X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fconsumer.c;h=35df86dd81c922217a6dbf628af93fd79d5b3432;hp=8b43257bd134987a3d0811320276010b724579b3;hb=58b1f4255ea457f2965f31b84205cb0eec21e71f;hpb=4bb94b7597f56f5200ebd6a88e906488172241fb

diff --git a/src/common/consumer.c b/src/common/consumer.c
index 8b43257bd..35df86dd8 100644
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -58,6 +58,17 @@ int consumer_poll_timeout = -1;
  */
 volatile int consumer_quit = 0;
 
+/*
+ * The following two hash tables are visible by all threads which are separated
+ * in different source files.
+ *
+ * Global hash table containing respectively metadata and data streams. The
+ * stream element in this ht should only be updated by the metadata poll thread
+ * for the metadata and the data poll thread for the data.
+ */
+struct lttng_ht *metadata_ht = NULL;
+struct lttng_ht *data_ht = NULL;
+
 /*
  * Find a stream. The consumer_data.lock must be locked during this
  * call.
@@ -89,7 +100,7 @@ static struct lttng_consumer_stream *consumer_find_stream(int key,
 	return stream;
 }
 
-static void consumer_steal_stream_key(int key, struct lttng_ht *ht)
+void consumer_steal_stream_key(int key, struct lttng_ht *ht)
 {
 	struct lttng_consumer_stream *stream;
 
@@ -161,17 +172,6 @@ void consumer_free_stream(struct rcu_head *head)
 	free(stream);
 }
 
-static
-void consumer_free_metadata_stream(struct rcu_head *head)
-{
-	struct lttng_ht_node_ulong *node =
-		caa_container_of(head, struct lttng_ht_node_ulong, head);
-	struct lttng_consumer_stream *stream =
-		caa_container_of(node, struct lttng_consumer_stream, waitfd_node);
-
-	free(stream);
-}
-
 /*
  * RCU protected relayd socket pair free.
  */
@@ -406,8 +406,25 @@ struct lttng_consumer_stream *consumer_allocate_stream(
 	stream->metadata_flag = metadata_flag;
 	strncpy(stream->path_name, path_name, sizeof(stream->path_name));
 	stream->path_name[sizeof(stream->path_name) - 1] = '\0';
-	lttng_ht_node_init_ulong(&stream->waitfd_node, stream->wait_fd);
-	lttng_ht_node_init_ulong(&stream->node, stream->key);
+
+	/*
+	 * Index differently the metadata node because the thread is using an
+	 * internal hash table to match streams in the metadata_ht to the epoll set
+	 * file descriptor.
+	 */
+	if (metadata_flag) {
+		lttng_ht_node_init_ulong(&stream->node, stream->wait_fd);
+	} else {
+		lttng_ht_node_init_ulong(&stream->node, stream->key);
+	}
+
+	/*
+	 * The cpu number is needed before using any ustctl_* actions. Ignored for
+	 * the kernel so the value does not matter.
+	 */
+	pthread_mutex_lock(&consumer_data.lock);
+	stream->cpu = stream->chan->cpucount++;
+	pthread_mutex_unlock(&consumer_data.lock);
 
 	DBG3("Allocated stream %s (key %d, shm_fd %d, wait_fd %d, mmap_len %llu,"
 			" out_fd %d, net_seq_idx %d)", stream->path_name, stream->key,
@@ -425,41 +442,24 @@ end:
 /*
  * Add a stream to the global list protected by a mutex.
  */
-int consumer_add_stream(struct lttng_consumer_stream *stream)
+static int consumer_add_stream(struct lttng_consumer_stream *stream,
+		struct lttng_ht *ht)
 {
 	int ret = 0;
 	struct consumer_relayd_sock_pair *relayd;
 
 	assert(stream);
+	assert(ht);
 
 	DBG3("Adding consumer stream %d", stream->key);
 
 	pthread_mutex_lock(&consumer_data.lock);
 	rcu_read_lock();
 
