Jonathan S. Shapiro said:
On Wed, 2005-02-23 at 18:29 +0100, Ronald Aigner wrote:
I'm personally convinced that you do not need finite IPC timeouts.
I believe that this was agreed at the Dresden L4 summit meeting. The only well-motivated case for timeouts appears to be interacting with physical real-world devices that have embedded timeouts (e.g. disk drives -- if the 15ms seek is not complete in 20ms, your drive is dead). That is, the "watchdog pattern".
My memory is that it was agreed that this case is rare enough, and occurs in software that is unusual enough, that it is not justified to preserve this function in the IPC.
The remaining cases of "no timeout" and "block indefinitely" should remain.
I don't recall that, but then: even better :-)
It was brought to my attention that pagefault timeouts _are_ important as to enforce trust relation with your communication partner. I don't know what the semantic of a zero pagefault timeout is. If it means that the page has to be present and a infinite pagefault timeout means that you don't care, then finite pagefault timeouts seems reasonable. Still, defining a useful value seems unpractical to me.
Ron.