This removes invocation-side completion queues from the _cygrpc API.
Invocation-side calls are changed to no longer share the same lifetime
as Core calls.
Illegal metadata is now detected on invocation rather than at the start
of a batch (so passing illegal metadata to a response-streaming method
will now raise an exception immediately rather than later on when
attempting to read the first response message).
It is no longer possible to create a call without immediately starting
at least one batch of operations on it. Only tests are affected by this
change; there are no real use cases in which one wants to start a call
but wait a little while before learning that the server has rejected
it.
It is now required that code above cygrpc.Channel spend threads on
next_event whenever events are pending. A cygrpc.Channel.close method
is introduced, but it merely blocks until the cygrpc.Channel's
completion queues are drained; it does not itself drain them.
Noteworthy here is that we drop the cygrpc.Channel.__dealloc__ method.
It is not the same as __del__ (which is not something that can be added
to cygrpc.Channel) and there is no guarantee that __dealloc__ will be
called at all or that it will be called while the cygrpc.Channel
instance's Python attributes are intact (in testing, I saw both in
different environments). This commit does not knowingly break any
garbage-collection-based memory management working (or "happening to
appear to work in some circumstances"), though if it does, the proper
remedy is to call grpc.Channel.close... which is the objective towards
which this commit builds.
Noah Eisen
Muxi Yan
Mehrdad Afshari
Vizerai
jiangtaoli2016
Nathaniel Manista
kpayson64
Mehrdad Afshari
Nicolas "Pixel" Noble
Jan Tattermusch
Mark D. Roth
David Garcia Quintas
Feng Li
Alexander Polcyn
Noah Eisen
Ruslan Nigmatullin