = lttng_poll_add(&events, ctx->consumer_metadata_pipe[0], LPOLLIN); + if (ret < 0) { + goto end; + } + + /* Main loop */ + DBG("Metadata main loop started"); + + while (1) { + lttng_poll_reset(&events); + + nb_fd = LTTNG_POLL_GETNB(&events); + + /* Only the metadata pipe is set */ + if (nb_fd == 0 && consumer_quit == 1) { + goto end; + } + +restart: + DBG("Metadata poll wait with %d fd(s)", nb_fd); + ret = lttng_poll_wait(&events, -1); + DBG("Metadata event catched in thread"); + if (ret < 0) { + if (errno == EINTR) { + ERR("Poll EINTR catched"); + goto restart; + } + goto error; + } + + /* From here, the event is a metadata wait fd */ + for (i = 0; i < nb_fd; i++) { + revents = LTTNG_POLL_GETEV(&events, i); + pollfd = LTTNG_POLL_GETFD(&events, i); + + /* Just don't waste time if no returned events for the fd */ + if (!revents) { + continue; + } + + if (pollfd == ctx->consumer_metadata_pipe[0]) { + if (revents & (LPOLLERR | LPOLLHUP )) { + DBG("Metadata thread pipe hung up"); + /* + * Remove the pipe from the poll set and continue the loop + * since their might be data to consume. + */ + lttng_poll_del(&events, ctx->consumer_metadata_pipe[0]); + close(ctx->consumer_metadata_pipe[0]); + continue; + } else if (revents & LPOLLIN) { + do { + /* Get the stream pointer received */ + ret = read(pollfd, &stream, sizeof(stream)); + } while (ret < 0 && errno == EINTR); + if (ret < 0 || + ret < sizeof(struct lttng_consumer_stream *)) { + PERROR("read metadata stream"); + /* + * Let's continue here and hope we can still work + * without stopping the consumer. XXX: Should we? + */ + continue; + } + + DBG("Adding metadata stream %d to poll set", + stream->wait_fd); + + ret = consumer_add_metadata_stream(stream, metadata_ht); + if (ret) { + ERR("Unable to add metadata stream"); + /* Stream was not setup properly. Continuing. */ + consumer_del_metadata_stream(stream, NULL); + continue; + } + + /* Add metadata stream to the global poll events list */ + lttng_poll_add(&events, stream->wait_fd, + LPOLLIN | LPOLLPRI); + } + + /* Handle other stream */ + continue; + } + + rcu_read_lock(); + lttng_ht_lookup(metadata_ht, (void *)((unsigned long) pollfd), + &iter); + node = lttng_ht_iter_get_node_ulong(&iter); + assert(node); + + stream = caa_container_of(node, struct lttng_consumer_stream, + node); + + /* Check for error event */ + if (revents & (LPOLLERR | LPOLLHUP)) { + DBG("Metadata fd %d is hup|err.", pollfd); + if (!stream->hangup_flush_done + && (consumer_data.type == LTTNG_CONSUMER32_UST + || consumer_data.type == LTTNG_CONSUMER64_UST)) { + DBG("Attempting to flush and consume the UST buffers"); + lttng_ustconsumer_on_stream_hangup(stream); + + /* We just flushed the stream now read it. */ + do { + len = ctx->on_buffer_ready(stream, ctx); + /* + * We don't check the return value here since if we get + * a negative len, it means an error occured thus we + * simply remove it from the poll set and free the + * stream. + */ + } while (len > 0); + } + + lttng_poll_del(&events, stream->wait_fd); + /* + * This call update the channel states, closes file descriptors + * and securely free the stream. + */ + consumer_del_metadata_stream(stream, metadata_ht); + } else if (revents & (LPOLLIN | LPOLLPRI)) { + /* Get the data out of the metadata file descriptor */ + DBG("Metadata available on fd %d", pollfd); + assert(stream->wait_fd == pollfd); + + len = ctx->on_buffer_ready(stream, ctx); + /* It's ok to have an unavailable sub-buffer */ + if (len < 0 && len != -EAGAIN && len != -ENODATA) { + rcu_read_unlock(); + goto end; + } else if (len > 0) { + stream->data_read = 1; + } + } + + /* Release RCU lock for the stream looked up */ + rcu_read_unlock(); + } + } + +error: +end: + DBG("Metadata poll thread exiting"); + lttng_poll_clean(&events); + + if (metadata_ht) { + destroy_stream_ht(metadata_ht); } + + rcu_unregister_thread(); + return NULL; } /* * This thread polls the fds in the set to