709736 - [OS.File] investigate OS-accelerated asynchronous back-ends

Status: RESOLVED WONTFIX

(Core :: Networking: File, enhancement)

Description

[David Teller [:Yoric] - still alive but not very active]

For the moment, JSFileAPI asynchronous IO is either main-thread IO cut in chunks or off-main thread synchronous IO.

We should investigate using AIO/epoll/iocp/libev/libevent to optimize this.

Comment 1

[David Teller [:Yoric] - still alive but not very active]

- libev, libevent, kqueue, epoll cannot handle regular files;
- from what I understand, AIO (under Linux) and IOCP (under Windows) can;
- on the Mac, from what I understand, the only solution is dispatching to another thread.

I believe that we should first implement dispatching to another thread, and then investigate AIO and IOCP.

Comment 2

[Brian Smith (:briansmith, :bsmith, use NEEDINFO?)]

Probably stating the obvious here, but the stream transport service (nsIStreamTransportService) already converts synchronous blocking I/O to asynchronous non-blocking I/O via a pool of background threads.

Comment 3

[David Teller [:Yoric] - still alive but not very active]

Sure. However, this bug is about whether we can do better than a background thread for specific I/O tasks. I am not too confident that we can, though.

Comment 4

[David Teller [:Yoric] - still alive but not very active]

This bug is probably not very useful after all.