X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fconsumer%2Fconsumer.cpp;fp=src%2Fcommon%2Fconsumer%2Fconsumer.cpp;h=47bb5bd98b1a1fbf0c10a8795672ca1af0a556e9;hp=0000000000000000000000000000000000000000;hb=97535efaa975ca52bf02c2d5e76351bfd2e3defa;hpb=7fe0498a9173fca00dcd45a41847e629b70cd941 diff --git a/src/common/consumer/consumer.cpp b/src/common/consumer/consumer.cpp new file mode 100644 index 000000000..47bb5bd98 --- /dev/null +++ b/src/common/consumer/consumer.cpp @@ -0,0 +1,5255 @@ +/* + * Copyright (C) 2011 Julien Desfossez + * Copyright (C) 2011 Mathieu Desnoyers + * Copyright (C) 2012 David Goulet + * + * SPDX-License-Identifier: GPL-2.0-only + * + */ + +#include "common/index/ctf-index.h" +#define _LGPL_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +lttng_consumer_global_data the_consumer_data; + +enum consumer_channel_action { + CONSUMER_CHANNEL_ADD, + CONSUMER_CHANNEL_DEL, + CONSUMER_CHANNEL_QUIT, +}; + +struct consumer_channel_msg { + enum consumer_channel_action action; + struct lttng_consumer_channel *chan; /* add */ + uint64_t key; /* del */ +}; + +/* Flag used to temporarily pause data consumption from testpoints. */ +int data_consumption_paused; + +/* + * Flag to inform the polling thread to quit when all fd hung up. Updated by + * the consumer_thread_receive_fds when it notices that all fds has hung up. + * Also updated by the signal handler (consumer_should_exit()). Read by the + * polling threads. + */ +int consumer_quit; + +/* + * 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. + */ +static struct lttng_ht *metadata_ht; +static struct lttng_ht *data_ht; + +static const char *get_consumer_domain(void) +{ + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + return DEFAULT_KERNEL_TRACE_DIR; + case LTTNG_CONSUMER64_UST: + /* Fall-through. */ + case LTTNG_CONSUMER32_UST: + return DEFAULT_UST_TRACE_DIR; + default: + abort(); + } +} + +/* + * Notify a thread lttng pipe to poll back again. This usually means that some + * global state has changed so we just send back the thread in a poll wait + * call. + */ +static void notify_thread_lttng_pipe(struct lttng_pipe *pipe) +{ + struct lttng_consumer_stream *null_stream = NULL; + + LTTNG_ASSERT(pipe); + + (void) lttng_pipe_write(pipe, &null_stream, sizeof(null_stream)); +} + +static void notify_health_quit_pipe(int *pipe) +{ + ssize_t ret; + + ret = lttng_write(pipe[1], "4", 1); + if (ret < 1) { + PERROR("write consumer health quit"); + } +} + +static void notify_channel_pipe(struct lttng_consumer_local_data *ctx, + struct lttng_consumer_channel *chan, + uint64_t key, + enum consumer_channel_action action) +{ + struct consumer_channel_msg msg; + ssize_t ret; + + memset(&msg, 0, sizeof(msg)); + + msg.action = action; + msg.chan = chan; + msg.key = key; + ret = lttng_write(ctx->consumer_channel_pipe[1], &msg, sizeof(msg)); + if (ret < sizeof(msg)) { + PERROR("notify_channel_pipe write error"); + } +} + +void notify_thread_del_channel(struct lttng_consumer_local_data *ctx, + uint64_t key) +{ + notify_channel_pipe(ctx, NULL, key, CONSUMER_CHANNEL_DEL); +} + +static int read_channel_pipe(struct lttng_consumer_local_data *ctx, + struct lttng_consumer_channel **chan, + uint64_t *key, + enum consumer_channel_action *action) +{ + struct consumer_channel_msg msg; + ssize_t ret; + + ret = lttng_read(ctx->consumer_channel_pipe[0], &msg, sizeof(msg)); + if (ret < sizeof(msg)) { + ret = -1; + goto error; + } + *action = msg.action; + *chan = msg.chan; + *key = msg.key; +error: + return (int) ret; +} + +/* + * Cleanup the stream list of a channel. Those streams are not yet globally + * visible + */ +static void clean_channel_stream_list(struct lttng_consumer_channel *channel) +{ + struct lttng_consumer_stream *stream, *stmp; + + LTTNG_ASSERT(channel); + + /* Delete streams that might have been left in the stream list. */ + cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head, + send_node) { + cds_list_del(&stream->send_node); + /* + * Once a stream is added to this list, the buffers were created so we + * have a guarantee that this call will succeed. Setting the monitor + * mode to 0 so we don't lock nor try to delete the stream from the + * global hash table. + */ + stream->monitor = 0; + consumer_stream_destroy(stream, NULL); + } +} + +/* + * Find a stream. The consumer_data.lock must be locked during this + * call. + */ +static struct lttng_consumer_stream *find_stream(uint64_t key, + struct lttng_ht *ht) +{ + struct lttng_ht_iter iter; + struct lttng_ht_node_u64 *node; + struct lttng_consumer_stream *stream = NULL; + + LTTNG_ASSERT(ht); + + /* -1ULL keys are lookup failures */ + if (key == (uint64_t) -1ULL) { + return NULL; + } + + rcu_read_lock(); + + lttng_ht_lookup(ht, &key, &iter); + node = lttng_ht_iter_get_node_u64(&iter); + if (node != NULL) { + stream = caa_container_of(node, struct lttng_consumer_stream, node); + } + + rcu_read_unlock(); + + return stream; +} + +static void steal_stream_key(uint64_t key, struct lttng_ht *ht) +{ + struct lttng_consumer_stream *stream; + + rcu_read_lock(); + stream = find_stream(key, ht); + if (stream) { + stream->key = (uint64_t) -1ULL; + /* + * 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 = (uint64_t) -1ULL; + } + rcu_read_unlock(); +} + +/* + * Return a channel object for the given key. + * + * RCU read side lock MUST be acquired before calling this function and + * protects the channel ptr. + */ +struct lttng_consumer_channel *consumer_find_channel(uint64_t key) +{ + struct lttng_ht_iter iter; + struct lttng_ht_node_u64 *node; + struct lttng_consumer_channel *channel = NULL; + + /* -1ULL keys are lookup failures */ + if (key == (uint64_t) -1ULL) { + return NULL; + } + + lttng_ht_lookup(the_consumer_data.channel_ht, &key, &iter); + node = lttng_ht_iter_get_node_u64(&iter); + if (node != NULL) { + channel = caa_container_of(node, struct lttng_consumer_channel, node); + } + + return channel; +} + +/* + * There is a possibility that the consumer does not have enough time between + * the close of the channel on the session daemon and the cleanup in here thus + * once we have a channel add with an existing key, we know for sure that this + * channel will eventually get cleaned up by all streams being closed. + * + * This function just nullifies the already existing channel key. + */ +static void steal_channel_key(uint64_t key) +{ + struct lttng_consumer_channel *channel; + + rcu_read_lock(); + channel = consumer_find_channel(key); + if (channel) { + channel->key = (uint64_t) -1ULL; + /* + * 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 = (uint64_t) -1ULL; + } + rcu_read_unlock(); +} + +static void free_channel_rcu(struct rcu_head *head) +{ + struct lttng_ht_node_u64 *node = + caa_container_of(head, struct lttng_ht_node_u64, head); + struct lttng_consumer_channel *channel = + caa_container_of(node, struct lttng_consumer_channel, node); + + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + lttng_ustconsumer_free_channel(channel); + break; + default: + ERR("Unknown consumer_data type"); + abort(); + } + free(channel); +} + +/* + * RCU protected relayd socket pair free. + */ +static void free_relayd_rcu(struct rcu_head *head) +{ + struct lttng_ht_node_u64 *node = + caa_container_of(head, struct lttng_ht_node_u64, head); + struct consumer_relayd_sock_pair *relayd = + caa_container_of(node, struct consumer_relayd_sock_pair, node); + + /* + * Close all sockets. This is done in the call RCU since we don't want the + * socket fds to be reassigned thus potentially creating bad state of the + * relayd object. + * + * We do not have to lock the control socket mutex here since at this stage + * there is no one referencing to this relayd object. + */ + (void) relayd_close(&relayd->control_sock); + (void) relayd_close(&relayd->data_sock); + + pthread_mutex_destroy(&relayd->ctrl_sock_mutex); + free(relayd); +} + +/* + * Destroy and free relayd socket pair object. + */ +void consumer_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(the_consumer_data.relayd_ht, &iter); + if (ret != 0) { + /* We assume the relayd is being or is destroyed */ + return; + } + + /* RCU free() call */ + call_rcu(&relayd->node.head, free_relayd_rcu); +} + +/* + * Remove a channel from the global list protected by a mutex. This function is + * also responsible for freeing its data structures. + */ +void consumer_del_channel(struct lttng_consumer_channel *channel) +{ + struct lttng_ht_iter iter; + + DBG("Consumer delete channel key %" PRIu64, channel->key); + + pthread_mutex_lock(&the_consumer_data.lock); + pthread_mutex_lock(&channel->lock); + + /* Destroy streams that might have been left in the stream list. */ + clean_channel_stream_list(channel); + + if (channel->live_timer_enabled == 1) { + consumer_timer_live_stop(channel); + } + if (channel->monitor_timer_enabled == 1) { + consumer_timer_monitor_stop(channel); + } + + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + lttng_ustconsumer_del_channel(channel); + break; + default: + ERR("Unknown consumer_data type"); + abort(); + goto end; + } + + lttng_trace_chunk_put(channel->trace_chunk); + channel->trace_chunk = NULL; + + if (channel->is_published) { + int ret; + + rcu_read_lock(); + iter.iter.node = &channel->node.node; + ret = lttng_ht_del(the_consumer_data.channel_ht, &iter); + LTTNG_ASSERT(!ret); + + iter.iter.node = &channel->channels_by_session_id_ht_node.node; + ret = lttng_ht_del(the_consumer_data.channels_by_session_id_ht, + &iter); + LTTNG_ASSERT(!ret); + rcu_read_unlock(); + } + + channel->is_deleted = true; + call_rcu(&channel->node.head, free_channel_rcu); +end: + pthread_mutex_unlock(&channel->lock); + pthread_mutex_unlock(&the_consumer_data.lock); +} + +/* + * Iterate over the relayd hash table and destroy each element. Finally, + * destroy the whole hash table. + */ +static void cleanup_relayd_ht(void) +{ + struct lttng_ht_iter iter; + struct consumer_relayd_sock_pair *relayd; + + rcu_read_lock(); + + cds_lfht_for_each_entry(the_consumer_data.relayd_ht->ht, &iter.iter, + relayd, node.node) { + consumer_destroy_relayd(relayd); + } + + rcu_read_unlock(); + + lttng_ht_destroy(the_consumer_data.relayd_ht); +} + +/* + * Update the end point status of all streams having the given network sequence + * index (relayd index). + * + * It's atomically set without having the stream mutex locked which is fine + * because we handle the write/read race with a pipe wakeup for each thread. + */ +static void update_endpoint_status_by_netidx(uint64_t net_seq_idx, + enum consumer_endpoint_status status) +{ + struct lttng_ht_iter iter; + struct lttng_consumer_stream *stream; + + DBG("Consumer set delete flag on stream by idx %" PRIu64, net_seq_idx); + + rcu_read_lock(); + + /* Let's begin with metadata */ + cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream, node.node) { + if (stream->net_seq_idx == net_seq_idx) { + uatomic_set(&stream->endpoint_status, status); + DBG("Delete flag set to metadata stream %d", stream->wait_fd); + } + } + + /* Follow up by the data streams */ + cds_lfht_for_each_entry(data_ht->ht, &iter.iter, stream, node.node) { + if (stream->net_seq_idx == net_seq_idx) { + uatomic_set(&stream->endpoint_status, status); + DBG("Delete flag set to data stream %d", stream->wait_fd); + } + } + rcu_read_unlock(); +} + +/* + * Cleanup a relayd object by flagging every associated streams for deletion, + * destroying the object meaning removing it from the relayd hash table, + * closing the sockets and freeing the memory in a RCU call. + * + * If a local data context is available, notify the threads that the streams' + * state have changed. + */ +void lttng_consumer_cleanup_relayd(struct consumer_relayd_sock_pair *relayd) +{ + uint64_t netidx; + + LTTNG_ASSERT(relayd); + + DBG("Cleaning up relayd object ID %" PRIu64, relayd->net_seq_idx); + + /* Save the net sequence index before destroying the object */ + netidx = relayd->net_seq_idx; + + /* + * Delete the relayd from the relayd hash table, close the sockets and free + * the object in a RCU call. + */ + consumer_destroy_relayd(relayd); + + /* Set inactive endpoint to all streams */ + update_endpoint_status_by_netidx(netidx, CONSUMER_ENDPOINT_INACTIVE); + + /* + * With a local data context, notify the threads that the streams' state + * have changed. The write() action on the pipe acts as an "implicit" + * memory barrier ordering the updates of the end point status from the + * read of this status which happens AFTER receiving this notify. + */ + notify_thread_lttng_pipe(relayd->ctx->consumer_data_pipe); + notify_thread_lttng_pipe(relayd->ctx->consumer_metadata_pipe); +} + +/* + * 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) +{ + LTTNG_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) { + consumer_destroy_relayd(relayd); + } +} + +/* + * Completly destroy stream from every visiable data structure and the given + * hash table if one. + * + * One this call returns, the stream object is not longer usable nor visible. + */ +void consumer_del_stream(struct lttng_consumer_stream *stream, + struct lttng_ht *ht) +{ + consumer_stream_destroy(stream, ht); +} + +/* + * XXX naming of del vs destroy is all mixed up. + */ +void consumer_del_stream_for_data(struct lttng_consumer_stream *stream) +{ + consumer_stream_destroy(stream, data_ht); +} + +void consumer_del_stream_for_metadata(struct lttng_consumer_stream *stream) +{ + consumer_stream_destroy(stream, metadata_ht); +} + +void consumer_stream_update_channel_attributes( + struct lttng_consumer_stream *stream, + struct lttng_consumer_channel *channel) +{ + stream->channel_read_only_attributes.tracefile_size = + channel->tracefile_size; +} + +/* + * Add a stream to the global list protected by a mutex. + */ +void consumer_add_data_stream(struct lttng_consumer_stream *stream) +{ + struct lttng_ht *ht = data_ht; + + LTTNG_ASSERT(stream); + LTTNG_ASSERT(ht); + + DBG3("Adding consumer stream %" PRIu64, stream->key); + + pthread_mutex_lock(&the_consumer_data.lock); + pthread_mutex_lock(&stream->chan->lock); + pthread_mutex_lock(&stream->chan->timer_lock); + pthread_mutex_lock(&stream->lock); + rcu_read_lock(); + + /* Steal stream identifier to avoid having streams with the same key */ + steal_stream_key(stream->key, ht); + + lttng_ht_add_unique_u64(ht, &stream->node); + + lttng_ht_add_u64(the_consumer_data.stream_per_chan_id_ht, + &stream->node_channel_id); + + /* + * 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_u64(the_consumer_data.stream_list_ht, + &stream->node_session_id); + + /* + * When nb_init_stream_left 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_stream_left) > 0) { + /* Increment refcount before decrementing nb_init_stream_left */ + cmm_smp_wmb(); + uatomic_dec(&stream->chan->nb_init_stream_left); + } + + /* Update consumer data once the node is inserted. */ + the_consumer_data.stream_count++; + the_consumer_data.need_update = 1; + + rcu_read_unlock(); + pthread_mutex_unlock(&stream->lock); + pthread_mutex_unlock(&stream->chan->timer_lock); + pthread_mutex_unlock(&stream->chan->lock); + pthread_mutex_unlock(&the_consumer_data.lock); +} + +/* + * 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_u64 *node; + struct lttng_ht_iter iter; + + LTTNG_ASSERT(relayd); + + lttng_ht_lookup(the_consumer_data.relayd_ht, &relayd->net_seq_idx, + &iter); + node = lttng_ht_iter_get_node_u64(&iter); + if (node != NULL) { + goto end; + } + lttng_ht_add_unique_u64(the_consumer_data.relayd_ht, &relayd->node); + +end: + return ret; +} + +/* + * Allocate and return a consumer relayd socket. + */ +static struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair( + uint64_t net_seq_idx) +{ + struct consumer_relayd_sock_pair *obj = NULL; + + /* net sequence index of -1 is a failure */ + if (net_seq_idx == (uint64_t) -1ULL) { + goto error; + } + + obj = (consumer_relayd_sock_pair *) 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; + obj->control_sock.sock.fd = -1; + obj->data_sock.sock.fd = -1; + lttng_ht_node_init_u64(&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(uint64_t key) +{ + struct lttng_ht_iter iter; + struct lttng_ht_node_u64 *node; + struct consumer_relayd_sock_pair *relayd = NULL; + + /* Negative keys are lookup failures */ + if (key == (uint64_t) -1ULL) { + goto error; + } + + lttng_ht_lookup(the_consumer_data.relayd_ht, &key, &iter); + node = lttng_ht_iter_get_node_u64(&iter); + if (node != NULL) { + relayd = caa_container_of(node, struct consumer_relayd_sock_pair, node); + } + +error: + return relayd; +} + +/* + * Find a relayd and send the stream + * + * Returns 0 on success, < 0 on error + */ +int consumer_send_relayd_stream(struct lttng_consumer_stream *stream, + char *path) +{ + int ret = 0; + struct consumer_relayd_sock_pair *relayd; + + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->net_seq_idx != -1ULL); + LTTNG_ASSERT(path); + + /* The stream is not metadata. Get relayd reference if exists. */ + rcu_read_lock(); + relayd = consumer_find_relayd(stream->net_seq_idx); + if (relayd != NULL) { + /* Add stream on the relayd */ + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + ret = relayd_add_stream(&relayd->control_sock, stream->name, + get_consumer_domain(), path, &stream->relayd_stream_id, + stream->chan->tracefile_size, + stream->chan->tracefile_count, + stream->trace_chunk); + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + if (ret < 0) { + ERR("Relayd add stream failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx); + lttng_consumer_cleanup_relayd(relayd); + goto end; + } + + uatomic_inc(&relayd->refcount); + stream->sent_to_relayd = 1; + } else { + ERR("Stream %" PRIu64 " relayd ID %" PRIu64 " unknown. Can't send it.", + stream->key, stream->net_seq_idx); + ret = -1; + goto end; + } + + DBG("Stream %s with key %" PRIu64 " sent to relayd id %" PRIu64, + stream->name, stream->key, stream->net_seq_idx); + +end: + rcu_read_unlock(); + return ret; +} + +/* + * Find a relayd and send the streams sent message + * + * Returns 0 on success, < 0 on error + */ +int consumer_send_relayd_streams_sent(uint64_t net_seq_idx) +{ + int ret = 0; + struct consumer_relayd_sock_pair *relayd; + + LTTNG_ASSERT(net_seq_idx != -1ULL); + + /* The stream is not metadata. Get relayd reference if exists. */ + rcu_read_lock(); + relayd = consumer_find_relayd(net_seq_idx); + if (relayd != NULL) { + /* Add stream on the relayd */ + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + ret = relayd_streams_sent(&relayd->control_sock); + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + if (ret < 0) { + ERR("Relayd streams sent failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx); + lttng_consumer_cleanup_relayd(relayd); + goto end; + } + } else { + ERR("Relayd ID %" PRIu64 " unknown. Can't send streams_sent.", + net_seq_idx); + ret = -1; + goto end; + } + + ret = 0; + DBG("All streams sent relayd id %" PRIu64, net_seq_idx); + +end: + rcu_read_unlock(); + return ret; +} + +/* + * Find a relayd and close the stream + */ +void close_relayd_stream(struct lttng_consumer_stream *stream) +{ + struct consumer_relayd_sock_pair *relayd; + + /* The stream is not metadata. Get relayd reference if exists. */ + rcu_read_lock(); + relayd = consumer_find_relayd(stream->net_seq_idx); + if (relayd) { + consumer_stream_relayd_close(stream, relayd); + } + rcu_read_unlock(); +} + +/* + * 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 */ + LTTNG_ASSERT(stream); + LTTNG_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.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); + + /* + * Note that net_seq_num below is assigned with the *current* value of + * next_net_seq_num and only after that the next_net_seq_num will be + * increment. This is why when issuing a command on the relayd using + * this next value, 1 should always be substracted in order to compare + * the last seen sequence number on the relayd side to the last sent. + */ + 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; + } + + ++stream->next_net_seq_num; + + /* Set to go on data socket */ + outfd = relayd->data_sock.sock.fd; + } + +error: + return outfd; +} + +/* + * Write a character on the metadata poll pipe to wake the metadata thread. + * Returns 0 on success, -1 on error. + */ +int consumer_metadata_wakeup_pipe(const struct lttng_consumer_channel *channel) +{ + int ret = 0; + + DBG("Waking up metadata poll thread (writing to pipe): channel name = '%s'", + channel->name); + if (channel->monitor && channel->metadata_stream) { + const char dummy = 'c'; + const ssize_t write_ret = lttng_write( + channel->metadata_stream->ust_metadata_poll_pipe[1], + &dummy, 1); + + if (write_ret < 1) { + if (errno == EWOULDBLOCK) { + /* + * This is fine, the metadata poll thread + * is having a hard time keeping-up, but + * it will eventually wake-up and consume + * the available data. + */ + ret = 0; + } else { + PERROR("Failed to write to UST metadata pipe while attempting to wake-up the metadata poll thread"); + ret = -1; + goto end; + } + } + } + +end: + return ret; +} + +/* + * Trigger a dump of the metadata content. Following/during the succesful + * completion of this call, the metadata poll thread will start receiving + * metadata packets to consume. + * + * The caller must hold the channel and stream locks. + */ +static +int consumer_metadata_stream_dump(struct lttng_consumer_stream *stream) +{ + int ret; + + ASSERT_LOCKED(stream->chan->lock); + ASSERT_LOCKED(stream->lock); + LTTNG_ASSERT(stream->metadata_flag); + LTTNG_ASSERT(stream->chan->trace_chunk); + + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + /* + * Reset the position of what has been read from the + * metadata cache to 0 so we can dump it again. + */ + ret = kernctl_metadata_cache_dump(stream->wait_fd); + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + /* + * Reset the position pushed from the metadata cache so it + * will write from the beginning on the next push. + */ + stream->ust_metadata_pushed = 0; + ret = consumer_metadata_wakeup_pipe(stream->chan); + break; + default: + ERR("Unknown consumer_data type"); + abort(); + } + if (ret < 0) { + ERR("Failed to dump the metadata cache"); + } + return ret; +} + +static +int lttng_consumer_channel_set_trace_chunk( + struct lttng_consumer_channel *channel, + struct lttng_trace_chunk *new_trace_chunk) +{ + pthread_mutex_lock(&channel->lock); + if (channel->is_deleted) { + /* + * The channel has been logically deleted and should no longer + * be used. It has released its reference to its current trace + * chunk and should not acquire a new one. + * + * Return success as there is nothing for the caller to do. + */ + goto end; + } + + /* + * The acquisition of the reference cannot fail (barring + * a severe internal error) since a reference to the published + * chunk is already held by the caller. + */ + if (new_trace_chunk) { + const bool acquired_reference = lttng_trace_chunk_get( + new_trace_chunk); + + LTTNG_ASSERT(acquired_reference); + } + + lttng_trace_chunk_put(channel->trace_chunk); + channel->trace_chunk = new_trace_chunk; +end: + pthread_mutex_unlock(&channel->lock); + return 0; +} + +/* + * Allocate and return a new lttng_consumer_channel object using the given key + * to initialize the hash table node. + * + * On error, return NULL. + */ +struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key, + uint64_t session_id, + const uint64_t *chunk_id, + const char *pathname, + const char *name, + uint64_t relayd_id, + enum lttng_event_output output, + uint64_t tracefile_size, + uint64_t tracefile_count, + uint64_t session_id_per_pid, + unsigned int monitor, + unsigned int live_timer_interval, + bool is_in_live_session, + const char *root_shm_path, + const char *shm_path) +{ + struct lttng_consumer_channel *channel = NULL; + struct lttng_trace_chunk *trace_chunk = NULL; + + if (chunk_id) { + trace_chunk = lttng_trace_chunk_registry_find_chunk( + the_consumer_data.chunk_registry, session_id, + *chunk_id); + if (!trace_chunk) { + ERR("Failed to find trace chunk reference during creation of channel"); + goto end; + } + } + + channel = (lttng_consumer_channel *) zmalloc(sizeof(*channel)); + if (channel == NULL) { + PERROR("malloc struct lttng_consumer_channel"); + goto end; + } + + channel->key = key; + channel->refcount = 0; + channel->session_id = session_id; + channel->session_id_per_pid = session_id_per_pid; + channel->relayd_id = relayd_id; + channel->tracefile_size = tracefile_size; + channel->tracefile_count = tracefile_count; + channel->monitor = monitor; + channel->live_timer_interval = live_timer_interval; + channel->is_live = is_in_live_session; + pthread_mutex_init(&channel->lock, NULL); + pthread_mutex_init(&channel->timer_lock, NULL); + + switch (output) { + case LTTNG_EVENT_SPLICE: + channel->output = CONSUMER_CHANNEL_SPLICE; + break; + case LTTNG_EVENT_MMAP: + channel->output = CONSUMER_CHANNEL_MMAP; + break; + default: + abort(); + free(channel); + channel = NULL; + goto end; + } + + /* + * In monitor mode, the streams associated with the channel will be put in + * a special list ONLY owned by this channel. So, the refcount is set to 1 + * here meaning that the channel itself has streams that are referenced. + * + * On a channel deletion, once the channel is no longer visible, the + * refcount is decremented and checked for a zero value to delete it. With + * streams in no monitor mode, it will now be safe to destroy the channel. + */ + if (!channel->monitor) { + channel->refcount = 1; + } + + strncpy(channel->pathname, pathname, sizeof(channel->pathname)); + channel->pathname[sizeof(channel->pathname) - 1] = '\0'; + + strncpy(channel->name, name, sizeof(channel->name)); + channel->name[sizeof(channel->name) - 1] = '\0'; + + if (root_shm_path) { + strncpy(channel->root_shm_path, root_shm_path, sizeof(channel->root_shm_path)); + channel->root_shm_path[sizeof(channel->root_shm_path) - 1] = '\0'; + } + if (shm_path) { + strncpy(channel->shm_path, shm_path, sizeof(channel->shm_path)); + channel->shm_path[sizeof(channel->shm_path) - 1] = '\0'; + } + + lttng_ht_node_init_u64(&channel->node, channel->key); + lttng_ht_node_init_u64(&channel->channels_by_session_id_ht_node, + channel->session_id); + + channel->wait_fd = -1; + CDS_INIT_LIST_HEAD(&channel->streams.head); + + if (trace_chunk) { + int ret = lttng_consumer_channel_set_trace_chunk(channel, + trace_chunk); + if (ret) { + goto error; + } + } + + DBG("Allocated channel (key %" PRIu64 ")", channel->key); + +end: + lttng_trace_chunk_put(trace_chunk); + return channel; +error: + consumer_del_channel(channel); + channel = NULL; + goto end; +} + +/* + * Add a channel to the global list protected by a mutex. + * + * Always return 0 indicating success. + */ +int consumer_add_channel(struct lttng_consumer_channel *channel, + struct lttng_consumer_local_data *ctx) +{ + pthread_mutex_lock(&the_consumer_data.lock); + pthread_mutex_lock(&channel->lock); + pthread_mutex_lock(&channel->timer_lock); + + /* + * This gives us a guarantee that the channel we are about to add to the + * channel hash table will be unique. See this function comment on the why + * we need to steel the channel key at this stage. + */ + steal_channel_key(channel->key); + + rcu_read_lock(); + lttng_ht_add_unique_u64(the_consumer_data.channel_ht, &channel->node); + lttng_ht_add_u64(the_consumer_data.channels_by_session_id_ht, + &channel->channels_by_session_id_ht_node); + rcu_read_unlock(); + channel->is_published = true; + + pthread_mutex_unlock(&channel->timer_lock); + pthread_mutex_unlock(&channel->lock); + pthread_mutex_unlock(&the_consumer_data.lock); + + if (channel->wait_fd != -1 && channel->type == CONSUMER_CHANNEL_TYPE_DATA) { + notify_channel_pipe(ctx, channel, -1, CONSUMER_CHANNEL_ADD); + } + + return 0; +} + +/* + * Allocate the pollfd structure and the local view of the out fds to avoid + * doing a lookup in the linked list and concurrency issues when writing is + * needed. Called with consumer_data.lock held. + * + * Returns the number of fds in the structures. + */ +static int update_poll_array(struct lttng_consumer_local_data *ctx, + struct pollfd **pollfd, struct lttng_consumer_stream **local_stream, + struct lttng_ht *ht, int *nb_inactive_fd) +{ + int i = 0; + struct lttng_ht_iter iter; + struct lttng_consumer_stream *stream; + + LTTNG_ASSERT(ctx); + LTTNG_ASSERT(ht); + LTTNG_ASSERT(pollfd); + LTTNG_ASSERT(local_stream); + + DBG("Updating poll fd array"); + *nb_inactive_fd = 0; + rcu_read_lock(); + cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) { + /* + * Only active streams with an active end point can be added to the + * poll set and local stream storage of the thread. + * + * There is a potential race here for endpoint_status to be updated + * just after the check. However, this is OK since the stream(s) will + * be deleted once the thread is notified that the end point state has + * changed where this function will be called back again. + * + * We track the number of inactive FDs because they still need to be + * closed by the polling thread after a wakeup on the data_pipe or + * metadata_pipe. + */ + if (stream->endpoint_status == CONSUMER_ENDPOINT_INACTIVE) { + (*nb_inactive_fd)++; + continue; + } + /* + * This clobbers way too much the debug output. Uncomment that if you + * need it for debugging purposes. + */ + (*pollfd)[i].fd = stream->wait_fd; + (*pollfd)[i].events = POLLIN | POLLPRI; + local_stream[i] = stream; + i++; + } + rcu_read_unlock(); + + /* + * 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 = lttng_pipe_get_readfd(ctx->consumer_data_pipe); + (*pollfd)[i].events = POLLIN | POLLPRI; + + (*pollfd)[i + 1].fd = lttng_pipe_get_readfd(ctx->consumer_wakeup_pipe); + (*pollfd)[i + 1].events = POLLIN | POLLPRI; + return i; +} + +/* + * Poll on the should_quit pipe and the command socket return -1 on + * error, 1 if should exit, 0 if data is available on the command socket + */ +int lttng_consumer_poll_socket(struct pollfd *consumer_sockpoll) +{ + int num_rdy; + +restart: + num_rdy = poll(consumer_sockpoll, 2, -1); + if (num_rdy == -1) { + /* + * Restart interrupted system call. + */ + if (errno == EINTR) { + goto restart; + } + PERROR("Poll error"); + return -1; + } + if (consumer_sockpoll[0].revents & (POLLIN | POLLPRI)) { + DBG("consumer_should_quit wake up"); + return 1; + } + return 0; +} + +/* + * Set the error socket. + */ +void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx, + int sock) +{ + ctx->consumer_error_socket = sock; +} + +/* + * Set the command socket path. + */ +void lttng_consumer_set_command_sock_path( + struct lttng_consumer_local_data *ctx, char *sock) +{ + ctx->consumer_command_sock_path = sock; +} + +/* + * Send return code to the session daemon. + * If the socket is not defined, we return 0, it is not a fatal error + */ +int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd) +{ + if (ctx->consumer_error_socket > 0) { + return lttcomm_send_unix_sock(ctx->consumer_error_socket, &cmd, + sizeof(enum lttcomm_sessiond_command)); + } + + return 0; +} + +/* + * Close all the tracefiles and stream fds and MUST be called when all + * instances are destroyed i.e. when all threads were joined and are ended. + */ +void lttng_consumer_cleanup(void) +{ + struct lttng_ht_iter iter; + struct lttng_consumer_channel *channel; + unsigned int trace_chunks_left; + + rcu_read_lock(); + + cds_lfht_for_each_entry(the_consumer_data.channel_ht->ht, &iter.iter, + channel, node.node) { + consumer_del_channel(channel); + } + + rcu_read_unlock(); + + lttng_ht_destroy(the_consumer_data.channel_ht); + lttng_ht_destroy(the_consumer_data.channels_by_session_id_ht); + + cleanup_relayd_ht(); + + lttng_ht_destroy(the_consumer_data.stream_per_chan_id_ht); + + /* + * This HT contains streams that are freed by either the metadata thread or + * the data thread so we do *nothing* on the hash table and simply destroy + * it. + */ + lttng_ht_destroy(the_consumer_data.stream_list_ht); + + /* + * Trace chunks in the registry may still exist if the session + * daemon has encountered an internal error and could not + * tear down its sessions and/or trace chunks properly. + * + * Release the session daemon's implicit reference to any remaining + * trace chunk and print an error if any trace chunk was found. Note + * that there are _no_ legitimate cases for trace chunks to be left, + * it is a leak. However, it can happen following a crash of the + * session daemon and not emptying the registry would cause an assertion + * to hit. + */ + trace_chunks_left = lttng_trace_chunk_registry_put_each_chunk( + the_consumer_data.chunk_registry); + if (trace_chunks_left) { + ERR("%u trace chunks are leaked by lttng-consumerd. " + "This can be caused by an internal error of the session daemon.", + trace_chunks_left); + } + /* Run all callbacks freeing each chunk. */ + rcu_barrier(); + lttng_trace_chunk_registry_destroy(the_consumer_data.chunk_registry); +} + +/* + * Called from signal handler. + */ +void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx) +{ + ssize_t ret; + + CMM_STORE_SHARED(consumer_quit, 1); + ret = lttng_write(ctx->consumer_should_quit[1], "4", 1); + if (ret < 1) { + PERROR("write consumer quit"); + } + + DBG("Consumer flag that it should quit"); +} + + +/* + * Flush pending writes to trace output disk file. + */ +static +void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream, + off_t