-	switch (consumer_data.type) {
-	case LTTNG_CONSUMER_KERNEL:
-		break;
-	case LTTNG_CONSUMER32_UST:
-	case LTTNG_CONSUMER64_UST:
-		stream->cpu = stream->chan->cpucount++;
-		ret = lttng_ustconsumer_add_stream(stream);
-		if (ret) {
-			ret = -EINVAL;
-			goto error;
-		}
+	/* Steal stream identifier to avoid having streams with the same key */
+	consumer_steal_stream_key(stream->key, ht);
 
-		/* Steal stream identifier only for UST */
-		consumer_steal_stream_key(stream->key, consumer_data.stream_ht);
-		break;
-	default:
-		ERR("Unknown consumer_data type");
-		assert(0);
-		ret = -ENOSYS;
-		goto error;
-	}
-
-	lttng_ht_add_unique_ulong(consumer_data.stream_ht, &stream->node);
+	lttng_ht_add_unique_ulong(ht, &stream->node);
 
 	/* Check and cleanup relayd */
 	relayd = consumer_find_relayd(stream->net_seq_idx);
@@ -485,7 +485,6 @@ int consumer_add_stream(struct lttng_consumer_stream *stream)
 	consumer_data.stream_count++;
 	consumer_data.need_update = 1;
 
-error:
 	rcu_read_unlock();
 	pthread_mutex_unlock(&consumer_data.lock);
 
@@ -798,9 +797,9 @@ end:
  *
  * Returns the number of fds in the structures.
  */
-int consumer_update_poll_array(
+static int consumer_update_poll_array(
 		struct lttng_consumer_local_data *ctx, struct pollfd **pollfd,
-		struct lttng_consumer_stream **local_stream)
+		struct lttng_consumer_stream **local_stream, struct lttng_ht *ht)
 {
 	int i = 0;
 	struct lttng_ht_iter iter;
@@ -808,8 +807,7 @@ int consumer_update_poll_array(
 
 	DBG("Updating poll fd array");
 	rcu_read_lock();
-	cds_lfht_for_each_entry(consumer_data.stream_ht->ht, &iter.iter, stream,
-			node.node) {
+	cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
 		if (stream->state != LTTNG_CONSUMER_ACTIVE_STREAM) {
 			continue;
 		}
@@ -1533,6 +1531,33 @@ int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 	}
 }
 
+/*
+ * Iterate over all streams of the hashtable and free them properly.
+ *
+ * WARNING: *MUST* be used with data stream only.
+ */
+static void destroy_data_stream_ht(struct lttng_ht *ht)
+{
+	int ret;
+	struct lttng_ht_iter iter;
+	struct lttng_consumer_stream *stream;
+
+	if (ht == NULL) {
+		return;
+	}
+
+	rcu_read_lock();
+	cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
+		ret = lttng_ht_del(ht, &iter);
+		assert(!ret);
+
+		call_rcu(&stream->node.head, consumer_free_stream);
+	}
+	rcu_read_unlock();
+
+	lttng_ht_destroy(ht);
+}
+
 /*
  * Iterate over all streams of the hashtable and free them properly.
  *
@@ -1549,11 +1574,11 @@ static void destroy_stream_ht(struct lttng_ht *ht)
 	}
 
 	rcu_read_lock();
-	cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, waitfd_node.node) {
+	cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
 		ret = lttng_ht_del(ht, &iter);
 		assert(!ret);
 
-		call_rcu(&stream->waitfd_node.head, consumer_free_metadata_stream);
+		call_rcu(&stream->node.head, consumer_free_stream);
 	}
 	rcu_read_unlock();
 
@@ -1585,12 +1610,6 @@ void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 		goto free_stream;
 	}
 
-	rcu_read_lock();
-	iter.iter.node = &stream->waitfd_node.node;
-	ret = lttng_ht_del(ht, &iter);
-	assert(!ret);
-	rcu_read_unlock();
-
 	pthread_mutex_lock(&consumer_data.lock);
 	switch (consumer_data.type) {
 	case LTTNG_CONSUMER_KERNEL:
@@ -1611,6 +1630,12 @@ void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 		goto end;
 	}
 
