Reviving the thread... if I understand correctly, there is no portable way to do disk I/O asynchronously (and the gist [1] provided by the OP is bogus: the read_data function will block the event loop). Is my understanding correct?
[1] https://gist.github.com/kunev/f83146d407c81a2d64a6 <https://www.google.com/url?q=https%3A%2F%2Fgist.github.com%2Fkunev%2Ff83146d407c81a2d64a6&sa=D&sntz=1&usg=AFQjCNG-U5Mxoo48n49VafkFEr4TnQVm8g> Second question: Node.js does have a complete async API for doing filesysem I/O, even an async stat function! But after reading Glyph's Q&A on Stackoverflow I conclude those filesystem I/O functions in Node must rely on threads underneath, since we can't rely on OS APIs for async filesystem I/O. Is that it? Thanks! Best, Luciano On Tuesday, August 26, 2014 at 11:11:51 PM UTC-3, Glyph Lefkowitz wrote: > > If anyone is curious about the abysmal state of asynchronous file I/O in > popular operating systems, this question I asked on Stack Overflow a while > back has got some really excellent answers on it: < > https://stackoverflow.com/questions/87892/what-is-the-status-of-posix-asynchronous-i-o-aio > >. > > -glyph > > On Aug 25, 2014, at 6:55 PM, Guido van Rossum <[email protected] > <javascript:>> wrote: > > On most OSes, select() and other polling APIs always report disk files to > be "ready", so you basically can't use asyncio with them. On Windows it > will fail; on *n*x it will appear to work but actually you are doing the > whole thing synchronously. The only way to overlap disk I/O with asyncio > events would be to do the disk I/O on a separate thread. > > Someone is working on sendfile support ( > https://code.google.com/p/tulip/issues/detail?id=144, > http://bugs.python.org/issue17552) which would help overlap disk I/O and > socket I/O for the specific case of serving a file from disk directly to a > socket, but even that would be pretty limited. > > > On Mon, Aug 25, 2014 at 3:06 PM, Ludovic Gasc <[email protected] > <javascript:>> wrote: > >> Hi, >> >> I'm looking for the best way to read/write files with AsyncIO. >> Ideally, I want to r/w asynchronously, like with network. >> >> I've found this: https://gist.github.com/kunev/f83146d407c81a2d64a6 >> >> Is it ok, or do you have a better suggestion ? >> >> Regards. >> > > > > -- > --Guido van Rossum (python.org/~guido) > > >
