From 157df58664846e22bdeea84dfcf717cb43360b3f Mon Sep 17 00:00:00 2001 From: Julien Desfossez Date: Thu, 12 Dec 2013 16:37:03 -0500 Subject: [PATCH] Fix: clear the CTF traces when all the streams are closed Signed-off-by: Julien Desfossez Signed-off-by: David Goulet --- src/bin/lttng-relayd/ctf-trace.h | 1 + src/bin/lttng-relayd/live.c | 151 ++++++++++++++++++++----------- src/bin/lttng-relayd/main.c | 7 +- 3 files changed, 106 insertions(+), 53 deletions(-) diff --git a/src/bin/lttng-relayd/ctf-trace.h b/src/bin/lttng-relayd/ctf-trace.h index 6e39af02b..66f7a1568 100644 --- a/src/bin/lttng-relayd/ctf-trace.h +++ b/src/bin/lttng-relayd/ctf-trace.h @@ -31,6 +31,7 @@ struct ctf_trace { uint64_t metadata_received; uint64_t metadata_sent; struct relay_stream *metadata_stream; + struct relay_viewer_stream *viewer_metadata_stream; }; void ctf_trace_assign(struct lttng_ht *ht, struct relay_stream *stream); diff --git a/src/bin/lttng-relayd/live.c b/src/bin/lttng-relayd/live.c index c1f0ff050..c312e78e9 100644 --- a/src/bin/lttng-relayd/live.c +++ b/src/bin/lttng-relayd/live.c @@ -707,11 +707,11 @@ int init_viewer_stream(struct relay_stream *stream, int seek_last) stream->oldest_tracefile_id; } - /* - * The deletion of this ctf_trace object is only done in a call RCU of the - * relay stream making it valid as long as we have the read side lock. - */ viewer_stream->ctf_trace = stream->ctf_trace; + if (viewer_stream->metadata_flag) { + viewer_stream->ctf_trace->viewer_metadata_stream = + viewer_stream; + } uatomic_inc(&viewer_stream->ctf_trace->refcount); lttng_ht_node_init_u64(&viewer_stream->stream_n, stream->stream_handle); @@ -992,10 +992,10 @@ send_reply: health_code_update(); /* - * Unknown or busy session, just return gracefully, the viewer knows what + * Unknown or empty session, just return gracefully, the viewer knows what * is happening. */ - if (!send_streams) { + if (!send_streams || !nb_streams) { ret = 0; goto end_unlock; } @@ -1063,6 +1063,72 @@ end: return stream; } +static +void deferred_free_viewer_stream(struct rcu_head *head) +{ + struct relay_viewer_stream *stream = + caa_container_of(head, struct relay_viewer_stream, rcu_node); + + free(stream->path_name); + free(stream->channel_name); + free(stream); +} + +static +void delete_viewer_stream(struct relay_viewer_stream *vstream) +{ + int delret; + struct lttng_ht_iter iter; + + iter.iter.node = &vstream->stream_n.node; + delret = lttng_ht_del(viewer_streams_ht, &iter); + assert(!delret); +} + +static +void destroy_viewer_stream(struct relay_viewer_stream *vstream) +{ + unsigned long ret_ref; + int ret; + + assert(vstream); + ret_ref = uatomic_add_return(&vstream->ctf_trace->refcount, -1); + assert(ret_ref >= 0); + + if (vstream->read_fd >= 0) { + ret = close(vstream->read_fd); + if (ret < 0) { + PERROR("close read_fd"); + } + } + if (vstream->index_read_fd >= 0) { + ret = close(vstream->index_read_fd); + if (ret < 0) { + PERROR("close index_read_fd"); + } + } + + /* + * If the only stream left in the HT is the metadata stream, + * we need to remove it because we won't detect a EOF for this + * stream. + */ + if (ret_ref == 1 && vstream->ctf_trace->metadata_stream) { + destroy_viewer_stream(vstream->ctf_trace->viewer_metadata_stream); + vstream->ctf_trace->metadata_stream = NULL; + DBG("Freeing ctf_trace %" PRIu64, vstream->ctf_trace->id); + /* + * The streaming-side is already closed and we can't receive a new + * stream concurrently at this point (since the session is being + * destroyed), so when we detect the refcount equals 0, we are the + * only owners of the ctf_trace and we can free it ourself. + */ + free(vstream->ctf_trace); + } + + call_rcu(&vstream->rcu_node, deferred_free_viewer_stream); +} + /* * Send the next index for a stream. * @@ -1143,6 +1209,8 @@ int viewer_get_next_index(struct relay_command *cmd, goto end_unlock; } else if (ret == 1) { viewer_index.status = htobe32(VIEWER_INDEX_HUP); + delete_viewer_stream(vstream); + destroy_viewer_stream(vstream); goto send_reply; } } @@ -1172,6 +1240,8 @@ int viewer_get_next_index(struct