X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Fviewer-stream.c;h=7c59cd05d88ea3797569e87d8d964d67aa61e562;hp=5ab7be790de867f42676f8c6c84bd2e86bfb7083;hb=ce3f3ba3aee62c0a317b448c2f19578ab7f057e4;hpb=56611b069e7d0a64148cd990f88b4090298a9a0f

diff --git a/src/bin/lttng-relayd/viewer-stream.c b/src/bin/lttng-relayd/viewer-stream.c
index 5ab7be790..7c59cd05d 100644
--- a/src/bin/lttng-relayd/viewer-stream.c
+++ b/src/bin/lttng-relayd/viewer-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
@@ -16,259 +17,345 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <common/common.h>
 #include <common/index/index.h>
+#include <common/compat/string.h>
 
 #include "lttng-relayd.h"
 #include "viewer-stream.h"
 
-static void free_stream(struct relay_viewer_stream *stream)
+static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
 {
-	assert(stream);
-
-	free(stream->path_name);
-	free(stream->channel_name);
-	free(stream);
+	free(vstream->path_name);
+	free(vstream->channel_name);
+	free(vstream);
 }
 
-static void deferred_free_viewer_stream(struct rcu_head *head)
+static void viewer_stream_destroy_rcu(struct rcu_head *head)
 {
-	struct relay_viewer_stream *stream =
+	struct relay_viewer_stream *vstream =
 		caa_container_of(head, struct relay_viewer_stream, rcu_node);
 
-	free_stream(stream);
+	viewer_stream_destroy(vstream);
 }
 
 struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
-		enum lttng_viewer_seek seek_t, struct ctf_trace *ctf_trace)
+		enum lttng_viewer_seek seek_t)
 {
 	struct relay_viewer_stream *vstream;
 
-	assert(stream);
-	assert(ctf_trace);
-
 	vstream = zmalloc(sizeof(*vstream));
 	if (!vstream) {
 		PERROR("relay viewer stream zmalloc");
 		goto error;
 	}
 
-	vstream->session_id = stream->session_id;
-	vstream->stream_handle = stream->stream_handle;
-	vstream->path_name = strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
-	vstream->channel_name = strndup(stream->channel_name,
+	vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
+	if (vstream->path_name == NULL) {
+		PERROR("relay viewer path_name alloc");
+		goto error;
+	}
+	vstream->channel_name = lttng_strndup(stream->channel_name,
 			LTTNG_VIEWER_NAME_MAX);
-	vstream->tracefile_count = stream->tracefile_count;
-	vstream->metadata_flag = stream->metadata_flag;
-	vstream->tracefile_count_last = -1ULL;
+	if (vstream->channel_name == NULL) {
+		PERROR("relay viewer channel_name alloc");
+		goto error;
+	}
+
+	if (!stream_get(stream)) {
+		ERR("Cannot get stream");
+		goto error;
+	}
+	vstream->stream = stream;
+
+	pthread_mutex_lock(&stream->lock);
+
+	if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
+		ERR("Cannot attach viewer metadata stream to trace (busy).");
+		goto error_unlock;
+	}
 
 	switch (seek_t) {
 	case LTTNG_VIEWER_SEEK_BEGINNING:
-		vstream->tracefile_count_current = stream->oldest_tracefile_id;
+	{
+		uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
+
+		if (seq_tail == -1ULL) {
+			/*
+			 * Tail may not be initialized yet. Nonetheless, we know
+			 * we want to send the first index once it becomes
+			 * available.
+			 */
+			seq_tail = 0;
+		}
+		vstream->current_tracefile_id =
+			tracefile_array_get_file_index_tail(stream->tfa);
+		vstream->index_sent_seqcount = seq_tail;
 		break;
+	}
 	case LTTNG_VIEWER_SEEK_LAST:
-		vstream->tracefile_count_current = stream->tracefile_count_current;
+		vstream->current_tracefile_id =
+			tracefile_array_get_file_index_head(stream->tfa);
+		/*
+		 * We seek at the very end of each stream, awaiting for
+		 * a future packet to eventually come in.
+		 *
+		 * We don't need to check the head position for -1ULL since the
+		 * increment will set it to 0.
+		 */
+		vstream->index_sent_seqcount =
+				tracefile_array_get_seq_head(stream->tfa) + 1;
 		break;
 	default:
-		assert(0);
-		goto error;
+		goto error_unlock;
 	}
 