+	rcu_read_lock();
+	iter.iter.node = &stream->node.node;
+	ret = lttng_ht_del(ht, &iter);
+	assert(!ret);
+	rcu_read_unlock();
+
 	if (stream->out_fd >= 0) {
 		ret = close(stream->out_fd);
 		if (ret) {
@@ -1677,7 +1702,7 @@ end:
 	}
 
 free_stream:
-	call_rcu(&stream->waitfd_node.head, consumer_free_metadata_stream);
+	call_rcu(&stream->node.head, consumer_free_stream);
 }
 
 /*
@@ -1697,27 +1722,6 @@ static int consumer_add_metadata_stream(struct lttng_consumer_stream *stream,
 
 	pthread_mutex_lock(&consumer_data.lock);
 
-	switch (consumer_data.type) {
-	case LTTNG_CONSUMER_KERNEL:
-		break;
-	case LTTNG_CONSUMER32_UST:
-	case LTTNG_CONSUMER64_UST:
-		ret = lttng_ustconsumer_add_stream(stream);
-		if (ret) {
-			ret = -EINVAL;
-			goto error;
-		}
-
-		/* Steal stream identifier only for UST */
-		consumer_steal_stream_key(stream->wait_fd, ht);
-		break;
-	default:
-		ERR("Unknown consumer_data type");
-		assert(0);
-		ret = -ENOSYS;
-		goto error;
-	}
-
 	/*
 	 * From here, refcounts are updated so be _careful_ when returning an error
 	 * after this point.
@@ -1744,10 +1748,12 @@ static int consumer_add_metadata_stream(struct lttng_consumer_stream *stream,
 		uatomic_dec(&stream->chan->nb_init_streams);
 	}
 
-	lttng_ht_add_unique_ulong(ht, &stream->waitfd_node);
+	/* Steal stream identifier to avoid having streams with the same key */
+	consumer_steal_stream_key(stream->key, ht);
+
+	lttng_ht_add_unique_ulong(ht, &stream->node);
 	rcu_read_unlock();
 
-error:
 	pthread_mutex_unlock(&consumer_data.lock);
 	return ret;
 }
@@ -1756,14 +1762,13 @@ error:
  * Thread polls on metadata file descriptor and write them on disk or on the
  * network.
  */
-void *lttng_consumer_thread_poll_metadata(void *data)
+void *consumer_thread_metadata_poll(void *data)
 {
 	int ret, i, pollfd;
 	uint32_t revents, nb_fd;
 	struct lttng_consumer_stream *stream = NULL;
 	struct lttng_ht_iter iter;
 	struct lttng_ht_node_ulong *node;
-	struct lttng_ht *metadata_ht = NULL;
 	struct lttng_poll_event events;
 	struct lttng_consumer_local_data *ctx = data;
 	ssize_t len;
@@ -1772,11 +1777,6 @@ void *lttng_consumer_thread_poll_metadata(void *data)
 
 	DBG("Thread metadata poll started");
 
-	metadata_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
-	if (metadata_ht == NULL) {
-		goto end;
-	}
-
 	/* Size is set to 1 for the consumer_metadata pipe */
 	ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
 	if (ret < 0) {
@@ -1876,7 +1876,7 @@ restart:
 			assert(node);
 
 			stream = caa_container_of(node, struct lttng_consumer_stream,
-					waitfd_node);
+					node);
 
 			/* Check for error event */
 			if (revents & (LPOLLERR | LPOLLHUP)) {
@@ -1912,7 +1912,7 @@ restart:
 
