X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Findex.c;h=80a4bb94d2a0651dc24100425c52ca4047b06209;hp=b7507a022076e0e6be789523111c08f4fcad2d66;hb=719155c2bed581d85290537fd95bafc787229dbc;hpb=5c32d0aeb3f1e338ff61f9b5c865a01763a3ec4b

diff --git a/src/bin/lttng-relayd/index.c b/src/bin/lttng-relayd/index.c
index b7507a022..80a4bb94d 100644
--- a/src/bin/lttng-relayd/index.c
+++ b/src/bin/lttng-relayd/index.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
@@ -16,7 +17,6 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
 #define _LGPL_SOURCE
 #include <assert.h>
 
@@ -24,190 +24,350 @@
 #include <common/utils.h>
 
 #include "lttng-relayd.h"
+#include "stream.h"
 #include "index.h"
 
 /*
- * Deferred free of a relay index object. MUST only be called by a call RCU.
+ * Allocate a new relay index object. Pass the stream in which it is
+ * contained as parameter. The sequence number will be used as the hash
+ * table key.
+ *
+ * Called with stream mutex held.
+ * Return allocated object or else NULL on error.
  */
-static void deferred_free_relay_index(struct rcu_head *head)
+static struct relay_index *relay_index_create(struct relay_stream *stream,
+		uint64_t net_seq_num)
 {
-	struct relay_index *index =
-		caa_container_of(head, struct relay_index, rcu_node);
+	struct relay_index *index;
 
-	if (index->to_close_fd >= 0) {
-		int ret;
+	DBG2("Creating relay index for stream id %" PRIu64 " and seqnum %" PRIu64,
+			stream->stream_handle, net_seq_num);
 
-		ret = close(index->to_close_fd);
-		if (ret < 0) {
-			PERROR("Relay index to close fd %d", index->to_close_fd);
-		}
+	index = zmalloc(sizeof(*index));
+	if (!index) {
+		PERROR("Relay index zmalloc");
+		goto end;
 	}
+	if (!stream_get(stream)) {
+		ERR("Cannot get stream");
+		free(index);
+		index = NULL;
+		goto end;
+	}
+	index->stream = stream;
+
+	lttng_ht_node_init_u64(&index->index_n, net_seq_num);
+	pthread_mutex_init(&index->lock, NULL);
+	pthread_mutex_init(&index->reflock, NULL);
+	urcu_ref_init(&index->ref);
 
-	relay_index_free(index);
+end:
+	return index;
 }
 
 /*
- * Allocate a new relay index object using the given stream ID and sequence
- * number as the hash table key.
+ * Add unique relay index to the given hash table. In case of a collision, the
+ * already existing object is put in the given _index variable.
  *
- * Return allocated object or else NULL on error.
+ * RCU read side lock MUST be acquired.
  */
-struct relay_index *relay_index_create(uint64_t stream_id,
-		uint64_t net_seq_num)
+static struct relay_index *relay_index_add_unique(struct relay_stream *stream,
+		struct relay_index *index)
 {
-	struct relay_index *index;
+	struct cds_lfht_node *node_ptr;
+	struct relay_index *_index;
 
-	DBG2("Creating relay index with stream id %" PRIu64 " and seqnum %" PRIu64,
-			stream_id, net_seq_num);
+	DBG2("Adding relay index with stream id %" PRIu64 " and seqnum %" PRIu64,
+			stream->stream_handle, index->index_n.key);
 
-	index = zmalloc(sizeof(*index));
-	if (index == NULL) {
-		PERROR("Relay index zmalloc");
-		goto error;
+	node_ptr = cds_lfht_add_unique(stream->indexes_ht->ht,
+			stream->indexes_ht->hash_fct(&index->index_n, lttng_ht_seed),
+			stream->indexes_ht->match_fct, &index->index_n,
+			&index->index_n.node);
+	if (node_ptr != &index->index_n.node) {
+		_index = caa_container_of(node_ptr, struct relay_index,
+				index_n.node);
+	} else {
+		_index = NULL;
 	}
+	return _index;
+}
 
