+/*
+ * Copyright (C) 2011 Julien Desfossez <julien.desfossez@polymtl.ca>
+ * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#include "common/index/ctf-index.h"
+#define _LGPL_SOURCE
+#include <poll.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <signal.h>
+
+#include <bin/lttng-consumerd/health-consumerd.h>
+#include <common/common.h>
+#include <common/utils.h>
+#include <common/time.h>
+#include <common/compat/poll.h>
+#include <common/compat/endian.h>
+#include <common/index/index.h>
+#include <common/kernel-ctl/kernel-ctl.h>
+#include <common/sessiond-comm/relayd.h>
+#include <common/sessiond-comm/sessiond-comm.h>
+#include <common/kernel-consumer/kernel-consumer.h>
+#include <common/relayd/relayd.h>
+#include <common/ust-consumer/ust-consumer.h>
+#include <common/consumer/consumer-timer.h>
+#include <common/consumer/consumer.h>
+#include <common/consumer/consumer-stream.h>
+#include <common/consumer/consumer-testpoint.h>
+#include <common/align.h>
+#include <common/consumer/consumer-metadata-cache.h>
+#include <common/trace-chunk.h>
+#include <common/trace-chunk-registry.h>
+#include <common/string-utils/format.h>
+#include <common/dynamic-array.h>
+
+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);
+}
projects / lttng-tools.git / blobdiff