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Publisher

DDS_Publisher entity and associated elements More...

Data Structures

struct  DDS_PublisherQos
 <<cert>> QoS policies supported by a DDS_Publisher entity. More...
struct  DDS_PublisherListener
 <<interface>> <<cert>> DDS_Listener for DDS_Publisher status. More...

Macros

#define DDS_PublisherQos_INITIALIZER
 <<cert>> Initializer for new QoS instances.
#define DDS_PublisherListener_INITIALIZER
 <<cert>> Initializer for new DDS_PublisherListener.

Typedefs

typedef struct DDS_PublisherImpl DDS_Publisher
 <<interface>> <<cert>> A publisher is the object responsible for the actual dissemination of publications.

Functions

DDS_ReturnCode_t DDS_PublisherQos_initialize (struct DDS_PublisherQos *self)
 Initializer for new QoS instances.
DDS_ReturnCode_t DDS_PublisherQos_copy (struct DDS_PublisherQos *self, const struct DDS_PublisherQos *source)
 Copy the contents of the given QoS into this QoS.
DDS_ReturnCode_t DDS_PublisherQos_finalize (struct DDS_PublisherQos *self)
 Free any dynamic memory allocated by the policies in this DDS_PublisherQos.
DDS_EntityDDS_Publisher_as_entity (DDS_Publisher *publisher)
 <<cert>> Access a DDS_Publisher's supertype instance.
DDS_ReturnCode_t DDS_Publisher_get_default_datawriter_qos (DDS_Publisher *self, struct DDS_DataWriterQos *qos)
 Copies the default DDS_DataWriterQos values into the provided DDS_DataWriterQos instance.
DDS_ReturnCode_t DDS_Publisher_set_default_datawriter_qos (DDS_Publisher *self, const struct DDS_DataWriterQos *qos)
 Sets the default DDS_DataWriterQos values for this publisher.
DDS_DataWriterDDS_Publisher_create_datawriter (DDS_Publisher *self, DDS_Topic *topic, const struct DDS_DataWriterQos *qos, const struct DDS_DataWriterListener *listener, DDS_StatusMask mask)
 <<cert>> Creates a DDS_DataWriter that will be attached and belong to the DDS_Publisher.
DDS_ReturnCode_t DDS_Publisher_enable (DDS_Entity *self)
 Enables a DDS_Publisher instance.
DDS_ReturnCode_t DDS_Publisher_delete_datawriter (DDS_Publisher *self, DDS_DataWriter *a_datawriter)
 Deletes a DDS_DataWriter that belongs to the DDS_Publisher.
DDS_DataWriterDDS_Publisher_lookup_datawriter (DDS_Publisher *self, const char *topic_name)
 <<cert>> Retrieves the DDS_DataWriter for a specific DDS_Topic.
DDS_DomainParticipantDDS_Publisher_get_participant (DDS_Publisher *self)
 <<cert>> Returns the DDS_DomainParticipant to which the DDS_Publisher belongs.
DDS_ReturnCode_t DDS_Publisher_delete_contained_entities (DDS_Publisher *self)
 Deletes all the entities that were created by means of the "create" operation on the DDS_Publisher.
DDS_ReturnCode_t DDS_Publisher_set_qos (DDS_Publisher *self, const struct DDS_PublisherQos *qos)
 Sets the publisher QoS.
DDS_ReturnCode_t DDS_Publisher_get_qos (DDS_Publisher *self, struct DDS_PublisherQos *qos)
 Gets the publisher QoS.
DDS_ReturnCode_t DDS_Publisher_set_listener (DDS_Publisher *self, const struct DDS_PublisherListener *listener, DDS_StatusMask mask)
 Sets the publisher listener.
struct DDS_PublisherListener DDS_Publisher_get_listener (DDS_Publisher *self)
 Get the publisher listener.

Variables

struct DDS_DataWriterQos DDS_DATAWRITER_QOS_DEFAULT
 <<cert>> Special value for creating DDS_DataWriter with default QoS

Detailed Description

DDS_Publisher entity and associated elements


Macro Definition Documentation

#define DDS_PublisherQos_INITIALIZER

<<cert>> Initializer for new QoS instances.

New DDS_PublisherQos instance stored on the stack should be initialized with this value before they are passed to any function. This step ensures that those contained QoS policies that use dynamic memory are properly initialized. This does not allocate memory.

