Messages in this thread | | | From | Denys Vlasenko <> | Subject | Re: F_DUPFD_CLOEXEC implementation | Date | Mon, 1 Oct 2007 19:49:03 +0100 |
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On Monday 01 October 2007 19:16, Al Viro wrote: > * it's on a bunch of cyclic lists. Have its neighbor > go away while you are doing all that crap => boom > * there's that thing call current position... It gets buggered. > * overwriting it while another task might be in the middle of > syscall involving it => boom
Hm, I suspected that it's herecy. Any idea how to do it cleanly?
> * non-cooperative tasks reading *in* *parallel* from the same > opened file are going to have a lot more serious problems than agreeing > on O_NONBLOCK anyway, so I really don't understand what the hell is that for.
They don't even need to read in parallel, just having shared fd is enough. Think about pipes, sockets and terminals. A real-world scenario:
* a process started from shell (interactive or shell script) * it sets O_NONBLOCK and does a read from fd 0... * it gets killed (kill -9, whatever) * shell suddenly has it's fd 0 in O_NONBLOCK mode * shell and all subsequent commands started from it unexpectedly have O_NONBLOCKed stdin. -- vda - 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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