X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Fstream.c;h=335a1cf5f79de497f3002beb3ae0a2a983da355f;hp=fff8065b0da3d269eee76a11b73115f36602effe;hb=ce3f3ba3aee62c0a317b448c2f19578ab7f057e4;hpb=2a174661a1e0ab551b41ff1cae7191688525fc1f

diff --git a/src/bin/lttng-relayd/stream.c b/src/bin/lttng-relayd/stream.c
index fff8065b0..335a1cf5f 100644
--- a/src/bin/lttng-relayd/stream.c
+++ b/src/bin/lttng-relayd/stream.c
@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
  *                      David Goulet <dgoulet@efficios.com>
+ *               2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * 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
@@ -16,138 +17,454 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <common/common.h>
+#include <common/utils.h>
+#include <common/defaults.h>
+#include <urcu/rculist.h>
+#include <sys/stat.h>
 
+#include "lttng-relayd.h"
 #include "index.h"
 #include "stream.h"
 #include "viewer-stream.h"
 
-static void rcu_destroy_stream(struct rcu_head *head)
+/* Should be called with RCU read-side lock held. */
+bool stream_get(struct relay_stream *stream)
 {
-	struct relay_stream *stream =
-		caa_container_of(head, struct relay_stream, rcu_node);
+	bool has_ref = false;
 
-	free(stream->path_name);
-	free(stream->channel_name);
-	free(stream);
+	pthread_mutex_lock(&stream->reflock);
+	if (stream->ref.refcount != 0) {
+		has_ref = true;
+		urcu_ref_get(&stream->ref);
+	}
+	pthread_mutex_unlock(&stream->reflock);
+
+	return has_ref;
 }
 
 /*
- * Get stream from stream id from the given hash table. Return stream if found
- * else NULL.
- *
- * Need to be called with RCU read-side lock held.
+ * Get stream from stream id from the streams hash table. Return stream
+ * if found else NULL. A stream reference is taken when a stream is
+ * returned. stream_put() must be called on that stream.
  */
-struct relay_stream *stream_find_by_id(struct lttng_ht *ht,
-		uint64_t stream_id)
+struct relay_stream *stream_get_by_id(uint64_t stream_id)
 {
 	struct lttng_ht_node_u64 *node;
 	struct lttng_ht_iter iter;
 	struct relay_stream *stream = NULL;
 
-	assert(ht);
-
-	lttng_ht_lookup(ht, &stream_id, &iter);
+	rcu_read_lock();
+	lttng_ht_lookup(relay_streams_ht, &stream_id, &iter);
 	node = lttng_ht_iter_get_node_u64(&iter);
-	if (node == NULL) {
+	if (!node) {
 		DBG("Relay stream %" PRIu64 " not found", stream_id);
 		goto end;
 	}
 	stream = caa_container_of(node, struct relay_stream, node);
-
+	if (!stream_get(stream)) {
+		stream = NULL;
+	}
 end:
+	rcu_read_unlock();
 	return stream;
 }
 
 /*
- * Close a given stream. If an assosiated viewer stream exists it is updated.
- *
- * RCU read side lock MUST be acquired.
- *
- * Return 0 if close was successful or 1 if already closed.
+ * We keep ownership of path_name and channel_name.
  */
-int stream_close(struct relay_session *session, struct relay_stream *stream)
+struct relay_stream *stream_create(struct ctf_trace *trace,
+	uint64_t stream_handle, char *path_name,
+	char *channel_name, uint64_t tracefile_size,
+	uint64_t tracefile_count)
 {
-	int delret, ret;
-	struct relay_viewer_stream *vstream;
-	struct ctf_trace *ctf_trace;
+	int ret;
+	struct relay_stream *stream = NULL;
+	struct relay_session *session = trace->session;
 
-	assert(stream);
+	stream = zmalloc(sizeof(struct relay_stream));
+	if (stream == NULL) {
+		PERROR("relay stream zmalloc");
+		ret = -1;
+		goto error_no_alloc;
+	}
 
-	pthread_mutex_lock(&stream->lock);
+	stream->stream_handle = stream_handle;
+	stream->prev_seq = -1ULL;
+	stream->last_net_seq_num = -1ULL;
+	stream->ctf_stream_id = -1ULL;
+	stream->tracefile_size = tracefile_size;
+	stream->tracefile_count = tracefile_count;
+	stream->path_name = path_name;
+	stream->channel_name = channel_name;
+	lttng_ht_node_init_u64(&stream->node, stream->stream_handle);
+	pthread_mutex_init(&stream->lock, NULL);
+	pthread_mutex_init(&stream->reflock, NULL);
+	urcu_ref_init(&stream->ref);
+	ctf_trace_get(trace);
+	stream->trace = trace;
 