The simplest way to create a new QoS structure is to initialize it on the stack at the time of its creation:

See also:
DDS_PublisherQos_finalize
#define DDS_PublisherListener_INITIALIZER

<<cert>> Initializer for new DDS_PublisherListener.

All the new DDS_PublisherListener instances allocated in the stack should be initialized to this value.No memory is allocated.

/* initialize listener functions */
DDS_Publisher_set_listener(myPublisher, &listener, mask);
See also:
DDS_Publisher_set_listener
DDS_PublisherListener

Typedef Documentation

typedef struct DDS_PublisherImpl DDS_Publisher

<<interface>> <<cert>> A publisher is the object responsible for the actual dissemination of publications.

QoS:
DDS_PublisherQos
Listener:
DDS_PublisherListener

A publisher acts on the behalf of one or several DDS_DataWriter objects that belong to it. When it is informed of a change to the data associated with one of its DDS_DataWriter objects, it decides when it is appropriate to actually send the data-update message. In making this decision, it considers any extra information that goes with the data (timestamp, writer, etc.) as well as the QoS of the DDS_Publisher and the DDS_DataWriter.

The following operations may be called even if the DDS_Publisher is not enabled. Other operations will fail with the value DDS_RETCODE_NOT_ENABLED if called on a disabled DDS_Publisher:


Function Documentation

DDS_ReturnCode_t DDS_PublisherQos_initialize ( struct DDS_PublisherQos self)

Initializer for new QoS instances.

New DDS_PublisherQos instances on heap should be initialized with this function before they are passed to any function. This step ensures that those contained QoS policies that use dynamic memory are properly initialized. This function does not allocate memory.

Parameters:
self<<in>> Cannot be NULL.
Returns:
One of the Standard Return Codes
See also:
DDS_PublisherQos_finalize
DDS_ReturnCode_t DDS_PublisherQos_copy ( struct DDS_PublisherQos self,
const struct DDS_PublisherQos source 
)

Copy the contents of the given QoS into this QoS.

DDS_PublisherQos instances can use dynamic memory because of the sequences contained in some QoS policies. A shallow copy by assignment is therefore unsafe. This function performs a deep-copy, allocating memory if necessary.

Parameters:
self<<in>> Cannot be NULL.
source<<in>> The DDS_PublisherQos to copy from.
Returns:
One of the Standard Return Codes
See also:
DDS_PublisherQos_INITIALIZER
DDS_PublisherQos_initialize
DDS_PublisherQos_finalize
DDS_ReturnCode_t DDS_PublisherQos_finalize ( struct DDS_PublisherQos self)

Free any dynamic memory allocated by the policies in this DDS_PublisherQos.

Some QoS policies may use dynamic memory (regardless of whether the QoS itself is in dynamic memory). This function frees that memory but otherwise leaves this QoS unchanged. It should be called on all instances before they are freed (or, in the case of stack-based instances, before they go out of scope).

This function does not leave this object in an invalid state. It is permissable to clear a QoS and then subsequently allocate new dynamic memory in one or more of its QoS policies.

Note that if this QoS instance is stored in heap memory, calling this function will not call free() on it; the user is responsible for explicitly freeing any heap-based QoS instance after calling this function.

Parameters:
self<<in>> Cannot be NULL.
Returns:
One of the Standard Return Codes
See also:
DDS_PublisherQos_INITIALIZER
DDS_PublisherQos_initialize
DDS_Entity* DDS_Publisher_as_entity ( DDS_Publisher publisher)

<<cert>> Access a DDS_Publisher's supertype instance.

Parameters:
publisher<<in>> Cannot be NULL.
Returns:
The DDS_Entity that is supertype instance of the publisher.
DDS_ReturnCode_t DDS_Publisher_get_default_datawriter_qos ( DDS_Publisher self,
struct DDS_DataWriterQos qos 
)

Copies the default DDS_DataWriterQos values into the provided DDS_DataWriterQos instance.

The retreived qos will match the set of values specified on the last successful call to DDS_Publisher_set_default_datawriter_qos or else, if the call was never made, the default values from is owning DDS_DomainParticipant.

This function may potentially allocate memory depending on the sequences contained in some QoS policies.

