How DDS errors are notified as exceptions in the API.

Most methods in the C# API report errors as exceptions associated with the standard DDS error codes.

The following table associates each DDS error code with an exception:

Error code	Exception
`DDS_RETCODE_OK`	(No exception)
`DDS_RETCODE_ERROR`	`Omg.Dds.Core.DdsException`
`DDS_RETCODE_NO_DATA`	(No exception, usually an empty collection is returned)
`DDS_RETCODE_BAD_PARAM`	`System.ArgumentException` or `System.NullArgumentException`
`DDS_RETCODE_PRECONDITION_NOT_MET`	`Omg.Dds.Core.PreconditionNotMetException`
`DDS_RETCODE_ILLEGAL_OPERATION`	`System.InvalidOperationException`
`DDS_RETCODE_OUT_OF_RESOURCES`	`Omg.Dds.Core.OutOfResourcesException`
`DDS_RETCODE_NOT_ENABLED`	`Omg.Dds.Core.NotEnabledException`
`DDS_RETCODE_IMMUTABLE_POLICY`	`Omg.Dds.Core.ImmutablePolicyException`
`DDS_RETCODE_INCONSISTENT_POLICY`	`Omg.Dds.Core.InconsistentPolicyException`
`DDS_RETCODE_ALREADY_DELETED`	`System.ObjectDisposedException`
`DDS_RETCODE_TIMEOUT`	`System.TimeoutException`
`DDS_RETCODE_UNSUPPORTED`	`System.NotSupportedException`
`DDS_RETCODE_NOT_ALLOWED_BY_SECURITY`	`Omg.Dds.Core.NotAllowedBySecurityException`

In most cases, the exception Message includes additional information about the error. This information may also be logged by Rti.Config.Logger.

Depending on the verbosity, Rti.Config.Logger will also log warnings and other informational messages that don't cause an exception.

Note: Errors that occur before the creation of the application's first DomainParticipant are also logged by Rti.Config.Logger, but the exception they produce may not include the details in its Message.

Methods and properties never return null to indicate an error. When a method can return null (for example, Rti.Dds.Domain.DomainParticipant.LookupDataReader()), it is explicitly documented and the method has the attribute [return: MaybeNull].

Methods and properties in general don't accept null arguments either. If an argument of property can be null (for example Rti.Dds.Core.QosProvider.DefaultProfile), it also documents it and has the [AllowNull] attribute.