Function dds_read_instance_wl

Function Documentation

dds_return_t dds_read_instance_wl(dds_entity_t reader_or_condition, void **buf, dds_sample_info_t *si, uint32_t maxs, dds_instance_handle_t handle)

Access and read loaned samples of data reader, readcondition or querycondition, scoped by the provided instance handle.

This operation implements the same functionality as dds_read_wl, except that only data scoped to the provided instance handle is read.

Parameters

  • reader_or_condition – [in] Reader, readcondition or querycondition entity.

  • buf – [out] An array of pointers to samples into which data is read (pointers can be NULL).

  • si – [out] Pointer to an array of dds_sample_info_t returned for each data value.

  • maxs – [in] Maximum number of samples to read.

  • handle – [in] Instance handle related to the samples to read.

Return values

  • >=0 – Number of samples read.

  • DDS_RETCODE_ERROR – An internal error has occurred.

  • DDS_RETCODE_BAD_PARAMETER – One of the given arguments is not valid.

  • DDS_RETCODE_ILLEGAL_OPERATION – The operation is invoked on an inappropriate object.

  • DDS_RETCODE_ALREADY_DELETED – The entity has already been deleted.

  • DDS_RETCODE_PRECONDITION_NOT_MET – The instance handle has not been registered with this reader.

Returns

A dds_return_t with the number of samples read or an error code.