* Remove dds_return_t / dds_retcode_t distinction (now there is only
dds_return_t and all error codes are always negative)
* Remove Q_ERR_... error codes and replace them by DDS_RETCODE_...
ones so that there is only one set of error codes
* Replace a whole bunch "int" return types that were used to return
Q_ERR_... codes by "dds_return_t" return types
Signed-off-by: Erik Boasson <eb@ilities.com>
The CDR deserializer failed to check it was staying within the bounds of
the received data, and it turns out it also was inconsistent in its
interpretation of the (undocumented) serializer instructions. This
commit adds some information on the instruction format obtained by
reverse engineering the code and studying the output of the IDL
preprocessor, and furthermore changes a lot of the types used in the
(de)serializer code to have some more compiler support. The IDL
preprocessor is untouched and the generated instructinos do exactly the
same thing (except where change was needed).
The bulk of this commit replaces the implementation of the
(de)serializer. It is still rather ugly, but at least the very long
functions with several levels of nested conditions and switch statements
have been split out into multiple functions. Most of these have single
call-sites, so the compiler hopefully inlines them nicely.
The other important thing is that it adds a "normalize" function that
validates the structure of the CDR and performs byteswapping if
necessary. This means the deserializer can now assume a well-formed
input in native byte-order. Checks and conditional byteswaps have been
removed accordingly.
It changes some types to make a compile-time distinction between
read-only, native-endianness input, a native-endianness output, and a
big-endian output for dealing with key hashes. This should reduce the
risk of accidentally mixing endianness or modifying an input stream.
The preprocessor has been modified to indicate the presence of unions in
a topic type in the descriptor flags. If a union is present, any
memory allocated in a sample is freed first and the sample is zero'd out
prior to deserializing the new value. This is to prevent reading
garbage pointers for strings and sequences when switching union cases.
The test tool has been included in the commit but it does not get run by
itself. Firstly, it requires the presence of OpenSplice DDS as an
alternative implementation to check the CDR processing against.
Secondly, it takes quite a while to run and is of no interest unless one
changes something in the (de)serialization.
Finally, I have no idea why there was a "CDR stream" interface among the
public functions. The existing interfaces are fundamentally broken by
the removal of arbitrary-endianness streams, and the interfaces were
already incapable of proper error notification. So, they have been
removed.
Signed-off-by: Erik Boasson <eb@ilities.com>
The name parameter and the name in the sertopic parameter had to match
because it used the one as a key in a lookup checking whether the topic
exists already, and the other as key for the nodes in that index. As
the name is (currently) included in the sertopic, it shouldn't be passed
in separately as well.
Signed-off-by: Erik Boasson <eb@ilities.com>
Extend the endpoint built-in topic data with the participant instance
handle (the GUID was already present). Having the instance handle
available makes it trivial to look up the participant, whereas a lookup
of the GUID is rather impractical.
Signed-off-by: Erik Boasson <eb@ilities.com>
The old entity handle mechanism suffered from a number of problems, the
most terrible one being that it would only ever allocate 1000 handles
(not even have at most 1000 in use at the same time). Secondarily, it
was protected by a single mutex that actually does show up as a limiting
factor in, say, a polling-based throughput test with small messages.
Thirdly, it tried to provide for various use cases that don't exist in
practice but add complexity and overhead.
This commit totally rewrites the mechanism, by replacing the old array
with a hash table and allowing a near-arbitrary number of handles as
well as reuse of handles. It also removes the entity "kind" bits in the
most significant bits of the handles, because they only resulted in
incorrect checking of argument validity. All that is taken out, but
there is still more cleaning up to be done. It furthermore removes an
indirection in the handle-to-entity lookup by embedding the
"dds_handle_link" structure in the entity.
Handle allocation is randomized to avoid the have a high probability of
quickly finding an available handle (the total number of handles is
limited to a number much smaller than the domain from which they are
allocated). The likelihood of handle reuse is still dependent on the
number of allocated handles -- the fewer handles there are, the longer
the expected time to reuse. Non-randomized handles would give a few
guarantees more, though.
It moreover moves the code from the "util" to the "core/ddsc" component,
because it really is only used for entities, and besides the new
implementation relies on the deferred freeing (a.k.a. garbage collection
mechanism) implemented in the core.
The actual handle management has two variants, selectable with a macro:
the preferred embodiment uses a concurrent hash table, the actually used
one performs all operations inside a single mutex and uses a
non-concurrent version of the hash table. The reason the
less-predeferred embodiment is used is that the concurrent version
requires the freeing of entity objects to be deferred (much like the
GUID-to-entity hash tables in DDSI function, or indeed the key value to
instance handle mapping). That is a fair bit of work, and the
non-concurrent version is a reasonable intermediate step.
Signed-off-by: Erik Boasson <eb@ilities.com>
- Replace os_result by dds_retcode_t and move DDS return code defines down.
Eliminates the need to convert between different return code types.
- Move dds_time_t down and remove os_time.
Eliminates the need to convert between different time representations and
reduces code duplication.
- Remove use of Microsoft source-code annotation language (SAL).
SAL annotations are Microsoft specific and not very well documented. This
makes it very difficult for contributers to write.
- Rearrange the abstraction layer to be feature-based. The previous layout
falsely assumed that the operating system dictates which implementation is
best suited. For general purpose operating systems this is mostly true, but
embedded targets require a slightly different approach and may not even offer
all features. The new layout makes it possible to mix-and-match feature
implementations and allows for features to not be implemented at all.
- Replace the os prefix by ddsrt to avoid name collisions.
- Remove various portions of unused and unwanted code.
- Export thread names on all supported platforms.
- Return native thread identifier on POSIX compatible platforms.
- Add timed wait for condition variables that takes an absolute time.
- Remove system abstraction for errno. The os_getErrno and os_setErrno were
incorrect. Functions that might fail now simply return a DDS return code
instead.
- Remove thread-specific memory abstraction. os_threadMemGet and accompanying
functions were a mess and their use has been eliminated by other changes in
this commit.
- Replace attribute (re)defines by ddsrt_ prefixed equivalents to avoid name
collisions and problems with faulty __nonnull__ attributes.
Signed-off-by: Jeroen Koekkoek <jeroen@koekkoek.nl>