orig_offset) +{ + int ret; + int outfd = stream->out_fd; + + /* + * This does a blocking write-and-wait on any page that belongs to the + * subbuffer prior to the one we just wrote. + * Don't care about error values, as these are just hints and ways to + * limit the amount of page cache used. + */ + if (orig_offset < stream->max_sb_size) { + return; + } + lttng_sync_file_range(outfd, orig_offset - stream->max_sb_size, + stream->max_sb_size, + SYNC_FILE_RANGE_WAIT_BEFORE + | SYNC_FILE_RANGE_WRITE + | SYNC_FILE_RANGE_WAIT_AFTER); + /* + * Give hints to the kernel about how we access the file: + * POSIX_FADV_DONTNEED : we won't re-access data in a near future after + * we write it. + * + * We need to call fadvise again after the file grows because the + * kernel does not seem to apply fadvise to non-existing parts of the + * file. + * + * Call fadvise _after_ having waited for the page writeback to + * complete because the dirty page writeback semantic is not well + * defined. So it can be expected to lead to lower throughput in + * streaming. + */ + ret = posix_fadvise(outfd, orig_offset - stream->max_sb_size, + stream->max_sb_size, POSIX_FADV_DONTNEED); + if (ret && ret != -ENOSYS) { + errno = ret; + PERROR("posix_fadvise on fd %i", outfd); + } +} + +/* + * Initialise the necessary environnement : + * - create a new context + * - create the poll_pipe + * - create the should_quit pipe (for signal handler) + * - create the thread pipe (for splice) + * + * Takes a function pointer as argument, this function is called when data is + * available on a buffer. This function is responsible to do the + * kernctl_get_next_subbuf, read the data with mmap or splice depending on the + * buffer configuration and then kernctl_put_next_subbuf at the end. + * + * Returns a pointer to the new context or NULL on error. + */ +struct lttng_consumer_local_data *lttng_consumer_create( + enum lttng_consumer_type type, + ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream, + struct lttng_consumer_local_data *ctx, bool locked_by_caller), + int (*recv_channel)(struct lttng_consumer_channel *channel), + int (*recv_stream)(struct lttng_consumer_stream *stream), + int (*update_stream)(uint64_t stream_key, uint32_t state)) +{ + int ret; + struct lttng_consumer_local_data *ctx; + + LTTNG_ASSERT(the_consumer_data.type == LTTNG_CONSUMER_UNKNOWN || + the_consumer_data.type == type); + the_consumer_data.type = type; + + ctx = (lttng_consumer_local_data *) zmalloc(sizeof(struct lttng_consumer_local_data)); + if (ctx == NULL) { + PERROR("allocating context"); + goto error; + } + + ctx->consumer_error_socket = -1; + ctx->consumer_metadata_socket = -1; + pthread_mutex_init(&ctx->metadata_socket_lock, NULL); + /* assign the callbacks */ + ctx->on_buffer_ready = buffer_ready; + ctx->on_recv_channel = recv_channel; + ctx->on_recv_stream = recv_stream; + ctx->on_update_stream = update_stream; + + ctx->consumer_data_pipe = lttng_pipe_open(0); + if (!ctx->consumer_data_pipe) { + goto error_poll_pipe; + } + + ctx->consumer_wakeup_pipe = lttng_pipe_open(0); + if (!ctx->consumer_wakeup_pipe) { + goto error_wakeup_pipe; + } + + ret = pipe(ctx->consumer_should_quit); + if (ret < 0) { + PERROR("Error creating recv pipe"); + goto error_quit_pipe; + } + + ret = pipe(ctx->consumer_channel_pipe); + if (ret < 0) { + PERROR("Error creating channel pipe"); + goto error_channel_pipe; + } + + ctx->consumer_metadata_pipe = lttng_pipe_open(0); + if (!ctx->consumer_metadata_pipe) { + goto error_metadata_pipe; + } + + ctx->channel_monitor_pipe = -1; + + return ctx; + +error_metadata_pipe: + utils_close_pipe(ctx->consumer_channel_pipe); +error_channel_pipe: + utils_close_pipe(ctx->consumer_should_quit); +error_quit_pipe: + lttng_pipe_destroy(ctx->consumer_wakeup_pipe); +error_wakeup_pipe: + lttng_pipe_destroy(ctx->consumer_data_pipe); +error_poll_pipe: + free(ctx); +error: + return NULL; +} + +/* + * Iterate over all streams of the hashtable and free them properly. + */ +static void destroy_data_stream_ht(struct lttng_ht *ht) +{ + 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) { + /* + * Ignore return value since we are currently cleaning up so any error + * can't be handled. + */ + (void) consumer_del_stream(stream, ht); + } + rcu_read_unlock(); + + lttng_ht_destroy(ht); +} + +/* + * Iterate over all streams of the metadata hashtable and free them + * properly. + */ +static void destroy_metadata_stream_ht(struct lttng_ht *ht) +{ + 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) { + /* + * Ignore return value since we are currently cleaning up so any error + * can't be handled. + */ + (void) consumer_del_metadata_stream(stream, ht); + } + rcu_read_unlock(); + + lttng_ht_destroy(ht); +} + +/* + * Close all fds associated with the instance and free the context. + */ +void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx) +{ + int ret; + + DBG("Consumer destroying it. Closing everything."); + + if (!ctx) { + return; + } + + destroy_data_stream_ht(data_ht); + destroy_metadata_stream_ht(metadata_ht); + + ret = close(ctx->consumer_error_socket); + if (ret) { + PERROR("close"); + } + ret = close(ctx->consumer_metadata_socket); + if (ret) { + PERROR("close"); + } + utils_close_pipe(ctx->consumer_channel_pipe); + lttng_pipe_destroy(ctx->consumer_data_pipe); + lttng_pipe_destroy(ctx->consumer_metadata_pipe); + lttng_pipe_destroy(ctx->consumer_wakeup_pipe); + utils_close_pipe(ctx->consumer_should_quit); + + unlink(ctx->consumer_command_sock_path); + free(ctx); +} + +/* + * Write the metadata stream id on the specified file descriptor. + */ +static int write_relayd_metadata_id(int fd, + struct lttng_consumer_stream *stream, + unsigned long padding) +{ + ssize_t ret; + struct lttcomm_relayd_metadata_payload hdr; + + hdr.stream_id = htobe64(stream->relayd_stream_id); + hdr.padding_size = htobe32(padding); + ret = lttng_write(fd, (void *) &hdr, sizeof(hdr)); + if (ret < sizeof(hdr)) { + /* + * This error means that the fd's end is closed so ignore the PERROR + * not to clubber the error output since this can happen in a normal + * code path. + */ + if (errno != EPIPE) { + PERROR("write metadata stream id"); + } + DBG3("Consumer failed to write relayd metadata id (errno: %d)", errno); + /* + * Set ret to a negative value because if ret != sizeof(hdr), we don't + * handle writting the missing part so report that as an error and + * don't lie to the caller. + */ + ret = -1; + goto end; + } + DBG("Metadata stream id %" PRIu64 " with padding %lu written before data", + stream->relayd_stream_id, padding); + +end: + return (int) 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. + * + * It must be called with the stream and the channel lock held. + * + * Careful review MUST be put if any changes occur! + * + * Returns the number of bytes written + */ +ssize_t lttng_consumer_on_read_subbuffer_mmap( + struct lttng_consumer_stream *stream, + const struct lttng_buffer_view *buffer, + unsigned long padding) +{ + ssize_t ret = 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; + unsigned int relayd_hang_up = 0; + const size_t subbuf_content_size = buffer->size - padding; + size_t write_len; + + /* RCU lock for the relayd pointer */ + rcu_read_lock(); + LTTNG_ASSERT(stream->net_seq_idx != (uint64_t) -1ULL || + stream->trace_chunk); + + /* Flag that the current stream if set for network streaming. */ + if (stream->net_seq_idx != (uint64_t) -1ULL) { + relayd = consumer_find_relayd(stream->net_seq_idx); + if (relayd == NULL) { + ret = -EPIPE; + goto end; + } + } + + /* Handle stream on the relayd if the output is on the network */ + if (relayd) { + unsigned long netlen = subbuf_content_size; + + /* + * 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); + if (stream->reset_metadata_flag) { + ret = relayd_reset_metadata(&relayd->control_sock, + stream->relayd_stream_id, + stream->metadata_version); + if (ret < 0) { + relayd_hang_up = 1; + goto write_error; + } + stream->reset_metadata_flag = 0; + } + netlen += sizeof(struct lttcomm_relayd_metadata_payload); + } + + ret = write_relayd_stream_header(stream, netlen, padding, relayd); + if (ret < 0) { + relayd_hang_up = 1; + goto write_error; + } + /* Use the returned socket. */ + outfd = ret; + + /* Write metadata stream id before payload */ + if (stream->metadata_flag) { + ret = write_relayd_metadata_id(outfd, stream, padding); + if (ret < 0) { + relayd_hang_up = 1; + goto write_error; + } + } + + write_len = subbuf_content_size; + } else { + /* No streaming; we have to write the full padding. */ + if (stream->metadata_flag && stream->reset_metadata_flag) { + ret = utils_truncate_stream_file(stream->out_fd, 0); + if (ret < 0) { + ERR("Reset metadata file"); + goto end; + } + stream->reset_metadata_flag = 0; + } + + /* + * Check if we need to change the tracefile before writing the packet. + */ + if (stream->chan->tracefile_size > 0 && + (stream->tracefile_size_current + buffer->size) > + stream->chan->tracefile_size) { + ret = consumer_stream_rotate_output_files(stream); + if (ret) { + goto end; + } + outfd = stream->out_fd; + orig_offset = 0; + } + stream->tracefile_size_current += buffer->size; + write_len = buffer->size; + } + + /* + * This call guarantee that len or less is returned. It's impossible to + * receive a ret value that is bigger than len. + */ + ret = lttng_write(outfd, buffer->data, write_len); + DBG("Consumer mmap write() ret %zd (len %zu)", ret, write_len); + if (ret < 0 || ((size_t) ret != write_len)) { + /* + * Report error to caller if nothing was written else at least send the + * amount written. + */ + if (ret < 0) { + ret = -errno; + } + relayd_hang_up = 1; + + /* Socket operation failed. We consider the relayd dead */ + if (errno == EPIPE) { + /* + * This is possible if the fd is closed on the other side + * (outfd) or any write problem. It can be verbose a bit for a + * normal execution if for instance the relayd is stopped + * abruptly. This can happen so set this to a DBG statement. + */ + DBG("Consumer mmap write detected relayd hang up"); + } else { + /* Unhandled error, print it and stop function right now. */ + PERROR("Error in write mmap (ret %zd != write_len %zu)", ret, + write_len); + } + goto write_error; + } + stream->output_written += 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, write_len, + SYNC_FILE_RANGE_WRITE); + stream->out_fd_offset += write_len; + lttng_consumer_sync_trace_file(stream, orig_offset); + } + +write_error: + /* + * This is a special case that the relayd has closed its socket. Let's + * cleanup the relayd object and all associated streams. + */ + if (relayd && relayd_hang_up) { + ERR("Relayd hangup. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx); + lttng_consumer_cleanup_relayd(relayd); + } + +end: + /* Unlock only if ctrl socket used */ + if (relayd && stream->metadata_flag) { + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + } + + rcu_read_unlock(); + return ret; +} + +/* + * Splice the data from the ring buffer to the tracefile. + * + * It must be called with the stream lock held. + * + * Returns the number of bytes spliced. + */ +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; + unsigned int relayd_hang_up = 0; + + switch (the_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"); + abort(); + } + + /* RCU lock for the relayd pointer */ + rcu_read_lock(); + + /* Flag that the current stream if set for network streaming. */ + if (stream->net_seq_idx != (uint64_t) -1ULL) { + relayd = consumer_find_relayd(stream->net_seq_idx); + if (relayd == NULL) { + written = -ret; + goto end; + } + } + splice_pipe = stream->splice_pipe; + + /* Write metadata stream id before payload */ + if (relayd) { + unsigned long 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); + + if (stream->reset_metadata_flag) { + ret = relayd_reset_metadata(&relayd->control_sock, + stream->relayd_stream_id, + stream->metadata_version); + if (ret < 0) { + relayd_hang_up = 1; + goto write_error; + } + stream->reset_metadata_flag = 0; + } + ret = write_relayd_metadata_id(splice_pipe[1], stream, + padding); + if (ret < 0) { + written = ret; + relayd_hang_up = 1; + goto write_error; + } + + total_len += sizeof(struct lttcomm_relayd_metadata_payload); + } + + ret = write_relayd_stream_header(stream, total_len, padding, relayd); + if (ret < 0) { + written = ret; + relayd_hang_up = 1; + goto write_error; + } + /* Use the returned socket. */ + outfd = ret; + } else { + /* No streaming, we have to set the len with the full padding */ + len += padding; + + if (stream->metadata_flag && stream->reset_metadata_flag) { + ret = utils_truncate_stream_file(stream->out_fd, 0); + if (ret < 0) { + ERR("Reset metadata file"); + goto end; + } + stream->reset_metadata_flag = 0; + } + /* + * Check if we need to change the tracefile before writing the packet. + */ + if (stream->chan->tracefile_size > 0 && + (stream->tracefile_size_current + len) > + stream->chan->tracefile_size) { + ret = consumer_stream_rotate_output_files(stream); + if (ret < 0) { + written = ret; + goto end; + } + outfd = stream->out_fd; + orig_offset = 0; + } + stream->tracefile_size_current += len; + } + + 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) { + ret = errno; + written = -ret; + PERROR("Error in relay splice"); + goto splice_error; + } + + /* Handle stream on the relayd if the output is on the network */ + if (relayd && 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 (out_fd: %d), ret %zd", + outfd, ret_splice); + if (ret_splice < 0) { + ret = errno; + written = -ret; + relayd_hang_up = 1; + goto write_error; + } else if (ret_splice > len) { + /* + * We don't expect this code path to be executed but you never know + * so this is an extra protection agains a buggy splice(). + */ + ret = errno; + written += ret_splice; + PERROR("Wrote more data than requested %zd (len: %lu)", ret_splice, + len); + goto splice_error; + } else { + /* All good, update current len and continue. */ + 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; + } + stream->output_written += ret_splice; + written += ret_splice; + } + if (!relayd) { + lttng_consumer_sync_trace_file(stream, orig_offset); + } + goto end; + +write_error: + /* + * This is a special case that the relayd has closed its socket. Let's + * cleanup the relayd object and all associated streams. + */ + if (relayd && relayd_hang_up) { + ERR("Relayd hangup. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx); + lttng_consumer_cleanup_relayd(relayd); + /* Skip splice error so the consumer does not fail */ + goto end; + } + +splice_error: + /* send the appropriate error description to sessiond */ + switch (ret) { + 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; +} + +/* + * Sample the snapshot positions for a specific fd + * + * Returns 0 on success, < 0 on error + */ +int lttng_consumer_sample_snapshot_positions(struct lttng_consumer_stream *stream) +{ + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + return lttng_kconsumer_sample_snapshot_positions(stream); + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + return lttng_ustconsumer_sample_snapshot_positions(stream); + default: + ERR("Unknown consumer_data type"); + abort(); + return -ENOSYS; + } +} +/* + * Take a snapshot for a specific fd + * + * Returns 0 on success, < 0 on error + */ +int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream) +{ + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + return lttng_kconsumer_take_snapshot(stream); + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + return lttng_ustconsumer_take_snapshot(stream); + default: + ERR("Unknown consumer_data type"); + abort(); + return -ENOSYS; + } +} + +/* + * Get the produced position + * + * Returns 0 on success, < 0 on error + */ +int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream, + unsigned long *pos) +{ + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + return lttng_kconsumer_get_produced_snapshot(stream, pos); + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + return lttng_ustconsumer_get_produced_snapshot(stream, pos); + default: + ERR("Unknown consumer_data type"); + abort(); + return -ENOSYS; + } +} + +/* + * Get the consumed position (free-running counter position in bytes). + * + * Returns 0 on success, < 0 on error + */ +int lttng_consumer_get_consumed_snapshot(struct lttng_consumer_stream *stream, + unsigned long *pos) +{ + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + return lttng_kconsumer_get_consumed_snapshot(stream, pos); + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + return lttng_ustconsumer_get_consumed_snapshot(stream, pos); + default: + ERR("Unknown consumer_data type"); + abort(); + return -ENOSYS; + } +} + +int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx, + int sock, struct pollfd *consumer_sockpoll) +{ + switch (the_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"); + abort(); + return -ENOSYS; + } +} + +static +void lttng_consumer_close_all_metadata(void) +{ + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + /* + * The Kernel consumer has a different metadata scheme so we don't + * close anything because the stream will be closed by the session + * daemon. + */ + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + /* + * Close all metadata streams. The metadata hash table is passed and + * this call iterates over it by closing all wakeup fd. This is safe + * because at this point we are sure that the metadata producer is + * either dead or blocked. + */ + lttng_ustconsumer_close_all_metadata(metadata_ht); + break; + default: + ERR("Unknown consumer_data type"); + abort(); + } +} + +/* + * Clean up a metadata stream and free its memory. + */ +void consumer_del_metadata_stream(struct lttng_consumer_stream *stream, + struct lttng_ht *ht) +{ + struct lttng_consumer_channel *channel = NULL; + bool free_channel = false; + + LTTNG_ASSERT(stream); + /* + * This call should NEVER receive regular stream. It must always be + * metadata stream and this is crucial for data structure synchronization. + */ + LTTNG_ASSERT(stream->metadata_flag); + + DBG3("Consumer delete metadata stream %d", stream->wait_fd); + + pthread_mutex_lock(&the_consumer_data.lock); + /* + * Note that this assumes that a stream's channel is never changed and + * that the stream's lock doesn't need to be taken to sample its + * channel. + */ + channel = stream->chan; + pthread_mutex_lock(&channel->lock); + pthread_mutex_lock(&stream->lock); + if (channel->metadata_cache) { + /* Only applicable to userspace consumers. */ + pthread_mutex_lock(&channel->metadata_cache->lock); + } + + /* Remove any reference to that stream. */ + consumer_stream_delete(stream, ht); + + /* Close down everything including the relayd if one. */ + consumer_stream_close(stream); + /* Destroy tracer buffers of the stream. */ + consumer_stream_destroy_buffers(stream); + + /* Atomically decrement channel refcount since other threads can use it. */ + if (!uatomic_sub_return(&channel->refcount, 1) + && !uatomic_read(&channel->nb_init_stream_left)) { + /* Go for channel deletion! */ + free_channel = true; + } + stream->chan = NULL; + + /* + * Nullify the stream reference so it is not used after deletion. The + * channel lock MUST be acquired before being able to check for a NULL + * pointer value. + */ + channel->metadata_stream = NULL; + + if (channel->metadata_cache) { + pthread_mutex_unlock(&channel->metadata_cache->lock); + } + pthread_mutex_unlock(&stream->lock); + pthread_mutex_unlock(&channel->lock); + pthread_mutex_unlock(&the_consumer_data.lock); + + if (free_channel) { + consumer_del_channel(channel); + } + + lttng_trace_chunk_put(stream->trace_chunk); + stream->trace_chunk = NULL; + consumer_stream_free(stream); +} + +/* + * Action done with the metadata stream when adding it to the consumer internal + * data structures to handle it. + */ +void consumer_add_metadata_stream(struct lttng_consumer_stream *stream) +{ + struct lttng_ht *ht = metadata_ht; + struct lttng_ht_iter iter; + struct lttng_ht_node_u64 *node; + + LTTNG_ASSERT(stream); + LTTNG_ASSERT(ht); + + DBG3("Adding metadata stream %" PRIu64 " to hash table", stream->key); + + pthread_mutex_lock(&the_consumer_data.lock); + pthread_mutex_lock(&stream->chan->lock); + pthread_mutex_lock(&stream->chan->timer_lock); + pthread_mutex_lock(&stream->lock); + + /* + * From here, refcounts are updated so be _careful_ when returning an error + * after this point. + */ + + rcu_read_lock(); + + /* + * Lookup the stream just to make sure it does not exist in our internal + * state. This should NEVER happen. + */ + lttng_ht_lookup(ht, &stream->key, &iter); + node = lttng_ht_iter_get_node_u64(&iter); + LTTNG_ASSERT(!node); + + /* + * When nb_init_stream_left 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_stream_left) > 0) { + /* Increment refcount before decrementing nb_init_stream_left */ + cmm_smp_wmb(); + uatomic_dec(&stream->chan->nb_init_stream_left); + } + + lttng_ht_add_unique_u64(ht, &stream->node); + + lttng_ht_add_u64(the_consumer_data.stream_per_chan_id_ht, + &stream->node_channel_id); + + /* + * 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_u64(the_consumer_data.stream_list_ht, + &stream->node_session_id); + + rcu_read_unlock(); + + pthread_mutex_unlock(&stream->lock); + pthread_mutex_unlock(&stream->chan->lock); + pthread_mutex_unlock(&stream->chan->timer_lock); + pthread_mutex_unlock(&the_consumer_data.lock); +} + +/* + * Delete data stream that are flagged for deletion (endpoint_status). + */ +static void validate_endpoint_status_data_stream(void) +{ + struct lttng_ht_iter iter; + struct lttng_consumer_stream *stream; + + DBG("Consumer delete flagged data stream"); + + rcu_read_lock(); + cds_lfht_for_each_entry(data_ht->ht, &iter.iter, stream, node.node) { + /* Validate delete flag of the stream */ + if (stream->endpoint_status == CONSUMER_ENDPOINT_ACTIVE) { + continue; + } + /* Delete it right now */ + consumer_del_stream(stream, data_ht); + } + rcu_read_unlock(); +} + +/* + * Delete metadata stream that are flagged for deletion (endpoint_status). + */ +static void validate_endpoint_status_metadata_stream( + struct lttng_poll_event *pollset) +{ + struct lttng_ht_iter iter; + struct lttng_consumer_stream *stream; + + DBG("Consumer delete flagged metadata stream"); + + LTTNG_ASSERT(pollset); + + rcu_read_lock(); + cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream, node.node) { + /* Validate delete flag of the stream */ + if (stream->endpoint_status == CONSUMER_ENDPOINT_ACTIVE) { + continue; + } + /* + * Remove from pollset so the metadata thread can continue without + * blocking on a deleted stream. + */ + lttng_poll_del(pollset, stream->wait_fd); + + /* Delete it right now */ + consumer_del_metadata_stream(stream, metadata_ht); + } + rcu_read_unlock(); +} + +/* + * Thread polls on metadata file descriptor and write them on disk or on the + * network. + */ +void *consumer_thread_metadata_poll(void *data) +{ + int ret, i, pollfd, err = -1; + uint32_t revents, nb_fd; + struct lttng_consumer_stream *stream = NULL; + struct lttng_ht_iter iter; + struct lttng_ht_node_u64 *node; + struct lttng_poll_event events; + struct lttng_consumer_local_data *ctx = (lttng_consumer_local_data *) data; + ssize_t len; + + rcu_register_thread(); + + health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_METADATA); + + if (testpoint(consumerd_thread_metadata)) { + goto error_testpoint; + } + + health_code_update(); + + 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_poll; + } + + ret = lttng_poll_add(&events, + lttng_pipe_get_readfd(ctx->consumer_metadata_pipe), LPOLLIN); + if (ret < 0) { + goto end; + } + + /* Main loop */ + DBG("Metadata main loop started"); + + while (1) { +restart: + health_code_update(); + health_poll_entry(); + DBG("Metadata poll wait"); + ret = lttng_poll_wait(&events, -1); + DBG("Metadata poll return from wait with %d fd(s)", + LTTNG_POLL_GETNB(&events)); + health_poll_exit(); + DBG("Metadata event caught in thread"); + if (ret < 0) { + if (errno == EINTR) { + ERR("Poll EINTR caught"); + goto restart; + } + if (LTTNG_POLL_GETNB(&events) == 0) { + err = 0; /* All is OK */ + } + goto end; + } + + nb_fd = ret; + + /* From here, the event is a metadata wait fd */ + for (i = 0; i < nb_fd; i++) { + health_code_update(); + + revents = LTTNG_POLL_GETEV(&events, i); + pollfd = LTTNG_POLL_GETFD(&events, i); + + if (pollfd == lttng_pipe_get_readfd(ctx->consumer_metadata_pipe)) { + if (revents & LPOLLIN) { + ssize_t pipe_len; + + pipe_len = lttng_pipe_read(ctx->consumer_metadata_pipe, + &stream, sizeof(stream)); + if (pipe_len < sizeof(stream)) { + if (pipe_len < 0) { + PERROR("read metadata stream"); + } + /* + * Remove the pipe from the poll set and continue the loop + * since their might be data to consume. + */ + lttng_poll_del(&events, + lttng_pipe_get_readfd(ctx->consumer_metadata_pipe)); + lttng_pipe_read_close(ctx->consumer_metadata_pipe); + continue; + } + + /* A NULL stream means that the state has changed. */ + if (stream == NULL) { + /* Check for deleted streams. */ + validate_endpoint_status_metadata_stream(&events); + goto restart; + } + + DBG("Adding metadata stream %d to poll set", + stream->wait_fd); + + /* Add metadata stream to the global poll events list */ + lttng_poll_add(&events, stream->wait_fd, + LPOLLIN | LPOLLPRI | LPOLLHUP); + } else 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, + lttng_pipe_get_readfd(ctx->consumer_metadata_pipe)); + lttng_pipe_read_close(ctx->consumer_metadata_pipe); + continue; + } else { + ERR("Unexpected poll events %u for sock %d", revents, pollfd); + goto end; + } + + /* Handle other stream */ + continue; + } + + rcu_read_lock(); + { + uint64_t tmp_id = (uint64_t) pollfd; + + lttng_ht_lookup(metadata_ht, &tmp_id, &iter); + } + node = lttng_ht_iter_get_node_u64(&iter); + LTTNG_ASSERT(node); + + stream = caa_container_of(node, struct lttng_consumer_stream, + node); + + if (revents & (LPOLLIN | LPOLLPRI)) { + /* Get the data out of the metadata file descriptor */ + DBG("Metadata available on fd %d", pollfd); + LTTNG_ASSERT(stream->wait_fd == pollfd); + + do { + health_code_update(); + + len = ctx->on_buffer_ready(stream, ctx, false); + /* + * We don't check the return value here since if we get + * a negative len, it means an error occurred thus we + * simply remove it from the poll set and free the + * stream. + */ + } while (len > 0); + + /* It's ok to have an unavailable sub-buffer */ + if (len < 0 && len != -EAGAIN && len != -ENODATA) { + /* Clean up stream from consumer and free it. */ + lttng_poll_del(&events, stream->wait_fd); + consumer_del_metadata_stream(stream, metadata_ht); + } + } else if (revents & (LPOLLERR | LPOLLHUP)) { + DBG("Metadata fd %d is hup|err.", pollfd); + if (!stream->hangup_flush_done && + (the_consumer_data.type == LTTNG_CONSUMER32_UST || + the_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 { + health_code_update(); + + len = ctx->on_buffer_ready(stream, ctx, false); + /* + * We don't check the return value here since if we get + * a negative len, it means an error occurred 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 { + ERR("Unexpected poll events %u for sock %d", revents, pollfd); + rcu_read_unlock(); + goto end; + } + /* Release RCU lock for the stream looked up */ + rcu_read_unlock(); + } + } + + /* All is OK */ + err = 0; +end: + DBG("Metadata poll thread exiting"); + + lttng_poll_clean(&events); +end_poll: +error_testpoint: + if (err) { + health_error(); + ERR("Health error occurred in %s", __func__); + } + health_unregister(health_consumerd); + 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 *consumer_thread_data_poll(void *data) +{ + int num_rdy, num_hup, high_prio, ret, i, err = -1; + struct pollfd *pollfd = NULL; + /* local view of the streams */ + struct lttng_consumer_stream **local_stream = NULL, *new_stream = NULL; + /* local view of consumer_data.fds_count */ + int nb_fd = 0; + /* 2 for the consumer_data_pipe and wake up pipe */ + const int nb_pipes_fd = 2; + /* Number of FDs with CONSUMER_ENDPOINT_INACTIVE but still open. */ + int nb_inactive_fd = 0; + struct lttng_consumer_local_data *ctx = (lttng_consumer_local_data *) data; + ssize_t len; + + rcu_register_thread(); + + health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_DATA); + + if (testpoint(consumerd_thread_data)) { + goto error_testpoint; + } + + health_code_update(); + + local_stream = (lttng_consumer_stream **) zmalloc(sizeof(struct lttng_consumer_stream *)); + if (local_stream == NULL) { + PERROR("local_stream malloc"); + goto end; + } + + while (1) { + health_code_update(); + + high_prio = 0; + num_hup = 0; + + /* + * the fds set has been updated, we need to update our + * local array as well + */ + pthread_mutex_lock(&the_consumer_data.lock); + if (the_consumer_data.need_update) { + free(pollfd); + pollfd = NULL; + + free(local_stream); + local_stream = NULL; + + /* Allocate for all fds */ + pollfd = (struct pollfd *) zmalloc((the_consumer_data.stream_count + + nb_pipes_fd) * + sizeof(struct pollfd)); + if (pollfd == NULL) { + PERROR("pollfd malloc"); + pthread_mutex_unlock(&the_consumer_data.lock); + goto end; + } + + local_stream = (lttng_consumer_stream **) zmalloc((the_consumer_data.stream_count + + nb_pipes_fd) * + sizeof(struct lttng_consumer_stream *)); + if (local_stream == NULL) { + PERROR("local_stream malloc"); + pthread_mutex_unlock(&the_consumer_data.lock); + goto end; + } + ret = update_poll_array(ctx, &pollfd, local_stream, + data_ht, &nb_inactive_fd); + if (ret < 0) { + ERR("Error in allocating pollfd or local_outfds"); + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR); + pthread_mutex_unlock(&the_consumer_data.lock); + goto end; + } + nb_fd = ret; + the_consumer_data.need_update = 0; + } + pthread_mutex_unlock(&the_consumer_data.lock); + + /* No FDs and consumer_quit, consumer_cleanup the thread */ + if (nb_fd == 0 && nb_inactive_fd == 0 && + CMM_LOAD_SHARED(consumer_quit) == 1) { + err = 0; /* All is OK */ + goto end; + } + /* poll on the array of fds */ + restart: + DBG("polling on %d fd", nb_fd + nb_pipes_fd); + if (testpoint(consumerd_thread_data_poll)) { + goto end; + } + health_poll_entry(); + num_rdy = poll(pollfd, nb_fd + nb_pipes_fd, -1); + health_poll_exit(); + DBG("poll num_rdy : %d", num_rdy); + if (num_rdy == -1) { + /* + * 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; + } + + if (caa_unlikely(data_consumption_paused)) { + DBG("Data consumption paused, sleeping..."); + sleep(1); + goto restart; + } + + /* + * 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 | POLLPRI)) { + ssize_t pipe_readlen; + + DBG("consumer_data_pipe wake up"); + pipe_readlen = lttng_pipe_read(ctx->consumer_data_pipe, + &new_stream, sizeof(new_stream)); + if (pipe_readlen < sizeof(new_stream)) { + PERROR("Consumer data pipe"); + /* Continue so we can at least handle the current stream(s). */ + continue; + } + + /* + * 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) { + validate_endpoint_status_data_stream(); + continue; + } + + /* Continue to update the local streams and handle prio ones */ + continue; + } + + /* Handle wakeup pipe. */ + if (pollfd[nb_fd + 1].revents & (POLLIN | POLLPRI)) { + char dummy; + ssize_t pipe_readlen; + + pipe_readlen = lttng_pipe_read(ctx->consumer_wakeup_pipe, &dummy, + sizeof(dummy)); + if (pipe_readlen < 0) { + PERROR("Consumer data wakeup pipe"); + } + /* We've been awakened to handle stream(s). */ + ctx->has_wakeup = 0; + } + + /* Take care of high priority channels first. */ + for (i = 0; i < nb_fd; i++) { + health_code_update(); + + if (local_stream[i] == NULL) { + continue; + } + if (pollfd[i].revents & POLLPRI) { + DBG("Urgent read on fd %d", pollfd[i].fd); + high_prio = 1; + len = ctx->on_buffer_ready(local_stream[i], ctx, false); + /* it's ok to have an unavailable sub-buffer */ + if (len < 0 && len != -EAGAIN && len != -ENODATA) { + /* Clean the stream and free it. */ + consumer_del_stream(local_stream[i], data_ht); + local_stream[i] = NULL; + } else if (len > 0) { + local_stream[i]->data_read = 1; + } + } + } + + /* + * 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. */ + for (i = 0; i < nb_fd; i++) { + health_code_update(); + + if (local_stream[i] == NULL) { + continue; + } + if ((pollfd[i].revents & POLLIN) || + local_stream[i]->hangup_flush_done || + local_stream[i]->has_data) { + DBG("Normal read on fd %d", pollfd[i].fd); + len = ctx->on_buffer_ready(local_stream[i], ctx, false); + /* it's ok to have an unavailable sub-buffer */ + if (len < 0 && len != -EAGAIN && len != -ENODATA) { + /* Clean the stream and free it. */ + consumer_del_stream(local_stream[i], data_ht); + local_stream[i] = NULL; + } else if (len > 0) { + local_stream[i]->data_read = 1; + } + } + } + + /* Handle hangup and errors */ + for (i = 0; i < nb_fd; i++) { + health_code_update(); + + if (local_stream[i] == NULL) { + continue; + } + if (!local_stream[i]->hangup_flush_done + && (pollfd[i].revents & (POLLHUP | POLLERR | POLLNVAL)) + && (the_consumer_data.type == LTTNG_CONSUMER32_UST + || the_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); + local_stream[i] = NULL; + 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); + local_stream[i] = NULL; + 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); + local_stream[i] = NULL; + num_hup++; + } + } + if (local_stream[i] != NULL) { + local_stream[i]->data_read = 0; + } + } + } + /* All is OK */ + err = 0; +end: + DBG("polling thread exiting"); + free(pollfd); + free(local_stream); + + /* + * 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. + */ + (void) lttng_pipe_write_close(ctx->consumer_metadata_pipe); + +error_testpoint: + if (err) { + health_error(); + ERR("Health error occurred in %s", __func__); + } + health_unregister(health_consumerd); + + rcu_unregister_thread(); + return NULL; +} + +/* + * Close wake-up end of each stream belonging to the channel. This will + * allow the poll() on the stream read-side to detect when the + * write-side (application) finally closes them. + */ +static +void consumer_close_channel_streams(struct lttng_consumer_channel *channel) +{ + struct lttng_ht *ht; + struct lttng_consumer_stream *stream; + struct lttng_ht_iter iter; + + ht = the_consumer_data.stream_per_chan_id_ht; + + rcu_read_lock(); + cds_lfht_for_each_entry_duplicate(ht->ht, + ht->hash_fct(&channel->key, lttng_ht_seed), + ht->match_fct, &channel->key, + &iter.iter, stream, node_channel_id.node) { + /* + * Protect against teardown with mutex. + */ + pthread_mutex_lock(&stream->lock); + if (cds_lfht_is_node_deleted(&stream->node.node)) { + goto next; + } + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + if (stream->metadata_flag) { + /* Safe and protected by the stream lock. */ + lttng_ustconsumer_close_metadata(stream->chan); + } else { + /* + * Note: a mutex is taken internally within + * liblttng-ust-ctl to protect timer wakeup_fd + * use from concurrent close. + */ + lttng_ustconsumer_close_stream_wakeup(stream); + } + break; + default: + ERR("Unknown consumer_data type"); + abort(); + } + next: + pthread_mutex_unlock(&stream->lock); + } + rcu_read_unlock(); +} + +static void destroy_channel_ht(struct lttng_ht *ht) +{ + struct lttng_ht_iter iter; + struct lttng_consumer_channel *channel; + int ret; + + if (ht == NULL) { + return; + } + + rcu_read_lock(); + cds_lfht_for_each_entry(ht->ht, &iter.iter, channel, wait_fd_node.node) { + ret = lttng_ht_del(ht, &iter); + LTTNG_ASSERT(ret != 0); + } + rcu_read_unlock(); + + lttng_ht_destroy(ht); +} + +/* + * This thread polls the channel fds to detect when they are being + * closed. It closes all related streams if the channel is detected as + * closed. It is currently only used as a shim layer for UST because the + * consumerd needs to keep the per-stream wakeup end of pipes open for + * periodical flush. + */ +void *consumer_thread_channel_poll(void *data) +{ + int ret, i, pollfd, err = -1; + uint32_t revents, nb_fd; + struct lttng_consumer_channel *chan = NULL; + struct lttng_ht_iter iter; + struct lttng_ht_node_u64 *node; + struct lttng_poll_event events; + struct lttng_consumer_local_data *ctx = (lttng_consumer_local_data *) data; + struct lttng_ht *channel_ht; + + rcu_register_thread(); + + health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_CHANNEL); + + if (testpoint(consumerd_thread_channel)) { + goto error_testpoint; + } + + health_code_update(); + + channel_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64); + if (!channel_ht) { + /* ENOMEM at this point. Better to bail out. */ + goto end_ht; + } + + DBG("Thread channel poll started"); + + /* Size is set to 1 for the consumer_channel pipe */ + ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC); + if (ret < 0) { + ERR("Poll set creation failed"); + goto end_poll; + } + + ret = lttng_poll_add(&events, ctx->consumer_channel_pipe[0], LPOLLIN); + if (ret < 0) { + goto end; + } + + /* Main loop */ + DBG("Channel main loop started"); + + while (1) { +restart: + health_code_update(); + DBG("Channel poll wait"); + health_poll_entry(); + ret = lttng_poll_wait(&events, -1); + DBG("Channel poll return from wait with %d fd(s)", + LTTNG_POLL_GETNB(&events)); + health_poll_exit(); + DBG("Channel event caught in thread"); + if (ret < 0) { + if (errno == EINTR) { + ERR("Poll EINTR caught"); + goto restart; + } + if (LTTNG_POLL_GETNB(&events) == 0) { + err = 0; /* All is OK */ + } + goto end; + } + + nb_fd = ret; + + /* From here, the event is a channel wait fd */ + for (i = 0; i < nb_fd; i++) { + health_code_update(); + + revents = LTTNG_POLL_GETEV(&events, i); + pollfd = LTTNG_POLL_GETFD(&events, i); + + if (pollfd == ctx->consumer_channel_pipe[0]) { + if (revents & LPOLLIN) { + enum consumer_channel_action action; + uint64_t key; + + ret = read_channel_pipe(ctx, &chan, &key, &action); + if (ret <= 0) { + if (ret < 0) { + ERR("Error reading channel pipe"); + } + lttng_poll_del(&events, ctx->consumer_channel_pipe[0]); + continue; + } + + switch (action) { + case CONSUMER_CHANNEL_ADD: + DBG("Adding channel %d to poll set", + chan->wait_fd); + + lttng_ht_node_init_u64(&chan->wait_fd_node, + chan->wait_fd); + rcu_read_lock(); + lttng_ht_add_unique_u64(channel_ht, + &chan->wait_fd_node); + rcu_read_unlock(); + /* Add channel to the global poll events list */ + lttng_poll_add(&events, chan->wait_fd, + LPOLLERR | LPOLLHUP); + break; + case CONSUMER_CHANNEL_DEL: + { + /* + * This command should never be called if the channel + * has streams monitored by either the data or metadata + * thread. The consumer only notify this thread with a + * channel del. command if it receives a destroy + * channel command from the session daemon that send it + * if a command prior to the GET_CHANNEL failed. + */ + + rcu_read_lock(); + chan = consumer_find_channel(key); + if (!chan) { + rcu_read_unlock(); + ERR("UST consumer get channel key %" PRIu64 " not found for del channel", key); + break; + } + lttng_poll_del(&events, chan->wait_fd); + iter.iter.node = &chan->wait_fd_node.node; + ret = lttng_ht_del(channel_ht, &iter); + LTTNG_ASSERT(ret == 0); + + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + health_code_update(); + /* Destroy streams that might have been left in the stream list. */ + clean_channel_stream_list(chan); + break; + default: + ERR("Unknown consumer_data type"); + abort(); + } + + /* + * Release our own refcount. Force channel deletion even if + * streams were not initialized. + */ + if (!uatomic_sub_return(&chan->refcount, 1)) { + consumer_del_channel(chan); + } + rcu_read_unlock(); + goto restart; + } + case CONSUMER_CHANNEL_QUIT: + /* + * Remove the pipe from the poll set and continue the loop + * since their might be data to consume. + */ + lttng_poll_del(&events, ctx->consumer_channel_pipe[0]); + continue; + default: + ERR("Unknown action"); + break; + } + } else if (revents & (LPOLLERR | LPOLLHUP)) { + DBG("Channel 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_channel_pipe[0]); + continue; + } else { + ERR("Unexpected poll events %u for sock %d", revents, pollfd); + goto end; + } + + /* Handle other stream */ + continue; + } + + rcu_read_lock(); + { + uint64_t tmp_id = (uint64_t) pollfd; + + lttng_ht_lookup(channel_ht, &tmp_id, &iter); + } + node = lttng_ht_iter_get_node_u64(&iter); + LTTNG_ASSERT(node); + + chan = caa_container_of(node, struct lttng_consumer_channel, + wait_fd_node); + + /* Check for error event */ + if (revents & (LPOLLERR | LPOLLHUP)) { + DBG("Channel fd %d is hup|err.", pollfd); + + lttng_poll_del(&events, chan->wait_fd); + ret = lttng_ht_del(channel_ht, &iter); + LTTNG_ASSERT(ret == 0); + + /* + * This will close the wait fd for each stream associated to + * this channel AND monitored by the data/metadata thread thus + * will be clean by the right thread. + */ + consumer_close_channel_streams(chan); + + /* Release our own refcount */ + if (!uatomic_sub_return(&chan->refcount, 1) + && !uatomic_read(&chan->nb_init_stream_left)) { + consumer_del_channel(chan); + } + } else { + ERR("Unexpected poll events %u for sock %d", revents, pollfd); + rcu_read_unlock(); + goto end; + } + + /* Release RCU lock for the channel looked up */ + rcu_read_unlock(); + } + } + + /* All is OK */ + err = 0; +end: + lttng_poll_clean(&events); +end_poll: + destroy_channel_ht(channel_ht); +end_ht: +error_testpoint: + DBG("Channel poll thread exiting"); + if (err) { + health_error(); + ERR("Health error occurred in %s", __func__); + } + health_unregister(health_consumerd); + rcu_unregister_thread(); + return NULL; +} + +static int set_metadata_socket(struct lttng_consumer_local_data *ctx, + struct pollfd *sockpoll, int client_socket) +{ + int ret; + + LTTNG_ASSERT(ctx); + LTTNG_ASSERT(sockpoll); + + ret = lttng_consumer_poll_socket(sockpoll); + if (ret) { + goto error; + } + DBG("Metadata connection on client_socket"); + + /* Blocking call, waiting for transmission */ + ctx->consumer_metadata_socket = lttcomm_accept_unix_sock(client_socket); + if (ctx->consumer_metadata_socket < 0) { + WARN("On accept metadata"); + ret = -1; + goto error; + } + ret = 0; + +error: + return ret; +} + +/* + * This thread listens on the consumerd socket and receives the file + * descriptors from the session daemon. + */ +void *consumer_thread_sessiond_poll(void *data) +{ + int sock = -1, client_socket, ret, err = -1; + /* + * structure to poll for incoming data on communication socket avoids + * making blocking sockets. + */ + struct pollfd consumer_sockpoll[2]; + struct lttng_consumer_local_data *ctx = (lttng_consumer_local_data *) data; + + rcu_register_thread(); + + health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_SESSIOND); + + if (testpoint(consumerd_thread_sessiond)) { + goto error_testpoint; + } + + health_code_update(); + + DBG("Creating command socket %s", ctx->consumer_command_sock_path); + unlink(ctx->consumer_command_sock_path); + client_socket = lttcomm_create_unix_sock(ctx->consumer_command_sock_path); + if (client_socket < 0) { + ERR("Cannot create command socket"); + goto end; + } + + ret = lttcomm_listen_unix_sock(client_socket); + if (ret < 0) { + goto end; + } + + DBG("Sending ready command to lttng-sessiond"); + 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"); + goto end; + } + + /* prepare the FDs to poll : to client socket and the should_quit pipe */ + consumer_sockpoll[0].fd = ctx->consumer_should_quit[0]; + consumer_sockpoll[0].events = POLLIN | POLLPRI; + consumer_sockpoll[1].fd = client_socket; + consumer_sockpoll[1].events = POLLIN | POLLPRI; + + ret = lttng_consumer_poll_socket(consumer_sockpoll); + if (ret) { + if (ret > 0) { + /* should exit */ + err = 0; + } + goto end; + } + DBG("Connection on client_socket"); + + /* Blocking call, waiting for transmission */ + sock = lttcomm_accept_unix_sock(client_socket); + if (sock < 0) { + WARN("On accept"); + goto end; + } + + /* + * Setup metadata socket which is the second socket connection on the + * command unix socket. + */ + ret = set_metadata_socket(ctx, consumer_sockpoll, client_socket); + if (ret) { + if (ret > 0) { + /* should exit */ + err = 0; + } + goto end; + } + + /* This socket is not useful anymore. */ + ret = close(client_socket); + if (ret < 0) { + PERROR("close client_socket"); + } + client_socket = -1; + + /* update the polling structure to poll on the established socket */ + consumer_sockpoll[1].fd = sock; + consumer_sockpoll[1].events = POLLIN | POLLPRI; + + while (1) { + health_code_update(); + + health_poll_entry(); + ret = lttng_consumer_poll_socket(consumer_sockpoll); + health_poll_exit(); + if (ret) { + if (ret > 0) { + /* should exit */ + err = 0; + } + goto end; + } + DBG("Incoming command on sock"); + ret = lttng_consumer_recv_cmd(ctx, sock, consumer_sockpoll); + if (ret <= 0) { + /* + * This could simply be a session daemon quitting. Don't output + * ERR() here. + */ + DBG("Communication interrupted on command socket"); + err = 0; + goto end; + } + if (CMM_LOAD_SHARED(consumer_quit)) { + DBG("consumer_thread_receive_fds received quit from signal"); + err = 0; /* All is OK */ + goto end; + } + DBG("Received command on sock"); + } + /* All is OK */ + err = 0; + +end: + DBG("Consumer thread sessiond poll exiting"); + + /* + * Close metadata streams since the producer is the session daemon which + * just died. + * + * NOTE: for now, this only applies to the UST tracer. + */ + lttng_consumer_close_all_metadata(); + + /* + * when all fds have hung up, the polling thread + * can exit cleanly + */ + CMM_STORE_SHARED(consumer_quit, 1); + + /* + * Notify the data poll thread to poll back again and test the + * consumer_quit state that we just set so to quit gracefully. + */ + notify_thread_lttng_pipe(ctx->consumer_data_pipe); + + notify_channel_pipe(ctx, NULL, -1, CONSUMER_CHANNEL_QUIT); + + notify_health_quit_pipe(health_quit_pipe); + + /* Cleaning up possibly open sockets. */ + if (sock >= 0) { + ret = close(sock); + if (ret < 0) { + PERROR("close sock sessiond poll"); + } + } + if (client_socket >= 0) { + ret = close(client_socket); + if (ret < 0) { + PERROR("close client_socket sessiond poll"); + } + } + +error_testpoint: + if (err) { + health_error(); + ERR("Health error occurred in %s", __func__); + } + health_unregister(health_consumerd); + + rcu_unregister_thread(); + return NULL; +} + +static int post_consume(struct lttng_consumer_stream *stream, + const struct stream_subbuffer *subbuffer, + struct lttng_consumer_local_data *ctx) +{ + size_t i; + int ret = 0; + const size_t count = lttng_dynamic_array_get_count( + &stream->read_subbuffer_ops.post_consume_cbs); + + for (i = 0; i < count; i++) { + const post_consume_cb op = *(post_consume_cb *) lttng_dynamic_array_get_element( + &stream->read_subbuffer_ops.post_consume_cbs, + i); + + ret = op(stream, subbuffer, ctx); + if (ret) { + goto end; + } + } +end: + return ret; +} + +ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream, + struct lttng_consumer_local_data *ctx, + bool locked_by_caller) +{ + ssize_t ret, written_bytes = 0; + int rotation_ret; + struct stream_subbuffer subbuffer = {}; + enum get_next_subbuffer_status get_next_status; + + if (!locked_by_caller) { + stream->read_subbuffer_ops.lock(stream); + } + + if (stream->read_subbuffer_ops.on_wake_up) { + ret = stream->read_subbuffer_ops.on_wake_up(stream); + if (ret) { + goto end; + } + } + + /* + * If the stream was flagged to be ready for rotation before we extract + * the next packet, rotate it now. + */ + if (stream->rotate_ready) { + DBG("Rotate stream before consuming data"); + ret = lttng_consumer_rotate_stream(ctx, stream); + if (ret < 0) { + ERR("Stream rotation error before consuming data"); + goto end; + } + } + + get_next_status = stream->read_subbuffer_ops.get_next_subbuffer( + stream, &subbuffer); + switch (get_next_status) { + case GET_NEXT_SUBBUFFER_STATUS_OK: + break; + case GET_NEXT_SUBBUFFER_STATUS_NO_DATA: + /* Not an error. */ + ret = 0; + goto sleep_stream; + case GET_NEXT_SUBBUFFER_STATUS_ERROR: + ret = -1; + goto end; + default: + abort(); + } + + ret = stream->read_subbuffer_ops.pre_consume_subbuffer( + stream, &subbuffer); + if (ret) { + goto error_put_subbuf; + } + + written_bytes = stream->read_subbuffer_ops.consume_subbuffer( + ctx, stream, &subbuffer); + if (written_bytes <= 0) { + ERR("Error consuming subbuffer: (%zd)", written_bytes); + ret = (int) written_bytes; + goto error_put_subbuf; + } + + ret = stream->read_subbuffer_ops.put_next_subbuffer(stream, &subbuffer); + if (ret) { + goto end; + } + + ret = post_consume(stream, &subbuffer, ctx); + if (ret) { + goto end; + } + + /* + * After extracting the packet, we check if the stream is now ready to + * be rotated and perform the action immediately. + * + * Don't overwrite `ret` as callers expect the number of bytes + * consumed to be returned on success. + */ + rotation_ret = lttng_consumer_stream_is_rotate_ready(stream); + if (rotation_ret == 1) { + rotation_ret = lttng_consumer_rotate_stream(ctx, stream); + if (rotation_ret < 0) { + ret = rotation_ret; + ERR("Stream rotation error after consuming data"); + goto end; + } + + } else if (rotation_ret < 0) { + ret = rotation_ret; + ERR("Failed to check if stream was ready to rotate after consuming data"); + goto end; + } + +sleep_stream: + if (stream->read_subbuffer_ops.on_sleep) { + stream->read_subbuffer_ops.on_sleep(stream, ctx); + } + + ret = written_bytes; +end: + if (!locked_by_caller) { + stream->read_subbuffer_ops.unlock(stream); + } + + return ret; +error_put_subbuf: + (void) stream->read_subbuffer_ops.put_next_subbuffer(stream, &subbuffer); + goto end; +} + +int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream) +{ + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + return lttng_kconsumer_on_recv_stream(stream); + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + return lttng_ustconsumer_on_recv_stream(stream); + default: + ERR("Unknown consumer_data type"); + abort(); + return -ENOSYS; + } +} + +/* + * Allocate and set consumer data hash tables. + */ +int lttng_consumer_init(void) +{ + the_consumer_data.channel_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64); + if (!the_consumer_data.channel_ht) { + goto error; + } + + the_consumer_data.channels_by_session_id_ht = + lttng_ht_new(0, LTTNG_HT_TYPE_U64); + if (!the_consumer_data.channels_by_session_id_ht) { + goto error; + } + + the_consumer_data.relayd_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64); + if (!the_consumer_data.relayd_ht) { + goto error; + } + + the_consumer_data.stream_list_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64); + if (!the_consumer_data.stream_list_ht) { + goto error; + } + + the_consumer_data.stream_per_chan_id_ht = + lttng_ht_new(0, LTTNG_HT_TYPE_U64); + if (!the_consumer_data.stream_per_chan_id_ht) { + goto error; + } + + data_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64); + if (!data_ht) { + goto error; + } + + metadata_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64); + if (!metadata_ht) { + goto error; + } + + the_consumer_data.chunk_registry = lttng_trace_chunk_registry_create(); + if (!the_consumer_data.chunk_registry) { + goto error; + } + + return 0; + +error: + return -1; +} + +/* + * 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. + */ + void consumer_add_relayd_socket(uint64_t net_seq_idx, int sock_type, + struct lttng_consumer_local_data *ctx, int sock, + struct pollfd *consumer_sockpoll, + struct lttcomm_relayd_sock *relayd_sock, uint64_t sessiond_id, + uint64_t relayd_session_id) +{ + int fd = -1, ret = -1, relayd_created = 0; + enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS; + struct consumer_relayd_sock_pair *relayd = NULL; + + LTTNG_ASSERT(ctx); + LTTNG_ASSERT(relayd_sock); + + DBG("Consumer adding relayd socket (idx: %" PRIu64 ")", net_seq_idx); + + /* Get relayd reference if exists. */ + relayd = consumer_find_relayd(net_seq_idx); + if (relayd == NULL) { + LTTNG_ASSERT(sock_type == LTTNG_STREAM_CONTROL); + /* Not found. Allocate one. */ + relayd = consumer_allocate_relayd_sock_pair(net_seq_idx); + if (relayd == NULL) { + ret_code = LTTCOMM_CONSUMERD_ENOMEM; + goto error; + } else { + relayd->sessiond_session_id = sessiond_id; + relayd_created = 1; + } + + /* + * This code path MUST continue to the consumer send status message to + * we can notify the session daemon and continue our work without + * killing everything. + */ + } else { + /* + * relayd key should never be found for control socket. + */ + LTTNG_ASSERT(sock_type != LTTNG_STREAM_CONTROL); + } + + /* First send a status message before receiving the fds. */ + ret = consumer_send_status_msg(sock, LTTCOMM_CONSUMERD_SUCCESS); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_FATAL); + goto error_nosignal; + } + + /* Poll on consumer socket. */ + ret = lttng_consumer_poll_socket(consumer_sockpoll); + if (ret) { + /* Needing to exit in the middle of a command: error. */ + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR); + goto error_nosignal; + } + + /* Get relayd socket from session daemon */ + ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); + if (ret != sizeof(fd)) { + fd = -1; /* Just in case it gets set with an invalid value. */ + + /* + * Failing to receive FDs might indicate a major problem such as + * reaching a fd limit during the receive where the kernel returns a + * MSG_CTRUNC and fails to cleanup the fd in the queue. Any case, we + * don't take any chances and stop everything. + * + * XXX: Feature request #558 will fix that and avoid this possible + * issue when reaching the fd limit. + */ + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD); + ret_code = LTTCOMM_CONSUMERD_ERROR_RECV_FD; + 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.sock, &relayd_sock->sock); + ret = lttcomm_create_sock(&relayd->control_sock.sock); + /* Handle create_sock error. */ + if (ret < 0) { + ret_code = LTTCOMM_CONSUMERD_ENOMEM; + goto error; + } + /* + * Close the socket created internally by + * lttcomm_create_sock, so we can replace it by the one + * received from sessiond. + */ + if (close(relayd->control_sock.sock.fd)) { + PERROR("close"); + } + + /* Assign new file descriptor */ + relayd->control_sock.sock.fd = fd; + /* Assign version values. */ + relayd->control_sock.major = relayd_sock->major; + relayd->control_sock.minor = relayd_sock->minor; + + relayd->relayd_session_id = relayd_session_id; + + break; + case LTTNG_STREAM_DATA: + /* Copy received lttcomm socket */ + lttcomm_copy_sock(&relayd->data_sock.sock, &relayd_sock->sock); + ret = lttcomm_create_sock(&relayd->data_sock.sock); + /* Handle create_sock error. */ + if (ret < 0) { + ret_code = LTTCOMM_CONSUMERD_ENOMEM; + goto error; + } + /* + * Close the socket created internally by + * lttcomm_create_sock, so we can replace it by the one + * received from sessiond. + */ + if (close(relayd->data_sock.sock.fd)) { + PERROR("close"); + } + + /* Assign new file descriptor */ + relayd->data_sock.sock.fd = fd; + /* Assign version values. */ + relayd->data_sock.major = relayd_sock->major; + relayd->data_sock.minor = relayd_sock->minor; + break; + default: + ERR("Unknown relayd socket type (%d)", sock_type); + ret_code = LTTCOMM_CONSUMERD_FATAL; + goto error; + } + + DBG("Consumer %s socket created successfully with net idx %" PRIu64 " (fd: %d)", + sock_type == LTTNG_STREAM_CONTROL ? "control" : "data", + relayd->net_seq_idx, fd); + /* + * We gave the ownership of the fd to the relayd structure. Set the + * fd to -1 so we don't call close() on it in the error path below. + */ + fd = -1; + + /* We successfully added the socket. Send status back. */ + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_FATAL); + goto error_nosignal; + } + + /* + * Add relayd socket pair to consumer data hashtable. If object already + * exists or on error, the function gracefully returns. + */ + relayd->ctx = ctx; + add_relayd(relayd); + + /* All good! */ + return; + +error: + if (consumer_send_status_msg(sock, ret_code) < 0) { + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_FATAL); + } + +error_nosignal: + /* Close received socket if valid. */ + if (fd >= 0) { + if (close(fd)) { + PERROR("close received socket"); + } + } + + if (relayd_created) { + free(relayd); + } +} + +/* + * Search for a relayd associated to the session id and return the reference. + * + * A rcu read side lock MUST be acquire before calling this function and locked + * until the relayd object is no longer necessary. + */ +static struct consumer_relayd_sock_pair *find_relayd_by_session_id(uint64_t id) +{ + struct lttng_ht_iter iter; + struct consumer_relayd_sock_pair *relayd = NULL; + + /* Iterate over all relayd since they are indexed by net_seq_idx. */ + cds_lfht_for_each_entry(the_consumer_data.relayd_ht->ht, &iter.iter, + relayd, node.node) { + /* + * Check by sessiond id which is unique here where the relayd session + * id might not be when having multiple relayd. + */ + if (relayd->sessiond_session_id == id) { + /* Found the relayd. There can be only one per id. */ + goto found; + } + } + + return NULL; + +found: + return relayd; +} + +/* + * Check if for a given session id there is still data needed to be extract + * from the buffers. + * + * Return 1 if data is pending or else 0 meaning ready to be read. + */ +int consumer_data_pending(uint64_t id) +{ + int ret; + struct lttng_ht_iter iter; + struct lttng_ht *ht; + struct lttng_consumer_stream *stream; + struct consumer_relayd_sock_pair *relayd = NULL; + int (*data_pending)(struct lttng_consumer_stream *); + + DBG("Consumer data pending command on session id %" PRIu64, id); + + rcu_read_lock(); + pthread_mutex_lock(&the_consumer_data.lock); + + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + data_pending = lttng_kconsumer_data_pending; + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + data_pending = lttng_ustconsumer_data_pending; + break; + default: + ERR("Unknown consumer data type"); + abort(); + } + + /* Ease our life a bit */ + ht = the_consumer_data.stream_list_ht; + + cds_lfht_for_each_entry_duplicate(ht->ht, + ht->hash_fct(&id, lttng_ht_seed), + ht->match_fct, &id, + &iter.iter, stream, node_session_id.node) { + pthread_mutex_lock(&stream->lock); + + /* + * A removed node from the hash table indicates that the stream has + * been deleted thus having a guarantee that the buffers are closed + * on the consumer side. However, data can still be transmitted + * over the network so don't skip the relayd check. + */ + ret = cds_lfht_is_node_deleted(&stream->node.node); + if (!ret) { + /* Check the stream if there is data in the buffers. */ + ret = data_pending(stream); + if (ret == 1) { + pthread_mutex_unlock(&stream->lock); + goto data_pending; + } + } + + pthread_mutex_unlock(&stream->lock); + } + + relayd = find_relayd_by_session_id(id); + if (relayd) { + unsigned int is_data_inflight = 0; + + /* Send init command for data pending. */ + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + ret = relayd_begin_data_pending(&relayd->control_sock, + relayd->relayd_session_id); + if (ret < 0) { + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + /* Communication error thus the relayd so no data pending. */ + goto data_not_pending; + } + + cds_lfht_for_each_entry_duplicate(ht->ht, + ht->hash_fct(&id, lttng_ht_seed), + ht->match_fct, &id, + &iter.iter, stream, node_session_id.node) { + if (stream->metadata_flag) { + ret = relayd_quiescent_control(&relayd->control_sock, + stream->relayd_stream_id); + } else { + ret = relayd_data_pending(&relayd->control_sock, + stream->relayd_stream_id, + stream->next_net_seq_num - 1); + } + + if (ret == 1) { + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + goto data_pending; + } else if (ret < 0) { + ERR("Relayd data pending failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx); + lttng_consumer_cleanup_relayd(relayd); + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + goto data_not_pending; + } + } + + /* Send end command for data pending. */ + ret = relayd_end_data_pending(&relayd->control_sock, + relayd->relayd_session_id, &is_data_inflight); + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + if (ret < 0) { + ERR("Relayd end data pending failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx); + lttng_consumer_cleanup_relayd(relayd); + goto data_not_pending; + } + if (is_data_inflight) { + goto data_pending; + } + } + + /* + * Finding _no_ node in the hash table and no inflight data means that the + * stream(s) have been removed thus data is guaranteed to be available for + * analysis from the trace files. + */ + +data_not_pending: + /* Data is available to be read by a viewer. */ + pthread_mutex_unlock(&the_consumer_data.lock); + rcu_read_unlock(); + return 0; + +data_pending: + /* Data is still being extracted from buffers. */ + pthread_mutex_unlock(&the_consumer_data.lock); + rcu_read_unlock(); + return 1; +} + +/* + * Send a ret code status message to the sessiond daemon. + * + * Return the sendmsg() return value. + */ +int consumer_send_status_msg(int sock, int ret_code) +{ + struct lttcomm_consumer_status_msg msg; + + memset(&msg, 0, sizeof(msg)); + msg.ret_code = (lttcomm_return_code) ret_code; + + return lttcomm_send_unix_sock(sock, &msg, sizeof(msg)); +} + +/* + * Send a channel status message to the sessiond daemon. + * + * Return the sendmsg() return value. + */ +int consumer_send_status_channel(int sock, + struct lttng_consumer_channel *channel) +{ + struct lttcomm_consumer_status_channel msg; + + LTTNG_ASSERT(sock >= 0); + + memset(&msg, 0, sizeof(msg)); + if (!channel) { + msg.ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL; + } else { + msg.ret_code = LTTCOMM_CONSUMERD_SUCCESS; + msg.key = channel->key; + msg.stream_count = channel->streams.count; + } + + return lttcomm_send_unix_sock(sock, &msg, sizeof(msg)); +} + +unsigned long consumer_get_consume_start_pos(unsigned long consumed_pos, + unsigned long produced_pos, uint64_t nb_packets_per_stream, + uint64_t max_sb_size) +{ + unsigned long start_pos; + + if (!nb_packets_per_stream) { + return consumed_pos; /* Grab everything */ + } + start_pos = produced_pos - lttng_offset_align_floor(produced_pos, max_sb_size); + start_pos -= max_sb_size * nb_packets_per_stream; + if ((long) (start_pos - consumed_pos) < 0) { + return consumed_pos; /* Grab everything */ + } + return start_pos; +} + +/* Stream lock must be held by the caller. */ +static int sample_stream_positions(struct lttng_consumer_stream *stream, + unsigned long *produced, unsigned long *consumed) +{ + int ret; + + ASSERT_LOCKED(stream->lock); + + ret = lttng_consumer_sample_snapshot_positions(stream); + if (ret < 0) { + ERR("Failed to sample snapshot positions"); + goto end; + } + + ret = lttng_consumer_get_produced_snapshot(stream, produced); + if (ret < 0) { + ERR("Failed to sample produced position"); + goto end; + } + + ret = lttng_consumer_get_consumed_snapshot(stream, consumed); + if (ret < 0) { + ERR("Failed to sample consumed position"); + goto end; + } + +end: + return ret; +} + +/* + * Sample the rotate position for all the streams of a channel. If a stream + * is already at the rotate position (produced == consumed), we flag it as + * ready for rotation. The rotation of ready streams occurs after we have + * replied to the session daemon that we have finished sampling the positions. + * Must be called with RCU read-side lock held to ensure existence of channel. + * + * Returns 0 on success, < 0 on error + */ +int lttng_consumer_rotate_channel(struct lttng_consumer_channel *channel, + uint64_t key, uint64_t relayd_id, uint32_t metadata, + struct lttng_consumer_local_data *ctx) +{ + int ret; + struct lttng_consumer_stream *stream; + struct lttng_ht_iter iter; + struct lttng_ht *ht = the_consumer_data.stream_per_chan_id_ht; + struct lttng_dynamic_array stream_rotation_positions; + uint64_t next_chunk_id, stream_count = 0; + enum lttng_trace_chunk_status chunk_status; + const bool is_local_trace = relayd_id == -1ULL; + struct consumer_relayd_sock_pair *relayd = NULL; + bool rotating_to_new_chunk = true; + /* Array of `struct lttng_consumer_stream *` */ + struct lttng_dynamic_pointer_array streams_packet_to_open; + size_t stream_idx; + + DBG("Consumer sample rotate position for channel %" PRIu64, key); + + lttng_dynamic_array_init(&stream_rotation_positions, + sizeof(struct relayd_stream_rotation_position), NULL); + lttng_dynamic_pointer_array_init(&streams_packet_to_open, NULL); + + rcu_read_lock(); + + pthread_mutex_lock(&channel->lock); + LTTNG_ASSERT(channel->trace_chunk); + chunk_status = lttng_trace_chunk_get_id(channel->trace_chunk, + &next_chunk_id); + if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { + ret = -1; + goto end_unlock_channel; + } + + cds_lfht_for_each_entry_duplicate(ht->ht, + ht->hash_fct(&channel->key, lttng_ht_seed), + ht->match_fct, &channel->key, &iter.iter, + stream, node_channel_id.node) { + unsigned long produced_pos = 0, consumed_pos = 0; + + health_code_update(); + + /* + * Lock stream because we are about to change its state. + */ + pthread_mutex_lock(&stream->lock); + + if (stream->trace_chunk == stream->chan->trace_chunk) { + rotating_to_new_chunk = false; + } + + /* + * Do not flush a packet when rotating from a NULL trace + * chunk. The stream has no means to output data, and the prior + * rotation which rotated to NULL performed that side-effect + * already. No new data can be produced when a stream has no + * associated trace chunk (e.g. a stop followed by a rotate). + */ + if (stream->trace_chunk) { + bool flush_active; + + if (stream->metadata_flag) { + /* + * Don't produce an empty metadata packet, + * simply close the current one. + * + * Metadata is regenerated on every trace chunk + * switch; there is no concern that no data was + * produced. + */ + flush_active = true; + } else { + /* + * Only flush an empty packet if the "packet + * open" could not be performed on transition + * to a new trace chunk and no packets were + * consumed within the chunk's lifetime. + */ + if (stream->opened_packet_in_current_trace_chunk) { + flush_active = true; + } else { + /* + * Stream could have been full at the + * time of rotation, but then have had + * no activity at all. + * + * It is important to flush a packet + * to prevent 0-length files from being + * produced as most viewers choke on + * them. + * + * Unfortunately viewers will not be + * able to know that tracing was active + * for this stream during this trace + * chunk's lifetime. + */ + ret = sample_stream_positions(stream, &produced_pos, &consumed_pos); + if (ret) { + goto end_unlock_stream; + } + + /* + * Don't flush an empty packet if data + * was produced; it will be consumed + * before the rotation completes. + */ + flush_active = produced_pos != consumed_pos; + if (!flush_active) { + const char *trace_chunk_name; + uint64_t trace_chunk_id; + + chunk_status = lttng_trace_chunk_get_name( + stream->trace_chunk, + &trace_chunk_name, + NULL); + if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_NONE) { + trace_chunk_name = "none"; + } + + /* + * Consumer trace chunks are + * never anonymous. + */ + chunk_status = lttng_trace_chunk_get_id( + stream->trace_chunk, + &trace_chunk_id); + LTTNG_ASSERT(chunk_status == + LTTNG_TRACE_CHUNK_STATUS_OK); + + DBG("Unable to open packet for stream during trace chunk's lifetime. " + "Flushing an empty packet to prevent an empty file from being created: " + "stream id = %" PRIu64 ", trace chunk name = `%s`, trace chunk id = %" PRIu64, + stream->key, trace_chunk_name, trace_chunk_id); + } + } + } + + /* + * Close the current packet before sampling the + * ring buffer positions. + */ + ret = consumer_stream_flush_buffer(stream, flush_active); + if (ret < 0) { + ERR("Failed to flush stream %" PRIu64 " during channel rotation", + stream->key); + goto end_unlock_stream; + } + } + + ret = lttng_consumer_take_snapshot(stream); + if (ret < 0 && ret != -ENODATA && ret != -EAGAIN) { + ERR("Failed to sample snapshot position during channel rotation"); + goto end_unlock_stream; + } + if (!ret) { + ret = lttng_consumer_get_produced_snapshot(stream, + &produced_pos); + if (ret < 0) { + ERR("Failed to sample produced position during channel rotation"); + goto end_unlock_stream; + } + + ret = lttng_consumer_get_consumed_snapshot(stream, + &consumed_pos); + if (ret < 0) { + ERR("Failed to sample consumed position during channel rotation"); + goto end_unlock_stream; + } + } + /* + * Align produced position on the start-of-packet boundary of the first + * packet going into the next trace chunk. + */ + produced_pos = lttng_align_floor(produced_pos, stream->max_sb_size); + if (consumed_pos == produced_pos) { + DBG("Set rotate ready for stream %" PRIu64 " produced = %lu consumed = %lu", + stream->key, produced_pos, consumed_pos); + stream->rotate_ready = true; + } else { + DBG("Different consumed and produced positions " + "for stream %" PRIu64 " produced = %lu consumed = %lu", + stream->key, produced_pos, consumed_pos); + } + /* + * The rotation position is based on the packet_seq_num of the + * packet following the last packet that was consumed for this + * stream, incremented by the offset between produced and + * consumed positions. This rotation position is a lower bound + * (inclusive) at which the next trace chunk starts. Since it + * is a lower bound, it is OK if the packet_seq_num does not + * correspond exactly to the same packet identified by the + * consumed_pos, which can happen in overwrite mode. + */ + if (stream->sequence_number_unavailable) { + /* + * Rotation should never be performed on a session which + * interacts with a pre-2.8 lttng-modules, which does + * not implement packet sequence number. + */ + ERR("Failure to rotate stream %" PRIu64 ": sequence number unavailable", + stream->key); + ret = -1; + goto end_unlock_stream; + } + stream->rotate_position = stream->last_sequence_number + 1 + + ((produced_pos - consumed_pos) / stream->max_sb_size); + DBG("Set rotation position for stream %" PRIu64 " at position %" PRIu64, + stream->key, stream->rotate_position); + + if (!is_local_trace) { + /* + * The relay daemon control protocol expects a rotation + * position as "the sequence number of the first packet + * _after_ the current trace chunk". + */ + const struct relayd_stream_rotation_position position = { + .stream_id = stream->relayd_stream_id, + .rotate_at_seq_num = stream->rotate_position, + }; + + ret = lttng_dynamic_array_add_element( + &stream_rotation_positions, + &position); + if (ret) { + ERR("Failed to allocate stream rotation position"); + goto end_unlock_stream; + } + stream_count++; + } + + stream->opened_packet_in_current_trace_chunk = false; + + if (rotating_to_new_chunk && !stream->metadata_flag) { + /* + * Attempt to flush an empty packet as close to the + * rotation point as possible. In the event where a + * stream remains inactive after the rotation point, + * this ensures that the new trace chunk has a + * beginning timestamp set at the begining of the + * trace chunk instead of only creating an empty + * packet when the trace chunk is stopped. + * + * This indicates to the viewers that the stream + * was being recorded, but more importantly it + * allows viewers to determine a useable trace + * intersection. + * + * This presents a problem in the case where the + * ring-buffer is completely full. + * + * Consider the following scenario: + * - The consumption of data is slow (slow network, + * for instance), + * - The ring buffer is full, + * - A rotation is initiated, + * - The flush below does nothing (no space left to + * open a new packet), + * - The other streams rotate very soon, and new + * data is produced in the new chunk, + * - This stream completes its rotation long after the + * rotation was initiated + * - The session is stopped before any event can be + * produced in this stream's buffers. + * + * The resulting trace chunk will have a single packet + * temporaly at the end of the trace chunk for this + * stream making the stream intersection more narrow + * than it should be. + * + * To work-around this, an empty flush is performed + * after the first consumption of a packet during a + * rotation if open_packet fails. The idea is that + * consuming a packet frees enough space to switch + * packets in this scenario and allows the tracer to + * "stamp" the beginning of the new trace chunk at the + * earliest possible point. + * + * The packet open is performed after the channel + * rotation to ensure that no attempt to open a packet + * is performed in a stream that has no active trace + * chunk. + */ + ret = lttng_dynamic_pointer_array_add_pointer( + &streams_packet_to_open, stream); + if (ret) { + PERROR("Failed to add a stream pointer to array of streams in which to open a packet"); + ret = -1; + goto end_unlock_stream; + } + } + + pthread_mutex_unlock(&stream->lock); + } + stream = NULL; + + if (!is_local_trace) { + relayd = consumer_find_relayd(relayd_id); + if (!relayd) { + ERR("Failed to find relayd %" PRIu64, relayd_id); + ret = -1; + goto end_unlock_channel; + } + + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + ret = relayd_rotate_streams(&relayd->control_sock, stream_count, + rotating_to_new_chunk ? &next_chunk_id : NULL, + (const struct relayd_stream_rotation_position *) + stream_rotation_positions.buffer + .data); + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + if (ret < 0) { + ERR("Relayd rotate stream failed. Cleaning up relayd %" PRIu64, + relayd->net_seq_idx); + lttng_consumer_cleanup_relayd(relayd); + goto end_unlock_channel; + } + } + + for (stream_idx = 0; + stream_idx < lttng_dynamic_pointer_array_get_count( + &streams_packet_to_open); + stream_idx++) { + enum consumer_stream_open_packet_status status; + + stream = (lttng_consumer_stream *) lttng_dynamic_pointer_array_get_pointer( + &streams_packet_to_open, stream_idx); + + pthread_mutex_lock(&stream->lock); + status = consumer_stream_open_packet(stream); + pthread_mutex_unlock(&stream->lock); + switch (status) { + case CONSUMER_STREAM_OPEN_PACKET_STATUS_OPENED: + DBG("Opened a packet after a rotation: stream id = %" PRIu64 + ", channel name = %s, session id = %" PRIu64, + stream->key, stream->chan->name, + stream->chan->session_id); + break; + case CONSUMER_STREAM_OPEN_PACKET_STATUS_NO_SPACE: + /* + * Can't open a packet as there is no space left + * in the buffer. A new packet will be opened + * once one has been consumed. + */ + DBG("No space left to open a packet after a rotation: stream id = %" PRIu64 + ", channel name = %s, session id = %" PRIu64, + stream->key, stream->chan->name, + stream->chan->session_id); + break; + case CONSUMER_STREAM_OPEN_PACKET_STATUS_ERROR: + /* Logged by callee. */ + ret = -1; + goto end_unlock_channel; + default: + abort(); + } + } + + pthread_mutex_unlock(&channel->lock); + ret = 0; + goto end; + +end_unlock_stream: + pthread_mutex_unlock(&stream->lock); +end_unlock_channel: + pthread_mutex_unlock(&channel->lock); +end: + rcu_read_unlock(); + lttng_dynamic_array_reset(&stream_rotation_positions); + lttng_dynamic_pointer_array_reset(&streams_packet_to_open); + return ret; +} + +static +int consumer_clear_buffer(struct lttng_consumer_stream *stream) +{ + int ret = 0; + unsigned long consumed_pos_before, consumed_pos_after; + + ret = lttng_consumer_sample_snapshot_positions(stream); + if (ret < 0) { + ERR("Taking snapshot positions"); + goto end; + } + + ret = lttng_consumer_get_consumed_snapshot(stream, &consumed_pos_before); + if (ret < 0) { + ERR("Consumed snapshot position"); + goto end; + } + + switch (the_consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + ret = kernctl_buffer_clear(stream->wait_fd); + if (ret < 0) { + ERR("Failed to clear kernel stream (ret = %d)", ret); + goto end; + } + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + ret = lttng_ustconsumer_clear_buffer(stream); + if (ret < 0) { + ERR("Failed to clear ust stream (ret = %d)", ret); + goto end; + } + break; + default: + ERR("Unknown consumer_data type"); + abort(); + } + + ret = lttng_consumer_sample_snapshot_positions(stream); + if (ret < 0) { + ERR("Taking snapshot positions"); + goto end; + } + ret = lttng_consumer_get_consumed_snapshot(stream, &consumed_pos_after); + if (ret < 0) { + ERR("Consumed snapshot position"); + goto end; + } + DBG("clear: before: %lu after: %lu", consumed_pos_before, consumed_pos_after); +end: + return ret; +} + +static +int consumer_clear_stream(struct lttng_consumer_stream *stream) +{ + int ret; + + ret = consumer_stream_flush_buffer(stream, 1); + if (ret < 0) { + ERR("Failed to flush stream %" PRIu64 " during channel clear", + stream->key); + ret = LTTCOMM_CONSUMERD_FATAL; + goto error; + } + + ret = consumer_clear_buffer(stream); + if (ret < 0) { + ERR("Failed to clear stream %" PRIu64 " during channel clear", + stream->key); + ret = LTTCOMM_CONSUMERD_FATAL; + goto error; + } + + ret = LTTCOMM_CONSUMERD_SUCCESS; +error: + return ret; +} + +static +int consumer_clear_unmonitored_channel(struct lttng_consumer_channel *channel) +{ + int ret; + struct lttng_consumer_stream *stream; + + rcu_read_lock(); + pthread_mutex_lock(&channel->lock); + cds_list_for_each_entry(stream, &channel->streams.head, send_node) { + health_code_update(); + pthread_mutex_lock(&stream->lock); + ret = consumer_clear_stream(stream); + if (ret) { + goto error_unlock; + } + pthread_mutex_unlock(&stream->lock); + } + pthread_mutex_unlock(&channel->lock); + rcu_read_unlock(); + return 0; + +error_unlock: + pthread_mutex_unlock(&stream->lock); + pthread_mutex_unlock(&channel->lock); + rcu_read_unlock(); + return ret; +} + +/* + * Check if a stream is ready to be rotated after extracting it. + * + * Return 1 if it is ready for rotation, 0 if it is not, a negative value on + * error. Stream lock must be held. + */ +int lttng_consumer_stream_is_rotate_ready(struct lttng_consumer_stream *stream) +{ + DBG("Check is rotate ready for stream %" PRIu64 + " ready %u rotate_position %" PRIu64 + " last_sequence_number %" PRIu64, + stream->key, stream->rotate_ready, + stream->rotate_position, stream->last_sequence_number); + if (stream->rotate_ready) { + return 1; + } + + /* + * If packet seq num is unavailable, it means we are interacting + * with a pre-2.8 lttng-modules which does not implement the + * sequence number. Rotation should never be used by sessiond in this + * scenario. + */ + if (stream->sequence_number_unavailable) { + ERR("Internal error: rotation used on stream %" PRIu64 + " with unavailable sequence number", + stream->key); + return -1; + } + + if (stream->rotate_position == -1ULL || + stream->last_sequence_number == -1ULL) { + return 0; + } + + /* + * Rotate position not reached yet. The stream rotate position is + * the position of the next packet belonging to the next trace chunk, + * but consumerd considers rotation ready when reaching the last + * packet of the current chunk, hence the "rotate_position - 1". + */ + + DBG("Check is rotate ready for stream %" PRIu64 + " last_sequence_number %" PRIu64 + " rotate_position %" PRIu64, + stream->key, stream->last_sequence_number, + stream->rotate_position); + if (stream->last_sequence_number >= stream->rotate_position - 1) { + return 1; + } + + return 0; +} + +/* + * Reset the state for a stream after a rotation occurred. + */ +void lttng_consumer_reset_stream_rotate_state(struct lttng_consumer_stream *stream) +{ + DBG("lttng_consumer_reset_stream_rotate_state for stream %" PRIu64, + stream->key); + stream->rotate_position = -1ULL; + stream->rotate_ready = false; +} + +/* + * Perform the rotation a local stream file. + */ +static +int rotate_local_stream(struct lttng_consumer_local_data *ctx, + struct lttng_consumer_stream *stream) +{ + int ret = 0; + + DBG("Rotate local stream: stream key %" PRIu64 ", channel key %" PRIu64, + stream->key, + stream->chan->key); + stream->tracefile_size_current = 0; + stream->tracefile_count_current = 0; + + if (stream->out_fd >= 0) { + ret = close(stream->out_fd); + if (ret) { + PERROR("Failed to close stream out_fd of channel \"%s\"", + stream->chan->name); + } + stream->out_fd = -1; + } + + if (stream->index_file) { + lttng_index_file_put(stream->index_file); + stream->index_file = NULL; + } + + if (!stream->trace_chunk) { + goto end; + } + + ret = consumer_stream_create_output_files(stream, true); +end: + return ret; +} + +/* + * Performs the stream rotation for the rotate session feature if needed. + * It must be called with the channel and stream locks held. + * + * Return 0 on success, a negative number of error. + */ +int lttng_consumer_rotate_stream(struct lttng_consumer_local_data *ctx, + struct lttng_consumer_stream *stream) +{ + int ret; + + DBG("Consumer rotate stream %" PRIu64, stream->key); + + /* + * Update the stream's 'current' chunk to the session's (channel) + * now-current chunk. + */ + lttng_trace_chunk_put(stream->trace_chunk); + if (stream->chan->trace_chunk == stream->trace_chunk) { + /* + * A channel can be rotated and not have a "next" chunk + * to transition to. In that case, the channel's "current chunk" + * has not been closed yet, but it has not been updated to + * a "next" trace chunk either. Hence, the stream, like its + * parent channel, becomes part of no chunk and can't output + * anything until a new trace chunk is created. + */ + stream->trace_chunk = NULL; + } else if (stream->chan->trace_chunk && + !lttng_trace_chunk_get(stream->chan->trace_chunk)) { + ERR("Failed to acquire a reference to channel's trace chunk during stream rotation"); + ret = -1; + goto error; + } else { + /* + * Update the stream's trace chunk to its parent channel's + * current trace chunk. + */ + stream->trace_chunk = stream->chan->trace_chunk; + } + + if (stream->net_seq_idx == (uint64_t) -1ULL) { + ret = rotate_local_stream(ctx, stream); + if (ret < 0) { + ERR("Failed to rotate stream, ret = %i", ret); + goto error; + } + } + + if (stream->metadata_flag && stream->trace_chunk) { + /* + * If the stream has transitioned to a new trace + * chunk, the metadata should be re-dumped to the + * newest chunk. + * + * However, it is possible for a stream to transition to + * a "no-chunk" state. This can happen if a rotation + * occurs on an inactive session. In such cases, the metadata + * regeneration will happen when the next trace chunk is + * created. + */ + ret = consumer_metadata_stream_dump(stream); + if (ret) { + goto error; + } + } + lttng_consumer_reset_stream_rotate_state(stream); + + ret = 0; + +error: + return ret; +} + +/* + * Rotate all the ready streams now. + * + * This is especially important for low throughput streams that have already + * been consumed, we cannot wait for their next packet to perform the + * rotation. + * Need to be called with RCU read-side lock held to ensure existence of + * channel. + * + * Returns 0 on success, < 0 on error + */ +int lttng_consumer_rotate_ready_streams(struct lttng_consumer_channel *channel, + uint64_t key, struct lttng_consumer_local_data *ctx) +{ + int ret; + struct lttng_consumer_stream *stream; + struct lttng_ht_iter iter; + struct lttng_ht *ht = the_consumer_data.stream_per_chan_id_ht; + + rcu_read_lock(); + + DBG("Consumer rotate ready streams in channel %" PRIu64, key); + + cds_lfht_for_each_entry_duplicate(ht->ht, + ht->hash_fct(&channel->key, lttng_ht_seed), + ht->match_fct, &channel->key, &iter.iter, + stream, node_channel_id.node) { + health_code_update(); + + pthread_mutex_lock(&stream->chan->lock); + pthread_mutex_lock(&stream->lock); + + if (!stream->rotate_ready) { + pthread_mutex_unlock(&stream->lock); + pthread_mutex_unlock(&stream->chan->lock); + continue; + } + DBG("Consumer rotate ready stream %" PRIu64, stream->key); + + ret = lttng_consumer_rotate_stream(ctx, stream); + pthread_mutex_unlock(&stream->lock); + pthread_mutex_unlock(&stream->chan->lock); + if (ret) { + goto end; + } + } + + ret = 0; + +end: + rcu_read_unlock(); + return ret; +} + +enum lttcomm_return_code lttng_consumer_init_command( + struct lttng_consumer_local_data *ctx, + const lttng_uuid sessiond_uuid) +{ + enum lttcomm_return_code ret; + char uuid_str[LTTNG_UUID_STR_LEN]; + + if (ctx->sessiond_uuid.is_set) { + ret = LTTCOMM_CONSUMERD_ALREADY_SET; + goto end; + } + + ctx->sessiond_uuid.is_set = true; + memcpy(ctx->sessiond_uuid.value, sessiond_uuid, sizeof(lttng_uuid)); + ret = LTTCOMM_CONSUMERD_SUCCESS; + lttng_uuid_to_str(sessiond_uuid, uuid_str); + DBG("Received session daemon UUID: %s", uuid_str); +end: + return ret; +} + +enum lttcomm_return_code lttng_consumer_create_trace_chunk( + const uint64_t *relayd_id, uint64_t session_id, + uint64_t chunk_id, + time_t chunk_creation_timestamp, + const char *chunk_override_name, + const struct lttng_credentials *credentials, + struct lttng_directory_handle *chunk_directory_handle) +{ + int ret; + enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS; + struct lttng_trace_chunk *created_chunk = NULL, *published_chunk = NULL; + enum lttng_trace_chunk_status chunk_status; + char relayd_id_buffer[MAX_INT_DEC_LEN(*relayd_id)]; + char creation_timestamp_buffer[ISO8601_STR_LEN]; + const char *relayd_id_str = "(none)"; + const char *creation_timestamp_str; + struct lttng_ht_iter iter; + struct lttng_consumer_channel *channel; + + if (relayd_id) { + /* Only used for logging purposes. */ + ret = snprintf(relayd_id_buffer, sizeof(relayd_id_buffer), + "%" PRIu64, *relayd_id); + if (ret > 0 && ret < sizeof(relayd_id_buffer)) { + relayd_id_str = relayd_id_buffer; + } else { + relayd_id_str = "(formatting error)"; + } + } + + /* Local protocol error. */ + LTTNG_ASSERT(chunk_creation_timestamp); + ret = time_to_iso8601_str(chunk_creation_timestamp, + creation_timestamp_buffer, + sizeof(creation_timestamp_buffer)); + creation_timestamp_str = !ret ? creation_timestamp_buffer : + "(formatting error)"; + + DBG("Consumer create trace chunk command: relay_id = %s" + ", session_id = %" PRIu64 ", chunk_id = %" PRIu64 + ", chunk_override_name = %s" + ", chunk_creation_timestamp = %s", + relayd_id_str, session_id, chunk_id, + chunk_override_name ? : "(none)", + creation_timestamp_str); + + /* + * The trace chunk registry, as used by the consumer daemon, implicitly + * owns the trace chunks. This is only needed in the consumer since + * the consumer has no notion of a session beyond session IDs being + * used to identify other objects. + * + * The lttng_trace_chunk_registry_publish() call below provides a + * reference which is not released; it implicitly becomes the session + * daemon's reference to the chunk in the consumer daemon. + * + * The lifetime of trace chunks in the consumer daemon is managed by + * the session daemon through the LTTNG_CONSUMER_CREATE_TRACE_CHUNK + * and LTTNG_CONSUMER_DESTROY_TRACE_CHUNK commands. + */ + created_chunk = lttng_trace_chunk_create(chunk_id, + chunk_creation_timestamp, NULL); + if (!created_chunk) { + ERR("Failed to create trace chunk"); + ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; + goto error; + } + + if (chunk_override_name) { + chunk_status = lttng_trace_chunk_override_name(created_chunk, + chunk_override_name); + if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { + ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; + goto error; + } + } + + if (chunk_directory_handle) { + chunk_status = lttng_trace_chunk_set_credentials(created_chunk, + credentials); + if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { + ERR("Failed to set trace chunk credentials"); + ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; + goto error; + } + /* + * The consumer daemon has no ownership of the chunk output + * directory. + */ + chunk_status = lttng_trace_chunk_set_as_user(created_chunk, + chunk_directory_handle); + chunk_directory_handle = NULL; + if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { + ERR("Failed to set trace chunk's directory handle"); + ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; + goto error; + } + } + + published_chunk = lttng_trace_chunk_registry_publish_chunk( + the_consumer_data.chunk_registry, session_id, + created_chunk); + lttng_trace_chunk_put(created_chunk); + created_chunk = NULL; + if (!published_chunk) { + ERR("Failed to publish trace chunk"); + ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; + goto error; + } + + rcu_read_lock(); + cds_lfht_for_each_entry_duplicate( + the_consumer_data.channels_by_session_id_ht->ht, + the_consumer_data.channels_by_session_id_ht->hash_fct( + &session_id, lttng_ht_seed), + the_consumer_data.channels_by_session_id_ht->match_fct, + &session_id, &iter.iter, channel, + channels_by_session_id_ht_node.node) { + ret = lttng_consumer_channel_set_trace_chunk(channel, + published_chunk); + if (ret) { + /* + * Roll-back the creation of this chunk. + * + * This is important since the session daemon will + * assume that the creation of this chunk failed and + * will never ask for it to be closed, resulting + * in a leak and an inconsistent state for some + * channels. + */ + enum lttcomm_return_code close_ret; + char path[LTTNG_PATH_MAX]; + + DBG("Failed to set new trace chunk on existing channels, rolling back"); + close_ret = lttng_consumer_close_trace_chunk(relayd_id, + session_id, chunk_id, + chunk_creation_timestamp, NULL, + path); + if (close_ret != LTTCOMM_CONSUMERD_SUCCESS) { + ERR("Failed to roll-back the creation of new chunk: session_id = %" PRIu64 ", chunk_id = %" PRIu64, + session_id, chunk_id); + } + + ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; + break; + } + } + + if (relayd_id) { + struct consumer_relayd_sock_pair *relayd; + + relayd = consumer_find_relayd(*relayd_id); + if (relayd) { + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + ret = relayd_create_trace_chunk( + &relayd->control_sock, published_chunk); + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + } else { + ERR("Failed to find relay daemon socket: relayd_id = %" PRIu64, *relayd_id); + } + + if (!relayd || ret) { + enum lttcomm_return_code close_ret; + char path[LTTNG_PATH_MAX]; + + close_ret = lttng_consumer_close_trace_chunk(relayd_id, + session_id, + chunk_id, + chunk_creation_timestamp, + NULL, path); + if (close_ret != LTTCOMM_CONSUMERD_SUCCESS) { + ERR("Failed to roll-back the creation of new chunk: session_id = %" PRIu64 ", chunk_id = %" PRIu64, + session_id, + chunk_id); + } + + ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; + goto error_unlock; + } + } +error_unlock: + rcu_read_unlock(); +error: + /* Release the reference returned by the "publish" operation. */ + lttng_trace_chunk_put(published_chunk); + lttng_trace_chunk_put(created_chunk); + return ret_code; +} + +enum lttcomm_return_code lttng_consumer_close_trace_chunk( + const uint64_t *relayd_id, uint64_t session_id, + uint64_t chunk_id, time_t chunk_close_timestamp, + const enum lttng_trace_chunk_command_type *close_command, + char *path) +{ + enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS; + struct lttng_trace_chunk *chunk; + char relayd_id_buffer[MAX_INT_DEC_LEN(*relayd_id)]; + const char *relayd_id_str = "(none)"; + const char *close_command_name = "none"; + struct lttng_ht_iter iter; + struct lttng_consumer_channel *channel; + enum lttng_trace_chunk_status chunk_status; + + if (relayd_id) { + int ret; + + /* Only used for logging purposes. */ + ret = snprintf(relayd_id_buffer, sizeof(relayd_id_buffer), + "%" PRIu64, *relayd_id); + if (ret > 0 && ret < sizeof(relayd_id_buffer)) { + relayd_id_str = relayd_id_buffer; + } else { + relayd_id_str = "(formatting error)"; + } + } + if (close_command) { + close_command_name = lttng_trace_chunk_command_type_get_name( + *close_command); + } + + DBG("Consumer close trace chunk command: relayd_id = %s" + ", session_id = %" PRIu64 ", chunk_id = %" PRIu64 + ", close command = %s", + relayd_id_str, session_id, chunk_id, + close_command_name); + + chunk = lttng_trace_chunk_registry_find_chunk( + the_consumer_data.chunk_registry, session_id, chunk_id); + if (!chunk) { + ERR("Failed to find chunk: session_id = %" PRIu64 + ", chunk_id = %" PRIu64, + session_id, chunk_id); + ret_code = LTTCOMM_CONSUMERD_UNKNOWN_TRACE_CHUNK; + goto end; + } + + chunk_status = lttng_trace_chunk_set_close_timestamp(chunk, + chunk_close_timestamp); + if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { + ret_code = LTTCOMM_CONSUMERD_CLOSE_TRACE_CHUNK_FAILED; + goto end; + } + + if (close_command) { + chunk_status = lttng_trace_chunk_set_close_command( + chunk, *close_command); + if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { + ret_code = LTTCOMM_CONSUMERD_CLOSE_TRACE_CHUNK_FAILED; + goto end; + } + } + + /* + * chunk is now invalid to access as we no longer hold a reference to + * it; it is only kept around to compare it (by address) to the + * current chunk found in the session's channels. + */ + rcu_read_lock(); + cds_lfht_for_each_entry(the_consumer_data.channel_ht->ht, &iter.iter, + channel, node.node) { + int ret; + + /* + * Only change the channel's chunk to NULL if it still + * references the chunk being closed. The channel may + * reference a newer channel in the case of a session + * rotation. When a session rotation occurs, the "next" + * chunk is created before the "current" chunk is closed. + */ + if (channel->trace_chunk != chunk) { + continue; + } + ret = lttng_consumer_channel_set_trace_chunk(channel, NULL); + if (ret) { + /* + * Attempt to close the chunk on as many channels as + * possible. + */ + ret_code = LTTCOMM_CONSUMERD_CLOSE_TRACE_CHUNK_FAILED; + } + } + + if (relayd_id) { + int ret; + struct consumer_relayd_sock_pair *relayd; + + relayd = consumer_find_relayd(*relayd_id); + if (relayd) { + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + ret = relayd_close_trace_chunk( + &relayd->control_sock, chunk, + path); + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + } else { + ERR("Failed to find relay daemon socket: relayd_id = %" PRIu64, + *relayd_id); + } + + if (!relayd || ret) { + ret_code = LTTCOMM_CONSUMERD_CLOSE_TRACE_CHUNK_FAILED; + goto error_unlock; + } + } +error_unlock: + rcu_read_unlock(); +end: + /* + * Release the reference returned by the "find" operation and + * the session daemon's implicit reference to the chunk. + */ + lttng_trace_chunk_put(chunk); + lttng_trace_chunk_put(chunk); + + return ret_code; +} + +enum lttcomm_return_code lttng_consumer_trace_chunk_exists( + const uint64_t *relayd_id, uint64_t session_id, + uint64_t chunk_id) +{ + int ret; + enum lttcomm_return_code ret_code; + char relayd_id_buffer[MAX_INT_DEC_LEN(*relayd_id)]; + const char *relayd_id_str = "(none)"; + const bool is_local_trace = !relayd_id; + struct consumer_relayd_sock_pair *relayd = NULL; + bool chunk_exists_local, chunk_exists_remote; + + if (relayd_id) { + /* Only used for logging purposes. */ + ret = snprintf(relayd_id_buffer, sizeof(relayd_id_buffer), + "%" PRIu64, *relayd_id); + if (ret > 0 && ret < sizeof(relayd_id_buffer)) { + relayd_id_str = relayd_id_buffer; + } else { + relayd_id_str = "(formatting error)"; + } + } + + DBG("Consumer trace chunk exists command: relayd_id = %s" + ", chunk_id = %" PRIu64, relayd_id_str, + chunk_id); + ret = lttng_trace_chunk_registry_chunk_exists( + the_consumer_data.chunk_registry, session_id, chunk_id, + &chunk_exists_local); + if (ret) { + /* Internal error. */ + ERR("Failed to query the existence of a trace chunk"); + ret_code = LTTCOMM_CONSUMERD_FATAL; + goto end; + } + DBG("Trace chunk %s locally", + chunk_exists_local ? "exists" : "does not exist"); + if (chunk_exists_local) { + ret_code = LTTCOMM_CONSUMERD_TRACE_CHUNK_EXISTS_LOCAL; + goto end; + } else if (is_local_trace) { + ret_code = LTTCOMM_CONSUMERD_UNKNOWN_TRACE_CHUNK; + goto end; + } + + rcu_read_lock(); + relayd = consumer_find_relayd(*relayd_id); + if (!relayd) { + ERR("Failed to find relayd %" PRIu64, *relayd_id); + ret_code = LTTCOMM_CONSUMERD_INVALID_PARAMETERS; + goto end_rcu_unlock; + } + DBG("Looking up existence of trace chunk on relay daemon"); + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + ret = relayd_trace_chunk_exists(&relayd->control_sock, chunk_id, + &chunk_exists_remote); + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + if (ret < 0) { + ERR("Failed to look-up the existence of trace chunk on relay daemon"); + ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL; + goto end_rcu_unlock; + } + + ret_code = chunk_exists_remote ? + LTTCOMM_CONSUMERD_TRACE_CHUNK_EXISTS_REMOTE : + LTTCOMM_CONSUMERD_UNKNOWN_TRACE_CHUNK; + DBG("Trace chunk %s on relay daemon", + chunk_exists_remote ? "exists" : "does not exist"); + +end_rcu_unlock: + rcu_read_unlock(); +end: + return ret_code; +} + +static +int consumer_clear_monitored_channel(struct lttng_consumer_channel *channel) +{ + struct lttng_ht *ht; + struct lttng_consumer_stream *stream; + struct lttng_ht_iter iter; + int ret; + + ht = the_consumer_data.stream_per_chan_id_ht; + + rcu_read_lock(); + cds_lfht_for_each_entry_duplicate(ht->ht, + ht->hash_fct(&channel->key, lttng_ht_seed), + ht->match_fct, &channel->key, + &iter.iter, stream, node_channel_id.node) { + /* + * Protect against teardown with mutex. + */ + pthread_mutex_lock(&stream->lock); + if (cds_lfht_is_node_deleted(&stream->node.node)) { + goto next; + } + ret = consumer_clear_stream(stream); + if (ret) { + goto error_unlock; + } + next: + pthread_mutex_unlock(&stream->lock); + } + rcu_read_unlock(); + return LTTCOMM_CONSUMERD_SUCCESS; + +error_unlock: + pthread_mutex_unlock(&stream->lock); + rcu_read_unlock(); + return ret; +} + +int lttng_consumer_clear_channel(struct lttng_consumer_channel *channel) +{ + int ret; + + DBG("Consumer clear channel %" PRIu64, channel->key); + + if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) { + /* + * Nothing to do for the metadata channel/stream. + * Snapshot mechanism already take care of the metadata + * handling/generation, and monitored channels only need to + * have their data stream cleared.. + */ + ret = LTTCOMM_CONSUMERD_SUCCESS; + goto end; + } + + if (!channel->monitor) { + ret = consumer_clear_unmonitored_channel(channel); + } else { + ret = consumer_clear_monitored_channel(channel); + } +end: + return ret; +} + +enum lttcomm_return_code lttng_consumer_open_channel_packets( + struct lttng_consumer_channel *channel) +{ + struct lttng_consumer_stream *stream; + enum lttcomm_return_code ret = LTTCOMM_CONSUMERD_SUCCESS; + + if (channel->metadata_stream) { + ERR("Open channel packets command attempted on a metadata channel"); + ret = LTTCOMM_CONSUMERD_INVALID_PARAMETERS; + goto end; + } + + rcu_read_lock(); + cds_list_for_each_entry(stream, &channel->streams.head, send_node) { + enum consumer_stream_open_packet_status status; + + pthread_mutex_lock(&stream->lock); + if (cds_lfht_is_node_deleted(&stream->node.node)) { + goto next; + } + + status = consumer_stream_open_packet(stream); + switch (status) { + case CONSUMER_STREAM_OPEN_PACKET_STATUS_OPENED: + DBG("Opened a packet in \"open channel packets\" command: stream id = %" PRIu64 + ", channel name = %s, session id = %" PRIu64, + stream->key, stream->chan->name, + stream->chan->session_id); + stream->opened_packet_in_current_trace_chunk = true; + break; + case CONSUMER_STREAM_OPEN_PACKET_STATUS_NO_SPACE: + DBG("No space left to open a packet in \"open channel packets\" command: stream id = %" PRIu64 + ", channel name = %s, session id = %" PRIu64, + stream->key, stream->chan->name, + stream->chan->session_id); + break; + case CONSUMER_STREAM_OPEN_PACKET_STATUS_ERROR: + /* + * Only unexpected internal errors can lead to this + * failing. Report an unknown error. + */ + ERR("Failed to flush empty buffer in \"open channel packets\" command: stream id = %" PRIu64 + ", channel id = %" PRIu64 + ", channel name = %s" + ", session id = %" PRIu64, + stream->key, channel->key, + channel->name, channel->session_id); + ret = LTTCOMM_CONSUMERD_UNKNOWN_ERROR; + goto error_unlock; + default: + abort(); + } + + next: + pthread_mutex_unlock(&stream->lock); + } + +end_rcu_unlock: + rcu_read_unlock(); +end: + return ret; + +error_unlock: + pthread_mutex_unlock(&stream->lock); + goto end_rcu_unlock; +} + +void lttng_consumer_sigbus_handle(void *addr) +{ + lttng_ustconsumer_sigbus_handle(addr); +}