On Saturday 19 of September 2009 21:56:57 Peter Stuge wrote: > Kamil Dudka wrote: > > > Daniel says that the io operation can in fact block anyway, when the > > > socket is in blocking mode. > > > > Can you reference any specification saying otherwise? > > Do man pages count? I've quoted a few, earlier in the thread. Mikhail > also quoted SUSv3 IIRC, which seemed to agree with the Linux select(2) > man page. > > --8<-- Linux select(2) > DESCRIPTION > select() and pselect() allow a program to monitor multiple file > descriptors, waiting until one or more of the file descriptors > become "ready" for some class of I/O operation (e.g., input possible). A > file descriptor is considered ready if it is possible to perform the corre‐ > sponding I/O operation (e.g., read(2)) without blocking. > -->8-- > > The paragraph "Select Law" in Linux select_tut(2) clarifies a little > further.
Sorry, I've overlooked that quotation ... but I am not sure if it says what you need to hear either. "socket ready" means it's *possible* to perform the I/O operation without blocking. IMO it does not *guarantee* it actually happens. But take it only as my opinion, I've been never good in the modal logic ;-) And to be frank, I've never used select(2) myself beyond some dummy school projects. Kamil _______________________________________________ libssh2-devel http://cool.haxx.se/cgi-bin/mailman/listinfo/libssh2-devel