-	if (vstream->metadata_flag) {
-		ctf_trace->viewer_metadata_stream = vstream;
-	}
-
-	/* Globally visible after the add unique. */
-	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
-	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
-
-	vstream->index_read_fd = -1;
-	vstream->read_fd = -1;
-
-	/*
-	 * This is to avoid a race between the initialization of this object and
-	 * the close of the given stream. If the stream is unable to find this
-	 * viewer stream when closing, this copy will at least take the latest
-	 * value. We also need that for the seek_last.
-	 */
-	vstream->total_index_received = stream->total_index_received;
-
 	/*
-	 * If we never received an index for the current stream, delay the opening
-	 * of the index, otherwise open it right now.
+	 * If we never received an index for the current stream, delay
+	 * the opening of the index, otherwise open it right now.
 	 */
-	if (vstream->tracefile_count_current == stream->tracefile_count_current
-			&& vstream->total_index_received == 0) {
-		vstream->index_read_fd = -1;
+	if (stream->index_received_seqcount == 0) {
+		vstream->index_fd = NULL;
 	} else {
 		int read_fd;
 
 		read_fd = index_open(vstream->path_name, vstream->channel_name,
-				vstream->tracefile_count, vstream->tracefile_count_current);
+				stream->tracefile_count,
+				vstream->current_tracefile_id);
 		if (read_fd < 0) {
-			goto error;
+			goto error_unlock;
+		}
+		vstream->index_fd = stream_fd_create(read_fd);
+		if (!vstream->index_fd) {
+			if (close(read_fd)) {
+				PERROR("close");
+			}
+			goto error_unlock;
 		}
-		vstream->index_read_fd = read_fd;
 	}
 
-	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_read_fd >= 0) {
+	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_fd) {
 		off_t lseek_ret;
 
-		lseek_ret = lseek(vstream->index_read_fd,
-				vstream->total_index_received * sizeof(struct ctf_packet_index),
-				SEEK_CUR);
+		lseek_ret = lseek(vstream->index_fd->fd, 0, SEEK_END);
 		if (lseek_ret < 0) {
-			goto error;
+			goto error_unlock;
 		}
-		vstream->last_sent_index = vstream->total_index_received;
 	}
+	if (stream->is_metadata) {
+		rcu_assign_pointer(stream->trace->viewer_metadata_stream,
+				vstream);
+	}
+	pthread_mutex_unlock(&stream->lock);
+
+	/* Globally visible after the add unique. */
+	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
+	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
+
+	pthread_mutex_init(&vstream->reflock, NULL);
+	urcu_ref_init(&vstream->ref);
 
 	return vstream;
 
+error_unlock:
+	pthread_mutex_unlock(&stream->lock);
 error:
 	if (vstream) {
-		free_stream(vstream);
+		viewer_stream_destroy(vstream);
 	}
 	return NULL;
 }
 
-void viewer_stream_delete(struct relay_viewer_stream *stream)
+static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
 {
 	int ret;
 	struct lttng_ht_iter iter;
 
-	iter.iter.node = &stream->stream_n.node;
+	iter.iter.node = &vstream->stream_n.node;
 	ret = lttng_ht_del(viewer_streams_ht, &iter);
 	assert(!ret);
 }
 
-void viewer_stream_destroy(struct ctf_trace *ctf_trace,
-		struct relay_viewer_stream *stream)
+static void viewer_stream_release(struct urcu_ref *ref)
 {
-	int ret;
-
-	assert(stream);
+	struct relay_viewer_stream *vstream = caa_container_of(ref,
+			struct relay_viewer_stream, ref);
 
-	if (ctf_trace) {
-		ctf_trace_put_ref(ctf_trace);
+	if (vstream->stream->is_metadata) {
+		rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
 	}
 
-	if (stream->read_fd >= 0) {
-		ret = close(stream->read_fd);
-		if (ret < 0) {
-			PERROR("close read_fd");
-		}
+	viewer_stream_unpublish(vstream);
+
+	if (vstream->stream_fd) {
+		stream_fd_put(vstream->stream_fd);
+		vstream->stream_fd = NULL;
 	}
-	if (stream->index_read_fd >= 0) {
-		ret = close(stream->index_read_fd);
-		if (ret < 0) {
-			PERROR("close index_read_fd");
-		}
+	if (vstream->index_fd) {
+		stream_fd_put(vstream->index_fd);
+		vstream->index_fd = NULL;
+	}
+	if (vstream->stream) {
+		stream_put(vstream->stream);
+		vstream->stream = NULL;
+	}
+	call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
+}
+
+/* Must be called with RCU read-side lock held. */
+bool viewer_stream_get(struct relay_viewer_stream *vstream)
+{
+	bool has_ref = false;
+
+	pthread_mutex_lock(&vstream->reflock);
+	if (vstream->ref.refcount != 0) {
+		has_ref = true;
+		urcu_ref_get(&vstream->ref);
 	}
+	pthread_mutex_unlock(&vstream->reflock);
 
-	call_rcu(&stream->rcu_node, deferred_free_viewer_stream);
+	return has_ref;
 }
 
 /*
- * Find viewer stream by id. RCU read side lock MUST be acquired.
+ * Get viewer stream by id.
  *
- * Return stream if found else NULL.
+ * Return viewer stream if found else NULL.
  */
-struct relay_viewer_stream *viewer_stream_find_by_id(uint64_t id)
+struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
 {
 	struct lttng_ht_node_u64 *node;
 	struct lttng_ht_iter iter;
-	struct relay_viewer_stream *stream = NULL;
+	struct relay_viewer_stream *vstream = NULL;
 
+	rcu_read_lock();
 	lttng_ht_lookup(viewer_streams_ht, &id, &iter);
 	node = lttng_ht_iter_get_node_u64(&iter);
 	if (!node) {
 		DBG("Relay viewer stream %" PRIu64 " not found", id);
 		goto end;
 	}
-	stream = caa_container_of(node, struct relay_viewer_stream, stream_n);
-
+	vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
+	if (!viewer_stream_get(vstream)) {
+		vstream = NULL;
+	}
 end:
-	return stream;
+	rcu_read_unlock();
+	return vstream;
+}
+
+void viewer_stream_put(struct relay_viewer_stream *vstream)
+{
+	rcu_read_lock();
+	pthread_mutex_lock(&vstream->reflock);
+	urcu_ref_put(&vstream->ref, viewer_stream_release);
+	pthread_mutex_unlock(&vstream->reflock);
+	rcu_read_unlock();
 }
 
 /*
  * Rotate a stream to the next tracefile.
  *
- * Must be called with viewer_stream_rotation_lock held.
+ * Must be called with the rstream lock held.
  * Returns 0 on success, 1 on EOF, a negative value on error.
  */
-int viewer_stream_rotate(struct relay_viewer_stream *vstream,
-		struct relay_stream *stream)
+int viewer_stream_rotate(struct relay_viewer_stream *vstream)
 {
 	int ret;
-	uint64_t tracefile_id;
-
-	assert(vstream);
-	assert(stream);
+	struct relay_stream *stream = vstream->stream;
+	uint64_t new_id;
 
-	if (vstream->tracefile_count == 0) {
-		/* Ignore rotation, there is none to do. */
-		ret = 0;
+	/* Detect the last tracefile to open. */
+	if (stream->index_received_seqcount
+			== vstream->index_sent_seqcount
+			&& stream->trace->session->connection_closed) {
+		ret = 1;
 		goto end;
 	}
 
-	tracefile_id = (vstream->tracefile_count_current + 1) %
-		vstream->tracefile_count;
-
-	/* Detect the last tracefile to open. */
-	if (vstream->tracefile_count_last != -1ULL &&
-			vstream->tracefile_count_last ==
-			vstream->tracefile_count_current) {
-		ret = 1;
+	if (stream->tracefile_count == 0) {
+		/* Ignore rotation, there is none to do. */
+		ret = 0;
 		goto end;
 	}
 
 	/*
-	 * The writer and the reader are not working in the same tracefile, we can
-	 * read up to EOF, we don't care about the total_index_received.
+	 * Try to move to the next file.
 	 */
-	if (stream->close_flag || (stream->tracefile_count_current != tracefile_id)) {
-		vstream->close_write_flag = 1;
+	new_id = (vstream->current_tracefile_id + 1)
+			% stream->tracefile_count;
+	if (tracefile_array_seq_in_file(stream->tfa, new_id,
+			vstream->index_sent_seqcount)) {
+		vstream->current_tracefile_id = new_id;
 	} else {
+		uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
+
 		/*
-		 * We are opening a file that is still open in write, make sure we
-		 * limit our reading to the number of indexes received.
+		 * This can only be reached on overwrite, which implies there
+		 * has been data written at some point, which will have set the
+		 * tail.
 		 */
-		vstream->close_write_flag = 0;
-		if (stream->close_flag) {
-			vstream->total_index_received = stream->total_index_received;
-		}
+		assert(seq_tail != -1ULL);
+		/*
+		 * We need to resync because we lag behind tail.
+		 */
+		vstream->current_tracefile_id =
+			tracefile_array_get_file_index_tail(stream->tfa);
+		vstream->index_sent_seqcount = seq_tail;
 	}
-	vstream->tracefile_count_current = tracefile_id;
 
-	ret = close(vstream->index_read_fd);
-	if (ret < 0) {
-		PERROR("close index file %d", vstream->index_read_fd);
+	if (vstream->index_fd) {
+		stream_fd_put(vstream->index_fd);
+		vstream->index_fd = NULL;
 	}
-	vstream->index_read_fd = -1;
-
-	ret = close(vstream->read_fd);
-	if (ret < 0) {
-		PERROR("close tracefile %d", vstream->read_fd);
+	if (vstream->stream_fd) {
+		stream_fd_put(vstream->stream_fd);
+		vstream->stream_fd = NULL;
 	}
-	vstream->read_fd = -1;
-
-	pthread_mutex_lock(&vstream->overwrite_lock);
-	vstream->abort_flag = 0;
-	pthread_mutex_unlock(&vstream->overwrite_lock);
 
 	ret = index_open(vstream->path_name, vstream->channel_name,
-			vstream->tracefile_count, vstream->tracefile_count_current);
+			stream->tracefile_count,
+			vstream->current_tracefile_id);
 	if (ret < 0) {
-		goto error;
+		goto end;
+	}
+	vstream->index_fd = stream_fd_create(ret);
+	if (vstream->index_fd) {
+		ret = 0;
+	} else {
+		if (close(ret)) {
+			PERROR("close");
+		}
+		ret = -1;
 	}
-	vstream->index_read_fd = ret;
-
-	ret = 0;
-
 end:
-error:
 	return ret;
 }
+
+void print_viewer_streams(void)
+{
+	struct lttng_ht_iter iter;
+	struct relay_viewer_stream *vstream;
+
+	if (!viewer_streams_ht) {
+		return;
+	}
+
+	rcu_read_lock();
+	cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
+			stream_n.node) {
+		if (!viewer_stream_get(vstream)) {
+			continue;
+		}
+		DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
+			" session %" PRIu64,
+			vstream,
+			vstream->ref.refcount,
+			vstream->stream->stream_handle,
+			vstream->stream->trace->id,
+			vstream->stream->trace->session->id);
+		viewer_stream_put(vstream);
+	}
+	rcu_read_unlock();
+}