consume the data and write * it to tracefile if necessary. */ -void *lttng_consumer_thread_poll_fds(void *data) +void *consumer_thread_data_poll(void *data) { int num_rdy, num_hup, high_prio, ret, i; struct pollfd *pollfd = NULL; /* local view of the streams */ - struct lttng_consumer_stream **local_stream = NULL; + struct lttng_consumer_stream **local_stream = NULL, *new_stream = NULL; /* local view of consumer_data.fds_count */ int nb_fd = 0; - char tmp; - int tmp2; struct lttng_consumer_local_data *ctx = data; + ssize_t len; rcu_register_thread(); + data_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); + if (data_ht == NULL) { + goto end; + } + local_stream = zmalloc(sizeof(struct lttng_consumer_stream)); while (1) { @@ -868,26 +1978,27 @@ void *lttng_consumer_thread_poll_fds(void *data) local_stream = NULL; } - /* allocate for all fds + 1 for the consumer_poll_pipe */ + /* allocate for all fds + 1 for the consumer_data_pipe */ pollfd = zmalloc((consumer_data.stream_count + 1) * sizeof(struct pollfd)); if (pollfd == NULL) { - perror("pollfd malloc"); + PERROR("pollfd malloc"); pthread_mutex_unlock(&consumer_data.lock); goto end; } - /* allocate for all fds + 1 for the consumer_poll_pipe */ + /* allocate for all fds + 1 for the consumer_data_pipe */ local_stream = zmalloc((consumer_data.stream_count + 1) * sizeof(struct lttng_consumer_stream)); if (local_stream == NULL) { - perror("local_stream malloc"); + PERROR("local_stream malloc"); pthread_mutex_unlock(&consumer_data.lock); goto end; } - ret = consumer_update_poll_array(ctx, &pollfd, local_stream); + ret = consumer_update_poll_array(ctx, &pollfd, local_stream, + data_ht); if (ret < 0) { ERR("Error in allocating pollfd or local_outfds"); - lttng_consumer_send_error(ctx, CONSUMERD_POLL_ERROR); + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR); pthread_mutex_unlock(&consumer_data.lock); goto end; } @@ -896,36 +2007,66 @@ void *lttng_consumer_thread_poll_fds(void *data) } pthread_mutex_unlock(&consumer_data.lock); + /* No FDs and consumer_quit, consumer_cleanup the thread */ + if (nb_fd == 0 && consumer_quit == 1) { + goto end; + } /* poll on the array of fds */ + restart: DBG("polling on %d fd", nb_fd + 1); num_rdy = poll(pollfd, nb_fd + 1, consumer_poll_timeout); DBG("poll num_rdy : %d", num_rdy); if (num_rdy == -1) { - perror("Poll error"); - lttng_consumer_send_error(ctx, CONSUMERD_POLL_ERROR); + /* + * Restart interrupted system call. + */ + if (errno == EINTR) { + goto restart; + } + PERROR("Poll error"); + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR); goto end; } else if (num_rdy == 0) { DBG("Polling thread timed out"); goto end; } - /* No FDs and consumer_quit, consumer_cleanup the thread */ - if (nb_fd == 0 && consumer_quit == 1) { - goto end; - } - /* - * If the consumer_poll_pipe triggered poll go - * directly to the beginning of the loop to update the - * array. We want to prioritize array update over - * low-priority reads. + * If the consumer_data_pipe triggered poll go directly to the + * beginning of the loop to update the array. We want to prioritize + * array update over low-priority reads. */ - if (pollfd[nb_fd].revents & POLLIN) { - DBG("consumer_poll_pipe wake up"); - tmp2 = read(ctx->consumer_poll_pipe[0], &tmp, 1); - if (tmp2 < 0) { - perror("read consumer poll"); + if (pollfd[nb_fd].revents & (POLLIN | POLLPRI)) { + size_t pipe_readlen; + + DBG("consumer_data_pipe wake up"); + /* Consume 1 byte of pipe data */ + do { + pipe_readlen = read(ctx->consumer_data_pipe[0], &new_stream, + sizeof(new_stream)); + } while (pipe_readlen == -1 && errno == EINTR); + + /* + * If the stream is NULL, just ignore it. It's also possible that + * the sessiond poll thread changed the consumer_quit state and is + * waking us up to test it. + */ + if (new_stream == NULL) { + continue; + } + + ret = consumer_add_stream(new_stream, data_ht); + if (ret) { + ERR("Consumer add stream %d