/*
* Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * 2012 - David Goulet <dgoulet@efficios.com>
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; only version 2
- * of the License.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2 only,
+ * as published by the Free Software Foundation.
*
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
*
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#define _GNU_SOURCE
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
+#include <inttypes.h>
#include <common/common.h>
+#include <common/utils.h>
+#include <common/compat/poll.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 "consumer.h"
.type = LTTNG_CONSUMER_UNKNOWN,
};
-/* timeout parameter, to control the polling thread grace period. */
-int consumer_poll_timeout = -1;
-
/*
* 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.
*/
-volatile int consumer_quit = 0;
+volatile 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;
+
+/*
+ * Notify a thread 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_pipe(int wpipe)
+{
+ int ret;
+
+ do {
+ struct lttng_consumer_stream *null_stream = NULL;
+
+ ret = write(wpipe, &null_stream, sizeof(null_stream));
+ } while (ret < 0 && errno == EINTR);
+}
/*
* Find a stream. The consumer_data.lock must be locked during this
* call.
*/
-static struct lttng_consumer_stream *consumer_find_stream(int key)
+static struct lttng_consumer_stream *find_stream(int key,
+ struct lttng_ht *ht)
{
struct lttng_ht_iter iter;
struct lttng_ht_node_ulong *node;
struct lttng_consumer_stream *stream = NULL;
+ assert(ht);
+
/* Negative keys are lookup failures */
- if (key < 0)
+ if (key < 0) {
return NULL;
+ }
rcu_read_lock();
- lttng_ht_lookup(consumer_data.stream_ht, (void *)((unsigned long) key),
- &iter);
+ lttng_ht_lookup(ht, (void *)((unsigned long) key), &iter);
node = lttng_ht_iter_get_node_ulong(&iter);
if (node != NULL) {
stream = caa_container_of(node, struct lttng_consumer_stream, node);
return stream;
}
-static void consumer_steal_stream_key(int key)
+static void steal_stream_key(int key, struct lttng_ht *ht)
{
struct lttng_consumer_stream *stream;
- stream = consumer_find_stream(key);
- if (stream)
+ rcu_read_lock();
+ stream = find_stream(key, ht);
+ if (stream) {
stream->key = -1;
+ /*
+ * We don't want the lookup to match, but we still need
+ * to iterate on this stream when iterating over the hash table. Just
+ * change the node key.
+ */
+ stream->node.key = -1;
+ }
+ rcu_read_unlock();
}
-static struct lttng_consumer_channel *consumer_find_channel(int key)
+/*
+ * 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(unsigned long key)
{
struct lttng_ht_iter iter;
struct lttng_ht_node_ulong *node;
struct lttng_consumer_channel *channel = NULL;
/* Negative keys are lookup failures */
- if (key < 0)
+ if (key < 0) {
return NULL;
+ }
- rcu_read_lock();
-
- lttng_ht_lookup(consumer_data.channel_ht, (void *)((unsigned long) key),
- &iter);
+ lttng_ht_lookup(consumer_data.channel_ht, (void *) key, &iter);
node = lttng_ht_iter_get_node_ulong(&iter);
if (node != NULL) {
channel = caa_container_of(node, struct lttng_consumer_channel, node);
}
- rcu_read_unlock();
-
return channel;
}
-static void consumer_steal_channel_key(int key)
+static void free_stream_rcu(struct rcu_head *head)
{
- struct lttng_consumer_channel *channel;
+ struct lttng_ht_node_ulong *node =
+ caa_container_of(head, struct lttng_ht_node_ulong, head);
+ struct lttng_consumer_stream *stream =
+ caa_container_of(node, struct lttng_consumer_stream, node);
+
+ free(stream);
+}
+
+static void free_channel_rcu(struct rcu_head *head)
+{
+ struct lttng_ht_node_ulong *node =
+ caa_container_of(head, struct lttng_ht_node_ulong, head);
+ struct lttng_consumer_channel *channel =
+ caa_container_of(node, struct lttng_consumer_channel, node);
- channel = consumer_find_channel(key);
- if (channel)
- channel->key = -1;
+ free(channel);
}
/*
- * Remove a stream from the global list protected by a mutex. This
- * function is also responsible for freeing its data structures.
+ * RCU protected relayd socket pair free.
+ */
+static void free_relayd_rcu(struct rcu_head *head)
+{
+ struct lttng_ht_node_ulong *node =
+ caa_container_of(head, struct lttng_ht_node_ulong, head);
+ struct consumer_relayd_sock_pair *relayd =
+ caa_container_of(node, struct consumer_relayd_sock_pair, node);
+
+ /*
+ * 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);
+
+ free(relayd);
+}
+
+/*
+ * Destroy and free relayd socket pair object.
+ *
+ * This function MUST be called with the consumer_data lock acquired.
*/
-void consumer_del_stream(struct lttng_consumer_stream *stream)
+static void destroy_relayd(struct consumer_relayd_sock_pair *relayd)
{
int ret;
struct lttng_ht_iter iter;
- struct lttng_consumer_channel *free_chan = NULL;
+
+ if (relayd == NULL) {
+ return;
+ }
+
+ DBG("Consumer destroy and close relayd socket pair");
+
+ iter.iter.node = &relayd->node.node;
+ ret = lttng_ht_del(consumer_data.relayd_ht, &iter);
+ if (ret != 0) {
+ /* We assume the relayd 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)
+{
+ int ret;
+ struct lttng_ht_iter iter;
+
+ DBG("Consumer delete channel key %d", channel->key);
pthread_mutex_lock(&consumer_data.lock);
switch (consumer_data.type) {
case LTTNG_CONSUMER_KERNEL:
- if (stream->mmap_base != NULL) {
- ret = munmap(stream->mmap_base, stream->mmap_len);
- if (ret != 0) {
- perror("munmap");
- }
- }
break;
case LTTNG_CONSUMER32_UST:
case LTTNG_CONSUMER64_UST:
- lttng_ustconsumer_del_stream(stream);
+ lttng_ustconsumer_del_channel(channel);
break;
default:
ERR("Unknown consumer_data type");
}
rcu_read_lock();
-
- /* Get stream node from hash table */
- lttng_ht_lookup(consumer_data.stream_ht,
- (void *)((unsigned long) stream->key), &iter);
- /* Remove stream node from hash table */
- ret = lttng_ht_del(consumer_data.stream_ht, &iter);
+ iter.iter.node = &channel->node.node;
+ ret = lttng_ht_del(consumer_data.channel_ht, &iter);
assert(!ret);
-
rcu_read_unlock();
- if (consumer_data.stream_count <= 0) {
- goto end;
- }
- consumer_data.stream_count--;
- if (!stream) {
- goto end;
- }
- if (stream->out_fd >= 0) {
- close(stream->out_fd);
- }
- if (stream->wait_fd >= 0 && !stream->wait_fd_is_copy) {
- close(stream->wait_fd);
- }
- if (stream->shm_fd >= 0 && stream->wait_fd != stream->shm_fd) {
- close(stream->shm_fd);
- }
- if (!--stream->chan->refcount)
- free_chan = stream->chan;
- free(stream);
+ call_rcu(&channel->node.head, free_channel_rcu);
end:
- consumer_data.need_update = 1;
pthread_mutex_unlock(&consumer_data.lock);
-
- if (free_chan)
- consumer_del_channel(free_chan);
}
-static void consumer_del_stream_rcu(struct rcu_head *head)
+/*
+ * 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_node_ulong *node =
- caa_container_of(head, struct lttng_ht_node_ulong, head);
- struct lttng_consumer_stream *stream =
- caa_container_of(node, struct lttng_consumer_stream, node);
+ struct lttng_ht_iter iter;
+ struct consumer_relayd_sock_pair *relayd;
+
+ rcu_read_lock();
+
+ cds_lfht_for_each_entry(consumer_data.relayd_ht->ht, &iter.iter, relayd,
+ node.node) {
+ destroy_relayd(relayd);
+ }
+
+ lttng_ht_destroy(consumer_data.relayd_ht);
- consumer_del_stream(stream);
+ rcu_read_unlock();
}
-struct lttng_consumer_stream *consumer_allocate_stream(
- int channel_key, int stream_key,
- int shm_fd, int wait_fd,
- enum lttng_consumer_stream_state state,
- uint64_t mmap_len,
- enum lttng_event_output output,
- const char *path_name,
- uid_t uid,
- gid_t gid)
+/*
+ * 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(int net_seq_idx,
+ enum consumer_endpoint_status status)
{
+ struct lttng_ht_iter iter;
struct lttng_consumer_stream *stream;
- int ret;
- stream = zmalloc(sizeof(*stream));
- if (stream == NULL) {
- perror("malloc struct lttng_consumer_stream");
- goto end;
- }
- stream->chan = consumer_find_channel(channel_key);
- if (!stream->chan) {
- perror("Unable to find channel key");
- goto end;
+ DBG("Consumer set delete flag on stream by idx %d", 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);
+ }
}
- stream->chan->refcount++;
- stream->key = stream_key;
- stream->shm_fd = shm_fd;
- stream->wait_fd = wait_fd;
- stream->out_fd = -1;
- stream->out_fd_offset = 0;
- stream->state = state;
- stream->mmap_len = mmap_len;
- stream->mmap_base = NULL;
- stream->output = output;
- stream->uid = uid;
- stream->gid = gid;
- strncpy(stream->path_name, path_name, PATH_MAX - 1);
- stream->path_name[PATH_MAX - 1] = '\0';
- lttng_ht_node_init_ulong(&stream->node, stream->key);
- switch (consumer_data.type) {
- case LTTNG_CONSUMER_KERNEL:
- break;
- case LTTNG_CONSUMER32_UST:
- case LTTNG_CONSUMER64_UST:
- stream->cpu = stream->chan->cpucount++;
- ret = lttng_ustconsumer_allocate_stream(stream);
- if (ret) {
- free(stream);
- return NULL;
+ /* 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);
}
- break;
- default:
- ERR("Unknown consumer_data type");
- assert(0);
- goto end;
}
- DBG("Allocated stream %s (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, out_fd %d)",
- stream->path_name, stream->key,
- stream->shm_fd,
- stream->wait_fd,
- (unsigned long long) stream->mmap_len,
- stream->out_fd);
-end:
- return stream;
+ rcu_read_unlock();
}
/*
- * Add a stream to the global list protected by a mutex.
