A mutex for inter-process ;-)
julian at elischer.org
Mon Mar 30 18:05:33 PDT 2009
Randall Stewart wrote:
>> I think davidxu@ deischen@ and julian@?
>> BTW. How do you handle with one process exit (abnormally) without
>> releasing the mutex? Just curious :)
> I have a couple of ways of dealing with this..
> 1) Of course the initialization routine calls atexit() to get a
> "cleanup handler" in place.
this is not really sufficient for a system supplied service.
> 2) Often times, of course, this can fail e.g. you get a SIGSEGV..
> or some such. When you attach the memory, an audit is done. The
> audit will validate that the pid is still alive and has the
> particular tid in it. Of course this is not 100% but as long as the
> tid's have not rolled over it should work. The function is also
> public (need to add that and many things to the manual pages ;-D)
> so that onecan call it whenever one wants :-)
TIDs do roll over the last I looked.. (this may have changed)
did you say man page? goodie..
lets' see it..
There have been a lot of IPC and mutex implementations
but the trick always comes with the requirement
that they handle process/thread death.
David has done some recent work in this space..
> I will ping Julian and the others...
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