relay_command *cmd, vstream->total_index_received == vstream->last_sent_index) { /* Last index sent and current tracefile closed in write */ viewer_index.status = htobe32(VIEWER_INDEX_HUP); + delete_viewer_stream(vstream); + destroy_viewer_stream(vstream); goto send_reply; } else { vstream->close_write_flag = 1; @@ -1196,6 +1266,8 @@ int viewer_get_next_index(struct relay_command *cmd, goto end_unlock; } else if (ret == 1) { viewer_index.status = htobe32(VIEWER_INDEX_HUP); + delete_viewer_stream(vstream); + destroy_viewer_stream(vstream); goto send_reply; } goto send_reply; @@ -1215,6 +1287,8 @@ int viewer_get_next_index(struct relay_command *cmd, goto end_unlock; } else if (ret == 1) { viewer_index.status = htobe32(VIEWER_INDEX_HUP); + delete_viewer_stream(vstream); + destroy_viewer_stream(vstream); goto send_reply; } } else { @@ -1664,66 +1738,38 @@ void deferred_free_connection(struct rcu_head *head) free(relay_connection); } -static -void deferred_free_viewer_stream(struct rcu_head *head) -{ - struct relay_viewer_stream *stream = - caa_container_of(head, struct relay_viewer_stream, rcu_node); - - if (stream->ctf_trace) { - uatomic_dec(&stream->ctf_trace->refcount); - assert(uatomic_read(&stream->ctf_trace->refcount) >= 0); - if (uatomic_read(&stream->ctf_trace->refcount) == 0) { - DBG("Freeing ctf_trace %" PRIu64, stream->ctf_trace->id); - free(stream->ctf_trace); - } - } - - free(stream->path_name); - free(stream->channel_name); - free(stream); -} - +/* + * Delete all streams for a specific session ID. + */ static void viewer_del_streams(uint64_t session_id) { - int ret; struct relay_viewer_stream *stream; - struct lttng_ht_node_u64 *node; struct lttng_ht_iter iter; rcu_read_lock(); - cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, node, node) { + cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, stream, + stream_n.node) { health_code_update(); - node = lttng_ht_iter_get_node_u64(&iter); - if (!node) { - continue; - } - - stream = caa_container_of(node, struct relay_viewer_stream, stream_n); if (stream->session_id != session_id) { continue; } - if (stream->read_fd >= 0) { - ret = close(stream->read_fd); - if (ret < 0) { - PERROR("close read_fd"); - } - } - if (stream->index_read_fd >= 0) { - ret = close(stream->index_read_fd); - if (ret < 0) { - PERROR("close index_read_fd"); - } - } - if (stream->metadata_flag && stream->ctf_trace) { + delete_viewer_stream(stream); + assert(stream->ctf_trace); + + if (stream->metadata_flag) { + /* + * The metadata viewer stream is destroyed once the refcount on the + * ctf trace goes to 0 in the destroy stream function thus there is + * no explicit call to that function here. + */ stream->ctf_trace->metadata_sent = 0; + stream->ctf_trace->viewer_metadata_stream = NULL; + } else { + destroy_viewer_stream(stream); } - ret = lttng_ht_del(viewer_streams_ht, &iter); - assert(!ret); - call_rcu(&stream->rcu_node, deferred_free_viewer_stream); } rcu_read_unlock(); } @@ -1743,6 +1789,9 @@ void del_connection(struct lttng_ht *relay_connections_ht, assert(iter); assert(relay_connection); + DBG("Cleaning connection of session ID %" PRIu64, + relay_connection->session_id); + ret = lttng_ht_del(relay_connections_ht, iter); assert(!ret); diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c index b8e2f72e6..a6b408a90 100644 --- a/src/bin/lttng-relayd/main.c +++ b/src/bin/lttng-relayd/main.c @@ -800,8 +800,6 @@ void deferred_free_stream(struct rcu_head *head) struct relay_stream *stream = caa_container_of(head, struct relay_stream, rcu_node); - ctf_trace_try_destroy(stream->ctf_trace); - free(stream->path_name); free(stream->channel_name); free(stream); @@ -865,6 +863,11 @@ static void destroy_stream(struct relay_stream *stream) iter.iter.node = &stream->ctf_trace_node.node; delret = lttng_ht_del(stream->ctf_traces_ht, &iter); assert(!delret); + + if (stream->ctf_trace) { + ctf_trace_try_destroy(stream->ctf_trace); + } + call_rcu(&stream->rcu_node, deferred_free_stream); DBG("Closed tracefile %d from close stream", stream->fd); } -- 2.34.1