-	if (stream->terminated_flag) {
-		/* This stream is already closed. Ignore. */
-		ret = 1;
-		goto end_unlock;
+	stream->indexes_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
+	if (!stream->indexes_ht) {
+		ERR("Cannot created indexes_ht");
+		ret = -1;
+		goto end;
 	}
 
-	DBG("Closing stream id %" PRIu64, stream->stream_handle);
+	ret = utils_mkdir_recursive(stream->path_name, S_IRWXU | S_IRWXG,
+			-1, -1);
+	if (ret < 0) {
+		ERR("relay creating output directory");
+		goto end;
+	}
 
-	if (stream->fd >= 0) {
-		delret = close(stream->fd);
-		if (delret < 0) {
-			PERROR("close stream");
+	/*
+	 * No need to use run_as API here because whatever we receive,
+	 * the relayd uses its own credentials for the stream files.
+	 */
+	ret = utils_create_stream_file(stream->path_name, stream->channel_name,
+			stream->tracefile_size, 0, -1, -1, NULL);
+	if (ret < 0) {
+		ERR("Create output file");
+		goto end;
+	}
+	stream->stream_fd = stream_fd_create(ret);
+	if (!stream->stream_fd) {
+		if (close(ret)) {
+			PERROR("Error closing file %d", ret);
 		}
+		ret = -1;
+		goto end;
+	}
+	stream->tfa = tracefile_array_create(stream->tracefile_count);
+	if (!stream->tfa) {
+		ret = -1;
+		goto end;
+	}
+	if (stream->tracefile_size) {
+		DBG("Tracefile %s/%s_0 created", stream->path_name, stream->channel_name);
+	} else {
+		DBG("Tracefile %s/%s created", stream->path_name, stream->channel_name);
 	}
 
-	if (stream->index_fd >= 0) {
-		delret = close(stream->index_fd);
-		if (delret < 0) {
-			PERROR("close stream index_fd");
+	if (!strncmp(stream->channel_name, DEFAULT_METADATA_NAME, LTTNG_NAME_MAX)) {
+		stream->is_metadata = 1;
+	}
+
+	stream->in_recv_list = true;
+
+	/*
+	 * Add the stream in the recv list of the session. Once the end stream
+	 * message is received, all session streams are published.
+	 */
+	pthread_mutex_lock(&session->recv_list_lock);
+	cds_list_add_rcu(&stream->recv_node, &session->recv_list);
+	session->stream_count++;
+	pthread_mutex_unlock(&session->recv_list_lock);
+
+	/*
+	 * Both in the ctf_trace object and the global stream ht since the data
+	 * side of the relayd does not have the concept of session.
+	 */
+	lttng_ht_add_unique_u64(relay_streams_ht, &stream->node);
+	stream->in_stream_ht = true;
+
+	DBG("Relay new stream added %s with ID %" PRIu64, stream->channel_name,
+			stream->stream_handle);
+	ret = 0;
+
+end:
+	if (ret) {
+		if (stream->stream_fd) {
+			stream_fd_put(stream->stream_fd);
+			stream->stream_fd = NULL;
 		}
+		stream_put(stream);
+		stream = NULL;
+	}
+	return stream;
+
+error_no_alloc:
+	/*
+	 * path_name and channel_name need to be freed explicitly here
+	 * because we cannot rely on stream_put().
+	 */
+	free(path_name);
+	free(channel_name);
+	return NULL;
+}
+
+/*
+ * Called with the session lock held.
+ */
+void stream_publish(struct relay_stream *stream)
+{
+	struct relay_session *session;
+
+	pthread_mutex_lock(&stream->lock);
+	if (stream->published) {
+		goto unlock;
+	}
+
+	session = stream->trace->session;
+
+	pthread_mutex_lock(&session->recv_list_lock);
+	if (stream->in_recv_list) {
+		cds_list_del_rcu(&stream->recv_node);
+		stream->in_recv_list = false;
+	}
+	pthread_mutex_unlock(&session->recv_list_lock);
+
+	pthread_mutex_lock(&stream->trace->stream_list_lock);
+	cds_list_add_rcu(&stream->stream_node, &stream->trace->stream_list);
+	pthread_mutex_unlock(&stream->trace->stream_list_lock);
+
+	stream->published = true;
+unlock:
+	pthread_mutex_unlock(&stream->lock);
+}
+
+/*
+ * Stream must be protected by holding the stream lock or by virtue of being
+ * called from stream_destroy, in which case it is guaranteed to be accessed
+ * from a single thread by the reflock.
+ */
+static void stream_unpublish(struct relay_stream *stream)
+{
+	if (stream->in_stream_ht) {
+		struct lttng_ht_iter iter;
+		int ret;
+
+		iter.iter.node = &stream->node.node;
+		ret = lttng_ht_del(relay_streams_ht, &iter);
+		assert(!ret);
+		stream->in_stream_ht = false;
+	}
+	if (stream->published) {
+		pthread_mutex_lock(&stream->trace->stream_list_lock);
+		cds_list_del_rcu(&stream->stream_node);
+		pthread_mutex_unlock(&stream->trace->stream_list_lock);
+		stream->published = false;
 	}
+}
 