+ * 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.
*/
-int consumer_add_stream(struct lttng_consumer_stream *stream)
+static void cleanup_relayd(struct consumer_relayd_sock_pair *relayd,
+ struct lttng_consumer_local_data *ctx)
{
- int ret = 0;
+ int netidx;
- pthread_mutex_lock(&consumer_data.lock);
- /* Steal stream identifier, for UST */
- consumer_steal_stream_key(stream->key);
- rcu_read_lock();
- lttng_ht_add_unique_ulong(consumer_data.stream_ht, &stream->node);
- rcu_read_unlock();
- consumer_data.stream_count++;
- consumer_data.need_update = 1;
+ assert(relayd);
- switch (consumer_data.type) {
- case LTTNG_CONSUMER_KERNEL:
- break;
- case LTTNG_CONSUMER32_UST:
- case LTTNG_CONSUMER64_UST:
- /* Streams are in CPU number order (we rely on this) */
- stream->cpu = stream->chan->nr_streams++;
- break;
- default:
- ERR("Unknown consumer_data type");
- assert(0);
- goto end;
- }
+ DBG("Cleaning up relayd sockets");
-end:
- pthread_mutex_unlock(&consumer_data.lock);
- return ret;
+ /* 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.
+ */
+ 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.
+ */
+ if (ctx) {
+ notify_thread_pipe(ctx->consumer_data_pipe[1]);
+ notify_thread_pipe(ctx->consumer_metadata_pipe[1]);
+ }
}
/*
- * Update a stream according to what we just received.
+ * 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_change_stream_state(int stream_key,
- enum lttng_consumer_stream_state state)
+void consumer_flag_relayd_for_destroy(struct consumer_relayd_sock_pair *relayd)
{
- struct lttng_consumer_stream *stream;
+ assert(relayd);
- pthread_mutex_lock(&consumer_data.lock);
- stream = consumer_find_stream(stream_key);
- if (stream) {
- stream->state = state;
+ /* Set destroy flag for this object */
+ uatomic_set(&relayd->destroy_flag, 1);
+
+ /* Destroy the relayd if refcount is 0 */
+ if (uatomic_read(&relayd->refcount) == 0) {
+ destroy_relayd(relayd);
}
- consumer_data.need_update = 1;
- pthread_mutex_unlock(&consumer_data.lock);
}
/*
- * Remove a channel from the global list protected by a mutex. This
+ * Remove a stream 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)
+void consumer_del_stream(struct lttng_consumer_stream *stream,
+ struct lttng_ht *ht)
{
int ret;
struct lttng_ht_iter iter;
+ struct lttng_consumer_channel *free_chan = NULL;
+ struct consumer_relayd_sock_pair *relayd;
+
+ assert(stream);
+
+ DBG("Consumer del stream %d", stream->wait_fd);
+
+ if (ht == NULL) {
+ /* Means the stream was allocated but not successfully added */
+ goto free_stream_rcu;
+ }
pthread_mutex_lock(&consumer_data.lock);
+ pthread_mutex_lock(&stream->lock);
switch (consumer_data.type) {
case LTTNG_CONSUMER_KERNEL:
+ if (stream->mmap_base != NULL) {
+ ret = munmap(stream->mmap_base, stream->mmap_len);
+ if (ret != 0) {
+ PERROR("munmap");
+ }
+ }
break;
case LTTNG_CONSUMER32_UST:
case LTTNG_CONSUMER64_UST:
- lttng_ustconsumer_del_channel(channel);
+ lttng_ustconsumer_del_stream(stream);
break;
default:
ERR("Unknown consumer_data type");
}
rcu_read_lock();
-
- lttng_ht_lookup(consumer_data.channel_ht,
- (void *)((unsigned long) channel->key), &iter);
- ret = lttng_ht_del(consumer_data.channel_ht, &iter);
+ iter.iter.node = &stream->node.node;
+ ret = lttng_ht_del(ht, &iter);
assert(!ret);
+ /* Remove node session id from the consumer_data stream ht */
+ iter.iter.node = &stream->node_session_id.node;
+ ret = lttng_ht_del(consumer_data.stream_list_ht, &iter);
+ assert(!ret);
rcu_read_unlock();
- if (channel->mmap_base != NULL) {
- ret = munmap(channel->mmap_base, channel->mmap_len);
- if (ret != 0) {
- perror("munmap");
+ assert(consumer_data.stream_count > 0);
+ consumer_data.stream_count--;
+
+ if (stream->out_fd >= 0) {
+ ret = close(stream->out_fd);
+ if (ret) {
+ PERROR("close");
}
}
- if (channel->wait_fd >= 0 && !channel->wait_fd_is_copy) {
- close(channel->wait_fd);
+
+ /* Check and cleanup relayd */
+ rcu_read_lock();
+ relayd = consumer_find_relayd(stream->net_seq_idx);
+ if (relayd != NULL) {
+ uatomic_dec(&relayd->refcount);
+ assert(uatomic_read(&relayd->refcount) >= 0);
+
+ /* Closing streams requires to lock the control socket. */
+ pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+ ret = relayd_send_close_stream(&relayd->control_sock,
+ stream->relayd_stream_id,
+ stream->next_net_seq_num - 1);
+ pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
+ if (ret < 0) {
+ DBG("Unable to close stream on the relayd. Continuing");
+ /*
+ * Continue here. There is nothing we can do for the relayd.
+ * Chances are that the relayd has closed the socket so we just
+ * continue cleaning up.
+ */
+ }
+
+ /* Both conditions are met, we destroy the relayd. */
+ if (uatomic_read(&relayd->refcount) == 0 &&
+ uatomic_read(&relayd->destroy_flag)) {
+ destroy_relayd(relayd);
+ }
}
- if (channel->shm_fd >= 0 && channel->wait_fd != channel->shm_fd) {
- close(channel->shm_fd);
+ rcu_read_unlock();
+
+ uatomic_dec(&stream->chan->refcount);
+ if (!uatomic_read(&stream->chan->refcount)
+ && !uatomic_read(&stream->chan->nb_init_stream_left)) {
+ free_chan = stream->chan;
}
- free(channel);
+
end:
+ consumer_data.need_update = 1;
+ pthread_mutex_unlock(&stream->lock);
pthread_mutex_unlock(&consumer_data.lock);
-}
-static void consumer_del_channel_rcu(struct rcu_head *head)
-{
- struct lttng_ht_node_ulong *node =
- caa_container_of(head, struct lttng_ht_node_ulong, head);
- struct lttng_consumer_channel *channel=
- caa_container_of(node, struct lttng_consumer_channel, node);
+ if (free_chan) {
+ consumer_del_channel(free_chan);
+ }
- consumer_del_channel(channel);
+free_stream_rcu:
+ call_rcu(&stream->node.head, free_stream_rcu);
}
-struct lttng_consumer_channel *consumer_allocate_channel(
- int channel_key,
- int shm_fd, int wait_fd,
- uint64_t mmap_len,
- uint64_t max_sb_size)
+struct lttng_consumer_stream *consumer_allocate_stream(int channel_key,
+ int stream_key,
+ enum lttng_consumer_stream_state state,
+ const char *channel_name,
+ uid_t uid,
+ gid_t gid,
+ int relayd_id,
+ uint64_t session_id,
+ int cpu,
+ int *alloc_ret,
+ enum consumer_channel_type type)
{
- struct lttng_consumer_channel *channel;
int ret;
+ struct lttng_consumer_stream *stream;
- channel = zmalloc(sizeof(*channel));
- if (channel == NULL) {
- perror("malloc struct lttng_consumer_channel");
+ stream = zmalloc(sizeof(*stream));
+ if (stream == NULL) {
+ PERROR("malloc struct lttng_consumer_stream");
+ ret = -ENOMEM;
goto end;
}
- channel->key = channel_key;
- channel->shm_fd = shm_fd;
- channel->wait_fd = wait_fd;
- channel->mmap_len = mmap_len;
- channel->max_sb_size = max_sb_size;
- channel->refcount = 0;
- channel->nr_streams = 0;
- lttng_ht_node_init_ulong(&channel->node, channel->key);
- switch (consumer_data.type) {
- case LTTNG_CONSUMER_KERNEL:
- channel->mmap_base = NULL;
- channel->mmap_len = 0;
- break;
- case LTTNG_CONSUMER32_UST:
- case LTTNG_CONSUMER64_UST:
- ret = lttng_ustconsumer_allocate_channel(channel);
- if (ret) {
- free(channel);
- return NULL;
- }
- break;
- default:
- ERR("Unknown consumer_data type");
- assert(0);
- goto end;
+ rcu_read_lock();
+
+ stream->key = stream_key;
+ stream->out_fd = -1;
+ stream->out_fd_offset = 0;
+ stream->state = state;
+ stream->uid = uid;
+ stream->gid = gid;
+ stream->net_seq_idx = relayd_id;
+ stream->session_id = session_id;
+ pthread_mutex_init(&stream->lock, NULL);
+
+ /* If channel is the metadata, flag this stream as metadata. */
+ if (type == CONSUMER_CHANNEL_TYPE_METADATA) {
+ stream->metadata_flag = 1;
+ /* Metadata is flat out. */
+ strncpy(stream->name, DEFAULT_METADATA_NAME, sizeof(stream->name));
+ } else {
+ /* Format stream name to <channel_name>_<cpu_number> */
+ ret = snprintf(stream->name, sizeof(stream->name), "%s_%d",
+ channel_name, cpu);
+ if (ret < 0) {
+ PERROR("snprintf stream name");
+ goto error;
+ }
+ }
+
+ /* Key is always the wait_fd for streams. */
+ lttng_ht_node_init_ulong(&stream->node, stream->key);
+
+ /* Init session id node with the stream session id */
+ lttng_ht_node_init_ulong(&stream->node_session_id, stream->session_id);
+
+ DBG3("Allocated stream %s (key %d, relayd_id %d, session_id %" PRIu64,
+ stream->name, stream->key, stream->net_seq_idx, stream->session_id);
+
+ rcu_read_unlock();
+ return stream;
+
+error:
+ rcu_read_unlock();
+ free(stream);
+end:
+ if (alloc_ret) {
+ *alloc_ret = ret;
+ }
+ return NULL;
+}
+
+/*
+ * Add a stream to the global list protected by a mutex.
