[Python-ideas] An alternate approach to async IO

[Richard Oudkerk]

On 27/11/2012 7:59pm, Trent Nelson wrote:
>> >But you have to allocate the buffer*before*  you initiate an overlapped
>> >read.  And you may as well make that buffer a Python bytes object (which
>> >can be shrunk if it is too large).  That leaves no "processing" that can
>> >usefully be done by a C level thread pool.
>      I'm a little confused by that last sentence.  The premise of my idea
>      is being able to service AIO via simple GIL-independent threads that
>      really just copy data from A to B.  The simple fact that they don't
>      have to acquire the GIL each time the completion port has an event
>      seems like a big win, no?
>
>      (So I'm not sure if you're saying that this wouldn't work because
>      you may as well use Python bytes objects, and they can't be accessed
>      willy-nilly from non-GIL threads... or if you're saying they can,
>      but there's no benefit from a C-level thread copying data to/from
>      buffers independent of the GIL.)
>

I am saying that there is no copying necessary if you use a bytes object 
as your buffer.  You can just use _PyBytes_Resize() afterwards to shrink 
it if necessary.

-- 
Richard