-	vstream = viewer_stream_find_by_id(stream->stream_handle);
-	if (vstream) {
+static void stream_destroy(struct relay_stream *stream)
+{
+	if (stream->indexes_ht) {
 		/*
-		 * Set the last good value into the viewer stream. This is done
-		 * right before the stream gets deleted from the hash table. The
-		 * lookup failure on the live thread side of a stream indicates
-		 * that the viewer stream index received value should be used.
+		 * Calling lttng_ht_destroy in call_rcu worker thread so
+		 * we don't hold the RCU read-side lock while calling
+		 * it.
 		 */
-		pthread_mutex_lock(&stream->viewer_stream_rotation_lock);
-		vstream->total_index_received = stream->total_index_received;
-		vstream->tracefile_count_last = stream->tracefile_count_current;
-		vstream->close_write_flag = 1;
-		pthread_mutex_unlock(&stream->viewer_stream_rotation_lock);
+		lttng_ht_destroy(stream->indexes_ht);
 	}
+	if (stream->tfa) {
+		tracefile_array_destroy(stream->tfa);
+	}
+	free(stream->path_name);
+	free(stream->channel_name);
+	free(stream);
+}
 
-	/* Cleanup index of that stream. */
-	relay_index_destroy_by_stream_id(stream->stream_handle);
+static void stream_destroy_rcu(struct rcu_head *rcu_head)
+{
+	struct relay_stream *stream =
+		caa_container_of(rcu_head, struct relay_stream, rcu_node);
 
-	ctf_trace = ctf_trace_find_by_path(session->ctf_traces_ht,
-			stream->path_name);
-	assert(ctf_trace);
-	ctf_trace_put_ref(ctf_trace);
+	stream_destroy(stream);
+}
 
-	stream->terminated_flag = 1;
-	ret = 0;
+/*
+ * No need to take stream->lock since this is only called on the final
+ * stream_put which ensures that a single thread may act on the stream.
+ *
+ * At that point, the object is also protected by the reflock which
+ * guarantees that no other thread may share ownership of this stream.
+ */
+static void stream_release(struct urcu_ref *ref)
+{
+	struct relay_stream *stream =
+		caa_container_of(ref, struct relay_stream, ref);
+	struct relay_session *session;
 
-end_unlock:
-	pthread_mutex_unlock(&stream->lock);
-	return ret;
+	session = stream->trace->session;
+
+	DBG("Releasing stream id %" PRIu64, stream->stream_handle);
+
+	pthread_mutex_lock(&session->recv_list_lock);
+	session->stream_count--;
+	if (stream->in_recv_list) {
+		cds_list_del_rcu(&stream->recv_node);
+		stream->in_recv_list = false;
+	}
+	pthread_mutex_unlock(&session->recv_list_lock);
+
+	stream_unpublish(stream);
+
+	if (stream->stream_fd) {
+		stream_fd_put(stream->stream_fd);
+		stream->stream_fd = NULL;
+	}
+	if (stream->index_fd) {
+		stream_fd_put(stream->index_fd);
+		stream->index_fd = NULL;
+	}
+	if (stream->trace) {
+		ctf_trace_put(stream->trace);
+		stream->trace = NULL;
+	}
+
+	call_rcu(&stream->rcu_node, stream_destroy_rcu);
 }
 
-void stream_delete(struct lttng_ht *ht, struct relay_stream *stream)
+void stream_put(struct relay_stream *stream)
 {
-	int ret;
-	struct lttng_ht_iter iter;
+	DBG("stream put for stream id %" PRIu64, stream->stream_handle);
+	/*
+	 * Ensure existence of stream->reflock for stream unlock.
+	 */
+	rcu_read_lock();
+	/*
+	 * Stream reflock ensures that concurrent test and update of
+	 * stream ref is atomic.
+	 */
+	pthread_mutex_lock(&stream->reflock);
+	assert(stream->ref.refcount != 0);
+	/*
+	 * Wait until we have processed all the stream packets before
+	 * actually putting our last stream reference.
+	 */
+	DBG("stream put stream id %" PRIu64 " refcount %d",
+			stream->stream_handle,
+			(int) stream->ref.refcount);
+	urcu_ref_put(&stream->ref, stream_release);
+	pthread_mutex_unlock(&stream->reflock);
+	rcu_read_unlock();
+}
+
+void try_stream_close(struct relay_stream *stream)
+{
+	DBG("Trying to close stream %" PRIu64, stream->stream_handle);
+	pthread_mutex_lock(&stream->lock);
+	/*
+	 * Can be called concurently by connection close and reception of last
+	 * pending data.
+	 */
+	if (stream->closed) {
+		pthread_mutex_unlock(&stream->lock);
+		DBG("closing stream %" PRIu64 " aborted since it is already marked as closed", stream->stream_handle);
+		return;
+	}
 
