Known Issues
============

Network interfaces cannot have non-ASCII characters in their name
.................................................................

If a network interface name contains one or more non-ASCII characters, creating
associated *DomainParticipants* may fail and return ``NULL``.

As a workaround, do not use non-ASCII characters in network interface names.

[RTI ISsue ID MICRO-11127]

Script errors when running from a directory with a space in its name
....................................................................

If the path where the ``rtime-make`` script resides includes a space, invoking
``rtime-make`` will cause a scripting error that includes the following:
``line 25: cd: too many arguments.``

As a workaround, install |me| in a directory with no spaces or other special
characters in its path.

[RTI Issue ID MICRO-11099]

Low resolution timestamps may cause Zero Copy samples to remain visible longer than expected
............................................................................................

While using the Zero Copy v2 transport, if a sample is pushed out of a
*DataWriter*'s history at the same time (with the same timestamp) as a
*DataReader* is created, the *DataReader* will still be able to observe it.
Additionally, Zero Copy samples with timestamps using a different clock than the
*DataReader* may be missed.

There is no known workaround for this issue.

[RTI Issue ID MICRO-10926]

DDS_WstringSeq instance may have inconsistent state when set_maximum fails
..........................................................................

If the function ``DDS_WstringSeq_set_maximum()`` fails and returns ``RTI_FALSE``,
the entire sequence object may have an inconsistent state.

As a workaround, do not use the ``DDS_WstringSeq`` instance after a call to its
``set_maximum`` has failed.

[RTI Issue ID MICRO-9999]

Logging mechanism is not included by default
............................................

|me| supports logging in its Debug libraries, but the Platform Support Library
(PSL) does not include a default logging mechanism. To see logging, you must
set a log handler or log display function in your application.

For more information, see :ref:`section-debugging`.

[RTI Issue ID MICRO-8534]

DDS_DomainParticipantFactory_get_instance() not memory safe on some architectures
.................................................................................

On architectures with weak memory ordering (such as ARM),
``DDS_DomainParticipantFactory_get_instance()`` is not guaranteed to be memory
safe.

As a workaround, use an OS API call that acts as a memory barrier before and
after calling ``DDS_DomainParticipantFactory_get_instance()``. For example:

.. code-block::

  mutex_lock(my_mutex);
  instance = DDS_DomainParticipantFactory_get_instance();
  mutex_unlock(my_mutex);

[RTI Issue ID MICRO-8004]

Samples cannot be reclaimed if Zero Copy application does not return loan
.........................................................................

If a *DomainParticipant* subscribing to Zero Copy data dies after reading or taking Zero 
Copy samples but before returning their loan, or never returns the loan for some 
other reason, then those samples can never be reclaimed for subsequent publishing 
and can be considered lost resources.

There is currently no known workaround that entirely removes the risk of samples 
becoming unavailable for reclaiming. The impact of such a scenario can be 
decreased by following these recommendations:

* On the receiving side, process samples one at a time, by setting the 
  ``max_samples`` parameter to 1 when invoking the ``read()`` or ``take()`` family 
  of functions. This will limit the impact of a dying process to a resource loss of 
  1 sample at most.

* Increase the ``max_samples`` resource limit on the *DataWriter*, to exceed the 
  number of expected matching *DataReaders*. If the previous recommendation is 
  followed as well, then the sample resources might decrease due to subscribing 
  process failures, but never be exhausted.

[RTI Issue ID MICRO-5834]

VOLATILE Zero Copy DataReaders behave as TRANSIENT_LOCAL
........................................................

When a *DataReader* matches a *DataWriter* via Zero Copy communication, 
it has visibility into all samples that are present at that time, independent 
of its setting for the ``DURABILITY`` QoS. This may be unexpected and is not 
consistent with *VOLATILE* *DataReaders* that match to that same *DataWriter* via 
other transports. 

[RTI Issue ID MICRO-5550]

Reliable DataWriters send Heartbeats to best-effort DataReaders
...............................................................

Reliable *DataWriters* incorrectly send periodic and piggybacked
Heartbeats to best-effort *DataReaders*.

[RTI Issue ID MICRO-2225]

Static endpoint discovery requires unique object IDs across all remote endpoints
................................................................................

When using static endpoint discovery (DPSE), |me| requires that the
``object_id`` for statically asserted remote endpoints must be unique across
all remote endpoints, as opposed to just among remote endpoints within the
same *DomainParticipant*.

[RTI Issue ID MICRO-211]