failed. Continuing", + new_stream->key); + /* + * At this point, if the add_stream fails, it is not in the + * hash table thus passing the NULL value here. + */ + consumer_del_stream(new_stream, NULL); } + + /* Continue to update the local streams and handle prio ones */ continue; } @@ -934,67 +2075,76 @@ void *lttng_consumer_thread_poll_fds(void *data) if (pollfd[i].revents & POLLPRI) { DBG("Urgent read on fd %d", pollfd[i].fd); high_prio = 1; - ret = ctx->on_buffer_ready(local_stream[i], ctx); + len = ctx->on_buffer_ready(local_stream[i], ctx); /* it's ok to have an unavailable sub-buffer */ - if (ret == EAGAIN) { - ret = 0; - } - } else if (pollfd[i].revents & POLLERR) { - ERR("Error returned in polling fd %d.", pollfd[i].fd); - rcu_read_lock(); - consumer_del_stream_rcu(&local_stream[i]->node.head); - rcu_read_unlock(); - num_hup++; - } else if (pollfd[i].revents & POLLNVAL) { - ERR("Polling fd %d tells fd is not open.", pollfd[i].fd); - rcu_read_lock(); - consumer_del_stream_rcu(&local_stream[i]->node.head); - rcu_read_unlock(); - num_hup++; - } else if ((pollfd[i].revents & POLLHUP) && - !(pollfd[i].revents & POLLIN)) { - if (consumer_data.type == LTTNG_CONSUMER32_UST - || consumer_data.type == LTTNG_CONSUMER64_UST) { - DBG("Polling fd %d tells it has hung up. Attempting flush and read.", - pollfd[i].fd); - if (!local_stream[i]->hangup_flush_done) { - lttng_ustconsumer_on_stream_hangup(local_stream[i]); - /* read after flush */ - do { - ret = ctx->on_buffer_ready(local_stream[i], ctx); - } while (ret == EAGAIN); - } - } else { - DBG("Polling fd %d tells it has hung up.", pollfd[i].fd); + if (len < 0 && len != -EAGAIN && len != -ENODATA) { + goto end; + } else if (len > 0) { + local_stream[i]->data_read = 1; } - rcu_read_lock(); - consumer_del_stream_rcu(&local_stream[i]->node.head); - rcu_read_unlock(); - num_hup++; } } - /* If every buffer FD has hung up, we end the read loop here */ - if (nb_fd > 0 && num_hup == nb_fd) { - DBG("every buffer FD has hung up\n"); - if (consumer_quit == 1) { - goto end; - } + /* + * If we read high prio channel in this loop, try again + * for more high prio data. + */ + if (high_prio) { continue; } /* Take care of low priority channels. */ - if (high_prio == 0) { - for (i = 0; i < nb_fd; i++) { - if (pollfd[i].revents & POLLIN) { - DBG("Normal read on fd %d", pollfd[i].fd); - ret = ctx->on_buffer_ready(local_stream[i], ctx); - /* it's ok to have an unavailable subbuffer */ - if (ret == EAGAIN) { - ret = 0; - } + for (i = 0; i < nb_fd; i++) { + if ((pollfd[i].revents & POLLIN) || + local_stream[i]->hangup_flush_done) { + DBG("Normal read on fd %d", pollfd[i].fd); + len = ctx->on_buffer_ready(local_stream[i], ctx); + /* it's ok to have an unavailable sub-buffer */ + if (len < 0 && len != -EAGAIN && len != -ENODATA) { + goto end; + } else if (len > 0) { + local_stream[i]->data_read = 1; + } + } + } + + /* Handle hangup and errors */ + for (i = 0; i < nb_fd; i++) { + if (!local_stream[i]->hangup_flush_done + && (pollfd[i].revents & (POLLHUP | POLLERR | POLLNVAL)) + && (consumer_data.type == LTTNG_CONSUMER32_UST + || consumer_data.type == LTTNG_CONSUMER64_UST)) { + DBG("fd %d is hup|err|nval. Attempting flush and read.", + pollfd[i].fd); + lttng_ustconsumer_on_stream_hangup(local_stream[i]); + /* Attempt read again, for the data we just flushed. */ + local_stream[i]->data_read = 1; + } + /* + * If the poll flag is HUP/ERR/NVAL and we have + * read no data in this pass, we can remove the + * stream from its hash table. + */ + if ((pollfd[i].revents & POLLHUP)) { + DBG("Polling fd %d tells it has hung up.", pollfd[i].fd); + if (!local_stream[i]->data_read) { + consumer_del_stream(local_stream[i], data_ht); + num_hup++; + } + } else if (pollfd[i].revents & POLLERR) { + ERR("Error returned in polling fd %d.", pollfd[i].fd); + if (!local_stream[i]->data_read) { + consumer_del_stream(local_stream[i], data_ht); + num_hup++; + } + } else