-	assert(ht);
-	assert(stream);
+	stream->close_requested = true;
 
-	iter.iter.node = &stream->node.node;
-	ret = lttng_ht_del(ht, &iter);
-	assert(!ret);
+	if (stream->last_net_seq_num == -1ULL) {
+		/*
+		 * Handle connection close without explicit stream close
+		 * command.
+		 *
+		 * We can be clever about indexes partially received in
+		 * cases where we received the data socket part, but not
+		 * the control socket part: since we're currently closing
+		 * the stream on behalf of the control socket, we *know*
+		 * there won't be any more control information for this
+		 * socket. Therefore, we can destroy all indexes for
+		 * which we have received only the file descriptor (from
+		 * data socket). This takes care of consumerd crashes
+		 * between sending the data and control information for
+		 * a packet. Since those are sent in that order, we take
+		 * care of consumerd crashes.
+		 */
+		relay_index_close_partial_fd(stream);
+		/*
+		 * Use the highest net_seq_num we currently have pending
+		 * As end of stream indicator.  Leave last_net_seq_num
+		 * at -1ULL if we cannot find any index.
+		 */
+		stream->last_net_seq_num = relay_index_find_last(stream);
+		/* Fall-through into the next check. */
+	}
 
-	cds_list_del(&stream->trace_list);
+	if (stream->last_net_seq_num != -1ULL &&
+			((int64_t) (stream->prev_seq - stream->last_net_seq_num)) < 0) {
+		/*
+		 * Don't close since we still have data pending. This
+		 * handles cases where an explicit close command has
+		 * been received for this stream, and cases where the
+		 * connection has been closed, and we are awaiting for
+		 * index information from the data socket. It is
+		 * therefore expected that all the index fd information
+		 * we need has already been received on the control
+		 * socket. Matching index information from data socket
+		 * should be Expected Soon(TM).
+		 *
+		 * TODO: We should implement a timer to garbage collect
+		 * streams after a timeout to be resilient against a
+		 * consumerd implementation that would not match this
+		 * expected behavior.
+		 */
+		pthread_mutex_unlock(&stream->lock);
+		DBG("closing stream %" PRIu64 " aborted since it still has data pending", stream->stream_handle);
+		return;
+	}
+	/*
+	 * We received all the indexes we can expect.
+	 */
+	stream_unpublish(stream);
+	stream->closed = true;
+	/* Relay indexes are only used by the "consumer/sessiond" end. */
+	relay_index_close_all(stream);
+	pthread_mutex_unlock(&stream->lock);
+	DBG("Succeeded in closing stream %" PRIu64, stream->stream_handle);
+	stream_put(stream);
 }
 
-void stream_destroy(struct relay_stream *stream)
+static void print_stream_indexes(struct relay_stream *stream)
 {
-	assert(stream);
+	struct lttng_ht_iter iter;
+	struct relay_index *index;
 
-	call_rcu(&stream->rcu_node, rcu_destroy_stream);
+	rcu_read_lock();
+	cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter, index,
+			index_n.node) {
+		DBG("index %p net_seq_num %" PRIu64 " refcount %ld"
+				" stream %" PRIu64 " trace %" PRIu64
+				" session %" PRIu64,
+				index,
+				index->index_n.key,
+				stream->ref.refcount,
+				index->stream->stream_handle,
+				index->stream->trace->id,
+				index->stream->trace->session->id);
+	}
+	rcu_read_unlock();
+}
+
+void print_relay_streams(void)
+{
+	struct lttng_ht_iter iter;
+	struct relay_stream *stream;
+
+	if (!relay_streams_ht) {
+		return;
+	}
+
+	rcu_read_lock();
+	cds_lfht_for_each_entry(relay_streams_ht->ht, &iter.iter, stream,
+			node.node) {
+		if (!stream_get(stream)) {
+			continue;
+		}
+		DBG("stream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
+				" session %" PRIu64,
+				stream,
+				stream->ref.refcount,
+				stream->stream_handle,
+				stream->trace->id,
+				stream->trace->session->id);
+		print_stream_indexes(stream);
+		stream_put(stream);
+	}
+	rcu_read_unlock();
 }