MT Safety:
UNSAFE. It is not safe to retrieve the default QoS value from a DDS_Publisher while another thread may be simultaneously calling DDS_Publisher_get_default_datawriter_qos or calling DDS_Publisher_create_datawriter with DDS_DATAWRITER_QOS_DEFAULT as the qos parameter.
Parameters:
self<<in>> Cannot be NULL.
qos<<inout>> DDS_DataWriterQos to be filled-up. Cannot be NULL.
Returns:
One of the Standard Return Codes
See also:
DDS_DATAWRITER_QOS_DEFAULT
DDS_Publisher_create_datawriter
DDS_ReturnCode_t DDS_Publisher_set_default_datawriter_qos ( DDS_Publisher self,
const struct DDS_DataWriterQos qos 
)

Sets the default DDS_DataWriterQos values for this publisher.

This call causes the default values inherited from the owning DDS_DomainParticipant to be overridden.

This default value will be used for newly created DDS_DataWriter if DDS_DATAWRITER_QOS_DEFAULT is specified as the qos parameter when DDS_Publisher_create_datawriter is called.

Precondition:
The specified QoS policies must be consistent, or else the operation will have no effect and fail with DDS_RETCODE_INCONSISTENT_POLICY
MT Safety:
UNSAFE. It is not safe to retrieve the default QoS value from a DDS_Publisher while another thread may be simultaneously calling DDS_Publisher_get_default_datawriter_qos or calling DDS_Publisher_create_datawriter with DDS_DATAWRITER_QOS_DEFAULT as the qos parameter.
Parameters:
self<<in>> Cannot be NULL.
qos<<in>> Default qos to be set. The special value DDS_DATAREADER_QOS_DEFAULT may be passed as qos to indicate that the default QoS should be reset back to the initial values the factory would have used if DDS_Publisher_set_default_datawriter_qos had never been called. Cannot be NULL.
Returns:
One of the Standard Return Codes, or DDS_RETCODE_INCONSISTENT_POLICY
DDS_DataWriter* DDS_Publisher_create_datawriter ( DDS_Publisher self,
DDS_Topic topic,
const struct DDS_DataWriterQos qos,
const struct DDS_DataWriterListener listener,
DDS_StatusMask  mask 
)

<<cert>> Creates a DDS_DataWriter that will be attached and belong to the DDS_Publisher.

Precondition:
If publisher is enabled, topic must have been enabled. Otherwise, this operation will fail and no DDS_DataWriter will be created.
The given DDS_Topic must have been created from the same participant as this publisher. If it was created from a different participant, this function will fail.
Parameters:
self<<in>> Cannot be NULL.
topic<<in>> The DDS_Topic that the DDS_DataWriter will be associated with. Cannot be NULL.
qos<<in>> QoS to be used for creating the new DDS_DataWriter. The special value DDS_DATAWRITER_QOS_DEFAULT can be used to indicate that the DDS_DataWriter should be created with the default DDS_DataWriterQos set in the DDS_Publisher.

Cannot be NULL.

Parameters:
listener<<in>> The listener of the DDS_DataWriter.
mask<<in>>. Changes of communication status to be invoked on the listener.
Returns:
A DDS_DataWriter of a derived class specific to the data type associated with the DDS_Topic or NULL if an error occurred.
See also:
Specifying QoS on entities for information on setting QoS before entity creation
DDS_DataWriterQos for rules on consistency among QoS
DDS_DATAWRITER_QOS_DEFAULT
DDS_ReturnCode_t DDS_Publisher_enable ( DDS_Entity self)

Enables a DDS_Publisher instance.

Parameters:
self<<in>> Cannot be NULL.
Returns:
One of the Standard Return Codes
See also:
DDS_Entity_enable
DDS_ReturnCode_t DDS_Publisher_delete_datawriter ( DDS_Publisher self,
DDS_DataWriter a_datawriter 
)

Deletes a DDS_DataWriter that belongs to the DDS_Publisher.

The deletion of the DDS_DataWriter will automatically unregister all instances.

Precondition:
If the DDS_DataWriter does not belong to the DDS_Publisher, the operation will fail with DDS_RETCODE_PRECONDITION_NOT_MET.
Postcondition:
Listener installed on the DDS_DataWriter will not be called after this function completes successfully.
Parameters:
self<<in>> Cannot be NULL.
a_datawriter<<in>> The DDS_DataWriter to be deleted.
Returns:
One of the Standard Return Codes or DDS_RETCODE_PRECONDITION_NOT_MET.
DDS_DataWriter* DDS_Publisher_lookup_datawriter ( DDS_Publisher self,
const char *  topic_name 
)

<<cert>> Retrieves the DDS_DataWriter for a specific DDS_Topic.

This returned DDS_DataWriter is either enabled or disabled.