+ */
+static int add_stream(struct lttng_consumer_stream *stream,
+ struct lttng_ht *ht)
+{
+ int ret = 0;
+ struct consumer_relayd_sock_pair *relayd;
+
+ assert(stream);
+ assert(ht);
+
+ DBG3("Adding consumer stream %d", stream->key);
+
+ pthread_mutex_lock(&consumer_data.lock);
+ 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_ulong(ht, &stream->node);
+
+ /*
+ * Add stream to the stream_list_ht of the consumer data. No need to steal
+ * the key since the HT does not use it and we allow to add redundant keys
+ * into this table.
+ */
+ lttng_ht_add_ulong(consumer_data.stream_list_ht, &stream->node_session_id);
+
+ /* Check and cleanup relayd */
+ relayd = consumer_find_relayd(stream->net_seq_idx);
+ if (relayd != NULL) {
+ uatomic_inc(&relayd->refcount);
+ }
+
+ /* Update channel refcount once added without error(s). */
+ uatomic_inc(&stream->chan->refcount);
+
+ /*
+ * When nb_init_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) {
+ uatomic_dec(&stream->chan->nb_init_stream_left);
+ }
+
+ /* Update consumer data once the node is inserted. */
+ consumer_data.stream_count++;
+ consumer_data.need_update = 1;
+
+ rcu_read_unlock();
+ pthread_mutex_unlock(&stream->lock);
+ pthread_mutex_unlock(&consumer_data.lock);
+
+ return ret;
+}
+
+/*
+ * Add relayd socket to global consumer data hashtable. RCU read side lock MUST
+ * be acquired before calling this.
+ */
+static int add_relayd(struct consumer_relayd_sock_pair *relayd)
+{
+ int ret = 0;
+ struct lttng_ht_node_ulong *node;
+ struct lttng_ht_iter iter;
+
+ assert(relayd);
+
+ lttng_ht_lookup(consumer_data.relayd_ht,
+ (void *)((unsigned long) relayd->net_seq_idx), &iter);
+ node = lttng_ht_iter_get_node_ulong(&iter);
+ if (node != NULL) {
+ goto end;
+ }
+ lttng_ht_add_unique_ulong(consumer_data.relayd_ht, &relayd->node);
+
+end:
+ return ret;
+}
+
+/*
+ * Allocate and return a consumer relayd socket.
+ */
+struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
+ int net_seq_idx)
+{
+ struct consumer_relayd_sock_pair *obj = NULL;
+
+ /* Negative net sequence index is a failure */
+ if (net_seq_idx < 0) {
+ goto error;
+ }
+
+ obj = zmalloc(sizeof(struct consumer_relayd_sock_pair));
+ if (obj == NULL) {
+ PERROR("zmalloc relayd sock");
+ goto error;
+ }
+
+ obj->net_seq_idx = net_seq_idx;
+ obj->refcount = 0;
+ obj->destroy_flag = 0;
+ lttng_ht_node_init_ulong(&obj->node, obj->net_seq_idx);
+ pthread_mutex_init(&obj->ctrl_sock_mutex, NULL);
+
+error:
+ return obj;
+}
+
+/*
+ * Find a relayd socket pair in the global consumer data.
+ *
+ * Return the object if found else NULL.
+ * RCU read-side lock must be held across this call and while using the
+ * returned object.
+ */
+struct consumer_relayd_sock_pair *consumer_find_relayd(int key)
+{
+ struct lttng_ht_iter iter;
+ struct lttng_ht_node_ulong *node;
+ struct consumer_relayd_sock_pair *relayd = NULL;
+
+ /* Negative keys are lookup failures */
+ if (key < 0) {
+ goto error;
+ }
+
+ lttng_ht_lookup(consumer_data.relayd_ht, (void *)((unsigned long) key),
+ &iter);
+ node = lttng_ht_iter_get_node_ulong(&iter);
+ if (node != NULL) {
+ relayd = caa_container_of(node, struct consumer_relayd_sock_pair, node);
+ }
+
+error:
+ return relayd;
+}
+
+/*
+ * Handle stream for relayd transmission if the stream applies for network
+ * streaming where the net sequence index is set.
+ *
+ * Return destination file descriptor or negative value on error.
+ */
+static int write_relayd_stream_header(struct lttng_consumer_stream *stream,
+ size_t data_size, unsigned long padding,
+ struct consumer_relayd_sock_pair *relayd)
+{
+ int outfd = -1, ret;
+ struct lttcomm_relayd_data_hdr data_hdr;
+
+ /* Safety net */
+ assert(stream);
+ assert(relayd);
+
+ /* Reset data header */
+ memset(&data_hdr, 0, sizeof(data_hdr));
+
+ if (stream->metadata_flag) {
+ /* Caller MUST acquire the relayd control socket lock */
+ ret = relayd_send_metadata(&relayd->control_sock, data_size);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Metadata are always sent on the control socket. */
+ outfd = relayd->control_sock.fd;
+ } else {
+ /* Set header with stream information */
+ data_hdr.stream_id = htobe64(stream->relayd_stream_id);
+ data_hdr.data_size = htobe32(data_size);
+ data_hdr.padding_size = htobe32(padding);
+ /*
+ * 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.fd;
+ }
+
+error:
+ return outfd;
+}
+
+/*
+ * 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(unsigned long key,
+ uint64_t session_id,
+ const char *pathname,
+ const char *name,
+ uid_t uid,
+ gid_t gid,
+ int relayd_id,
+ enum lttng_event_output output)
+{
+ struct lttng_consumer_channel *channel;
+
+ channel = zmalloc(sizeof(*channel));
+ if (channel == NULL) {
+ PERROR("malloc struct lttng_consumer_channel");
+ goto end;
}
- DBG("Allocated channel (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, max_sb_size %llu)",
- channel->key,
- channel->shm_fd,
- channel->wait_fd,
- (unsigned long long) channel->mmap_len,
- (unsigned long long) channel->max_sb_size);
+
+ channel->key = key;
+ channel->refcount = 0;
+ channel->session_id = session_id;
+ channel->uid = uid;
+ channel->gid = gid;
+ channel->relayd_id = relayd_id;
+ channel->output = output;
+
+ 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';
+
+ lttng_ht_node_init_ulong(&channel->node, channel->key);
+ CDS_INIT_LIST_HEAD(&channel->streams.head);
+
+ DBG("Allocated channel (key %d)", channel->key)
+
end:
return channel;
}
*/
int consumer_add_channel(struct lttng_consumer_channel *channel)
{
+ int ret = 0;
+ struct lttng_ht_node_ulong *node;
+ struct lttng_ht_iter iter;
+
pthread_mutex_lock(&consumer_data.lock);
- /* Steal channel identifier, for UST */
- consumer_steal_channel_key(channel->key);
rcu_read_lock();
+
+ lttng_ht_lookup(consumer_data.channel_ht,
+ (void *)((unsigned long) channel->key), &iter);
+ node = lttng_ht_iter_get_node_ulong(&iter);
+ if (node != NULL) {
+ /* Channel already exist. Ignore the insertion */
+ ERR("Consumer add channel key %d already exists!", channel->key);
+ ret = -1;
+ goto end;
+ }
+
lttng_ht_add_unique_ulong(consumer_data.channel_ht, &channel->node);
+
+end:
rcu_read_unlock();
pthread_mutex_unlock(&consumer_data.lock);
- return 0;
+
+ return ret;
}
/*
*
* Returns the number of fds in the structures.
*/
-int consumer_update_poll_array(
- struct lttng_consumer_local_data *ctx, struct pollfd **pollfd,
- struct lttng_consumer_stream **local_stream)
+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 i = 0;
struct lttng_ht_iter iter;
struct lttng_consumer_stream *stream;
+ assert(ctx);
+ assert(ht);
+ assert(pollfd);
+ assert(local_stream);
+
DBG("Updating poll fd array");
- cds_lfht_for_each_entry(consumer_data.stream_ht->ht, &iter.iter, stream,
- node.node) {
- if (stream->state != LTTNG_CONSUMER_ACTIVE_STREAM) {
+ 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.
+ */
+ if (stream->state != LTTNG_CONSUMER_ACTIVE_STREAM ||
+ stream->endpoint_status == CONSUMER_ENDPOINT_INACTIVE) {
continue;
}
DBG("Active FD %d", stream->wait_fd);
local_stream[i] = stream;
i++;
}
+ rcu_read_unlock();
/*
- * Insert the consumer_poll_pipe at the end of the array and don't
+ * Insert the consumer_data_pipe at the end of the array and don't
* increment i so nb_fd is the number of real FD.
*/
- (*pollfd)[i].fd = ctx->consumer_poll_pipe[0];
- (*pollfd)[i].events = POLLIN;
+ (*pollfd)[i].fd = ctx->consumer_data_pipe[0];
+ (*pollfd)[i].events = POLLIN | POLLPRI;
return i;
}
if (errno == EINTR) {
goto restart;
}
- perror("Poll error");
+ PERROR("Poll error");
goto exit;
}
- if (consumer_sockpoll[0].revents == POLLIN) {
+ if (consumer_sockpoll[0].revents & (POLLIN | POLLPRI)) {
DBG("consumer_should_quit wake up");
goto exit;
}
/*
* Set the error socket.
*/
-void lttng_consumer_set_error_sock(
- struct lttng_consumer_local_data *ctx, int sock)
+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)
{
* 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)
+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,
}
/*
- * Close all the tracefiles and stream fds, should be called when all instances
- * are destroyed.
+ * 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)
{
- int ret;
struct lttng_ht_iter iter;
- struct lttng_ht_node_ulong *node;
+ struct lttng_consumer_channel *channel;
rcu_read_lock();
- /*
- * close all outfd. Called when there are no more threads running (after
- * joining on the threads), no need to protect list iteration with mutex.
- */
- cds_lfht_for_each_entry(consumer_data.stream_ht->ht, &iter.iter, node,
- node) {
- ret = lttng_ht_del(consumer_data.stream_ht, &iter);
- assert(!ret);
- call_rcu(&node->head, consumer_del_stream_rcu);
- }
-
- cds_lfht_for_each_entry(consumer_data.channel_ht->ht, &iter.iter, node,
- node) {
- ret = lttng_ht_del(consumer_data.channel_ht, &iter);
- assert(!ret);
- call_rcu(&node->head, consumer_del_channel_rcu);
+ cds_lfht_for_each_entry(consumer_data.channel_ht->ht, &iter.iter, channel,
+ node.node) {
+ consumer_del_channel(channel);
}
rcu_read_unlock();
+
+ lttng_ht_destroy(consumer_data.channel_ht);
+
+ cleanup_relayd_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(consumer_data.stream_list_ht);
}
/*
{
int ret;
consumer_quit = 1;
- ret = write(ctx->consumer_should_quit[1], "4", 1);
- if (ret < 0) {
- perror("write consumer quit");
+ do {
+ ret = write(ctx->consumer_should_quit[1], "4", 1);
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0 || ret != 1) {
+ PERROR("write consumer quit");
}
+
+ DBG("Consumer flag that it should quit");
}
-void lttng_consumer_sync_trace_file(
- struct lttng_consumer_stream *stream, off_t orig_offset)
+void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
+ off_t orig_offset)
{
int outfd = stream->out_fd;
* 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->chan->max_sb_size) {
+ if (orig_offset < stream->max_sb_size) {
return;
}
- lttng_sync_file_range(outfd, orig_offset - stream->chan->max_sb_size,
- stream->chan->max_sb_size,
+ 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);
* defined. So it can be expected to lead to lower throughput in
* streaming.
*/
- posix_fadvise(outfd, orig_offset - stream->chan->max_sb_size,
- stream->chan->max_sb_size, POSIX_FADV_DONTNEED);
+ posix_fadvise(outfd, orig_offset - stream->max_sb_size,
+ stream->max_sb_size, POSIX_FADV_DONTNEED);
}
/*
ctx = zmalloc(sizeof(struct lttng_consumer_local_data));
if (ctx == NULL) {
- perror("allocating context");
+ PERROR("allocating context");
goto error;
}
ctx->on_recv_stream = recv_stream;
ctx->on_update_stream = update_stream;
- ret = pipe(ctx->consumer_poll_pipe);
+ ret = pipe(ctx->consumer_data_pipe);
if (ret < 0) {
- perror("Error creating poll pipe");
+ PERROR("Error creating poll pipe");
goto error_poll_pipe;
}
+ /* set read end of the pipe to non-blocking */
+ ret = fcntl(ctx->consumer_data_pipe[0], F_SETFL, O_NONBLOCK);
+ if (ret < 0) {
+ PERROR("fcntl O_NONBLOCK");
+ goto error_poll_fcntl;
+ }
+
+ /* set write end of the pipe to non-blocking */
+ ret = fcntl(ctx->consumer_data_pipe[1], F_SETFL, O_NONBLOCK);
+ if (ret < 0) {
+ PERROR("fcntl O_NONBLOCK");
+ goto error_poll_fcntl;
+ }
+
ret = pipe(ctx->consumer_should_quit);
if (ret < 0) {
- perror("Error creating recv pipe");
+ PERROR("Error creating recv pipe");
goto error_quit_pipe;
}
ret = pipe(ctx->consumer_thread_pipe);
if (ret < 0) {
- perror("Error creating thread pipe");
+ PERROR("Error creating thread pipe");
goto error_thread_pipe;
}
- return ctx;
+ ret = utils_create_pipe(ctx->consumer_metadata_pipe);
+ if (ret < 0) {
+ goto error_metadata_pipe;
+ }
+
+ ret = utils_create_pipe(ctx->consumer_splice_metadata_pipe);
+ if (ret < 0) {
+ goto error_splice_pipe;
+ }
+ return ctx;
+error_splice_pipe:
+ utils_close_pipe(ctx->consumer_metadata_pipe);
+error_metadata_pipe:
+ utils_close_pipe(ctx->consumer_thread_pipe);
error_thread_pipe:
for (i = 0; i < 2; i++) {
int err;
err = close(ctx->consumer_should_quit[i]);
- assert(!err);
+ if (err) {
+ PERROR("close");
+ }
}
+error_poll_fcntl:
error_quit_pipe:
for (i = 0; i < 2; i++) {
int err;
- err = close(ctx->consumer_poll_pipe[i]);
- assert(!err);
+ err = close(ctx->consumer_data_pipe[i]);
+ if (err) {
+ PERROR("close");
+ }
}
error_poll_pipe:
free(ctx);
*/
void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx)
{
- close(ctx->consumer_error_socket);
- close(ctx->consumer_thread_pipe[0]);
- close(ctx->consumer_thread_pipe[1]);
- close(ctx->consumer_poll_pipe[0]);
- close(ctx->consumer_poll_pipe[1]);
- close(ctx->consumer_should_quit[0]);
- close(ctx->consumer_should_quit[1]);
+ int ret;
+
+ DBG("Consumer destroying it. Closing everything.");
+
+ ret = close(ctx->consumer_error_socket);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_thread_pipe[0]);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_thread_pipe[1]);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_data_pipe[0]);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_data_pipe[1]);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_should_quit[0]);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_should_quit[1]);
+ if (ret) {
+ PERROR("close");
+ }
+ utils_close_pipe(ctx->consumer_splice_metadata_pipe);
+
unlink(ctx->consumer_command_sock_path);
free(ctx);
}
/*
- * Mmap the ring buffer, read it and write the data to the tracefile.
- *
- * Returns the number of bytes written
+ * Write the metadata stream id on the specified file descriptor.
*/
-ssize_t lttng_consumer_on_read_subbuffer_mmap(
- struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream, unsigned long len)
+static int write_relayd_metadata_id(int fd,
+ struct lttng_consumer_stream *stream,
+ struct consumer_relayd_sock_pair *relayd, unsigned long padding)
{
- switch (consumer_data.type) {
- case LTTNG_CONSUMER_KERNEL:
- return lttng_kconsumer_on_read_subbuffer_mmap(ctx, stream, len);
- case LTTNG_CONSUMER32_UST:
- case LTTNG_CONSUMER64_UST:
- return lttng_ustconsumer_on_read_subbuffer_mmap(ctx, stream, len);
- default:
- ERR("Unknown consumer_data type");
- assert(0);
+ int ret;
+ struct lttcomm_relayd_metadata_payload hdr;
+
+ hdr.stream_id = htobe64(stream->relayd_stream_id);
+ hdr.padding_size = htobe32(padding);
+ do {
+ ret = write(fd, (void *) &hdr, sizeof(hdr));
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0 || 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);
- return 0;
+end:
+ return ret;
}
/*
- * Splice the data from the ring buffer to the tracefile.
+ * 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.
*
- * Returns the number of bytes spliced.
+ * It must be called with the stream lock held.
+ *
+ * Careful review MUST be put if any changes occur!
+ *
+ * Returns the number of bytes written
*/
-ssize_t lttng_consumer_on_read_subbuffer_splice(
+ssize_t lttng_consumer_on_read_subbuffer_mmap(
struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream, unsigned long len)
+ struct lttng_consumer_stream *stream, unsigned long len,
+ unsigned long padding)
{
+ unsigned long mmap_offset;
+ void *mmap_base;
+ ssize_t ret = 0, written = 0;
+ off_t orig_offset = stream->out_fd_offset;
+ /* Default is on the disk */
+ int outfd = stream->out_fd;
+ struct consumer_relayd_sock_pair *relayd = NULL;
+ unsigned int relayd_hang_up = 0;
+
+ /* RCU lock for the relayd pointer */
+ rcu_read_lock();
+
+ /* Flag that the current stream if set for network streaming. */
+ if (stream->net_seq_idx != -1) {
+ relayd = consumer_find_relayd(stream->net_seq_idx);
+ if (relayd == NULL) {
+ goto end;
+ }
+ }
+
+ /* get the offset inside the fd to mmap */
switch (consumer_data.type) {
case LTTNG_CONSUMER_KERNEL:
- return lttng_kconsumer_on_read_subbuffer_splice(ctx, stream, len);
+ mmap_base = stream->mmap_base;
+ ret = kernctl_get_mmap_read_offset(stream->wait_fd, &mmap_offset);
+ break;
case LTTNG_CONSUMER32_UST:
case LTTNG_CONSUMER64_UST:
- return -ENOSYS;
+ mmap_base = lttng_ustctl_get_mmap_base(stream);
+ if (!mmap_base) {
+ ERR("read mmap get mmap base for stream %s", stream->name);
+ written = -1;
+ goto end;
+ }
+ ret = lttng_ustctl_get_mmap_read_offset(stream, &mmap_offset);
+ break;
default:
ERR("Unknown consumer_data type");
assert(0);
+ }
+ if (ret != 0) {
+ errno = -ret;
+ PERROR("tracer ctl get_mmap_read_offset");
+ written = ret;
+ goto end;
+ }
+
+ /* Handle stream on the relayd if the output is on the network */
+ if (relayd) {
+ unsigned long netlen = len;
+
+ /*
+ * Lock the control socket for the complete duration of the function
+ * since from this point on we will use the socket.
+ */
+ if (stream->metadata_flag) {
+ /* Metadata requires the control socket. */
+ pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+ netlen += sizeof(struct lttcomm_relayd_metadata_payload);
+ }
+
+ ret = write_relayd_stream_header(stream, netlen, padding, relayd);
+ if (ret >= 0) {
+ /* Use the returned socket. */
+ outfd = ret;
+
+ /* Write metadata stream id before payload */
+ if (stream->metadata_flag) {
+ ret = write_relayd_metadata_id(outfd, stream, relayd, padding);
+ if (ret < 0) {
+ written = ret;
+ /* Socket operation failed. We consider the relayd dead */
+ if (ret == -EPIPE || ret == -EINVAL) {
+ relayd_hang_up = 1;
+ goto write_error;
+ }
+ goto end;
+ }
+ }
+ } else {
+ /* Socket operation failed. We consider the relayd dead */
+ if (ret == -EPIPE || ret == -EINVAL) {
+ relayd_hang_up = 1;
+ goto write_error;
+ }
+ /* Else, use the default set before which is the filesystem. */
+ }
+ } else {
+ /* No streaming, we have to set the len with the full padding */
+ len += padding;
+ }
+
+ while (len > 0) {
+ do {
+ ret = write(outfd, mmap_base + mmap_offset, len);
+ } while (ret < 0 && errno == EINTR);
+ DBG("Consumer mmap write() ret %zd (len %lu)", ret, len);
+ if (ret < 0) {
+ /*
+ * 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("Error in file write mmap");
+ if (written == 0) {
+ written = ret;
+ }
+ /* Socket operation failed. We consider the relayd dead */
+ if (errno == EPIPE || errno == EINVAL) {
+ relayd_hang_up = 1;
+ goto write_error;
+ }
+ goto end;
+ } else if (ret > len) {
+ PERROR("Error in file write (ret %zd > len %lu)", ret, len);
+ written += ret;
+ goto end;
+ } else {
+ len -= ret;
+ mmap_offset += ret;
+ }
+
+ /* This call is useless on a socket so better save a syscall. */
+ if (!relayd) {
+ /* This won't block, but will start writeout asynchronously */
+ lttng_sync_file_range(outfd, stream->out_fd_offset, ret,
+ SYNC_FILE_RANGE_WRITE);
+ stream->out_fd_offset += ret;
+ }
+ written += ret;
+ }
+ lttng_consumer_sync_trace_file(stream, orig_offset);
+
+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) {
+ cleanup_relayd(relayd, ctx);
+ }
+
+end:
+ /* Unlock only if ctrl socket used */
+ if (relayd && stream->metadata_flag) {
+ pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
+ }
+
+ rcu_read_unlock();
+ return written;
+}
+
+/*
+ * 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 (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ break;
+ case LTTNG_CONSUMER32_UST:
+ case LTTNG_CONSUMER64_UST:
+ /* Not supported for user space tracing */
return -ENOSYS;
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ }
+
+ /* RCU lock for the relayd pointer */
+ rcu_read_lock();
+
+ /* Flag that the current stream if set for network streaming. */
+ if (stream->net_seq_idx != -1) {
+ relayd = consumer_find_relayd(stream->net_seq_idx);
+ if (relayd == NULL) {
+ goto end;
+ }
+ }
+
+ /*
+ * Choose right pipe for splice. Metadata and trace data are handled by
+ * different threads hence the use of two pipes in order not to race or
+ * corrupt the written data.
+ */
+ if (stream->metadata_flag) {
+ splice_pipe = ctx->consumer_splice_metadata_pipe;
+ } else {
+ splice_pipe = ctx->consumer_thread_pipe;
+ }
+
+ /* Write metadata stream id before payload */
+ if (relayd) {
+ int total_len = len;
+
+ if (stream->metadata_flag) {
+ /*
+ * Lock the control socket for the complete duration of the function
+ * since from this point on we will use the socket.
+ */
+ pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+
+ ret = write_relayd_metadata_id(splice_pipe[1], stream, relayd,
+ padding);
+ if (ret < 0) {
+ written = ret;
+ /* Socket operation failed. We consider the relayd dead */
+ if (ret == -EBADF) {
+ WARN("Remote relayd disconnected. Stopping");
+ relayd_hang_up = 1;
+ goto write_error;
+ }
+ goto end;
+ }
+
+ total_len += sizeof(struct lttcomm_relayd_metadata_payload);
+ }
+
+ ret = write_relayd_stream_header(stream, total_len, padding, relayd);
+ if (ret >= 0) {
+ /* Use the returned socket. */
+ outfd = ret;
+ } else {
+ /* Socket operation failed. We consider the relayd dead */
+ if (ret == -EBADF) {
+ WARN("Remote relayd disconnected. Stopping");
+ relayd_hang_up = 1;
+ goto write_error;
+ }
+ goto end;
+ }
+ } else {
+ /* No streaming, we have to set the len with the full padding */
+ len += padding;
}
+ while (len > 0) {
+ DBG("splice chan to pipe offset %lu of len %lu (fd : %d, pipe: %d)",
+ (unsigned long)offset, len, fd, splice_pipe[1]);
+ ret_splice = splice(fd, &offset, splice_pipe[1], NULL, len,
+ SPLICE_F_MOVE | SPLICE_F_MORE);
+ DBG("splice chan to pipe, ret %zd", ret_splice);
+ if (ret_splice < 0) {
+ PERROR("Error in relay splice");
+ if (written == 0) {
+ written = ret_splice;
+ }
+ ret = errno;
+ goto splice_error;
+ }
+
+ /* Handle stream on the relayd if the output is on the network */
+ if (relayd) {
+ if (stream->metadata_flag) {
+ size_t metadata_payload_size =
+ sizeof(struct lttcomm_relayd_metadata_payload);
+
+ /* Update counter to fit the spliced data */
+ ret_splice += metadata_payload_size;
+ len += metadata_payload_size;
+ /*
+ * We do this so the return value can match the len passed as
+ * argument to this function.
+ */
+ written -= metadata_payload_size;
+ }
+ }
+
+ /* Splice data out */
+ ret_splice = splice(splice_pipe[0], NULL, outfd, NULL,
+ ret_splice, SPLICE_F_MOVE | SPLICE_F_MORE);
+ DBG("Consumer splice pipe to file, ret %zd", ret_splice);
+ if (ret_splice < 0) {
+ PERROR("Error in file splice");
+ if (written == 0) {
+ written = ret_splice;
+ }
+ /* Socket operation failed. We consider the relayd dead */
+ if (errno == EBADF || errno == EPIPE) {
+ WARN("Remote relayd disconnected. Stopping");
+ relayd_hang_up = 1;
+ goto write_error;
+ }
+ ret = errno;
+ goto splice_error;
+ } else if (ret_splice > len) {
+ errno = EINVAL;
+ PERROR("Wrote more data than requested %zd (len: %lu)",
+ ret_splice, len);
+ written += ret_splice;
+ ret = errno;
+ goto splice_error;
+ }
+ len -= ret_splice;
+
+ /* This call is useless on a socket so better save a syscall. */
+ if (!relayd) {
+ /* This won't block, but will start writeout asynchronously */
+ lttng_sync_file_range(outfd, stream->out_fd_offset, ret_splice,
+ SYNC_FILE_RANGE_WRITE);
+ stream->out_fd_offset += ret_splice;
+ }
+ written += ret_splice;
+ }
+ lttng_consumer_sync_trace_file(stream, orig_offset);
+
+ ret = ret_splice;
+
+ goto end;
+
+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) {
+ cleanup_relayd(relayd, ctx);
+ /* 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;
}
/*
*
* Returns 0 on success, < 0 on error
*/
-int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream)
+int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream)
{
switch (consumer_data.type) {
case LTTNG_CONSUMER_KERNEL:
- return lttng_kconsumer_take_snapshot(ctx, stream);
+ return lttng_kconsumer_take_snapshot(stream);
case LTTNG_CONSUMER32_UST:
case LTTNG_CONSUMER64_UST:
- return lttng_ustconsumer_take_snapshot(ctx, stream);
+ return lttng_ustconsumer_take_snapshot(stream);
default:
ERR("Unknown consumer_data type");
assert(0);
*
* Returns 0 on success, < 0 on error
*/
-int lttng_consumer_get_produced_snapshot(
- struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream,
+int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
unsigned long *pos)
{
switch (consumer_data.type) {
case LTTNG_CONSUMER_KERNEL:
- return lttng_kconsumer_get_produced_snapshot(ctx, stream, pos);
+ return lttng_kconsumer_get_produced_snapshot(stream, pos);
case LTTNG_CONSUMER32_UST:
case LTTNG_CONSUMER64_UST:
- return lttng_ustconsumer_get_produced_snapshot(ctx, stream, pos);
+ return lttng_ustconsumer_get_produced_snapshot(stream, pos);
default:
ERR("Unknown consumer_data type");
assert(0);
}
}
-int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
- int sock, struct pollfd *consumer_sockpoll)
-{
- switch (consumer_data.type) {
- case LTTNG_CONSUMER_KERNEL:
- return lttng_kconsumer_recv_cmd(ctx, sock, consumer_sockpoll);
- case LTTNG_CONSUMER32_UST:
- case LTTNG_CONSUMER64_UST:
- return lttng_ustconsumer_recv_cmd(ctx, sock, consumer_sockpoll);
- default:
- ERR("Unknown consumer_data type");
- assert(0);
- return -ENOSYS;
+int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
+ int sock, struct pollfd *consumer_sockpoll)
+{
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ return lttng_kconsumer_recv_cmd(ctx, sock, consumer_sockpoll);
+ case LTTNG_CONSUMER32_UST:
+ case LTTNG_CONSUMER64_UST:
+ return lttng_ustconsumer_recv_cmd(ctx, sock, consumer_sockpoll);
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ return -ENOSYS;
+ }
+}
+
+/*
+ * Iterate over all streams of the hashtable and free them properly.
+ *
+ * WARNING: *MUST* be used with data stream only.
+ */
+static void destroy_data_stream_ht(struct lttng_ht *ht)
+{
+ 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 hashtable and free them properly.
+ *
+ * XXX: Should not be only for metadata stream or else use an other name.
+ */
+static void destroy_stream_ht(struct lttng_ht *ht)
+{
+ 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);
+}
+
+/*
+ * Clean up a metadata stream and free its memory.
+ */
+void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
+ struct lttng_ht *ht)
+{
+ int ret;
+ struct lttng_ht_iter iter;
+ struct lttng_consumer_channel *free_chan = NULL;
+ struct consumer_relayd_sock_pair *relayd;
+
+ assert(stream);
+ /*
+ * This call should NEVER receive regular stream. It must always be
+ * metadata stream and this is crucial for data structure synchronization.
+ */
+ assert(stream->metadata_flag);
+
+ DBG3("Consumer delete metadata stream %d", stream->wait_fd);
+
+ if (ht == NULL) {
+ /* Means the stream was allocated but not successfully added */
+ goto free_stream_rcu;
+ }
+
+ pthread_mutex_lock(&consumer_data.lock);
+ pthread_mutex_lock(&stream->lock);
+
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ if (stream->mmap_base != NULL) {
+ ret = munmap(stream->mmap_base, stream->mmap_len);
+ if (ret != 0) {
+ PERROR("munmap metadata stream");
+ }
+ }
+ break;
+ case LTTNG_CONSUMER32_UST:
+ case LTTNG_CONSUMER64_UST:
+ lttng_ustconsumer_del_stream(stream);
+ break;
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ goto end;
+ }
+
+ rcu_read_lock();
+ iter.iter.node = &stream->node.node;
+ ret = lttng_ht_del(ht, &iter);
+ assert(!ret);
+
+ /* Remove node session id from the consumer_data stream ht */
+ iter.iter.node = &stream->node_session_id.node;
+ ret = lttng_ht_del(consumer_data.stream_list_ht, &iter);
+ assert(!ret);
+ rcu_read_unlock();
+
+ if (stream->out_fd >= 0) {
+ ret = close(stream->out_fd);
+ if (ret) {
+ PERROR("close");
+ }
+ }
+
+ /* Check and cleanup relayd */
+ rcu_read_lock();
+ relayd = consumer_find_relayd(stream->net_seq_idx);
+ if (relayd != NULL) {
+ uatomic_dec(&relayd->refcount);
+ assert(uatomic_read(&relayd->refcount) >= 0);
+
+ /* Closing streams requires to lock the control socket. */
+ pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+ ret = relayd_send_close_stream(&relayd->control_sock,
+ stream->relayd_stream_id, stream->next_net_seq_num - 1);
+ pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
+ if (ret < 0) {
+ DBG("Unable to close stream on the relayd. Continuing");
+ /*
+ * Continue here. There is nothing we can do for the relayd.
+ * Chances are that the relayd has closed the socket so we just
+ * continue cleaning up.
+ */
+ }
+
+ /* Both conditions are met, we destroy the relayd. */
+ if (uatomic_read(&relayd->refcount) == 0 &&
+ uatomic_read(&relayd->destroy_flag)) {
+ destroy_relayd(relayd);
+ }
+ }
+ rcu_read_unlock();
+
+ /* Atomically decrement channel refcount since other threads can use it. */
+ uatomic_dec(&stream->chan->refcount);
+ if (!uatomic_read(&stream->chan->refcount)
+ && !uatomic_read(&stream->chan->nb_init_stream_left)) {
+ /* Go for channel deletion! */
+ free_chan = stream->chan;
+ }
+
+end:
+ pthread_mutex_unlock(&stream->lock);
+ pthread_mutex_unlock(&consumer_data.lock);
+
+ if (free_chan) {
+ consumer_del_channel(free_chan);
+ }
+
+free_stream_rcu:
+ call_rcu(&stream->node.head, free_stream_rcu);
+}
+
+/*
+ * Action done with the metadata stream when adding it to the consumer internal
+ * data structures to handle it.
+ */
+static int add_metadata_stream(struct lttng_consumer_stream *stream,
+ struct lttng_ht *ht)
+{
+ int ret = 0;
+ struct consumer_relayd_sock_pair *relayd;
+ struct lttng_ht_iter iter;
+ struct lttng_ht_node_ulong *node;
+
+ assert(stream);
+ assert(ht);
+
+ DBG3("Adding metadata stream %d to hash table", stream->key);
+
+ pthread_mutex_lock(&consumer_data.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, (void *)((unsigned long) stream->key), &iter);
+ node = lttng_ht_iter_get_node_ulong(&iter);
+ assert(!node);
+
+ /* Find relayd and, if one is found, increment refcount. */
+ relayd = consumer_find_relayd(stream->net_seq_idx);
+ if (relayd != NULL) {
+ uatomic_inc(&relayd->refcount);
+ }
+
+ /* Update channel refcount once added without error(s). */
+ uatomic_inc(&stream->chan->refcount);
+
+ /*
+ * When nb_init_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) {
+ uatomic_dec(&stream->chan->nb_init_stream_left);
+ }
+
+ lttng_ht_add_unique_ulong(ht, &stream->node);
+
+ /*
+ * Add stream to the stream_list_ht of the consumer data. No need to steal
+ * the key since the HT does not use it and we allow to add redundant keys
+ * into this table.
+ */
+ lttng_ht_add_ulong(consumer_data.stream_list_ht, &stream->node_session_id);
+
+ rcu_read_unlock();
+
+ pthread_mutex_unlock(&stream->lock);
+ pthread_mutex_unlock(&consumer_data.lock);
+ return ret;
+}
+
+/*
+ * 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");
+
+ 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;
+ uint32_t revents, nb_fd;
+ struct lttng_consumer_stream *stream = NULL;
+ struct lttng_ht_iter iter;
+ struct lttng_ht_node_ulong *node;
+ struct lttng_poll_event events;
+ struct lttng_consumer_local_data *ctx = data;
+ ssize_t len;
+
+ rcu_register_thread();
+
+ metadata_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+ if (!metadata_ht) {
+ /* ENOMEM at this point. Better to bail out. */
+ goto error;
+ }
+
+ 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;
+ }
+
+ ret = lttng_poll_add(&events, ctx->consumer_metadata_pipe[0], LPOLLIN);
+ if (ret < 0) {
+ goto end;
+ }
+
+ /* Main loop */
+ DBG("Metadata main loop started");
+
+ while (1) {
+ /* Only the metadata pipe is set */
+ if (LTTNG_POLL_GETNB(&events) == 0 && consumer_quit == 1) {
+ goto end;
+ }
+
+restart:
+ DBG("Metadata poll wait with %d fd(s)", LTTNG_POLL_GETNB(&events));
+ ret = lttng_poll_wait(&events, -1);
+ DBG("Metadata event catched in thread");
+ if (ret < 0) {
+ if (errno == EINTR) {
+ ERR("Poll EINTR catched");
+ goto restart;
+ }
+ goto error;
+ }
+
+ nb_fd = ret;
+
+ /* From here, the event is a metadata wait fd */
+ for (i = 0; i < nb_fd; i++) {
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Just don't waste time if no returned events for the fd */
+ if (!revents) {
+ continue;
+ }
+
+ if (pollfd == ctx->consumer_metadata_pipe[0]) {
+ if (revents & (LPOLLERR | LPOLLHUP )) {
+ DBG("Metadata thread pipe hung up");
+ /*
+ * Remove the pipe from the poll set and continue the loop
+ * since their might be data to consume.
+ */
+ lttng_poll_del(&events, ctx->consumer_metadata_pipe[0]);
+ ret = close(ctx->consumer_metadata_pipe[0]);
+ if (ret < 0) {
+ PERROR("close metadata pipe");
+ }
+ continue;
+ } else if (revents & LPOLLIN) {
+ do {
+ /* Get the stream pointer received */
+ ret = read(pollfd, &stream, sizeof(stream));
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0 ||
+ ret < sizeof(struct lttng_consumer_stream *)) {
+ PERROR("read metadata stream");
+ /*
+ * Let's continue here and hope we can still work
+ * without stopping the consumer. XXX: Should we?
+ */
+ continue;
+ }
+
+ /* 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);
+
+ ret = add_metadata_stream(stream, metadata_ht);
+ if (ret) {
+ ERR("Unable to add metadata stream");
+ /* Stream was not setup properly. Continuing. */
+ consumer_del_metadata_stream(stream, NULL);
+ continue;
+ }
+
+ /* Add metadata stream to the global poll events list */
+ lttng_poll_add(&events, stream->wait_fd,
+ LPOLLIN | LPOLLPRI);
+ }
+
+ /* Handle other stream */
+ continue;
+ }
+
+ rcu_read_lock();
+ lttng_ht_lookup(metadata_ht, (void *)((unsigned long) pollfd),
+ &iter);
+ node = lttng_ht_iter_get_node_ulong(&iter);
+ assert(node);
+
+ stream = caa_container_of(node, struct lttng_consumer_stream,
+ node);
+
+ /* Check for error event */
+ if (revents & (LPOLLERR | LPOLLHUP)) {
+ DBG("Metadata fd %d is hup|err.", pollfd);
+ if (!stream->hangup_flush_done
+ && (consumer_data.type == LTTNG_CONSUMER32_UST
+ || consumer_data.type == LTTNG_CONSUMER64_UST)) {
+ DBG("Attempting to flush and consume the UST buffers");
+ lttng_ustconsumer_on_stream_hangup(stream);
+
+ /* We just flushed the stream now read it. */
+ do {
+ len = ctx->on_buffer_ready(stream, ctx);
+ /*
+ * We don't check the return value here since if we get
+ * a negative len, it means an error occured thus we
+ * simply remove it from the poll set and free the
+ * stream.
