X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Ftrace-chunk-registry.h;h=5442d7997893eb744121d7661706d677fcbae127;hb=999af9c1150784f8676c6fce0764772d2314854a;hp=23df91a3eca24a13ac64b0eb3a0a5d9b983d5ebf;hpb=e10aec8f225c0822811c65401710a039d7e2d7d7;p=lttng-tools.git

diff --git a/src/common/trace-chunk-registry.h b/src/common/trace-chunk-registry.h
index 23df91a3e..5442d7997 100644
--- a/src/common/trace-chunk-registry.h
+++ b/src/common/trace-chunk-registry.h
@@ -1,18 +1,8 @@
 /*
- * 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
@@ -41,7 +31,6 @@ struct lttng_trace_chunk_registry;
  *
  * 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);
 
 /*
@@ -49,7 +38,6 @@ 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);
 
@@ -66,10 +54,32 @@ void lttng_trace_chunk_registry_destroy(
  *
  * 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.
@@ -77,26 +87,32 @@ struct lttng_trace_chunk *lttng_trace_chunk_registry_publish_chunk(
  *
  * 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 */