Parameters:
self<<in>> Cannot be NULL.
topic_name<<in>> Name of the DDS_Topic associated with the DDS_DataWriter that is to be looked up. Cannot be NULL.
Returns:
A DDS_DataWriter that belongs to the DDS_Publisher attached to the DDS_Topic with topic_name. If no such DDS_DataWriter exists, this operation returns NULL.

If more than one DDS_DataWriter is attached to the DDS_Publisher with the same topic_name, then this operation may return any one of them.

MT Safety:
UNSAFE. It is not safe to lookup a DDS_DataWriter in one thread while another thread is simultaneously creating or destroying that DDS_DataWriter.
DDS_DomainParticipant* DDS_Publisher_get_participant ( DDS_Publisher self)

<<cert>> Returns the DDS_DomainParticipant to which the DDS_Publisher belongs.

Parameters:
self<<in>> Cannot be NULL.
Returns:
the DDS_DomainParticipant to which the DDS_Publisher belongs.
DDS_ReturnCode_t DDS_Publisher_delete_contained_entities ( DDS_Publisher self)

Deletes all the entities that were created by means of the "create" operation on the DDS_Publisher.

Deletes all contained DDS_DataWriter objects. Once DDS_Publisher_delete_contained_entities completes successfully, the application may delete the DDS_Publisher, knowing that it has no contained DDS_DataWriter objects.

The operation will fail with DDS_RETCODE_PRECONDITION_NOT_MET if any of the contained entities is in a state where it cannot be deleted.

Parameters:
self<<in>> Cannot be NULL.
Returns:
One of the Standard Return Codes or DDS_RETCODE_PRECONDITION_NOT_MET.
DDS_ReturnCode_t DDS_Publisher_set_qos ( DDS_Publisher self,
const struct DDS_PublisherQos qos 
)

Sets the publisher QoS.

This operation modifies the QoS of the DDS_Publisher.

The DDS_PublisherQos::entity_factory can be changed. The other policies are immutable.

Parameters:
self<<in>> Cannot be NULL.
qos<<in>> DDS_PublisherQos to be set to. Policies must be consistent. Policies cannot be changed after DDS_Publisher is enabled. The special value DDS_PUBLISHER_QOS_DEFAULT can be used to indicate that the QoS of the DDS_Publisher should be changed to match the current default DDS_PublisherQos set in the DDS_DomainParticipant. Cannot be NULL.
Returns:
One of the Standard Return Codes, DDS_RETCODE_IMMUTABLE_POLICY, or DDS_RETCODE_INCONSISTENT_POLICY.
See also:
DDS_PublisherQos for rules on consistency among QoS
set_qos (abstract)
DDS_ReturnCode_t DDS_Publisher_get_qos ( DDS_Publisher self,
struct DDS_PublisherQos qos 
)

Gets the publisher QoS.

This function may potentially allocate memory depending on the sequences contained in some QoS policies.

Parameters:
self<<in>> Cannot be NULL.
qos<<in>> DDS_PublisherQos to be filled in. Cannot be NULL.
Returns:
One of the Standard Return Codes
See also:
get_qos (abstract)
DDS_ReturnCode_t DDS_Publisher_set_listener ( DDS_Publisher self,
const struct DDS_PublisherListener listener,
DDS_StatusMask  mask 
)

Sets the publisher listener.

Parameters:
self<<in>> Cannot be NULL.
listener<<in>> DDS_PublisherListener to set to.
mask<<in>> DDS_StatusMask associated with the DDS_PublisherListener. The callback function on the listener cannot be NULL if the corresponding status is turned on in the mask.
Returns:
One of the Standard Return Codes
See also:
set_listener (abstract)
struct DDS_PublisherListener DDS_Publisher_get_listener ( DDS_Publisher self)
read

Get the publisher listener.

Parameters:
self<<in>> Cannot be NULL.
Returns:
DDS_PublisherListener of the DDS_Publisher.

Variable Documentation

struct DDS_DataWriterQos DDS_DATAWRITER_QOS_DEFAULT

<<cert>> Special value for creating DDS_DataWriter with default QoS

When used in DDS_Publisher_create_datawriter, this special value is used to indicate that the DDS_DataWriter should be created with the default DDS_DataWriter QoS.

See also:
DDS_Publisher_create_datawriter

RTI Connext DDS Micro C API Version 2.4.12 Copyright © Tue Feb 4 2020 Real-Time Innovations, Inc