+ */
+ } while (len > 0);
+ }
+
+ lttng_poll_del(&events, stream->wait_fd);
+ /*
+ * This call update the channel states, closes file descriptors
+ * and securely free the stream.
+ */
+ consumer_del_metadata_stream(stream, metadata_ht);
+ } else if (revents & (LPOLLIN | LPOLLPRI)) {
+ /* Get the data out of the metadata file descriptor */
+ DBG("Metadata available on fd %d", pollfd);
+ assert(stream->wait_fd == pollfd);
+
+ len = ctx->on_buffer_ready(stream, ctx);
+ /* It's ok to have an unavailable sub-buffer */
+ if (len < 0 && len != -EAGAIN && len != -ENODATA) {
+ /* Clean up stream from consumer and free it. */
+ lttng_poll_del(&events, stream->wait_fd);
+ consumer_del_metadata_stream(stream, metadata_ht);
+ } else if (len > 0) {
+ stream->data_read = 1;
+ }
+ }
+
+ /* Release RCU lock for the stream looked up */
+ rcu_read_unlock();
+ }
}
+
+error:
+end:
+ DBG("Metadata poll thread exiting");
+ lttng_poll_clean(&events);
+
+ destroy_stream_ht(metadata_ht);
+
+ rcu_unregister_thread();
+ return NULL;
}
/*
* This thread polls the fds in the set to consume the data and write
* it to tracefile if necessary.
*/
-void *lttng_consumer_thread_poll_fds(void *data)
+void *consumer_thread_data_poll(void *data)
{
int num_rdy, num_hup, high_prio, ret, i;
struct pollfd *pollfd = NULL;
/* local view of the streams */
- struct lttng_consumer_stream **local_stream = NULL;
+ struct lttng_consumer_stream **local_stream = NULL, *new_stream = NULL;
/* local view of consumer_data.fds_count */
int nb_fd = 0;
- char tmp;
- int tmp2;
struct lttng_consumer_local_data *ctx = data;
+ ssize_t len;
rcu_register_thread();
+ data_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+ if (data_ht == NULL) {
+ /* ENOMEM at this point. Better to bail out. */
+ goto end;
+ }
+
local_stream = zmalloc(sizeof(struct lttng_consumer_stream));
while (1) {
*/
pthread_mutex_lock(&consumer_data.lock);
if (consumer_data.need_update) {
- if (pollfd != NULL) {
- free(pollfd);
- pollfd = NULL;
- }
- if (local_stream != NULL) {
- free(local_stream);
- local_stream = NULL;
- }
+ free(pollfd);
+ pollfd = NULL;
- /* allocate for all fds + 1 for the consumer_poll_pipe */
+ free(local_stream);
+ local_stream = NULL;
+
+ /* allocate for all fds + 1 for the consumer_data_pipe */
pollfd = zmalloc((consumer_data.stream_count + 1) * sizeof(struct pollfd));
if (pollfd == NULL) {
- perror("pollfd malloc");
+ PERROR("pollfd malloc");
pthread_mutex_unlock(&consumer_data.lock);
goto end;
}
- /* allocate for all fds + 1 for the consumer_poll_pipe */
+ /* allocate for all fds + 1 for the consumer_data_pipe */
local_stream = zmalloc((consumer_data.stream_count + 1) *
sizeof(struct lttng_consumer_stream));
if (local_stream == NULL) {
- perror("local_stream malloc");
+ PERROR("local_stream malloc");
pthread_mutex_unlock(&consumer_data.lock);
goto end;
}
- ret = consumer_update_poll_array(ctx, &pollfd, local_stream);
+ ret = update_poll_array(ctx, &pollfd, local_stream,
+ data_ht);
if (ret < 0) {
ERR("Error in allocating pollfd or local_outfds");
- lttng_consumer_send_error(ctx, CONSUMERD_POLL_ERROR);
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR);
pthread_mutex_unlock(&consumer_data.lock);
goto end;
}
/* poll on the array of fds */
restart:
DBG("polling on %d fd", nb_fd + 1);
- num_rdy = poll(pollfd, nb_fd + 1, consumer_poll_timeout);
+ num_rdy = poll(pollfd, nb_fd + 1, -1);
DBG("poll num_rdy : %d", num_rdy);
if (num_rdy == -1) {
/*
if (errno == EINTR) {
goto restart;
}
- perror("Poll error");
- lttng_consumer_send_error(ctx, CONSUMERD_POLL_ERROR);
+ PERROR("Poll error");
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR);
goto end;
} else if (num_rdy == 0) {
DBG("Polling thread timed out");
}
/*
- * If the consumer_poll_pipe triggered poll go
- * directly to the beginning of the loop to update the
- * array. We want to prioritize array update over
- * low-priority reads.
+ * If the consumer_data_pipe triggered poll go directly to the
+ * beginning of the loop to update the array. We want to prioritize
+ * array update over low-priority reads.
*/
- if (pollfd[nb_fd].revents & POLLIN) {
- DBG("consumer_poll_pipe wake up");
- tmp2 = read(ctx->consumer_poll_pipe[0], &tmp, 1);
- if (tmp2 < 0) {
- perror("read consumer poll");
+ if (pollfd[nb_fd].revents & (POLLIN | POLLPRI)) {
+ ssize_t pipe_readlen;
+
+ DBG("consumer_data_pipe wake up");
+ /* Consume 1 byte of pipe data */
+ do {
+ pipe_readlen = read(ctx->consumer_data_pipe[0], &new_stream,
+ sizeof(new_stream));
+ } while (pipe_readlen == -1 && errno == EINTR);
+ if (pipe_readlen < 0) {
+ PERROR("read 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;
+ }
+
+ ret = add_stream(new_stream, data_ht);
+ if (ret) {
+ ERR("Consumer add stream %d failed. Continuing",
+ new_stream->key);
+ /*
+ * At this point, if the add_stream fails, it is not in the
+ * hash table thus passing the NULL value here.
+ */
+ consumer_del_stream(new_stream, NULL);
}
+
+ /* Continue to update the local streams and handle prio ones */
continue;
}
/* Take care of high priority channels first. */
for (i = 0; i < nb_fd; i++) {
+ if (local_stream[i] == NULL) {
+ continue;
+ }
if (pollfd[i].revents & POLLPRI) {
- ssize_t len;
-
DBG("Urgent read on fd %d", pollfd[i].fd);
high_prio = 1;
len = ctx->on_buffer_ready(local_stream[i], ctx);
/* it's ok to have an unavailable sub-buffer */
- if (len < 0 && len != -EAGAIN) {
- goto end;
+ 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;
}
/* Take care of low priority channels. */
for (i = 0; i < nb_fd; i++) {
+ if (local_stream[i] == NULL) {
+ continue;
+ }
if ((pollfd[i].revents & POLLIN) ||
local_stream[i]->hangup_flush_done) {
- ssize_t len;
-
- assert(!(pollfd[i].revents & POLLERR));
- assert(!(pollfd[i].revents & POLLNVAL));
DBG("Normal read on fd %d", pollfd[i].fd);
len = ctx->on_buffer_ready(local_stream[i], ctx);
/* it's ok to have an unavailable sub-buffer */
- if (len < 0 && len != -EAGAIN) {
- goto end;
+ 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++) {
+ if (local_stream[i] == NULL) {
+ continue;
+ }
if (!local_stream[i]->hangup_flush_done
&& (pollfd[i].revents & (POLLHUP | POLLERR | POLLNVAL))
&& (consumer_data.type == LTTNG_CONSUMER32_UST
|| consumer_data.type == LTTNG_CONSUMER64_UST)) {
DBG("fd %d is hup|err|nval. Attempting flush and read.",
- pollfd[i].fd);
+ 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 ((pollfd[i].revents & POLLHUP)) {
DBG("Polling fd %d tells it has hung up.", pollfd[i].fd);
if (!local_stream[i]->data_read) {
- rcu_read_lock();
- consumer_del_stream_rcu(&local_stream[i]->node.head);
- rcu_read_unlock();
+ 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) {
- rcu_read_lock();
- consumer_del_stream_rcu(&local_stream[i]->node.head);
- rcu_read_unlock();
+ 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) {
- rcu_read_lock();
- consumer_del_stream_rcu(&local_stream[i]->node.head);
- rcu_read_unlock();
+ consumer_del_stream(local_stream[i], data_ht);
+ local_stream[i] = NULL;
num_hup++;
}
}
- local_stream[i]->data_read = 0;
+ if (local_stream[i] != NULL) {
+ local_stream[i]->data_read = 0;
+ }
}
}
end:
DBG("polling thread exiting");
- if (pollfd != NULL) {
- free(pollfd);
- pollfd = NULL;
- }
- if (local_stream != NULL) {
- free(local_stream);
- local_stream = NULL;
+ 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.
+ */
+ ret = close(ctx->consumer_metadata_pipe[1]);
+ if (ret < 0) {
+ PERROR("close data pipe");
}
+
+ destroy_data_stream_ht(data_ht);
+
rcu_unregister_thread();
return NULL;
}
* This thread listens on the consumerd socket and receives the file
* descriptors from the session daemon.
*/
-void *lttng_consumer_thread_receive_fds(void *data)
+void *consumer_thread_sessiond_poll(void *data)
{
- int sock, client_socket, ret;
+ int sock = -1, client_socket, ret;
/*
* structure to poll for incoming data on communication socket avoids
* making blocking sockets.