if (pollfd[i].revents & POLLNVAL) { + ERR("Polling fd %d tells fd is not open.", pollfd[i].fd); + if (!local_stream[i]->data_read) { + consumer_del_stream(local_stream[i], data_ht); + num_hup++; } } + local_stream[i]->data_read = 0; } } end: @@ -1007,6 +2157,21 @@ end: free(local_stream); local_stream = NULL; } + + /* + * Close the write side of the pipe so epoll_wait() in + * consumer_thread_metadata_poll can catch it. The thread is monitoring the + * read side of the pipe. If we close them both, epoll_wait strangely does + * not return and could create a endless wait period if the pipe is the + * only tracked fd in the poll set. The thread will take care of closing + * the read side. + */ + close(ctx->consumer_metadata_pipe[1]); + + if (data_ht) { + destroy_data_stream_ht(data_ht); + } + rcu_unregister_thread(); return NULL; } @@ -1015,7 +2180,7 @@ end: * This thread listens on the consumerd socket and receives the file * descriptors from the session daemon. */ -void *lttng_consumer_thread_receive_fds(void *data) +void *consumer_thread_sessiond_poll(void *data) { int sock, client_socket, ret; /* @@ -1041,7 +2206,7 @@ void *lttng_consumer_thread_receive_fds(void *data) } DBG("Sending ready command to lttng-sessiond"); - ret = lttng_consumer_send_error(ctx, CONSUMERD_COMMAND_SOCK_READY); + ret = lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_COMMAND_SOCK_READY); /* return < 0 on error, but == 0 is not fatal */ if (ret < 0) { ERR("Error sending ready command to lttng-sessiond"); @@ -1050,7 +2215,7 @@ void *lttng_consumer_thread_receive_fds(void *data) ret = fcntl(client_socket, F_SETFL, O_NONBLOCK); if (ret < 0) { - perror("fcntl O_NONBLOCK"); + PERROR("fcntl O_NONBLOCK"); goto end; } @@ -1073,7 +2238,7 @@ void *lttng_consumer_thread_receive_fds(void *data) } ret = fcntl(sock, F_SETFL, O_NONBLOCK); if (ret < 0) { - perror("fcntl O_NONBLOCK"); + PERROR("fcntl O_NONBLOCK"); goto end; } @@ -1091,8 +2256,12 @@ void *lttng_consumer_thread_receive_fds(void *data) DBG("Received STOP command"); goto end; } - if (ret < 0) { - ERR("Communication interrupted on command socket"); + if (ret <= 0) { + /* + * This could simply be a session daemon quitting. Don't output + * ERR() here. + */ + DBG("Communication interrupted on command socket"); goto end; } if (consumer_quit) { @@ -1117,16 +2286,22 @@ end: */ consumer_poll_timeout = LTTNG_CONSUMER_POLL_TIMEOUT; - /* wake up the polling thread */ - ret = write(ctx->consumer_poll_pipe[1], "4", 1); - if (ret < 0) { - perror("poll pipe write"); - } + /* + * Notify the data poll thread to poll back again and test the + * consumer_quit state to quit gracefully. + */ + do { + struct lttng_consumer_stream *null_stream = NULL; + + ret = write(ctx->consumer_data_pipe[1], &null_stream, + sizeof(null_stream)); + } while (ret < 0 && errno == EINTR); + rcu_unregister_thread(); return NULL; } -int lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream, +ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream, struct lttng_consumer_local_data *ctx) { switch (consumer_data.type) { @@ -1162,7 +2337,167 @@ int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream) */ void lttng_consumer_init(void) { - consumer_data.stream_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); consumer_data.channel_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); + consumer_data.relayd_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); + consumer_data.stream_list_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); + + metadata_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); + assert(metadata_ht); + data_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG); + assert(data_ht); +} + +/* + * Process the ADD_RELAYD command receive by a consumer. + * + * This will create a relayd socket pair and add it to the relayd hash table. + * The caller MUST acquire a RCU read side lock before calling it. + */ +int consumer_add_relayd_socket(int