niklas/cyclonedds
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Relax constraints on topic entities

Browse source 
This commit changes the implementation of topics so that multiple topic
entities can exist in a single participant for the same topic.
Different entities may refer to different topic implementations
(sertopics, akin to a type support in the DDS specification).  All
entities (for the same participant) always have the same QoS, via the
new "ktopic" table in the participant.

Readers and writers are bound to a topic entity and inherit its
properties.  If a topic comes in two definitions, say one for C and one
for C++, one can have a single participant with a reader delivering the
data in C representation and another reader delivering it in C++
representation.

This changes the behaviour of create_topic and find_topic: these now (on
successful return) always return a new entity (and thus with a unique
handle), where previously these would simply return a existing one when
possible.

This also requires some small additions to the sertopic/serdata
interface.

Signed-off-by: Erik Boasson <eb@ilities.com>
This commit is contained in:
Erik Boasson 2020-01-28 21:29:14 +01:00 • committed by eboasson
parent 08c9db0934
commit 27d7c72626
29 changed files with 946 additions and 530 deletions
Download patch file Download diff file Expand all files Collapse all files

45
src/core/ddsc/include/dds/dds.h
View file

@ -555,7 +555,9 @@ dds_set_enabled_status(dds_entity_t entity, uint32_t mask);
* @param[in] entity Entity on which to get qos.
* @param[out] qos Pointer to the qos structure that returns the set policies.
*
* @returns A dds_return_t indicating success or failure.
* @returns A dds_return_t indicating success or failure. The QoS object will have
* at least all QoS relevant for the entity present and the corresponding dds_qget_...
* will return true.
*
* @retval DDS_RETCODE_OK
* The existing set of QoS policy values applied to the entity
@ -962,7 +964,9 @@ dds_lookup_participant(
* @brief Creates a new topic with default type handling.
*
* The type name for the topic is taken from the generated descriptor. Topic
* matching is done on a combination of topic name and type name.
* matching is done on a combination of topic name and type name. Each successful
* call to dds_create_topic creates a new topic entity sharing the same QoS
* settings with all other topics of the same name.
*
* @param[in] participant Participant on which to create the topic.
* @param[in] descriptor An IDL generated topic descriptor.
@ -970,14 +974,20 @@ dds_lookup_participant(
* @param[in] qos QoS to set on the new topic (can be NULL).
* @param[in] listener Any listener functions associated with the new topic (can be NULL).
*
* @returns A valid topic handle or an error code.
* @returns A valid, unique topic handle or an error code.
*
* @retval >=0
* A valid topic handle.
* A valid unique topic handle.
* @retval DDS_RETCODE_BAD_PARAMETER
* Either participant, descriptor, name or qos is invalid.
* @retval DDS_RETCODE_BAD_PARAMETER
* Either participant, descriptor, name or qos is invalid.
* @retval DDS_RETCODE_INCONSISTENT_POLICY
* QoS mismatch between qos and an existing topic's QoS.
* @retval DDS_RETCODE_PRECONDITION_NOT_MET
* Mismatch between type name in descriptor and pre-existing
* topic's type name.
*/
/* TODO: Check list of retcodes is complete. */
DDS_EXPORT dds_entity_t
dds_create_topic(
dds_entity_t participant,
@ -992,7 +1002,13 @@ struct nn_plist;
* @brief Creates a new topic with arbitrary type handling.
*
* The type name for the topic is taken from the provided "sertopic" object. Topic
* matching is done on a combination of topic name and type name.
* matching is done on a combination of topic name and type name. Each successful
* call to dds_create_topic creates a new topic entity sharing the same QoS
* settings with all other topics of the same name.
*
* If sertopic is not yet known in the domain, it is added and its refcount
* incremented; if an equivalent sertopic object is already known, then the known
* one is used instead.
*
* @param[in] participant Participant on which to create the topic.
* @param[in] sertopic Internal description of the topic type (includes name).
@ -1000,14 +1016,20 @@ struct nn_plist;
* @param[in] listener Any listener functions associated with the new topic (can be NULL).
* @param[in] sedp_plist Topic description to be published as part of discovery (if NULL, not published).
*
* @returns A valid topic handle or an error code.
* @returns A valid, unique topic handle or an error code.
*
* @retval >=0
* A valid topic handle.
* A valid unique topic handle.
* @retval DDS_RETCODE_BAD_PARAMETER
* Either participant, descriptor, name or qos is invalid.
* @retval DDS_RETCODE_BAD_PARAMETER
* Either participant, descriptor, name or qos is invalid.
* @retval DDS_RETCODE_INCONSISTENT_POLICY
* QoS mismatch between qos and an existing topic's QoS.
* @retval DDS_RETCODE_PRECONDITION_NOT_MET
* Mismatch between type name in sertopic and pre-existing
* topic's type name.
*/
/* TODO: Check list of retcodes is complete. */
DDS_EXPORT dds_entity_t
dds_create_topic_arbitrary (
dds_entity_t participant,
@ -1030,8 +1052,9 @@ dds_create_topic_arbitrary (
* A valid topic handle.
* @retval DDS_RETCODE_BAD_PARAMETER
* Participant was invalid.
* @retval DDS_RETCODE_PRECONDITION_NOT_MET
* No topic of this name existed yet in the participant
*/
/* TODO: Check list of retcodes is complete. */
DDS_EXPORT dds_entity_t
dds_find_topic(dds_entity_t participant, const char *name);
@ -1047,8 +1070,6 @@ dds_find_topic(dds_entity_t participant, const char *name);
* @retval DDS_RETCODE_OK
* Success.
*/
/* TODO: do we need a convenience version as well that allocates and add a _s suffix to this one? */
/* TODO: Check annotation. Could be _Out_writes_to_(size, return + 1) as well. */
DDS_EXPORT dds_return_t
dds_get_name(dds_entity_t topic, char *name, size_t size);