/*
- * Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License, version 2.1 only,
- * as published by the Free Software Foundation.
+ * SPDX-License-Identifier: LGPL-2.1-only
*
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
- * for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef LTTNG_TRACE_CHUNK_REGISTRY_H
*
* Note that a trace chunk registry may only be accessed by an RCU thread.
*/
-LTTNG_HIDDEN
struct lttng_trace_chunk_registry *lttng_trace_chunk_registry_create(void);
/*
* (i.e. all references to the trace chunks it contains must be released) before
* it is destroyed.
*/
-LTTNG_HIDDEN
void lttng_trace_chunk_registry_destroy(
struct lttng_trace_chunk_registry *registry);
*
* Returns an lttng_trace_chunk on success, NULL on error.
*/
-LTTNG_HIDDEN
struct lttng_trace_chunk *lttng_trace_chunk_registry_publish_chunk(
struct lttng_trace_chunk_registry *registry,
uint64_t session_id, struct lttng_trace_chunk *chunk);
+/*
+ * Adds the `previously_published` parameter which allows the caller
+ * to know if a trace chunk equivalent to `chunk` was previously published.
+ *
+ * The registry holds a reference to the published trace chunks it contains.
+ * Trace chunks automatically unpublish themselves from their registry on
+ * destruction.
+ *
+ * This information is necessary to drop the reference of newly published
+ * chunks when a user doesn't wish to explicitly maintain all references
+ * to a given trace chunk.
+ *
+ * For instance, the relay daemon doesn't need the registry to hold a
+ * reference since it controls the lifetime of its trace chunks.
+ * Conversely, the consumer daemons rely on the session daemon to inform
+ * them of the end of life of a trace chunk and the trace chunks don't
+ * belong to a specific top-level object: they are always retrieved from
+ * the registry by `id`.
+ */
+struct lttng_trace_chunk *lttng_trace_chunk_registry_publish_chunk(
+ struct lttng_trace_chunk_registry *registry,
+ uint64_t session_id, struct lttng_trace_chunk *chunk,
+ bool *previously_published);
/*
* Look-up a trace chunk by session_id and chunk_id.
*
* Returns an lttng_trace_chunk on success, NULL if the chunk does not exist.
*/
-LTTNG_HIDDEN
struct lttng_trace_chunk *
lttng_trace_chunk_registry_find_chunk(
const struct lttng_trace_chunk_registry *registry,
uint64_t session_id, uint64_t chunk_id);
+/*
+ * Query the existence of a trace chunk by session_id and chunk_id.
+ *
+ * Returns 0 on success, a negative value on error.
+ */
+int lttng_trace_chunk_registry_chunk_exists(
+ const struct lttng_trace_chunk_registry *registry,
+ uint64_t session_id, uint64_t chunk_id, bool *chunk_exists);
+
/*
* Look-up an anonymous trace chunk by session_id.
* A reference is acquired on behalf of the caller.
*
* Returns an lttng_trace_chunk on success, NULL if the chunk does not exist.
*/
-LTTNG_HIDDEN
struct lttng_trace_chunk *
lttng_trace_chunk_registry_find_anonymous_chunk(
const struct lttng_trace_chunk_registry *registry,
uint64_t session_id);
-LTTNG_HIDDEN
unsigned int lttng_trace_chunk_registry_put_each_chunk(
- struct lttng_trace_chunk_registry *registry);
+ const struct lttng_trace_chunk_registry *registry);
#endif /* LTTNG_TRACE_CHUNK_REGISTRY_H */