Re: scrolling optimization + asynchronous updates impossible

[Roland McGrath]

> Actually, fs_notify.defs is using routines, not simpleroutines, and we have
> special hacks in libdiskfs and console to get simpleroutines... delivering
> them synchronously would work as well, although it would not be so good if
> you have multiple clients.

I think that might just have been an oversight, and it seems entirely
reasonable for filesystems to refuse to do anything synchronous (let the
message queuing do it).

> BTW, if the port queue is full, the call blocks in the server, even if it is
> a simple routine, because the MiG stubs don't have a timeout (or notify
> port).  I just tried it: Using ports_manage...one_thread, the server will
> block during operation, and the effect is that we have almost synchronizity
> where the server is always a couple RPCs ahead (as many as the queue can
> hold).  In the case of several clients, this would block other clients, too.

Ack.  It should use timeout=0 and let the user lose if he didn't drain his
port queue fast enough.