On Mon, 21 Mar 2005, Donovan Baarda wrote: > > > The only ways to ensure that a select process does not block like this, > > > without using non-blocking mode, are;
> > 3) Use os.read / os.write. > [...] > > but os.read / os.write will block too. No. >Try it... replace the file > read/writes in selector.py. They will only do partial reads if the file is > put into non-blocking mode. I've just tried it; I replaced: data = o.read(BUFF_SIZE) with: data = os.read(o.fileno(), BUFF_SIZE) Works for me without any hangs. Another example is the subprocess module, which does not use non-blocking mode in any way. (If you are using pipes, however, you shouldn't write more than PIPE_BUF bytes in each write.) > > > I think the fread/fwrite and read/write behaviour is posix standard and > > > possibly C standard stuff... so it _should_ be the same on other > > > platforms. > > > > Sorry if I've misunderstood your point, but fread()/fwrite() does not > > return EAGAIN. > > no, fread()/fwrite() will return 0 if nothing was read/written, and ferror() > will return EAGAIN to indicated that it was a "would block" condition.... at > least I think it does... the man page simply says ferror() returns a > non-zero value. fread() should loop internally on EAGAIN, in blocking mode. /Peter Åstrand <[EMAIL PROTECTED]> _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