 				len = ctx->on_buffer_ready(stream, ctx);
 				/* It's ok to have an unavailable sub-buffer */
-				if (len < 0 && len != -EAGAIN) {
+				if (len < 0 && len != -EAGAIN && len != -ENODATA) {
 					rcu_read_unlock();
 					goto end;
 				} else if (len > 0) {
@@ -1942,26 +1942,21 @@ end:
  * This thread polls the fds in the set to consume the data and write
  * it to tracefile if necessary.
  */
-void *lttng_consumer_thread_poll_fds(void *data)
+void *consumer_thread_data_poll(void *data)
 {
 	int num_rdy, num_hup, high_prio, ret, i;
 	struct pollfd *pollfd = NULL;
 	/* local view of the streams */
-	struct lttng_consumer_stream **local_stream = NULL;
+	struct lttng_consumer_stream **local_stream = NULL, *new_stream = NULL;
 	/* local view of consumer_data.fds_count */
 	int nb_fd = 0;
 	struct lttng_consumer_local_data *ctx = data;
 	ssize_t len;
-	pthread_t metadata_thread;
-	void *status;
 
 	rcu_register_thread();
 
-	/* Start metadata polling thread */
-	ret = pthread_create(&metadata_thread, NULL,
-			lttng_consumer_thread_poll_metadata, (void *) ctx);
-	if (ret < 0) {
-		PERROR("pthread_create metadata thread");
+	data_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+	if (data_ht == NULL) {
 		goto end;
 	}
 
@@ -2002,7 +1997,8 @@ void *lttng_consumer_thread_poll_fds(void *data)
 				pthread_mutex_unlock(&consumer_data.lock);
 				goto end;
 			}
-			ret = consumer_update_poll_array(ctx, &pollfd, local_stream);
+			ret = consumer_update_poll_array(ctx, &pollfd, local_stream,
+					data_ht);
 			if (ret < 0) {
 				ERR("Error in allocating pollfd or local_outfds");
 				lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR);
@@ -2045,13 +2041,35 @@ void *lttng_consumer_thread_poll_fds(void *data)
 		 */
 		if (pollfd[nb_fd].revents & (POLLIN | POLLPRI)) {
 			size_t pipe_readlen;
-			char tmp;
 
 			DBG("consumer_poll_pipe wake up");
 			/* Consume 1 byte of pipe data */
 			do {
-				pipe_readlen = read(ctx->consumer_poll_pipe[0], &tmp, 1);
+				pipe_readlen = read(ctx->consumer_poll_pipe[0], &new_stream,
+						sizeof(new_stream));
 			} while (pipe_readlen == -1 && errno == EINTR);
+
+			/*
+			 * If the stream is NULL, just ignore it. It's also possible that
+			 * the sessiond poll thread changed the consumer_quit state and is
+			 * waking us up to test it.
+			 */
+			if (new_stream == NULL) {
+				continue;
+			}
+
+			ret = consumer_add_stream(new_stream, data_ht);
+			if (ret) {
+				ERR("Consumer add stream %d failed. Continuing",
+						new_stream->key);
+				/*
+				 * At this point, if the add_stream fails, it is not in the
+				 * hash table thus passing the NULL value here.
+				 */
+				consumer_del_stream(new_stream, NULL);
+			}
+
+			/* Continue to update the local streams and handle prio ones */
 			continue;
 		}
 