net_seq_idx, int sock_type, + struct lttng_consumer_local_data *ctx, int sock, + struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock) +{ + int fd, ret = -1; + struct consumer_relayd_sock_pair *relayd; + + DBG("Consumer adding relayd socket (idx: %d)", net_seq_idx); + + /* Get relayd reference if exists. */ + relayd = consumer_find_relayd(net_seq_idx); + if (relayd == NULL) { + /* Not found. Allocate one. */ + relayd = consumer_allocate_relayd_sock_pair(net_seq_idx); + if (relayd == NULL) { + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); + goto error; + } + } + + /* Poll on consumer socket. */ + if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { + ret = -EINTR; + goto error; + } + + /* Get relayd socket from session daemon */ + ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); + if (ret != sizeof(fd)) { + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD); + ret = -1; + goto error; + } + + /* Copy socket information and received FD */ + switch (sock_type) { + case LTTNG_STREAM_CONTROL: + /* Copy received lttcomm socket */ + lttcomm_copy_sock(&relayd->control_sock, relayd_sock); + ret = lttcomm_create_sock(&relayd->control_sock); + if (ret < 0) { + goto error; + } + + /* Close the created socket fd which is useless */ + close(relayd->control_sock.fd); + + /* Assign new file descriptor */ + relayd->control_sock.fd = fd; + break; + case LTTNG_STREAM_DATA: + /* Copy received lttcomm socket */ + lttcomm_copy_sock(&relayd->data_sock, relayd_sock); + ret = lttcomm_create_sock(&relayd->data_sock); + if (ret < 0) { + goto error; + } + + /* Close the created socket fd which is useless */ + close(relayd->data_sock.fd); + + /* Assign new file descriptor */ + relayd->data_sock.fd = fd; + break; + default: + ERR("Unknown relayd socket type (%d)", sock_type); + goto error; + } + + DBG("Consumer %s socket created successfully with net idx %d (fd: %d)", + sock_type == LTTNG_STREAM_CONTROL ? "control" : "data", + relayd->net_seq_idx, fd); + + /* + * Add relayd socket pair to consumer data hashtable. If object already + * exists or on error, the function gracefully returns. + */ + add_relayd(relayd); + + /* All good! */ + ret = 0; + +error: + return ret; } +/* + * Check if for a given session id there is still data needed to be extract + * from the buffers. + * + * Return 1 if data is in fact available to be read or else 0. + */ +int consumer_data_available(uint64_t id) +{ + int ret; + struct lttng_ht_iter iter; + struct lttng_ht *ht; + struct lttng_consumer_stream *stream; + int (*data_available)(struct lttng_consumer_stream *); + + DBG("Consumer data available command on session id %" PRIu64, id); + + pthread_mutex_lock(&consumer_data.lock); + + switch (consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + data_available = lttng_kconsumer_data_available; + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + data_available = lttng_ustconsumer_data_available; + break; + default: + ERR("Unknown consumer data type"); + assert(0); + } + + /* Ease our life a bit */ + ht = consumer_data.stream_list_ht; + + cds_lfht_for_each_entry_duplicate(ht->ht, (long unsigned int) ht->hash_fct, + ht->match_fct, (void *)((unsigned long) id), + &iter.iter, stream, node_session_id.node) { + /* Check the stream for data. */ + ret = data_available(stream); + if (ret == 0) { + goto data_not_available; + } + } + + /* TODO: Support to ask the relayd if the streams are remote */ + + /* + * Finding _no_ node in the hash table means that the stream(s) have been + * removed thus data is guaranteed to be available for analysis from the + * trace files. This is *only* true for local consumer and not network + * streaming. + */ + + /* Data is available to be read by a viewer. */ + pthread_mutex_unlock(&consumer_data.lock); + return 1; + +data_not_available: + /* Data is still being extracted from buffers. */ + pthread_mutex_unlock(&consumer_data.lock); + return 0; +}