}
DBG("Sending ready command to lttng-sessiond");
- ret = lttng_consumer_send_error(ctx, CONSUMERD_COMMAND_SOCK_READY);
+ ret = lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_COMMAND_SOCK_READY);
/* return < 0 on error, but == 0 is not fatal */
if (ret < 0) {
ERR("Error sending ready command to lttng-sessiond");
ret = fcntl(client_socket, F_SETFL, O_NONBLOCK);
if (ret < 0) {
- perror("fcntl O_NONBLOCK");
+ PERROR("fcntl O_NONBLOCK");
goto end;
}
/* Blocking call, waiting for transmission */
sock = lttcomm_accept_unix_sock(client_socket);
- if (sock <= 0) {
+ if (sock < 0) {
WARN("On accept");
goto end;
}
ret = fcntl(sock, F_SETFL, O_NONBLOCK);
if (ret < 0) {
- perror("fcntl O_NONBLOCK");
+ PERROR("fcntl O_NONBLOCK");
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;
DBG("Received STOP command");
goto end;
}
- if (ret < 0) {
- ERR("Communication interrupted on command socket");
+ if (ret <= 0) {
+ /*
+ * This could simply be a session daemon quitting. Don't output
+ * ERR() here.
+ */
+ DBG("Communication interrupted on command socket");
goto end;
}
if (consumer_quit) {
DBG("consumer_thread_receive_fds received quit from signal");
goto end;
}
- DBG("received fds on sock");
+ DBG("received command on sock");
}
end:
- DBG("consumer_thread_receive_fds exiting");
+ DBG("Consumer thread sessiond poll exiting");
/*
* when all fds have hung up, the polling thread
consumer_quit = 1;
/*
- * 2s of grace period, if no polling events occur during
- * this period, the polling thread will exit even if there
- * are still open FDs (should not happen, but safety mechanism).
+ * Notify the data poll thread to poll back again and test the
+ * consumer_quit state that we just set so to quit gracefully.
*/
- consumer_poll_timeout = LTTNG_CONSUMER_POLL_TIMEOUT;
+ notify_thread_pipe(ctx->consumer_data_pipe[1]);
- /* wake up the polling thread */
- ret = write(ctx->consumer_poll_pipe[1], "4", 1);
- if (ret < 0) {
- perror("poll pipe write");
+ /* 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(sock);
+ if (ret < 0) {
+ PERROR("close client_socket sessiond poll");
+ }
}
+
rcu_unregister_thread();
return NULL;
}
ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
struct lttng_consumer_local_data *ctx)
{
+ ssize_t ret;
+
+ pthread_mutex_lock(&stream->lock);
+
switch (consumer_data.type) {
case LTTNG_CONSUMER_KERNEL:
- return lttng_kconsumer_read_subbuffer(stream, ctx);
+ ret = lttng_kconsumer_read_subbuffer(stream, ctx);
+ break;
case LTTNG_CONSUMER32_UST:
case LTTNG_CONSUMER64_UST:
- return lttng_ustconsumer_read_subbuffer(stream, ctx);
+ ret = lttng_ustconsumer_read_subbuffer(stream, ctx);
+ break;
default:
ERR("Unknown consumer_data type");
assert(0);
- return -ENOSYS;
+ ret = -ENOSYS;
+ break;
}
+
+ pthread_mutex_unlock(&stream->lock);
+ return ret;
}
int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream)
*/
void lttng_consumer_init(void)
{
- consumer_data.stream_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
consumer_data.channel_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+ consumer_data.relayd_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+ consumer_data.stream_list_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+}
+
+/*
+ * Process the ADD_RELAYD command receive by a consumer.
+ *
+ * This will create a relayd socket pair and add it to the relayd hash table.
+ * The caller MUST acquire a RCU read side lock before calling it.
+ */
+int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
+ struct lttng_consumer_local_data *ctx, int sock,
+ struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock,
+ unsigned int sessiond_id)
+{
+ int fd = -1, ret = -1, relayd_created = 0;
+ enum lttng_error_code ret_code = LTTNG_OK;
+ struct consumer_relayd_sock_pair *relayd;
+
+ DBG("Consumer adding relayd socket (idx: %d)", net_seq_idx);
+
+ /* First send a status message before receiving the fds. */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto error;
+ }
+
+ /* Get relayd reference if exists. */
+ relayd = consumer_find_relayd(net_seq_idx);
+ if (relayd == NULL) {
+ /* Not found. Allocate one. */
+ relayd = consumer_allocate_relayd_sock_pair(net_seq_idx);
+ if (relayd == NULL) {
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
+ ret = -1;
+ goto error;
+ }
+ relayd->sessiond_session_id = (uint64_t) sessiond_id;
+ relayd_created = 1;
+ }
+
+ /* Poll on consumer socket. */
+ if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
+ ret = -EINTR;
+ goto error;
+ }
+
+ /* Get relayd socket from session daemon */
+ ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
+ if (ret != sizeof(fd)) {
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD);
+ ret = -1;
+ fd = -1; /* Just in case it gets set with an invalid value. */
+ goto error_close;
+ }
+
+ /* We have the fds without error. Send status back. */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto error;
+ }
+
+ /* Copy socket information and received FD */
+ switch (sock_type) {
+ case LTTNG_STREAM_CONTROL:
+ /* Copy received lttcomm socket */
+ lttcomm_copy_sock(&relayd->control_sock, relayd_sock);
+ ret = lttcomm_create_sock(&relayd->control_sock);
+ /* Immediately try to close the created socket if valid. */
+ if (relayd->control_sock.fd >= 0) {
+ if (close(relayd->control_sock.fd)) {
+ PERROR("close relayd control socket");
+ }
+ }
+ /* Handle create_sock error. */
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Assign new file descriptor */
+ relayd->control_sock.fd = fd;
+
+ /*
+ * Create a session on the relayd and store the returned id. Lock the
+ * control socket mutex if the relayd was NOT created before.
+ */
+ if (!relayd_created) {
+ pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+ }
+ ret = relayd_create_session(&relayd->control_sock,
+ &relayd->relayd_session_id);
+ if (!relayd_created) {
+ pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
+ }
+ if (ret < 0) {
+ /*
+ * Close all sockets of a relayd object. It will be freed if it was
+ * created at the error code path or else it will be garbage
+ * collect.
+ */
+ (void) relayd_close(&relayd->control_sock);
+ (void) relayd_close(&relayd->data_sock);
+ goto error;
+ }
+
+ break;
+ case LTTNG_STREAM_DATA:
+ /* Copy received lttcomm socket */
+ lttcomm_copy_sock(&relayd->data_sock, relayd_sock);
+ ret = lttcomm_create_sock(&relayd->data_sock);
+ /* Immediately try to close the created socket if valid. */
+ if (relayd->data_sock.fd >= 0) {
+ if (close(relayd->data_sock.fd)) {
+ PERROR("close relayd data socket");
+ }
+ }
+ /* Handle create_sock error. */
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Assign new file descriptor */
+ relayd->data_sock.fd = fd;
+ break;
+ default:
+ ERR("Unknown relayd socket type (%d)", sock_type);
+ ret = -1;
+ goto error;
+ }
+
+ DBG("Consumer %s socket created successfully with net idx %d (fd: %d)",
+ sock_type == LTTNG_STREAM_CONTROL ? "control" : "data",
+ relayd->net_seq_idx, fd);
+
+ /*
+ * Add relayd socket pair to consumer data hashtable. If object already
+ * exists or on error, the function gracefully returns.
+ */
+ add_relayd(relayd);
+
+ /* All good! */
+ return 0;
+
+error:
+ /* Close received socket if valid. */
+ if (fd >= 0) {
+ if (close(fd)) {
+ PERROR("close received socket");
+ }
+ }
+
+error_close:
+ if (relayd_created) {
+ free(relayd);
+ }
+
+ return ret;
+}
+
+/*
+ * Try to lock the stream mutex.
+ *
+ * On success, 1 is returned else 0 indicating that the mutex is NOT lock.
+ */
+static int stream_try_lock(struct lttng_consumer_stream *stream)
+{
+ int ret;
+
+ assert(stream);
+
+ /*
+ * Try to lock the stream mutex. On failure, we know that the stream is
+ * being used else where hence there is data still being extracted.
+ */
+ ret = pthread_mutex_trylock(&stream->lock);
+ if (ret) {
+ /* For both EBUSY and EINVAL error, the mutex is NOT locked. */
+ ret = 0;
+ goto end;
+ }
+
+ ret = 1;
+
+end:
+ return ret;
+}
+
+/*
+ * 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(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(&consumer_data.lock);
+
+ switch (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");
+ assert(0);
+ }
+
+ /* Ease our life a bit */
+ ht = consumer_data.stream_list_ht;
+
+ relayd = find_relayd_by_session_id(id);
+ if (relayd) {
+ /* 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);
+ pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
+ if (ret < 0) {
+ /* Communication error thus the relayd so no data pending. */
+ goto data_not_pending;
+ }
+ }
+
+ cds_lfht_for_each_entry_duplicate(ht->ht,
+ ht->hash_fct((void *)((unsigned long) id), lttng_ht_seed),
+ ht->match_fct, (void *)((unsigned long) id),
+ &iter.iter, stream, node_session_id.node) {
+ /* If this call fails, the stream is being used hence data pending. */
+ ret = stream_try_lock(stream);
+ if (!ret) {
+ goto data_pending;
+ }
+
+ /*
+ * 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;
+ }
+ }
+
+ /* Relayd check */
+ if (relayd) {
+ pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+ 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);
+ }
+ pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
+ if (ret == 1) {
+ pthread_mutex_unlock(&stream->lock);
+ goto data_pending;
+ }
+ }
+ pthread_mutex_unlock(&stream->lock);
+ }
+
+ if (relayd) {
+ unsigned int is_data_inflight = 0;
+
+ /* Send init command for data pending. */
+ pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+ 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) {
+ 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(&consumer_data.lock);
+ rcu_read_unlock();
+ return 0;
+
+data_pending:
+ /* Data is still being extracted from buffers. */
+ pthread_mutex_unlock(&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;
+
+ msg.ret_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;
+
+ assert(sock >= 0);
+
+ if (!channel) {
+ msg.ret_code = -LTTNG_ERR_UST_CHAN_FAIL;
+ } else {
+ msg.ret_code = LTTNG_OK;
+ msg.key = channel->key;
+ msg.stream_count = channel->streams.count;
+ }
+
+ return lttcomm_send_unix_sock(sock, &msg, sizeof(msg));
+}