User Data Type Support
[Topic Module]

Defines generic classes and macros to support user data types. More...


Data Structures
struct	Foo
	A representative user-defined data type. More...
struct	FooTypeSupport
	<<interface>> <<generic>> User data type specific interface. More...
struct	DDS_InstanceHandleSeq
	Instantiates `FooSeq` < DDS_InstanceHandle_t > . More...
Defines
#define	DDS_TYPESUPPORT_C(TTypeSupport, TData)
	Declares the interface required to support a user data type.
#define	DDS_DATAWRITER_C(TDataWriter, TData)
	Declares the interface required to support a user data type specific data writer.
#define	DDS_DATAREADER_C(TDataReader, TDataSeq, TData)
	Declares the interface required to support a user data type-specific data reader.
Typedefs
typedef DDS_HANDLE_TYPE_NATIVE	DDS_InstanceHandle_t
	Type definition for an instance handle.
typedef struct DDS_TypeSupportImpl	DDS_TypeSupport
	<<interface>> An abstract marker interface that has to be specialized for each concrete user data type that will be used by the application.
Functions
Foo *	FooTypeSupport_create_data ()
	<<eXtension>> Create a data type and initialize it.
Foo *	FooTypeSupport_create_data_ex (DDS_Boolean allocatePointers)
	<<eXtension>> Create a data type and initialize it.
DDS_ReturnCode_t	FooTypeSupport_copy_data (Foo dst_data, const Foo src_data)
	<<eXtension>> Copy data type.
DDS_ReturnCode_t	FooTypeSupport_delete_data (Foo *a_data)
	<<eXtension>> Destroy a user data type instance.
DDS_ReturnCode_t	FooTypeSupport_delete_data_ex (Foo *a_data, DDS_Boolean deletePointers)
	<<eXtension>> Destroy a user data type instance.
DDS_ReturnCode_t	FooTypeSupport_initialize_data (Foo *a_data)
	<<eXtension>> Initialize data type.
DDS_ReturnCode_t	FooTypeSupport_initialize_data_ex (Foo *a_data, DDS_Boolean allocatePointers)
	<<eXtension>> Initialize data type.
DDS_ReturnCode_t	FooTypeSupport_finalize_data (Foo *a_data)
	<<eXtension>> Finalize data type.
DDS_ReturnCode_t	FooTypeSupport_finalize_data_ex (Foo *a_data, DDS_Boolean deletePointers)
	<<eXtension>> Finalize data type.
const char *	FooTypeSupport_get_type_name ()
	Get the default name for this type.
DDS_ReturnCode_t	FooTypeSupport_register_type (DDS_DomainParticipant participant, const char type_name)
	Allows an application to communicate to RTI Data Distribution Service the existence of a data type.
DDS_ReturnCode_t	FooTypeSupport_unregister_type (DDS_DomainParticipant participant, const char type_name)
	Allows an application to unregister a data type from RTI Data Distribution Service. After calling unregister_type, no further communication using that type is possible.
void	FooTypeSupport_print_data (Foo *a_data)
	<<eXtension>> Print value of data type to standard out.
DDS_Boolean	DDS_InstanceHandle_equals (const DDS_InstanceHandle_t self, const DDS_InstanceHandle_t other)
	Compares this instance handle with another handle for equality.
DDS_Boolean	DDS_InstanceHandle_is_nil (const DDS_InstanceHandle_t *self)
	Compare this handle to DDS_HANDLE_NIL.
Variables
const DDS_InstanceHandle_t	DDS_HANDLE_NIL
	The NIL instance handle.

Detailed Description

Defines generic classes and macros to support user data types.

DDS specifies strongly typed interfaces to read and write user data. For each data class defined by the application, there is a number of specialised classes that are required to facilitate the type-safe interaction of the application with RTI Data Distribution Service.

RTI Data Distribution Service provides an automatic means to generate all these type-specific classes with the rtiddsgen utility. The complete set of automatic classes created for a hypothetical user data type named Foo are shown below.

Classes auto-created for an application data type named Foo

The macros defined here declare the strongly typed APIs needed to support an arbitrary user defined data of type Foo.

See also:: rtiddsgen

Define Documentation

#define DDS_TYPESUPPORT_C	(	TTypeSupport,
		TData		)

Declares the interface required to support a user data type.

Defines:: FooTypeSupport TypeSupport of type Foo, i.e. FooTypeSupport

Examples:: HelloWorldSupport.c.

