X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fconsumer.c;h=efd9e7eb3d368552685c3e0a7bd3f54362943318;hp=132e3ec6891f925006b8b43910b2a24b3e22f468;hb=4e9a468645939ea62541fa802893b928b01888b7;hpb=a98dae5fe5dc81dcf7e5146d3d6915dd6b3d055a diff --git a/src/common/consumer.c b/src/common/consumer.c index 132e3ec68..efd9e7eb3 100644 --- a/src/common/consumer.c +++ b/src/common/consumer.c @@ -69,6 +69,21 @@ volatile int consumer_quit; struct lttng_ht *metadata_ht; 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. @@ -182,6 +197,17 @@ static void consumer_rcu_free_relayd(struct rcu_head *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); } @@ -204,20 +230,88 @@ static void destroy_relayd(struct consumer_relayd_sock_pair *relayd) iter.iter.node = &relayd->node.node; ret = lttng_ht_del(consumer_data.relayd_ht, &iter); if (ret != 0) { - /* We assume the relayd was already destroyed */ + /* We assume the relayd is being or is destroyed */ return; } - /* Close all sockets */ - pthread_mutex_lock(&relayd->ctrl_sock_mutex); - (void) relayd_close(&relayd->control_sock); - pthread_mutex_unlock(&relayd->ctrl_sock_mutex); - (void) relayd_close(&relayd->data_sock); - /* RCU free() call */ call_rcu(&relayd->node.head, consumer_rcu_free_relayd); } +/* + * 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; + + 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); + } + } + + /* 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. + */ +static void cleanup_relayd(struct consumer_relayd_sock_pair *relayd, + struct lttng_consumer_local_data *ctx) +{ + int netidx; + + assert(relayd); + + /* 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]); + } +} + /* * Flag a relayd socket pair for destruction. Destroy it if the refcount * reaches zero. @@ -251,11 +345,14 @@ void consumer_del_stream(struct lttng_consumer_stream *stream, 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; } + pthread_mutex_lock(&stream->lock); pthread_mutex_lock(&consumer_data.lock); switch (consumer_data.type) { @@ -349,6 +446,7 @@ void consumer_del_stream(struct lttng_consumer_stream *stream, end: consumer_data.need_update = 1; pthread_mutex_unlock(&consumer_data.lock); + pthread_mutex_unlock(&stream->lock); if (free_chan) { consumer_del_channel(free_chan); @@ -804,7 +902,17 @@ static int consumer_update_poll_array( DBG("Updating poll fd array"); rcu_read_lock(); cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) { - if (stream->state != LTTNG_CONSUMER_ACTIVE_STREAM) { + /* + * 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) { continue; } DBG("Active FD %d", stream->wait_fd); @@ -923,6 +1031,8 @@ void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx) if (ret < 0) { PERROR("write consumer quit"); } + + DBG("Consumer flag that it should quit"); } void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream, @@ -1084,6 +1194,8 @@ void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx) { int ret; + DBG("Consumer destroying it. Closing everything."); + ret = close(ctx->consumer_error_socket); if (ret) { PERROR("close"); @@ -1165,6 +1277,7 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap( /* 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(); @@ -1224,11 +1337,22 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap( 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, use the default set before which is the filesystem. */ } else { /* No streaming, we have to set the len with the full padding */ len += padding; @@ -1244,6 +1368,11 @@ ssize_t lttng_consumer_on_read_subbuffer_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); @@ -1265,12 +1394,21 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap( } 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: - pthread_mutex_unlock(&stream->lock); /* Unlock only if ctrl socket used */ if (relayd && stream->metadata_flag) { pthread_mutex_unlock(&relayd->ctrl_sock_mutex); } + pthread_mutex_unlock(&stream->lock); rcu_read_unlock(); return written; @@ -1294,6 +1432,7 @@ ssize_t lttng_consumer_on_read_subbuffer_splice( 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: @@ -1346,6 +1485,12 @@ ssize_t lttng_consumer_on_read_subbuffer_splice( 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; } @@ -1357,7 +1502,12 @@ ssize_t lttng_consumer_on_read_subbuffer_splice( /* Use the returned socket. */ outfd = ret; } else { - ERR("Remote relayd disconnected. Stopping"); + /* 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 { @@ -1406,6 +1556,12 @@ ssize_t lttng_consumer_on_read_subbuffer_splice( if (written == 0) { written = ret_splice; } + /* Socket operation failed. We consider the relayd dead */ + if (errno == EBADF) { + WARN("Remote relayd disconnected. Stopping"); + relayd_hang_up = 1; + goto write_error; + } ret = errno; goto splice_error; } else if (ret_splice > len) { @@ -1433,12 +1589,20 @@ ssize_t lttng_consumer_on_read_subbuffer_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 EBADF: - lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_EBADF); - break; case EINVAL: lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_EINVAL); break; @@ -1451,10 +1615,10 @@ splice_error: } end: - pthread_mutex_unlock(&stream->lock); if (relayd && stream->metadata_flag) { pthread_mutex_unlock(&relayd->ctrl_sock_mutex); } + pthread_mutex_unlock(&stream->lock); rcu_read_unlock(); return written; @@ -1600,6 +1764,8 @@ void consumer_del_metadata_stream(struct lttng_consumer_stream *stream, goto free_stream; } + pthread_mutex_lock(&stream->lock); + pthread_mutex_lock(&consumer_data.lock); switch (consumer_data.type) { case LTTNG_CONSUMER_KERNEL: @@ -1691,6 +1857,7 @@ void consumer_del_metadata_stream(struct lttng_consumer_stream *stream, end: pthread_mutex_unlock(&consumer_data.lock); + pthread_mutex_unlock(&stream->lock); if (free_chan) { consumer_del_channel(free_chan); @@ -1761,6 +1928,59 @@ static int consumer_add_metadata_stream(struct lttng_consumer_stream *stream, 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) { + 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) { + 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. @@ -1852,6 +2072,13 @@ restart: continue; } + /* A NULL stream means that the state has changed. */ + if (stream == NULL) { + /* Check for deleted streams. */ + validate_endpoint_status_metadata_stream(&events); + continue; + } + DBG("Adding metadata stream %d to poll set", stream->wait_fd); @@ -1916,8 +2143,9 @@ restart: len = ctx->on_buffer_ready(stream, ctx); /* It's ok to have an unavailable sub-buffer */ if (len < 0 && len != -EAGAIN && len != -ENODATA) { - rcu_read_unlock(); - goto end; + /* 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; } @@ -2058,6 +2286,7 @@ void *consumer_thread_data_poll(void *data) * waking us up to test it. */ if (new_stream == NULL) { + validate_endpoint_status_data_stream(); continue; } @@ -2084,7 +2313,8 @@ void *consumer_thread_data_poll(void *data) len = ctx->on_buffer_ready(local_stream[i], ctx); /* it's ok to have an unavailable sub-buffer */ if (len < 0 && len != -EAGAIN && len != -ENODATA) { - goto end; + /* Clean the stream and free it. */ + consumer_del_stream(local_stream[i], data_ht); } else if (len > 0) { local_stream[i]->data_read = 1; } @@ -2107,7 +2337,8 @@ void *consumer_thread_data_poll(void *data) len = ctx->on_buffer_ready(local_stream[i], ctx); /* it's ok to have an unavailable sub-buffer */ if (len < 0 && len != -EAGAIN && len != -ENODATA) { - goto end; + /* Clean the stream and free it. */ + consumer_del_stream(local_stream[i], data_ht); } else if (len > 0) { local_stream[i]->data_read = 1; } @@ -2294,14 +2525,9 @@ end: /* * Notify the data poll thread to poll back again and test the - * consumer_quit state to quit gracefully. + * consumer_quit state that we just set so to quit gracefully. */ - do { - struct lttng_consumer_stream *null_stream = NULL; - - ret = write(ctx->consumer_data_pipe[1], &null_stream, - sizeof(null_stream)); - } while (ret < 0 && errno == EINTR); + notify_thread_pipe(ctx->consumer_data_pipe[1]); rcu_unregister_thread(); return NULL; @@ -2445,6 +2671,34 @@ error: 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; +} + /* * Check if for a given session id there is still data needed to be extract * from the buffers. @@ -2462,6 +2716,7 @@ int consumer_data_available(uint64_t id) DBG("Consumer data available command on session id %" PRIu64, id); + rcu_read_lock(); pthread_mutex_lock(&consumer_data.lock); switch (consumer_data.type) { @@ -2477,8 +2732,6 @@ int consumer_data_available(uint64_t id) assert(0); } - rcu_read_lock(); - /* Ease our life a bit */ ht = consumer_data.stream_list_ht; @@ -2486,17 +2739,42 @@ int consumer_data_available(uint64_t id) ht->hash_fct((void *)((unsigned long) id), 0x42UL), ht->match_fct, (void *)((unsigned long) id), &iter.iter, stream, node_session_id.node) { - /* Check the stream for data. */ - ret = data_available(stream); - if (ret == 0) { + /* If this call fails, the stream is being used hence data pending. */ + ret = stream_try_lock(stream); + if (!ret) { goto data_not_available; } + /* + * 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_available(stream); + if (ret == 0) { + pthread_mutex_unlock(&stream->lock); + goto data_not_available; + } + } + + /* Relayd check */ if (stream->net_seq_idx != -1) { relayd = consumer_find_relayd(stream->net_seq_idx); - assert(relayd); + if (!relayd) { + /* + * At this point, if the relayd object is not available for the + * given stream, it is because the relayd is being cleaned up + * so every stream associated with it (for a session id value) + * are or will be marked for deletion hence no data pending. + */ + pthread_mutex_unlock(&stream->lock); + goto data_not_available; + } - pthread_mutex_lock(&stream->lock); pthread_mutex_lock(&relayd->ctrl_sock_mutex); if (stream->metadata_flag) { ret = relayd_quiescent_control(&relayd->control_sock); @@ -2505,11 +2783,12 @@ int consumer_data_available(uint64_t id) stream->relayd_stream_id, stream->next_net_seq_num); } pthread_mutex_unlock(&relayd->ctrl_sock_mutex); - pthread_mutex_unlock(&stream->lock); if (ret == 0) { + pthread_mutex_unlock(&stream->lock); goto data_not_available; } } + pthread_mutex_unlock(&stream->lock); } /*