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David Schwartz wrote: > You are doing something wrong. You are using 'select' along with blocking > I/O operations. You can't make bricks without clay. If you don't want to > block, you must use non-blocking socket operations. End of story. That's funny, I was under the impression that the whole point of using select() was to enable the use of blocking I/O. If you are on a uniprocessor system, in a single thread, and select() says that a socket is writeable, then I had darn well better be able to write to that socket! Sure, this gets more complicated when multiprocessing or multithreading, but the test program does neither of these. > Just because 'select' indicates a write hit, you are not assured that some > particular write at a later time will not block. Past performance does not > guarantee future results. Think about the whole reason for select()'s existance. If a single-threaded app calls select() and is told a socket is writeable, then a write to that socket should either immediately succeed or immediately fail (if the other socket disappeared in between the calls, for instance). Now granted I use non-blocking I/O out of paranoia, but even there if select() says it is writeable and the send call returns EAGAIN then we get into a nice little infinite loop. select() should be reliable. Chris -- Chris Friesen | MailStop: 043/33/F10 Nortel Networks | work: (613) 765-0557 3500 Carling Avenue | fax: (613) 765-2986 Nepean, ON K2H 8E9 Canada | email: cfriesen@nortelnetworks.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | |||||||||
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