@@ -2062,7 +2080,7 @@ void *lttng_consumer_thread_poll_fds(void *data)
 				high_prio = 1;
 				len = ctx->on_buffer_ready(local_stream[i], ctx);
 				/* it's ok to have an unavailable sub-buffer */
-				if (len < 0 && len != -EAGAIN) {
+				if (len < 0 && len != -EAGAIN && len != -ENODATA) {
 					goto end;
 				} else if (len > 0) {
 					local_stream[i]->data_read = 1;
@@ -2085,7 +2103,7 @@ void *lttng_consumer_thread_poll_fds(void *data)
 				DBG("Normal read on fd %d", pollfd[i].fd);
 				len = ctx->on_buffer_ready(local_stream[i], ctx);
 				/* it's ok to have an unavailable sub-buffer */
-				if (len < 0 && len != -EAGAIN) {
+				if (len < 0 && len != -EAGAIN && len != -ENODATA) {
 					goto end;
 				} else if (len > 0) {
 					local_stream[i]->data_read = 1;
@@ -2113,22 +2131,19 @@ void *lttng_consumer_thread_poll_fds(void *data)
 			if ((pollfd[i].revents & POLLHUP)) {
 				DBG("Polling fd %d tells it has hung up.", pollfd[i].fd);
 				if (!local_stream[i]->data_read) {
-					consumer_del_stream(local_stream[i],
-							consumer_data.stream_ht);
+					consumer_del_stream(local_stream[i], data_ht);
 					num_hup++;
 				}
 			} else if (pollfd[i].revents & POLLERR) {
 				ERR("Error returned in polling fd %d.", pollfd[i].fd);
 				if (!local_stream[i]->data_read) {
-					consumer_del_stream(local_stream[i],
-							consumer_data.stream_ht);
+					consumer_del_stream(local_stream[i], data_ht);
 					num_hup++;
 				}
 			} else if (pollfd[i].revents & POLLNVAL) {
 				ERR("Polling fd %d tells fd is not open.", pollfd[i].fd);
 				if (!local_stream[i]->data_read) {
-					consumer_del_stream(local_stream[i],
-							consumer_data.stream_ht);
+					consumer_del_stream(local_stream[i], data_ht);
 					num_hup++;
 				}
 			}
@@ -2148,18 +2163,16 @@ end:
 
 	/*
 	 * Close the write side of the pipe so epoll_wait() in
-	 * lttng_consumer_thread_poll_metadata can catch it. The thread is
-	 * monitoring the read side of the pipe. If we close them both, epoll_wait
-	 * strangely does not return and could create a endless wait period if the
-	 * pipe is the only tracked fd in the poll set. The thread will take care
-	 * of closing the read side.
+	 * consumer_thread_metadata_poll can catch it. The thread is monitoring the
+	 * read side of the pipe. If we close them both, epoll_wait strangely does
+	 * not return and could create a endless wait period if the pipe is the
+	 * only tracked fd in the poll set. The thread will take care of closing
+	 * the read side.
 	 */
 	close(ctx->consumer_metadata_pipe[1]);
-	if (ret) {
-		ret = pthread_join(metadata_thread, &status);
-		if (ret < 0) {
-			PERROR("pthread_join metadata thread");
-		}
+
+	if (data_ht) {
+		destroy_data_stream_ht(data_ht);
 	}
 
 	rcu_unregister_thread();
@@ -2170,7 +2183,7 @@ end:
  * This thread listens on the consumerd socket and receives the file
  * descriptors from the session daemon.
  */
-void *lttng_consumer_thread_receive_fds(void *data)
+void *consumer_thread_sessiond_poll(void *data)
 {
 	int sock, client_socket, ret;
 	/*
@@ -2277,19 +2290,16 @@ end:
 	consumer_poll_timeout = LTTNG_CONSUMER_POLL_TIMEOUT;
 
 	/*
-	 * Wake-up the other end by writing a null byte in the pipe
-	 * (non-blocking). Important note: Because writing into the
-	 * pipe is non-blocking (and therefore we allow dropping wakeup
-	 * data, as long as there is wakeup data present in the pipe
-	 * buffer to wake up the other end), the other end should
-	 * perform the following sequence for waiting:
-	 * 1) empty the pipe (reads).
-	 * 2) perform update operation.
-	 * 3) wait on the pipe (poll).
+	 * Notify the data poll thread to poll back again and test the
+	 * consumer_quit state to quit gracefully.
 	 */
 	do {
-		ret = write(ctx->consumer_poll_pipe[1], "", 1);
+		struct lttng_consumer_stream *null_stream = NULL;
+
+		ret = write(ctx->consumer_poll_pipe[1], &null_stream,
+				sizeof(null_stream));
 	} while (ret < 0 && errno == EINTR);
+
 	rcu_unregister_thread();
 	return NULL;
 }
@@ -2333,6 +2343,11 @@ void lttng_consumer_init(void)
 	consumer_data.stream_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 	consumer_data.channel_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 	consumer_data.relayd_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+
+	metadata_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+	assert(metadata_ht);
+	data_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+	assert(data_ht);
 }
 
 /*