On 05/28/2014 11:52 PM, John Lumby wrote:
The patch is attached. It is based on clone of today's 9.4dev source. I have noticed that this source is (not suprisingly) quite a moving target at present, meaning that this patch becomes stale quite quickly. So although this copy is fine for reviewing, it may quite probably soon not be correct for the current source tree. As mentioned before, if anyone wishes to try this feature out on 9.3.4, I will be making a patch for that soon which I can supply on request.
Wow, that's a huge patch. I took a very brief look, focusing on the basic design. ignoring the style & other minor things for now:
The patch seems to assume that you can put the aiocb struct in shared memory, initiate an asynchronous I/O request from one process, and wait for its completion from another process. I'm pretty surprised if that works on any platform.
How portable is POSIX aio nowadays? Googling around, it still seems that on Linux, it's implemented using threads. Does the thread-emulation implementation cause problems with the rest of the backend, which assumes that there is only a single thread? In any case, I think we'll want to encapsulate the AIO implementation behind some kind of an API, to allow other implementations to co-exist.
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