[zeromq-dev] Passing a python object (PyZMQ)

[Arnaud Loonstra]

A python dictionary is not thread safe, AFAIK. So if multiple producers(threads) write to the dictionary you'll run into trouble.

Rg,

Arnaud

On June 8, 2015 6:05:08 PM GMT+02:00, Min RK <benjaminrk at gmail.com> wrote:
>
>
>> On Jun 8, 2015, at 01:35, Arnaud Loonstra <arnaud at sphaero.org> wrote:
>> 
>>> On 06/06/2015 01:52 AM, MinRK wrote:
>>> Without using ctypes, you could pass the objects through a
>namespace:
>>> 
>>> |# shared namespace
>>> ns = {}
>>> 
>>> # sender
>>> ns[id(obj)] = obj
>>> pipe_out.send(struct.pack(b'Q',1))
>>> 
>>> # receiver
>>> id_bytes = pipe_in.recv()
>>> obj_id = struct.unpack(b'Q', id_bytes)[0]
>>> obj = ns.pop(obj_id)
>>> |
>>> 
>>> The ctypes cast approach doesn’t hold a reference to the object
>while
>>> it’s in transit, so it’s possible for the restoration to fail if the
>>> object has been garbage collected in between send/recv.
>> 
>> You're right I ended up doing something very similar to workaround
>early 
>> garbage collection but this is much nicer. However it only works
>between 
>> a producer and consumer thread, not more. So every producer thread
>needs 
>> its own namespace.
>
>I'm not sure why. You should only need one namespace per process.
>
>-MinRK
>
>> 
>> Rg,
>> 
>> Arnaud
>> -- 
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