#define DDS_DATAWRITER_C	(	TDataWriter,
		TData		)

Declares the interface required to support a user data type specific data writer.

Uses:: FooTypeSupport user data type, Foo

Defines:: FooDataWriter DDS_DataWriter of type Foo, i.e. FooDataWriter

Examples:: HelloWorldSupport.c.

#define DDS_DATAREADER_C	(	TDataReader,
		TDataSeq,
		TData	)

Declares the interface required to support a user data type-specific data reader.

Uses:: FooTypeSupport user data type, Foo FooSeq sequence of user data type, sequence<::Foo>

Defines:: FooDataReader DDS_DataReader of type Foo, i.e. FooDataReader

See also:: FooSeq

Examples:: HelloWorldSupport.c.

Typedef Documentation

typedef DDS_HANDLE_TYPE_NATIVE DDS_InstanceHandle_t

Type definition for an instance handle.

Handle to identiy different instances of the same DDS_Topic of a certain type.

See also:: FooDataWriter_register_instance
DDS_SampleInfo::instance_handle

Examples:: HelloWorld_publisher.c.

typedef struct DDS_TypeSupportImpl DDS_TypeSupport

<<interface>> An abstract marker interface that has to be specialized for each concrete user data type that will be used by the application.

The implementation provides an automatic means to generate a type-specific class, FooTypeSupport, from a description of the type in IDL.

A DDS_TypeSupport must be registered using the FooTypeSupport_register_type operation on this type-specific class before it can be used to create DDS_Topic objects.

See also:: FooTypeSupport
rtiddsgen

Function Documentation

Foo* FooTypeSupport_create_data ( )

<<eXtension>> Create a data type and initialize it.

The generated implementation of the operation knows how to instantiate a data type and initialize it properly.

All memory for the type is deeply allocated.

Returns:: newly created data type

See also:: FooTypeSupport_delete_data

Foo* FooTypeSupport_create_data_ex ( DDS_Boolean allocatePointers )

<<eXtension>> Create a data type and initialize it.

The generated implementation of the operation knows how to instantiate a data type and initialize it properly.

When allocatePointers is DDS_BOOLEAN_TRUE, all the references (pointers) in the type are recursively allocated.

Parameters:

allocatePointers

<<in>> Whether or not to recursively allocate pointers.

Returns:: newly created data type

See also:: FooTypeSupport_delete_data_ex

DDS_ReturnCode_t FooTypeSupport_copy_data	(	Foo *	dst_data,
		const Foo *	src_data
	)

<<eXtension>> Copy data type.

The generated implementation of the operation knows how to copy value of a data type.

Parameters:

	dst_data	<<inout>> Data type to copy value to. Cannot be NULL.
	src_data	<<in>> Data type to copy value from. Cannot be NULL.

Returns:: One of the Standard Return Codes

DDS_ReturnCode_t FooTypeSupport_delete_data ( Foo * a_data )

<<eXtension>> Destroy a user data type instance.

The generated implementation of the operation knows how to destroy a data type and return all resources.

Parameters:

a_data

<<in>> Cannot be NULL.

Returns:: One of the Standard Return Codes

See also:: FooTypeSupport_create_data

DDS_ReturnCode_t FooTypeSupport_delete_data_ex	(	Foo *	a_data,
		DDS_Boolean	deletePointers
	)

<<eXtension>> Destroy a user data type instance.

The generated implementation of the operation knows how to destroy a data type and return all resources.

When deletePointers is DDS_BOOLEAN_TRUE, all the references (pointers) are destroyed as well.

Parameters:

	a_data	<<in>> Cannot be NULL.
	deletePointers	<<in>> Whether or not to destroy pointers.

Returns:: One of the Standard Return Codes

See also:: FooTypeSupport_create_data_ex

DDS_ReturnCode_t FooTypeSupport_initialize_data ( Foo * a_data )

<<eXtension>> Initialize data type.

The generated implementation of the operation knows how to initialize a data type. This function is typically called to initialize a data type that is allocated on the stack.

Parameters:

a_data

<<inout>> Cannot be NULL.

Returns:: One of the Standard Return Codes

See also:: FooTypeSupport_finalize_data

DDS_ReturnCode_t FooTypeSupport_initialize_data_ex	(	Foo *	a_data,
		DDS_Boolean	allocatePointers
	)

<<eXtension>> Initialize data type.

