
On Fri, 8 Sep 2017 16:04:27 -0700 Eric Snow <ericsnowcurrently@gmail.com> wrote:
The module provides the following functions:
``list()``::
Return a list of all existing interpreters.
It's called ``enumerate()`` in the threading module. Not sure there's a point in choosing a different name here.
The module also provides the following classes:
``Interpreter(id)``::
run(code):
Run the provided Python code in the interpreter, in the current OS thread. If the interpreter is already running then raise RuntimeError in the interpreter that called ``run()``.
The current interpreter (which called ``run()``) will block until the subinterpreter finishes running the requested code. Any uncaught exception in that code will bubble up to the current interpreter.
Why does it block? How is concurrency supposed to be achieved in that model? It would be more flexible if run(code) returned an object that can later be waited on. Something like... a Future :-) And why guarantee that it executes in the "current OS thread"? I would say you don't want to specify where it executes exactly, as it opens the door for more sophisticated implementations (such as automatic assignment of subinterpreters inside a pool of threads).
get_fifo(name):
Return the FIFO object with the given name that is associated with this interpreter. If no such FIFO exists then raise KeyError. The FIFO will be either a "FIFOReader" or a "FIFOWriter", depending on which "add_*_fifo()" was called.
list_fifos():
Return a list of all fifos associated with the interpreter.
If fifos are uniquely named, why not return a name->fifo mapping?
``FIFOReader(name)``:: [...]
I don't think the method naming choice is very adequate here. The API model for the FIFO objects can either be a (threading or multiprocessing) Queue or a multiprocessing Pipe. - if a Queue, then it should have a get() / put() pair of methods - if a Pipe, then it should have a recv() / send() pair of methods Now, since Queues are multi-producer multi-consumer, while Pipes are single-producer single-consumer (they aren't "synchronized"), the better analogy seems to the multiprocessing Pipe here, so I would vote for recv() / send(). But, in any case, definitely not a pop() / push() pair. Has any thought been given to how FIFOs could integrate with async code driven by an event loop (e.g. asyncio)? I think the model of executing several asyncio (or Tornado) applications each in their own subinterpreter may prove quite interesting to reconcile multi-core concurrency with ease of programming. That would require the FIFOs to be able to synchronize on something an event loop can wait on (probably a file descriptor?). Regards Antoine.