X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fconsumer%2Fconsumer.c;h=27a01bd7a4c162c83b92f8c5ff10386771f9dab9;hp=716b560a96ddbf9cd397147fe3ed01eb076781ad;hb=3c215c837498a125ac4a981447368c30fbd92bb4;hpb=ecd1a12fac39784bded85c0f06e47ace2dc98cde diff --git a/src/common/consumer/consumer.c b/src/common/consumer/consumer.c index 716b560a9..27a01bd7a 100644 --- a/src/common/consumer/consumer.c +++ b/src/common/consumer/consumer.c @@ -1,22 +1,13 @@ /* - * Copyright (C) 2011 - Julien Desfossez - * Mathieu Desnoyers - * 2012 - David Goulet + * Copyright (C) 2011 Julien Desfossez + * Copyright (C) 2011 Mathieu Desnoyers + * Copyright (C) 2012 David Goulet * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License, version 2 only, - * as published by the Free Software Foundation. + * SPDX-License-Identifier: GPL-2.0-only * - * 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., - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ +#include "common/index/ctf-index.h" #define _LGPL_SOURCE #include #include @@ -91,6 +82,20 @@ int consumer_quit; static struct lttng_ht *metadata_ht; static struct lttng_ht *data_ht; +static const char *get_consumer_domain(void) +{ + switch (consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + return DEFAULT_KERNEL_TRACE_DIR; + case LTTNG_CONSUMER64_UST: + /* Fall-through. */ + case LTTNG_CONSUMER32_UST: + return DEFAULT_UST_TRACE_DIR; + default: + abort(); + } +} + /* * Notify a thread lttng pipe to poll back again. This usually means that some * global state has changed so we just send back the thread in a poll wait @@ -564,94 +569,6 @@ void consumer_stream_update_channel_attributes( channel->tracefile_size; } -struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key, - uint64_t stream_key, - const char *channel_name, - uint64_t relayd_id, - uint64_t session_id, - struct lttng_trace_chunk *trace_chunk, - int cpu, - int *alloc_ret, - enum consumer_channel_type type, - unsigned int monitor) -{ - int ret; - struct lttng_consumer_stream *stream; - - stream = zmalloc(sizeof(*stream)); - if (stream == NULL) { - PERROR("malloc struct lttng_consumer_stream"); - ret = -ENOMEM; - goto end; - } - - if (trace_chunk && !lttng_trace_chunk_get(trace_chunk)) { - ERR("Failed to acquire trace chunk reference during the creation of a stream"); - ret = -1; - goto error; - } - - rcu_read_lock(); - stream->key = stream_key; - stream->trace_chunk = trace_chunk; - stream->out_fd = -1; - stream->out_fd_offset = 0; - stream->output_written = 0; - stream->net_seq_idx = relayd_id; - stream->session_id = session_id; - stream->monitor = monitor; - stream->endpoint_status = CONSUMER_ENDPOINT_ACTIVE; - stream->index_file = NULL; - stream->last_sequence_number = -1ULL; - pthread_mutex_init(&stream->lock, NULL); - pthread_mutex_init(&stream->metadata_timer_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)); - /* Live rendez-vous point. */ - pthread_cond_init(&stream->metadata_rdv, NULL); - pthread_mutex_init(&stream->metadata_rdv_lock, NULL); - } else { - /* Format stream name to _ */ - 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_u64(&stream->node, stream->key); - - /* Init node per channel id key */ - lttng_ht_node_init_u64(&stream->node_channel_id, channel_key); - - /* Init session id node with the stream session id */ - lttng_ht_node_init_u64(&stream->node_session_id, stream->session_id); - - DBG3("Allocated stream %s (key %" PRIu64 ", chan_key %" PRIu64 - " relayd_id %" PRIu64 ", session_id %" PRIu64, - stream->name, stream->key, channel_key, - stream->net_seq_idx, stream->session_id); - - rcu_read_unlock(); - return stream; - -error: - rcu_read_unlock(); - lttng_trace_chunk_put(stream->trace_chunk); - free(stream); -end: - if (alloc_ret) { - *alloc_ret = ret; - } - return NULL; -} - /* * Add a stream to the global list protected by a mutex. */ @@ -709,11 +626,6 @@ void consumer_add_data_stream(struct lttng_consumer_stream *stream) pthread_mutex_unlock(&consumer_data.lock); } -void consumer_del_data_stream(struct lttng_consumer_stream *stream) -{ - consumer_del_stream(stream, data_ht); -} - /* * Add relayd socket to global consumer data hashtable. RCU read side lock MUST * be acquired before calling this. @@ -820,7 +732,7 @@ int consumer_send_relayd_stream(struct lttng_consumer_stream *stream, /* Add stream on the relayd */ pthread_mutex_lock(&relayd->ctrl_sock_mutex); ret = relayd_add_stream(&relayd->control_sock, stream->name, - path, &stream->relayd_stream_id, + get_consumer_domain(), path, &stream->relayd_stream_id, stream->chan->tracefile_size, stream->chan->tracefile_count, stream->trace_chunk); @@ -965,6 +877,43 @@ error: return outfd; } +/* + * Write a character on the metadata poll pipe to wake the metadata thread. + * Returns 0 on success, -1 on error. + */ +int consumer_metadata_wakeup_pipe(const struct lttng_consumer_channel *channel) +{ + int ret = 0; + + DBG("Waking up metadata poll thread (writing to pipe): channel name = '%s'", + channel->name); + if (channel->monitor && channel->metadata_stream) { + const char dummy = 'c'; + const ssize_t write_ret = lttng_write( + channel->metadata_stream->ust_metadata_poll_pipe[1], + &dummy, 1); + + if (write_ret < 1) { + if (errno == EWOULDBLOCK) { + /* + * This is fine, the metadata poll thread + * is having a hard time keeping-up, but + * it will eventually wake-up and consume + * the available data. + */ + ret = 0; + } else { + PERROR("Failed to write to UST metadata pipe while attempting to wake-up the metadata poll thread"); + ret = -1; + goto end; + } + } + } + +end: + return ret; +} + /* * Trigger a dump of the metadata content. Following/during the succesful * completion of this call, the metadata poll thread will start receiving @@ -1014,13 +963,6 @@ int lttng_consumer_channel_set_trace_chunk( struct lttng_consumer_channel *channel, struct lttng_trace_chunk *new_trace_chunk) { - int ret = 0; - const bool is_local_trace = channel->relayd_id == -1ULL; - bool update_stream_trace_chunk; - struct cds_lfht_iter iter; - struct lttng_consumer_stream *stream; - unsigned long channel_hash; - pthread_mutex_lock(&channel->lock); if (channel->is_deleted) { /* @@ -1032,24 +974,6 @@ int lttng_consumer_channel_set_trace_chunk( */ goto end; } - /* - * A stream can transition to a state where it and its channel - * no longer belong to a trace chunk. For instance, this happens when - * a session is rotated while it is inactive. After the rotation - * of an inactive session completes, the channel and its streams no - * longer belong to a trace chunk. - * - * However, if a session is stopped, rotated, and started again, - * the session daemon will create a new chunk and send it to its peers. - * In that case, the streams' transition to a new chunk can be performed - * immediately. - * - * This trace chunk transition could also be performed lazily when - * a buffer is consumed. However, creating the files here allows the - * consumer daemon to report any creation error to the session daemon - * and cause the start of the tracing session to fail. - */ - update_stream_trace_chunk = !channel->trace_chunk && new_trace_chunk; /* * The acquisition of the reference cannot fail (barring @@ -1065,59 +989,9 @@ int lttng_consumer_channel_set_trace_chunk( lttng_trace_chunk_put(channel->trace_chunk); channel->trace_chunk = new_trace_chunk; - if (!is_local_trace || !new_trace_chunk) { - /* Not an error. */ - goto end; - } - - if (!update_stream_trace_chunk) { - goto end; - } - - channel_hash = consumer_data.stream_per_chan_id_ht->hash_fct( - &channel->key, lttng_ht_seed); - rcu_read_lock(); - cds_lfht_for_each_entry_duplicate(consumer_data.stream_per_chan_id_ht->ht, - channel_hash, - consumer_data.stream_per_chan_id_ht->match_fct, - &channel->key, &iter, stream, node_channel_id.node) { - bool acquired_reference, should_regenerate_metadata = false; - - acquired_reference = lttng_trace_chunk_get(channel->trace_chunk); - assert(acquired_reference); - - pthread_mutex_lock(&stream->lock); - - /* - * On a transition from "no-chunk" to a new chunk, a metadata - * stream's content must be entirely dumped. This must occcur - * _after_ the creation of the metadata stream's output files - * as the consumption thread (not necessarily the one executing - * this) may start to consume during the call to - * consumer_metadata_stream_dump(). - */ - should_regenerate_metadata = - stream->metadata_flag && - !stream->trace_chunk && channel->trace_chunk; - stream->trace_chunk = channel->trace_chunk; - ret = consumer_stream_create_output_files(stream, true); - if (ret) { - pthread_mutex_unlock(&stream->lock); - goto end_rcu_unlock; - } - if (should_regenerate_metadata) { - ret = consumer_metadata_stream_dump(stream); - } - pthread_mutex_unlock(&stream->lock); - if (ret) { - goto end_rcu_unlock; - } - } -end_rcu_unlock: - rcu_read_unlock(); end: pthread_mutex_unlock(&channel->lock); - return ret; + return 0; } /* @@ -1138,6 +1012,7 @@ struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key, uint64_t session_id_per_pid, unsigned int monitor, unsigned int live_timer_interval, + bool is_in_live_session, const char *root_shm_path, const char *shm_path) { @@ -1169,6 +1044,7 @@ struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key, channel->tracefile_count = tracefile_count; channel->monitor = monitor; channel->live_timer_interval = live_timer_interval; + channel->is_live = is_in_live_session; pthread_mutex_init(&channel->lock, NULL); pthread_mutex_init(&channel->timer_lock, NULL); @@ -1537,7 +1413,7 @@ void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream, struct lttng_consumer_local_data *lttng_consumer_create( enum lttng_consumer_type type, ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream, - struct lttng_consumer_local_data *ctx), + struct lttng_consumer_local_data *ctx, bool locked_by_caller), int (*recv_channel)(struct lttng_consumer_channel *channel), int (*recv_stream)(struct lttng_consumer_stream *stream), int (*update_stream)(uint64_t stream_key, uint32_t state)) @@ -1744,19 +1620,18 @@ end: * Returns the number of bytes written */ ssize_t lttng_consumer_on_read_subbuffer_mmap( - struct lttng_consumer_local_data *ctx, - struct lttng_consumer_stream *stream, unsigned long len, - unsigned long padding, - struct ctf_packet_index *index) + struct lttng_consumer_stream *stream, + const struct lttng_buffer_view *buffer, + unsigned long padding) { - unsigned long mmap_offset; - void *mmap_base; ssize_t ret = 0; off_t orig_offset = stream->out_fd_offset; /* Default is on the disk */ int outfd = stream->out_fd; struct consumer_relayd_sock_pair *relayd = NULL; unsigned int relayd_hang_up = 0; + const size_t subbuf_content_size = buffer->size - padding; + size_t write_len; /* RCU lock for the relayd pointer */ rcu_read_lock(); @@ -1772,39 +1647,9 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap( } } - /* get the offset inside the fd to mmap */ - switch (consumer_data.type) { - case LTTNG_CONSUMER_KERNEL: - mmap_base = stream->mmap_base; - ret = kernctl_get_mmap_read_offset(stream->wait_fd, &mmap_offset); - if (ret < 0) { - PERROR("tracer ctl get_mmap_read_offset"); - goto end; - } - break; - case LTTNG_CONSUMER32_UST: - case LTTNG_CONSUMER64_UST: - mmap_base = lttng_ustctl_get_mmap_base(stream); - if (!mmap_base) { - ERR("read mmap get mmap base for stream %s", stream->name); - ret = -EPERM; - goto end; - } - ret = lttng_ustctl_get_mmap_read_offset(stream, &mmap_offset); - if (ret != 0) { - PERROR("tracer ctl get_mmap_read_offset"); - ret = -EINVAL; - goto end; - } - break; - default: - ERR("Unknown consumer_data type"); - assert(0); - } - /* Handle stream on the relayd if the output is on the network */ if (relayd) { - unsigned long netlen = len; + unsigned long netlen = subbuf_content_size; /* * Lock the control socket for the complete duration of the function @@ -1842,10 +1687,10 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap( goto write_error; } } - } else { - /* No streaming, we have to set the len with the full padding */ - len += padding; + write_len = subbuf_content_size; + } else { + /* No streaming; we have to write the full padding. */ if (stream->metadata_flag && stream->reset_metadata_flag) { ret = utils_truncate_stream_file(stream->out_fd, 0); if (ret < 0) { @@ -1859,7 +1704,7 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap( * Check if we need to change the tracefile before writing the packet. */ if (stream->chan->tracefile_size > 0 && - (stream->tracefile_size_current + len) > + (stream->tracefile_size_current + buffer->size) > stream->chan->tracefile_size) { ret = consumer_stream_rotate_output_files(stream); if (ret) { @@ -1868,19 +1713,17 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap( outfd = stream->out_fd; orig_offset = 0; } - stream->tracefile_size_current += len; - if (index) { - index->offset = htobe64(stream->out_fd_offset); - } + stream->tracefile_size_current += buffer->size; + write_len = buffer->size; } /* * This call guarantee that len or less is returned. It's impossible to * receive a ret value that is bigger than len. */ - ret = lttng_write(outfd, mmap_base + mmap_offset, len); - DBG("Consumer mmap write() ret %zd (len %lu)", ret, len); - if (ret < 0 || ((size_t) ret != len)) { + ret = lttng_write(outfd, buffer->data, write_len); + DBG("Consumer mmap write() ret %zd (len %zu)", ret, write_len); + if (ret < 0 || ((size_t) ret != write_len)) { /* * Report error to caller if nothing was written else at least send the * amount written. @@ -1901,7 +1744,8 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap( DBG("Consumer mmap write detected relayd hang up"); } else { /* Unhandled error, print it and stop function right now. */ - PERROR("Error in write mmap (ret %zd != len %lu)", ret, len); + PERROR("Error in write mmap (ret %zd != write_len %zu)", ret, + write_len); } goto write_error; } @@ -1910,9 +1754,9 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap( /* 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, len, + lttng_sync_file_range(outfd, stream->out_fd_offset, write_len, SYNC_FILE_RANGE_WRITE); - stream->out_fd_offset += len; + stream->out_fd_offset += write_len; lttng_consumer_sync_trace_file(stream, orig_offset); } @@ -1946,8 +1790,7 @@ end: 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, - struct ctf_packet_index *index) + unsigned long padding) { ssize_t ret = 0, written = 0, ret_splice = 0; loff_t offset = 0; @@ -2051,7 +1894,6 @@ ssize_t lttng_consumer_on_read_subbuffer_splice( orig_offset = 0; } stream->tracefile_size_current += len; - index->offset = htobe64(stream->out_fd_offset); } while (len > 0) { @@ -2254,6 +2096,7 @@ int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx, } } +static void lttng_consumer_close_all_metadata(void) { switch (consumer_data.type) { @@ -2617,7 +2460,7 @@ restart: do { health_code_update(); - len = ctx->on_buffer_ready(stream, ctx); + len = ctx->on_buffer_ready(stream, ctx, false); /* * We don't check the return value here since if we get * a negative len, it means an error occurred thus we @@ -2644,7 +2487,7 @@ restart: do { health_code_update(); - len = ctx->on_buffer_ready(stream, ctx); + len = ctx->on_buffer_ready(stream, ctx, false); /* * We don't check the return value here since if we get * a negative len, it means an error occurred thus we @@ -2860,7 +2703,7 @@ void *consumer_thread_data_poll(void *data) if (pollfd[i].revents & POLLPRI) { DBG("Urgent read on fd %d", pollfd[i].fd); high_prio = 1; - len = ctx->on_buffer_ready(local_stream[i], ctx); + len = ctx->on_buffer_ready(local_stream[i], ctx, false); /* it's ok to have an unavailable sub-buffer */ if (len < 0 && len != -EAGAIN && len != -ENODATA) { /* Clean the stream and free it. */ @@ -2891,7 +2734,7 @@ void *consumer_thread_data_poll(void *data) local_stream[i]->hangup_flush_done || local_stream[i]->has_data) { DBG("Normal read on fd %d", pollfd[i].fd); - len = ctx->on_buffer_ready(local_stream[i], ctx); + len = ctx->on_buffer_ready(local_stream[i], ctx, false); /* it's ok to have an unavailable sub-buffer */ if (len < 0 && len != -EAGAIN && len != -ENODATA) { /* Clean the stream and free it. */ @@ -3447,7 +3290,7 @@ void *consumer_thread_sessiond_poll(void *data) err = 0; /* All is OK */ goto end; } - DBG("received command on sock"); + DBG("Received command on sock"); } /* All is OK */ err = 0; @@ -3504,40 +3347,132 @@ error_testpoint: return NULL; } -ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream, +static int post_consume(struct lttng_consumer_stream *stream, + const struct stream_subbuffer *subbuffer, struct lttng_consumer_local_data *ctx) { - ssize_t ret; + size_t i; + int ret = 0; + const size_t count = lttng_dynamic_array_get_count( + &stream->read_subbuffer_ops.post_consume_cbs); - pthread_mutex_lock(&stream->chan->lock); - pthread_mutex_lock(&stream->lock); - if (stream->metadata_flag) { - pthread_mutex_lock(&stream->metadata_rdv_lock); + for (i = 0; i < count; i++) { + const post_consume_cb op = *(post_consume_cb *) lttng_dynamic_array_get_element( + &stream->read_subbuffer_ops.post_consume_cbs, + i); + + ret = op(stream, subbuffer, ctx); + if (ret) { + goto end; + } } +end: + return ret; +} - switch (consumer_data.type) { - case LTTNG_CONSUMER_KERNEL: - ret = lttng_kconsumer_read_subbuffer(stream, ctx); - break; - case LTTNG_CONSUMER32_UST: - case LTTNG_CONSUMER64_UST: - ret = lttng_ustconsumer_read_subbuffer(stream, ctx); - break; - default: - ERR("Unknown consumer_data type"); - assert(0); - ret = -ENOSYS; - break; +ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream, + struct lttng_consumer_local_data *ctx, + bool locked_by_caller) +{ + ssize_t ret, written_bytes = 0; + int rotation_ret; + struct stream_subbuffer subbuffer = {}; + + if (!locked_by_caller) { + stream->read_subbuffer_ops.lock(stream); } - if (stream->metadata_flag) { - pthread_cond_broadcast(&stream->metadata_rdv); - pthread_mutex_unlock(&stream->metadata_rdv_lock); + if (stream->read_subbuffer_ops.on_wake_up) { + ret = stream->read_subbuffer_ops.on_wake_up(stream); + if (ret) { + goto end; + } + } + + /* + * If the stream was flagged to be ready for rotation before we extract + * the next packet, rotate it now. + */ + if (stream->rotate_ready) { + DBG("Rotate stream before consuming data"); + ret = lttng_consumer_rotate_stream(ctx, stream); + if (ret < 0) { + ERR("Stream rotation error before consuming data"); + goto end; + } + } + + ret = stream->read_subbuffer_ops.get_next_subbuffer(stream, &subbuffer); + if (ret) { + if (ret == -ENODATA) { + /* Not an error. */ + ret = 0; + goto sleep_stream; + } + goto end; + } + + ret = stream->read_subbuffer_ops.pre_consume_subbuffer( + stream, &subbuffer); + if (ret) { + goto error_put_subbuf; + } + + written_bytes = stream->read_subbuffer_ops.consume_subbuffer( + ctx, stream, &subbuffer); + if (written_bytes <= 0) { + ERR("Error consuming subbuffer: (%zd)", written_bytes); + ret = (int) written_bytes; + goto error_put_subbuf; + } + + ret = stream->read_subbuffer_ops.put_next_subbuffer(stream, &subbuffer); + if (ret) { + goto end; + } + + ret = post_consume(stream, &subbuffer, ctx); + if (ret) { + goto end; + } + + /* + * After extracting the packet, we check if the stream is now ready to + * be rotated and perform the action immediately. + * + * Don't overwrite `ret` as callers expect the number of bytes + * consumed to be returned on success. + */ + rotation_ret = lttng_consumer_stream_is_rotate_ready(stream); + if (rotation_ret == 1) { + rotation_ret = lttng_consumer_rotate_stream(ctx, stream); + if (rotation_ret < 0) { + ret = rotation_ret; + ERR("Stream rotation error after consuming data"); + goto end; + } + + } else if (rotation_ret < 0) { + ret = rotation_ret; + ERR("Failed to check if stream was ready to rotate after consuming data"); + goto end; + } + +sleep_stream: + if (stream->read_subbuffer_ops.on_sleep) { + stream->read_subbuffer_ops.on_sleep(stream, ctx); + } + + ret = written_bytes; +end: + if (!locked_by_caller) { + stream->read_subbuffer_ops.unlock(stream); } - pthread_mutex_unlock(&stream->lock); - pthread_mutex_unlock(&stream->chan->lock); return ret; +error_put_subbuf: + (void) stream->read_subbuffer_ops.put_next_subbuffer(stream, &subbuffer); + goto end; } int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream) @@ -4011,26 +3946,30 @@ unsigned long consumer_get_consume_start_pos(unsigned long consumed_pos, return start_pos; } -static -int consumer_flush_buffer(struct lttng_consumer_stream *stream, int producer_active) +/* Stream lock must be held by the caller. */ +static int sample_stream_positions(struct lttng_consumer_stream *stream, + unsigned long *produced, unsigned long *consumed) { - int ret = 0; + int ret; - switch (consumer_data.type) { - case LTTNG_CONSUMER_KERNEL: - ret = kernctl_buffer_flush(stream->wait_fd); - if (ret < 0) { - ERR("Failed to flush kernel stream"); - goto end; - } - break; - case LTTNG_CONSUMER32_UST: - case LTTNG_CONSUMER64_UST: - lttng_ustctl_flush_buffer(stream, producer_active); - break; - default: - ERR("Unknown consumer_data type"); - abort(); + ASSERT_LOCKED(stream->lock); + + ret = lttng_consumer_sample_snapshot_positions(stream); + if (ret < 0) { + ERR("Failed to sample snapshot positions"); + goto end; + } + + ret = lttng_consumer_get_produced_snapshot(stream, produced); + if (ret < 0) { + ERR("Failed to sample produced position"); + goto end; + } + + ret = lttng_consumer_get_consumed_snapshot(stream, consumed); + if (ret < 0) { + ERR("Failed to sample consumed position"); + goto end; } end: @@ -4060,11 +3999,15 @@ int lttng_consumer_rotate_channel(struct lttng_consumer_channel *channel, const bool is_local_trace = relayd_id == -1ULL; struct consumer_relayd_sock_pair *relayd = NULL; bool rotating_to_new_chunk = true; + /* Array of `struct lttng_consumer_stream *` */ + struct lttng_dynamic_pointer_array streams_packet_to_open; + size_t stream_idx; DBG("Consumer sample rotate position for channel %" PRIu64, key); lttng_dynamic_array_init(&stream_rotation_positions, sizeof(struct relayd_stream_rotation_position), NULL); + lttng_dynamic_pointer_array_init(&streams_packet_to_open, NULL); rcu_read_lock(); @@ -4081,7 +4024,7 @@ int lttng_consumer_rotate_channel(struct lttng_consumer_channel *channel, ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct, &channel->key, &iter.iter, stream, node_channel_id.node) { - unsigned long consumed_pos; + unsigned long produced_pos = 0, consumed_pos = 0; health_code_update(); @@ -4094,65 +4037,173 @@ int lttng_consumer_rotate_channel(struct lttng_consumer_channel *channel, rotating_to_new_chunk = false; } - ret = lttng_consumer_sample_snapshot_positions(stream); - if (ret < 0) { - ERR("Failed to sample snapshot position during channel rotation"); - goto end_unlock_stream; - } - - ret = lttng_consumer_get_produced_snapshot(stream, - &stream->rotate_position); - if (ret < 0) { - ERR("Failed to sample produced position during channel rotation"); - goto end_unlock_stream; - } - - lttng_consumer_get_consumed_snapshot(stream, - &consumed_pos); - if (consumed_pos == stream->rotate_position) { - stream->rotate_ready = true; - } - /* - * Active flush; has no effect if the production position - * is at a packet boundary. + * Do not flush a packet when rotating from a NULL trace + * chunk. The stream has no means to output data, and the prior + * rotation which rotated to NULL performed that side-effect + * already. No new data can be produced when a stream has no + * associated trace chunk (e.g. a stop followed by a rotate). */ - ret = consumer_flush_buffer(stream, 1); - if (ret < 0) { - ERR("Failed to flush stream %" PRIu64 " during channel rotation", - stream->key); - goto end_unlock_stream; - } + if (stream->trace_chunk) { + bool flush_active; - if (!is_local_trace) { - /* - * The relay daemon control protocol expects a rotation - * position as "the sequence number of the first packet - * _after_ the current trace chunk. - * - * At the moment when the positions of the buffers are - * sampled, the production position does not necessarily - * sit at a packet boundary. The 'active' flush - * operation above will push the production position to - * the next packet boundary _if_ it is not already - * sitting at such a boundary. - * - * Assuming a current production position that is not - * on the bound of a packet, the 'target' sequence - * number is - * (consumed_pos / subbuffer_size) + 1 - * Note the '+ 1' to ensure the current packet is - * part of the current trace chunk. - * - * However, if the production position is already at - * a packet boundary, the '+ 1' is not necessary as the - * last packet of the current chunk is already - * 'complete'. + if (stream->metadata_flag) { + /* + * Don't produce an empty metadata packet, + * simply close the current one. + * + * Metadata is regenerated on every trace chunk + * switch; there is no concern that no data was + * produced. + */ + flush_active = true; + } else { + /* + * Only flush an empty packet if the "packet + * open" could not be performed on transition + * to a new trace chunk and no packets were + * consumed within the chunk's lifetime. + */ + if (stream->opened_packet_in_current_trace_chunk) { + flush_active = true; + } else { + /* + * Stream could have been full at the + * time of rotation, but then have had + * no activity at all. + * + * It is important to flush a packet + * to prevent 0-length files from being + * produced as most viewers choke on + * them. + * + * Unfortunately viewers will not be + * able to know that tracing was active + * for this stream during this trace + * chunk's lifetime. + */ + ret = sample_stream_positions(stream, &produced_pos, &consumed_pos); + if (ret) { + goto end_unlock_stream; + } + + /* + * Don't flush an empty packet if data + * was produced; it will be consumed + * before the rotation completes. + */ + flush_active = produced_pos != consumed_pos; + if (!flush_active) { + const char *trace_chunk_name; + uint64_t trace_chunk_id; + + chunk_status = lttng_trace_chunk_get_name( + stream->trace_chunk, + &trace_chunk_name, + NULL); + if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_NONE) { + trace_chunk_name = "none"; + } + + /* + * Consumer trace chunks are + * never anonymous. + */ + chunk_status = lttng_trace_chunk_get_id( + stream->trace_chunk, + &trace_chunk_id); + assert(chunk_status == + LTTNG_TRACE_CHUNK_STATUS_OK); + + DBG("Unable to open packet for stream during trace chunk's lifetime. " + "Flushing an empty packet to prevent an empty file from being created: " + "stream id = %" PRIu64 ", trace chunk name = `%s`, trace chunk id = %" PRIu64, + stream->key, trace_chunk_name, trace_chunk_id); + } + } + } + + /* + * Close the current packet before sampling the + * ring buffer positions. + */ + ret = consumer_stream_flush_buffer(stream, flush_active); + if (ret < 0) { + ERR("Failed to flush stream %" PRIu64 " during channel rotation", + stream->key); + goto end_unlock_stream; + } + } + + ret = lttng_consumer_take_snapshot(stream); + if (ret < 0 && ret != -ENODATA && ret != -EAGAIN) { + ERR("Failed to sample snapshot position during channel rotation"); + goto end_unlock_stream; + } + if (!ret) { + ret = lttng_consumer_get_produced_snapshot(stream, + &produced_pos); + if (ret < 0) { + ERR("Failed to sample produced position during channel rotation"); + goto end_unlock_stream; + } + + ret = lttng_consumer_get_consumed_snapshot(stream, + &consumed_pos); + if (ret < 0) { + ERR("Failed to sample consumed position during channel rotation"); + goto end_unlock_stream; + } + } + /* + * Align produced position on the start-of-packet boundary of the first + * packet going into the next trace chunk. + */ + produced_pos = ALIGN_FLOOR(produced_pos, stream->max_sb_size); + if (consumed_pos == produced_pos) { + DBG("Set rotate ready for stream %" PRIu64 " produced = %lu consumed = %lu", + stream->key, produced_pos, consumed_pos); + stream->rotate_ready = true; + } else { + DBG("Different consumed and produced positions " + "for stream %" PRIu64 " produced = %lu consumed = %lu", + stream->key, produced_pos, consumed_pos); + } + /* + * The rotation position is based on the packet_seq_num of the + * packet following the last packet that was consumed for this + * stream, incremented by the offset between produced and + * consumed positions. This rotation position is a lower bound + * (inclusive) at which the next trace chunk starts. Since it + * is a lower bound, it is OK if the packet_seq_num does not + * correspond exactly to the same packet identified by the + * consumed_pos, which can happen in overwrite mode. + */ + if (stream->sequence_number_unavailable) { + /* + * Rotation should never be performed on a session which + * interacts with a pre-2.8 lttng-modules, which does + * not implement packet sequence number. + */ + ERR("Failure to rotate stream %" PRIu64 ": sequence number unavailable", + stream->key); + ret = -1; + goto end_unlock_stream; + } + stream->rotate_position = stream->last_sequence_number + 1 + + ((produced_pos - consumed_pos) / stream->max_sb_size); + DBG("Set rotation position for stream %" PRIu64 " at position %" PRIu64, + stream->key, stream->rotate_position); + + if (!is_local_trace) { + /* + * The relay daemon control protocol expects a rotation + * position as "the sequence number of the first packet + * _after_ the current trace chunk". */ const struct relayd_stream_rotation_position position = { .stream_id = stream->relayd_stream_id, - .rotate_at_seq_num = (stream->rotate_position / stream->max_sb_size) + - !!(stream->rotate_position % stream->max_sb_size), + .rotate_at_seq_num = stream->rotate_position, }; ret = lttng_dynamic_array_add_element( @@ -4164,36 +4215,135 @@ int lttng_consumer_rotate_channel(struct lttng_consumer_channel *channel, } stream_count++; } + + stream->opened_packet_in_current_trace_chunk = false; + + if (rotating_to_new_chunk && !stream->metadata_flag) { + /* + * Attempt to flush an empty packet as close to the + * rotation point as possible. In the event where a + * stream remains inactive after the rotation point, + * this ensures that the new trace chunk has a + * beginning timestamp set at the begining of the + * trace chunk instead of only creating an empty + * packet when the trace chunk is stopped. + * + * This indicates to the viewers that the stream + * was being recorded, but more importantly it + * allows viewers to determine a useable trace + * intersection. + * + * This presents a problem in the case where the + * ring-buffer is completely full. + * + * Consider the following scenario: + * - The consumption of data is slow (slow network, + * for instance), + * - The ring buffer is full, + * - A rotation is initiated, + * - The flush below does nothing (no space left to + * open a new packet), + * - The other streams rotate very soon, and new + * data is produced in the new chunk, + * - This stream completes its rotation long after the + * rotation was initiated + * - The session is stopped before any event can be + * produced in this stream's buffers. + * + * The resulting trace chunk will have a single packet + * temporaly at the end of the trace chunk for this + * stream making the stream intersection more narrow + * than it should be. + * + * To work-around this, an empty flush is performed + * after the first consumption of a packet during a + * rotation if open_packet fails. The idea is that + * consuming a packet frees enough space to switch + * packets in this scenario and allows the tracer to + * "stamp" the beginning of the new trace chunk at the + * earliest possible point. + * + * The packet open is performed after the channel + * rotation to ensure that no attempt to open a packet + * is performed in a stream that has no active trace + * chunk. + */ + ret = lttng_dynamic_pointer_array_add_pointer( + &streams_packet_to_open, stream); + if (ret) { + PERROR("Failed to add a stream pointer to array of streams in which to open a packet"); + ret = -1; + goto end_unlock_stream; + } + } + pthread_mutex_unlock(&stream->lock); } stream = NULL; - pthread_mutex_unlock(&channel->lock); - if (is_local_trace) { - ret = 0; - goto end; - } + if (!is_local_trace) { + relayd = consumer_find_relayd(relayd_id); + if (!relayd) { + ERR("Failed to find relayd %" PRIu64, relayd_id); + ret = -1; + goto end_unlock_channel; + } - relayd = consumer_find_relayd(relayd_id); - if (!relayd) { - ERR("Failed to find relayd %" PRIu64, relayd_id); - ret = -1; - goto end; + pthread_mutex_lock(&relayd->ctrl_sock_mutex); + ret = relayd_rotate_streams(&relayd->control_sock, stream_count, + rotating_to_new_chunk ? &next_chunk_id : NULL, + (const struct relayd_stream_rotation_position *) + stream_rotation_positions.buffer + .data); + pthread_mutex_unlock(&relayd->ctrl_sock_mutex); + if (ret < 0) { + ERR("Relayd rotate stream failed. Cleaning up relayd %" PRIu64, + relayd->net_seq_idx); + lttng_consumer_cleanup_relayd(relayd); + goto end_unlock_channel; + } } - pthread_mutex_lock(&relayd->ctrl_sock_mutex); - ret = relayd_rotate_streams(&relayd->control_sock, stream_count, - rotating_to_new_chunk ? &next_chunk_id : NULL, - (const struct relayd_stream_rotation_position *) - stream_rotation_positions.buffer.data); - pthread_mutex_unlock(&relayd->ctrl_sock_mutex); - if (ret < 0) { - ERR("Relayd rotate stream failed. Cleaning up relayd %" PRIu64, - relayd->net_seq_idx); - lttng_consumer_cleanup_relayd(relayd); - goto end; + for (stream_idx = 0; + stream_idx < lttng_dynamic_pointer_array_get_count( + &streams_packet_to_open); + stream_idx++) { + enum consumer_stream_open_packet_status status; + + stream = lttng_dynamic_pointer_array_get_pointer( + &streams_packet_to_open, stream_idx); + + pthread_mutex_lock(&stream->lock); + status = consumer_stream_open_packet(stream); + pthread_mutex_unlock(&stream->lock); + switch (status) { + case CONSUMER_STREAM_OPEN_PACKET_STATUS_OPENED: + DBG("Opened a packet after a rotation: stream id = %" PRIu64 + ", channel name = %s, session id = %" PRIu64, + stream->key, stream->chan->name, + stream->chan->session_id); + break; + case CONSUMER_STREAM_OPEN_PACKET_STATUS_NO_SPACE: + /* + * Can't open a packet as there is no space left + * in the buffer. A new packet will be opened + * once one has been consumed. + */ + DBG("No space left to open a packet after a rotation: stream id = %" PRIu64 + ", channel name = %s, session id = %" PRIu64, + stream->key, stream->chan->name, + stream->chan->session_id); + break; + case CONSUMER_STREAM_OPEN_PACKET_STATUS_ERROR: + /* Logged by callee. */ + ret = -1; + goto end_unlock_channel; + default: + abort(); + } } + pthread_mutex_unlock(&channel->lock); ret = 0; goto end; @@ -4204,63 +4354,176 @@ end_unlock_channel: end: rcu_read_unlock(); lttng_dynamic_array_reset(&stream_rotation_positions); + lttng_dynamic_pointer_array_reset(&streams_packet_to_open); return ret; } -/* - * Check if a stream is ready to be rotated after extracting it. - * - * Return 1 if it is ready for rotation, 0 if it is not, a negative value on - * error. Stream lock must be held. - */ -int lttng_consumer_stream_is_rotate_ready(struct lttng_consumer_stream *stream) +static +int consumer_clear_buffer(struct lttng_consumer_stream *stream) { - int ret; - unsigned long consumed_pos; + int ret = 0; + unsigned long consumed_pos_before, consumed_pos_after; - if (!stream->rotate_position && !stream->rotate_ready) { - ret = 0; + ret = lttng_consumer_sample_snapshot_positions(stream); + if (ret < 0) { + ERR("Taking snapshot positions"); goto end; } - if (stream->rotate_ready) { - ret = 1; + ret = lttng_consumer_get_consumed_snapshot(stream, &consumed_pos_before); + if (ret < 0) { + ERR("Consumed snapshot position"); goto end; } - /* - * If we don't have the rotate_ready flag, check the consumed position - * to determine if we need to rotate. - */ + switch (consumer_data.type) { + case LTTNG_CONSUMER_KERNEL: + ret = kernctl_buffer_clear(stream->wait_fd); + if (ret < 0) { + ERR("Failed to clear kernel stream (ret = %d)", ret); + goto end; + } + break; + case LTTNG_CONSUMER32_UST: + case LTTNG_CONSUMER64_UST: + lttng_ustconsumer_clear_buffer(stream); + break; + default: + ERR("Unknown consumer_data type"); + abort(); + } + ret = lttng_consumer_sample_snapshot_positions(stream); if (ret < 0) { ERR("Taking snapshot positions"); goto end; } - - ret = lttng_consumer_get_consumed_snapshot(stream, &consumed_pos); + ret = lttng_consumer_get_consumed_snapshot(stream, &consumed_pos_after); if (ret < 0) { ERR("Consumed snapshot position"); goto end; } + DBG("clear: before: %lu after: %lu", consumed_pos_before, consumed_pos_after); +end: + return ret; +} - /* Rotate position not reached yet (with check for overflow). */ - if ((long) (consumed_pos - stream->rotate_position) < 0) { - ret = 0; - goto end; +static +int consumer_clear_stream(struct lttng_consumer_stream *stream) +{ + int ret; + + ret = consumer_stream_flush_buffer(stream, 1); + if (ret < 0) { + ERR("Failed to flush stream %" PRIu64 " during channel clear", + stream->key); + ret = LTTCOMM_CONSUMERD_FATAL; + goto error; } - ret = 1; -end: + ret = consumer_clear_buffer(stream); + if (ret < 0) { + ERR("Failed to clear stream %" PRIu64 " during channel clear", + stream->key); + ret = LTTCOMM_CONSUMERD_FATAL; + goto error; + } + + ret = LTTCOMM_CONSUMERD_SUCCESS; +error: return ret; } +static +int consumer_clear_unmonitored_channel(struct lttng_consumer_channel *channel) +{ + int ret; + struct lttng_consumer_stream *stream; + + rcu_read_lock(); + pthread_mutex_lock(&channel->lock); + cds_list_for_each_entry(stream, &channel->streams.head, send_node) { + health_code_update(); + pthread_mutex_lock(&stream->lock); + ret = consumer_clear_stream(stream); + if (ret) { + goto error_unlock; + } + pthread_mutex_unlock(&stream->lock); + } + pthread_mutex_unlock(&channel->lock); + rcu_read_unlock(); + return 0; + +error_unlock: + pthread_mutex_unlock(&stream->lock); + pthread_mutex_unlock(&channel->lock); + rcu_read_unlock(); + return ret; +} + +/* + * Check if a stream is ready to be rotated after extracting it. + * + * Return 1 if it is ready for rotation, 0 if it is not, a negative value on + * error. Stream lock must be held. + */ +int lttng_consumer_stream_is_rotate_ready(struct lttng_consumer_stream *stream) +{ + DBG("Check is rotate ready for stream %" PRIu64 + " ready %u rotate_position %" PRIu64 + " last_sequence_number %" PRIu64, + stream->key, stream->rotate_ready, + stream->rotate_position, stream->last_sequence_number); + if (stream->rotate_ready) { + return 1; + } + + /* + * If packet seq num is unavailable, it means we are interacting + * with a pre-2.8 lttng-modules which does not implement the + * sequence number. Rotation should never be used by sessiond in this + * scenario. + */ + if (stream->sequence_number_unavailable) { + ERR("Internal error: rotation used on stream %" PRIu64 + " with unavailable sequence number", + stream->key); + return -1; + } + + if (stream->rotate_position == -1ULL || + stream->last_sequence_number == -1ULL) { + return 0; + } + + /* + * Rotate position not reached yet. The stream rotate position is + * the position of the next packet belonging to the next trace chunk, + * but consumerd considers rotation ready when reaching the last + * packet of the current chunk, hence the "rotate_position - 1". + */ + + DBG("Check is rotate ready for stream %" PRIu64 + " last_sequence_number %" PRIu64 + " rotate_position %" PRIu64, + stream->key, stream->last_sequence_number, + stream->rotate_position); + if (stream->last_sequence_number >= stream->rotate_position - 1) { + return 1; + } + + return 0; +} + /* * Reset the state for a stream after a rotation occurred. */ void lttng_consumer_reset_stream_rotate_state(struct lttng_consumer_stream *stream) { - stream->rotate_position = 0; + DBG("lttng_consumer_reset_stream_rotate_state for stream %" PRIu64, + stream->key); + stream->rotate_position = -1ULL; stream->rotate_ready = false; } @@ -4435,7 +4698,7 @@ enum lttcomm_return_code lttng_consumer_init_command( const lttng_uuid sessiond_uuid) { enum lttcomm_return_code ret; - char uuid_str[UUID_STR_LEN]; + char uuid_str[LTTNG_UUID_STR_LEN]; if (ctx->sessiond_uuid.is_set) { ret = LTTCOMM_CONSUMERD_ALREADY_SET; @@ -4461,7 +4724,7 @@ enum lttcomm_return_code lttng_consumer_create_trace_chunk( { int ret; enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS; - struct lttng_trace_chunk *created_chunk, *published_chunk; + struct lttng_trace_chunk *created_chunk = NULL, *published_chunk = NULL; enum lttng_trace_chunk_status chunk_status; char relayd_id_buffer[MAX_INT_DEC_LEN(*relayd_id)]; char creation_timestamp_buffer[ISO8601_STR_LEN]; @@ -4479,9 +4742,9 @@ enum lttcomm_return_code lttng_consumer_create_trace_chunk( } else { relayd_id_str = "(formatting error)"; } - } + } - /* Local protocol error. */ + /* Local protocol error. */ assert(chunk_creation_timestamp); ret = time_to_iso8601_str(chunk_creation_timestamp, creation_timestamp_buffer, @@ -4512,11 +4775,11 @@ enum lttcomm_return_code lttng_consumer_create_trace_chunk( * and LTTNG_CONSUMER_DESTROY_TRACE_CHUNK commands. */ created_chunk = lttng_trace_chunk_create(chunk_id, - chunk_creation_timestamp); + chunk_creation_timestamp, NULL); if (!created_chunk) { ERR("Failed to create trace chunk"); ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; - goto end; + goto error; } if (chunk_override_name) { @@ -4524,7 +4787,7 @@ enum lttcomm_return_code lttng_consumer_create_trace_chunk( chunk_override_name); if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; - goto end; + goto error; } } @@ -4534,7 +4797,7 @@ enum lttcomm_return_code lttng_consumer_create_trace_chunk( if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { ERR("Failed to set trace chunk credentials"); ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; - goto end; + goto error; } /* * The consumer daemon has no ownership of the chunk output @@ -4542,10 +4805,11 @@ enum lttcomm_return_code lttng_consumer_create_trace_chunk( */ chunk_status = lttng_trace_chunk_set_as_user(created_chunk, chunk_directory_handle); + chunk_directory_handle = NULL; if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { ERR("Failed to set trace chunk's directory handle"); ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; - goto end; + goto error; } } @@ -4557,7 +4821,7 @@ enum lttcomm_return_code lttng_consumer_create_trace_chunk( if (!published_chunk) { ERR("Failed to publish trace chunk"); ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; - goto end; + goto error; } rcu_read_lock(); @@ -4626,14 +4890,15 @@ enum lttcomm_return_code lttng_consumer_create_trace_chunk( } ret_code = LTTCOMM_CONSUMERD_CREATE_TRACE_CHUNK_FAILED; - goto error; + goto error_unlock; } } -error: +error_unlock: rcu_read_unlock(); +error: /* Release the reference returned by the "publish" operation. */ lttng_trace_chunk_put(published_chunk); -end: + lttng_trace_chunk_put(created_chunk); return ret_code; } @@ -4771,16 +5036,13 @@ enum lttcomm_return_code lttng_consumer_trace_chunk_exists( { int ret; enum lttcomm_return_code ret_code; - struct lttng_trace_chunk *chunk; char relayd_id_buffer[MAX_INT_DEC_LEN(*relayd_id)]; const char *relayd_id_str = "(none)"; const bool is_local_trace = !relayd_id; struct consumer_relayd_sock_pair *relayd = NULL; - bool chunk_exists_remote; + bool chunk_exists_local, chunk_exists_remote; if (relayd_id) { - int ret; - /* Only used for logging purposes. */ ret = snprintf(relayd_id_buffer, sizeof(relayd_id_buffer), "%" PRIu64, *relayd_id); @@ -4789,18 +5051,24 @@ enum lttcomm_return_code lttng_consumer_trace_chunk_exists( } else { relayd_id_str = "(formatting error)"; } - } + } DBG("Consumer trace chunk exists command: relayd_id = %s" ", chunk_id = %" PRIu64, relayd_id_str, chunk_id); - chunk = lttng_trace_chunk_registry_find_chunk( + ret = lttng_trace_chunk_registry_chunk_exists( consumer_data.chunk_registry, session_id, - chunk_id); - DBG("Trace chunk %s locally", chunk ? "exists" : "does not exist"); - if (chunk) { + chunk_id, &chunk_exists_local); + if (ret) { + /* Internal error. */ + ERR("Failed to query the existence of a trace chunk"); + ret_code = LTTCOMM_CONSUMERD_FATAL; + goto end; + } + DBG("Trace chunk %s locally", + chunk_exists_local ? "exists" : "does not exist"); + if (chunk_exists_local) { ret_code = LTTCOMM_CONSUMERD_TRACE_CHUNK_EXISTS_LOCAL; - lttng_trace_chunk_put(chunk); goto end; } else if (is_local_trace) { ret_code = LTTCOMM_CONSUMERD_UNKNOWN_TRACE_CHUNK; @@ -4836,3 +5104,134 @@ end_rcu_unlock: end: return ret_code; } + +static +int consumer_clear_monitored_channel(struct lttng_consumer_channel *channel) +{ + struct lttng_ht *ht; + struct lttng_consumer_stream *stream; + struct lttng_ht_iter iter; + int ret; + + ht = consumer_data.stream_per_chan_id_ht; + + rcu_read_lock(); + cds_lfht_for_each_entry_duplicate(ht->ht, + ht->hash_fct(&channel->key, lttng_ht_seed), + ht->match_fct, &channel->key, + &iter.iter, stream, node_channel_id.node) { + /* + * Protect against teardown with mutex. + */ + pthread_mutex_lock(&stream->lock); + if (cds_lfht_is_node_deleted(&stream->node.node)) { + goto next; + } + ret = consumer_clear_stream(stream); + if (ret) { + goto error_unlock; + } + next: + pthread_mutex_unlock(&stream->lock); + } + rcu_read_unlock(); + return LTTCOMM_CONSUMERD_SUCCESS; + +error_unlock: + pthread_mutex_unlock(&stream->lock); + rcu_read_unlock(); + return ret; +} + +int lttng_consumer_clear_channel(struct lttng_consumer_channel *channel) +{ + int ret; + + DBG("Consumer clear channel %" PRIu64, channel->key); + + if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) { + /* + * Nothing to do for the metadata channel/stream. + * Snapshot mechanism already take care of the metadata + * handling/generation, and monitored channels only need to + * have their data stream cleared.. + */ + ret = LTTCOMM_CONSUMERD_SUCCESS; + goto end; + } + + if (!channel->monitor) { + ret = consumer_clear_unmonitored_channel(channel); + } else { + ret = consumer_clear_monitored_channel(channel); + } +end: + return ret; +} + +enum lttcomm_return_code lttng_consumer_open_channel_packets( + struct lttng_consumer_channel *channel) +{ + struct lttng_consumer_stream *stream; + enum lttcomm_return_code ret = LTTCOMM_CONSUMERD_SUCCESS; + + if (channel->metadata_stream) { + ERR("Open channel packets command attempted on a metadata channel"); + ret = LTTCOMM_CONSUMERD_INVALID_PARAMETERS; + goto end; + } + + rcu_read_lock(); + cds_list_for_each_entry(stream, &channel->streams.head, send_node) { + enum consumer_stream_open_packet_status status; + + pthread_mutex_lock(&stream->lock); + if (cds_lfht_is_node_deleted(&stream->node.node)) { + goto next; + } + + status = consumer_stream_open_packet(stream); + switch (status) { + case CONSUMER_STREAM_OPEN_PACKET_STATUS_OPENED: + DBG("Opened a packet in \"open channel packets\" command: stream id = %" PRIu64 + ", channel name = %s, session id = %" PRIu64, + stream->key, stream->chan->name, + stream->chan->session_id); + stream->opened_packet_in_current_trace_chunk = true; + break; + case CONSUMER_STREAM_OPEN_PACKET_STATUS_NO_SPACE: + DBG("No space left to open a packet in \"open channel packets\" command: stream id = %" PRIu64 + ", channel name = %s, session id = %" PRIu64, + stream->key, stream->chan->name, + stream->chan->session_id); + break; + case CONSUMER_STREAM_OPEN_PACKET_STATUS_ERROR: + /* + * Only unexpected internal errors can lead to this + * failing. Report an unknown error. + */ + ERR("Failed to flush empty buffer in \"open channel packets\" command: stream id = %" PRIu64 + ", channel id = %" PRIu64 + ", channel name = %s" + ", session id = %" PRIu64, + stream->key, channel->key, + channel->name, channel->session_id); + ret = LTTCOMM_CONSUMERD_UNKNOWN_ERROR; + goto error_unlock; + default: + abort(); + } + + next: + pthread_mutex_unlock(&stream->lock); + } + +end_rcu_unlock: + rcu_read_unlock(); +end: + return ret; + +error_unlock: + pthread_mutex_unlock(&stream->lock); + goto end_rcu_unlock; +}