The generated implementation of the operation knows how to initialize a data type. This function is typically called to initialize a data type that is allocated on the stack.

When allocatePointers is DDS_BOOLEAN_TRUE, all the references (pointers) in the type are recursively allocated.

Parameters:

	a_data	<<inout>> Cannot be NULL.
	allocatePointers	<<in>> Whether or not to recursively allocate pointers.

Returns:: One of the Standard Return Codes

See also:: FooTypeSupport_finalize_data_ex

DDS_ReturnCode_t FooTypeSupport_finalize_data ( Foo * a_data )

<<eXtension>> Finalize data type.

The generated implementation of the operation knows how to finalize a data type. This function is typically called to finalize a data type that has previouslly been initialized.

Parameters:

a_data

<<in>> Cannot be NULL.

Returns:: One of the Standard Return Codes

See also:: FooTypeSupport_initialize_data

DDS_ReturnCode_t FooTypeSupport_finalize_data_ex	(	Foo *	a_data,
		DDS_Boolean	deletePointers
	)

<<eXtension>> Finalize data type.

The generated implementation of the operation knows how to finalize a data type. This function is typically called to finalize a data type that has previouslly been initialized.

When deletePointers is DDS_BOOLEAN_TRUE, the memory required by the references (pointers) associated to the type is freed.

Parameters:

	a_data	<<in>> Cannot be NULL.
	deletePointers	<<in>> Whether or not to free memory allocated by the pointers.

Returns:: One of the Standard Return Codes

See also:: FooTypeSupport_initialize_data_ex

const char* FooTypeSupport_get_type_name ( )

Get the default name for this type.

Can be used for calling FooTypeSupport_register_type or creating DDS_Topic

Returns:: default name for this type

See also:: FooTypeSupport_register_type
DDS_DomainParticipant_create_topic

DDS_ReturnCode_t FooTypeSupport_register_type	(	DDS_DomainParticipant *	participant,
		const char *	type_name
	)

Allows an application to communicate to RTI Data Distribution Service the existence of a data type.

The generated implementation of the operation embeds all the knowledge that has to be communicated to the middleware in order to make it able to manage the contents of data of that type. This includes in particular the key definition that will allow RTI Data Distribution Service to distinguish different instances of the same type.

The same DDS_TypeSupport can be registered multiple times with a DDS_DomainParticipant using the same or different values for the type_name. If register_type is called multiple times on the same DDS_TypeSupport with the same DDS_DomainParticipant and type_name, the second (and subsequent) registrations are ignored by the operation fails with DDS_RETCODE_OK.

Precondition:: Cannot use the same type_name to register two different DDS_TypeSupport with the same DDS_DomainParticipant, or else the operation will fail and DDS_RETCODE_PRECONDITION_NOT_MET will be returned.

Parameters:

	participant	<<in>> the DDS_DomainParticipant to register the data type `Foo` with. Cannot be NULL.
	type_name	<<in>> the type name under with the data type `Foo` is registered with the participant; this type name is used when creating a new DDS_Topic. (See DDS_DomainParticipant_create_topic.) The name may not be NULL or longer than 255 characters.

Returns:: One of the Standard Return Codes, DDS_RETCODE_PRECONDITION_NOT_MET or DDS_RETCODE_OUT_OF_RESOURCES.

MT Safety:: UNSAFE on the FIRST call. It is not safe for two threads to simultaneously make the first call to register a type. Subsequent calls are thread safe.

See also:: DDS_DomainParticipant_create_topic

DDS_ReturnCode_t FooTypeSupport_unregister_type	(	DDS_DomainParticipant *	participant,
		const char *	type_name
	)

Allows an application to unregister a data type from RTI Data Distribution Service. After calling unregister_type, no further communication using that type is possible.

The generated implementation of the operation removes all the information about a type from RTI Data Distribution Service. No further communication using that type is possible.

Precondition:: A type with type_name is registered with the participant and all DDS_Topic objects referencing the type have been destroyed. If the type is not registered with the participant, or if any DDS_Topic is associated with the type, the operation will fail with DDS_RETCODE_ERROR.

Postcondition:: All information about the type is removed from RTI Data Distribution Service. No further communication using this type is possible.

Parameters:

	participant	<<in>> the DDS_DomainParticipant to unregister the data type `Foo` from. Cannot be NULL.
	type_name	<<in>> the type name under with the data type `Foo` is registered with the participant. The name should match a name that has been previously used to register a type with the participant. Cannot be NULL.