Messages in this thread | | | Date | Wed, 8 Sep 1999 23:16:33 -0600 (MDT) | From | The Lost Wizard <> | Subject | Re: clone() and CLONE_PID |
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On 9 Sep 1999, David Wragg wrote:
> POSIX is just an API; it doesn't tell you how to design a > kernel. Generally Linux directly implements POSIX features because > that is simpler, but for POSIX threads it's worth stepping back and > asking what it really needs from the kernel. My opinion is that doesn't > include pid sharing and tids. > > David Wragg
It is my understanding that signals cannot be guaranteed to work according to the POSIX threads specification without the CLONE_PID option. Please don't say this can be done reliably in userspace; it takes a severe performance hit for signal handling and adds several levels of complexity to any pthreads library that uses clone. The way I understand it (and it has been a while since I read anything on the subject) is that certain fatal signals are supposed to be received by all threads/affect all threads no matter which thread receives it. I believe this includes at least one signal that cannot be handled. So how do you propogate this signal reliably to all other threads in the process?
Of course, I may have no idea what I'm talking about, too.
William Astle "Floppity, floppity, flip / The mouse on the mobius strip; / The strip revolved, / The mouse disolved / In a chronodimensional skip."
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