-	index->to_close_fd = -1;
-	lttng_ht_node_init_two_u64(&index->index_n, stream_id, net_seq_num);
+/*
+ * Should be called with RCU read-side lock held.
+ */
+static bool relay_index_get(struct relay_index *index)
+{
+	bool has_ref = false;
 
-error:
-	return index;
+	DBG2("index get for stream id %" PRIu64 " and seqnum %" PRIu64 " refcount %d",
+			index->stream->stream_handle, index->index_n.key,
+			(int) index->ref.refcount);
+
+	/* Confirm that the index refcount has not reached 0. */
+	pthread_mutex_lock(&index->reflock);
+	if (index->ref.refcount != 0) {
+		has_ref = true;
+		urcu_ref_get(&index->ref);
+	}
+	pthread_mutex_unlock(&index->reflock);
+
+	return has_ref;
 }
 
 /*
- * Find a relayd index in the given hash table.
+ * Get a relayd index in within the given stream, or create it if not
+ * present.
  *
+ * Called with stream mutex held.
  * Return index object or else NULL on error.
  */
-struct relay_index *relay_index_find(uint64_t stream_id, uint64_t net_seq_num)
+struct relay_index *relay_index_get_by_id_or_create(struct relay_stream *stream,
+		 uint64_t net_seq_num)
 {
-	struct lttng_ht_node_two_u64 *node;
+	struct lttng_ht_node_u64 *node;
 	struct lttng_ht_iter iter;
-	struct lttng_ht_two_u64 key;
 	struct relay_index *index = NULL;
 
 	DBG3("Finding index for stream id %" PRIu64 " and seq_num %" PRIu64,
-			stream_id, net_seq_num);
-
-	key.key1 = stream_id;
-	key.key2 = net_seq_num;
+			stream->stream_handle, net_seq_num);
 
-	lttng_ht_lookup(indexes_ht, (void *)(&key), &iter);
-	node = lttng_ht_iter_get_node_two_u64(&iter);
-	if (node == NULL) {
-		goto end;
+	rcu_read_lock();
+	lttng_ht_lookup(stream->indexes_ht, &net_seq_num, &iter);
+	node = lttng_ht_iter_get_node_u64(&iter);
+	if (node) {
+		index = caa_container_of(node, struct relay_index, index_n);
+	} else {
+		struct relay_index *oldindex;
+
+		index = relay_index_create(stream, net_seq_num);
+		if (!index) {
+			ERR("Cannot create index for stream id %" PRIu64 " and seq_num %" PRIu64,
+				stream->stream_handle, net_seq_num);
+			goto end;
+		}
+		oldindex = relay_index_add_unique(stream, index);
+		if (oldindex) {
+			/* Added concurrently, keep old. */
+			relay_index_put(index);
+			index = oldindex;
+			if (!relay_index_get(index)) {
+				index = NULL;
+			}
+		} else {
+			stream->indexes_in_flight++;
+			index->in_hash_table = true;
+		}
 	}
-	index = caa_container_of(node, struct relay_index, index_n);
-
 end:
-	DBG2("Index %sfound in HT for stream ID %" PRIu64 " and seqnum %" PRIu64,
-			(index == NULL) ? "NOT " : "", stream_id, net_seq_num);
+	rcu_read_unlock();
+	DBG2("Index %sfound or created in HT for stream ID %" PRIu64 " and seqnum %" PRIu64,
+			(index == NULL) ? "NOT " : "", stream->stream_handle, net_seq_num);
 	return index;
 }
 
-/*
- * Add unique relay index to the given hash table. In case of a collision, the
- * already existing object is put in the given _index variable.
- *
- * RCU read side lock MUST be acquired.
- */
-void relay_index_add(struct relay_index *index, struct relay_index **_index)
+int relay_index_set_fd(struct relay_index *index, struct stream_fd *index_fd,
+		uint64_t data_offset)
 {
-	struct cds_lfht_node *node_ptr;
+	int ret = 0;
 
-	assert(index);
+	pthread_mutex_lock(&index->lock);
+	if (index->index_fd) {
+		ret = -1;
+		goto end;
+	}
+	stream_fd_get(index_fd);
+	index->index_fd = index_fd;
+	index->index_data.offset = data_offset;
+end:
+	pthread_mutex_unlock(&index->lock);
+	return ret;
+}
 
