"Volkmar Uhlig" <[EMAIL PROTECTED]> writes: > > Next problem: > > > > The server must then run some function: > > > > get_permissions(sender-id, file-id) -> permissions > > > > to determine what operations are permitted. Note that if this > > operation is performed faithfully and correctly, it is impossible > > to emulate correctly the behavior of the UNIX I_SENDFD socket > > operation without many additional calls to a shared service -- the > > design of the operation makes descriptor transfer an inherently > > expensive operation. > > I would say that is a weak argument considering all the shortcomings of > the POSIX API. Implementing fork within a distributed system is very > expensive--so what? We know for more than 10 years that fork is broken. > I will look into I_SENDFD into more detail and try to give you a > satisfactory answer.
This is related to the problem the L4/Hurd people discussed some month ago. They also have the problem how to transfer access rights from one thread to another in a save way. If I remember correctly they came up with a protocol solving this problem. Maybe a short review of this discussion will help. Regards, Jean _______________________________________________ l4-hackers mailing list [EMAIL PROTECTED] http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers
