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Multi-domain support

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Depends on some improvements to Cyclone, source compatible with versions
that lack those improvements.

Signed-off-by: Erik Boasson <eb@ilities.com>
This commit is contained in:
Erik Boasson 2019-09-01 15:30:19 +02:00 • committed by eboasson
parent fb8c08bd7f
commit a63cc8b84d
5 changed files with 429 additions and 91 deletions
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21
README.md
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@ -38,29 +38,8 @@ There are a number of known limitations:
* Cyclone DDS does not yet implement DDS Security. Consequently, there is no support for security
in this RMW implementation either.
* Cyclone DDS does not allow creating a waitset or a guard condition outside a participant, and this
forces the creation of an additional participant. It can be fixed in the RMW layer, or it can be
dealt with in Cyclone DDS, but the trouble with the latter is that there are solid reasons for not
allowing it, even if it is easy to support it today. (E.g., a remote procedure call interface
...)
* Cyclone DDS does not currently support multiple domains simultaneously (waiting in a PR for the
final polish), and so this RMW implementation ignores the domain\_id parameter in create\_node,
instead creating all nodes/participants (including the special participant mentioned above) in the
default domain, which can be controlled via CYCLONEDDS\_URI.
* Deserialization only handles native format (it doesn't do any byte swapping). This is pure
laziness, adding it is trivial.
* Deserialization assumes the input is valid and will do terrible things if it isn't. Again, pure
laziness, it's just adding some bounds checks and other validation code.
* There are some "oddities" with the way service requests and replies are serialized and what it
uses as a "GUID". (It actually uses an almost-certainly-unique 64-bit number, the Cyclone DDS
instance id, instead of a real GUID.) I'm pretty sure the format is wildly different from that in
other RMW implementations, and so services presumably will not function cross-implementation.
* The name mangling seems to be compatibl-ish with the FastRTPS implementation and in some cases
using the ros2 CLI for querying the system works cross-implementation, but not always. The one in
this implementation is reverse-engineered, so trouble may be lurking somewhere. As a related
point: the "no_demangle" option is currently ignored ... it causes a compiler warning.