Re: Improving read/write/close system call reliability when used with pthreads
From: Fredrik Noring
Date: Mon Aug 13 2007 - 08:28:33 EST
David,
True. Even though there is a point in making the kernel detect and
behave consistently in this case applications (often) end up with
their own mess they cannot easily handle. A few more use cases would
now work OK but probably not enough to make the improvement worthwhile.
Thanks,
Fredrik
13 aug 2007 kl. 05.14 skrev David Schwartz:
Since there's no atomic "unlock and read" function, any code that
could ever
close a socket in one thread while another thread is blocked on
read might
call close just before another thread blocks in read. Nothing stops
another
thread from opening something, getting the same file descriptor,
and then
allowing the thread to call "read" on the wrong file descriptor
entirely.
Since this can never be made sane in general, I see little point in
making
one variation of what can go wrong a bit saner. It is still
irresponsible to
code like this.
DS
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