-	DBG2("Adding relay index with stream id %" PRIu64 " and seqnum %" PRIu64,
-			index->index_n.key.key1, index->index_n.key.key2);
+int relay_index_set_data(struct relay_index *index,
+                const struct ctf_packet_index *data)
+{
+	int ret = 0;
 
-	node_ptr = cds_lfht_add_unique(indexes_ht->ht,
-			indexes_ht->hash_fct((void *) &index->index_n.key, lttng_ht_seed),
-			indexes_ht->match_fct, (void *) &index->index_n.key,
-			&index->index_n.node);
-	if (node_ptr != &index->index_n.node) {
-		*_index = caa_container_of(node_ptr, struct relay_index, index_n.node);
+	pthread_mutex_lock(&index->lock);
+	if (index->has_index_data) {
+		ret = -1;
+		goto end;
 	}
+	/* Set everything except data_offset. */
+	index->index_data.packet_size = data->packet_size;
+	index->index_data.content_size = data->content_size;
+	index->index_data.timestamp_begin = data->timestamp_begin;
+	index->index_data.timestamp_end = data->timestamp_end;
+	index->index_data.events_discarded = data->events_discarded;
+	index->index_data.stream_id = data->stream_id;
+	index->has_index_data = true;
+end:
+	pthread_mutex_unlock(&index->lock);
+	return ret;
 }
 
-/*
- * Write index on disk to the given fd. Once done error or not, it is removed
- * from the hash table and destroy the object.
- *
- * MUST be called with a RCU read side lock held.
- *
- * Return 0 on success else a negative value.
- */
-int relay_index_write(int fd, struct relay_index *index)
+static void index_destroy(struct relay_index *index)
+{
+	free(index);
+}
+
+static void index_destroy_rcu(struct rcu_head *rcu_head)
+{
+	struct relay_index *index =
+		caa_container_of(rcu_head, struct relay_index, rcu_node);
+
+	index_destroy(index);
+}
+
+/* Stream lock must be held by the caller. */
+static void index_release(struct urcu_ref *ref)
 {
+	struct relay_index *index = caa_container_of(ref, struct relay_index, ref);
+	struct relay_stream *stream = index->stream;
 	int ret;
 	struct lttng_ht_iter iter;
 
-	DBG2("Writing index for stream ID %" PRIu64 " and seq num %" PRIu64
-			" on fd %d", index->index_n.key.key1,
-			index->index_n.key.key2, fd);
+	if (index->index_fd) {
+		stream_fd_put(index->index_fd);
+		index->index_fd = NULL;
+	}
+	if (index->in_hash_table) {
+		/* Delete index from hash table. */
+		iter.iter.node = &index->index_n.node;
+		ret = lttng_ht_del(stream->indexes_ht, &iter);
+		assert(!ret);
+		stream->indexes_in_flight--;
+	}
 
-	/* Delete index from hash table. */
-	iter.iter.node = &index->index_n.node;
-	ret = lttng_ht_del(indexes_ht, &iter);
-	assert(!ret);
-	call_rcu(&index->rcu_node, deferred_free_relay_index);
+	stream_put(index->stream);
+	index->stream = NULL;
 
-	return index_write(fd, &index->index_data, sizeof(index->index_data));
+	call_rcu(&index->rcu_node, index_destroy_rcu);
 }
 
 /*
- * Free the given index.
+ * Called with stream mutex held.
+ *
+ * Stream lock must be held by the caller.
  */
-void relay_index_free(struct relay_index *index)
+void relay_index_put(struct relay_index *index)
 {
-	free(index);
+	DBG2("index put for stream id %" PRIu64 " and seqnum %" PRIu64 " refcount %d",
+			index->stream->stream_handle, index->index_n.key,
+			(int) index->ref.refcount);
+	/*
+	 * Ensure existance of index->lock for index unlock.
+	 */
+	rcu_read_lock();
+	/*
+	 * Index lock ensures that concurrent test and update of stream
+	 * ref is atomic.
+	 */
+	pthread_mutex_lock(&index->reflock);
+	assert(index->ref.refcount != 0);
+	urcu_ref_put(&index->ref, index_release);
+	pthread_mutex_unlock(&index->reflock);
+	rcu_read_unlock();
 }
 
 /*
- * Safely free the given index using a call RCU.
+ * Try to flush index to disk. Releases self-reference to index once
+ * flush succeeds.
+ *
+ * Stream lock must be held by the caller.
+ * Return 0 on successful flush, a negative value on error, or positive
+ * value if no flush was performed.
  */
-void relay_index_free_safe(struct relay_index *index)
+int relay_index_try_flush(struct relay_index *index)
 {
-	if (!index) {
-		return;
+	int ret = 1;
+	bool flushed = false;
+	int fd;
+
+	pthread_mutex_lock(&index->lock);
+	if (index->flushed) {
+		goto skip;
+	}
+	/* Check if we are ready to flush. */
+	if (!index->has_index_data || !index->index_fd) {
+		goto skip;
+	}
+	fd = index->index_fd->fd;
+	DBG2("Writing index for stream ID %" PRIu64 " and seq num %" PRIu64
+			" on fd %d", index->stream->stream_handle,
+			index->index_n.key, fd);
+	flushed = true;
+	index->flushed = true;
+	ret = index_write(fd, &index->index_data, sizeof(index->index_data));
+	if (ret == sizeof(index->index_data)) {
+		ret = 0;
+	} else {
+		ret = -1;
 	}
+skip:
+	pthread_mutex_unlock(&index->lock);
 
-	call_rcu(&index->rcu_node, deferred_free_relay_index);
+	if (flushed) {
+		/* Put self-ref from index now that it has been flushed. */
+		relay_index_put(index);
+	}
+	return ret;
 }
 
 /*
- * Delete index from the given hash table.
- *
- * RCU read side lock MUST be acquired.
+ * Close every relay index within a given stream, without flushing
+ * them.
  */
-void relay_index_delete(struct relay_index *index)
+void relay_index_close_all(struct relay_stream *stream)
 {
-	int ret;
 	struct lttng_ht_iter iter;
+	struct relay_index *index;
+
+	rcu_read_lock();
+	cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter,
+			index, index_n.node) {
+		/* Put self-ref from index. */
+		relay_index_put(index);
+	}
+	rcu_read_unlock();
+}
 
-	DBG3("Relay index with stream ID %" PRIu64 " and seq num %" PRIu64
-			" deleted.", index->index_n.key.key1,
-			index->index_n.key.key2);
+void relay_index_close_partial_fd(struct relay_stream *stream)
+{
+	struct lttng_ht_iter iter;
+	struct relay_index *index;
 
-	/* Delete index from hash table. */
-	iter.iter.node = &index->index_n.node;
-	ret = lttng_ht_del(indexes_ht, &iter);
-	assert(!ret);
+	rcu_read_lock();
+	cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter,
+			index, index_n.node) {
+		if (!index->index_fd) {
+			continue;
+		}
+		/*
+		 * Partial index has its index_fd: we have only
+		 * received its info from the data socket.
+		 * Put self-ref from index.
+		 */
+		relay_index_put(index);
+	}
+	rcu_read_unlock();
 }
 
-/*
- * Destroy every relay index with the given stream id as part of the key.
- */
-void relay_index_destroy_by_stream_id(uint64_t stream_id)
+uint64_t relay_index_find_last(struct relay_stream *stream)
 {
 	struct lttng_ht_iter iter;
 	struct relay_index *index;
+	uint64_t net_seq_num = -1ULL;
 
 	rcu_read_lock();
-	cds_lfht_for_each_entry(indexes_ht->ht, &iter.iter, index, index_n.node) {
-		if (index->index_n.key.key1 == stream_id) {
-			relay_index_delete(index);
-			relay_index_free_safe(index);
+	cds_lfht_for_each_entry(stream->indexes_ht->ht, &iter.iter,
+			index, index_n.node) {
+		if (net_seq_num == -1ULL ||
+				index->index_n.key > net_seq_num) {
+			net_seq_num = index->index_n.key;
 		}
 	}
 	rcu_read_unlock();
+	return net_seq_num;
 }