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On Fri, Apr 4, 2014 at 10:00 PM, Michael Richter <ttmrichter@gmail.com> wrote:
On 5 April 2014 07:56, Sean Conner <sean@conman.org> wrote:
[1]     And oddly enough, performance.  Back in the mid-90s, some friends of
        mine worked at a company that produced commercial X servers.  Their
        fastest version ran on QNX [2], a purely message passing based
        operating system.  Even the X servers that used shared memory were
        slower than their QNX version.

It's even funnier than that.  I worked at Quantum-later-QNX.  There was a phase (pre-QNX4) where the '386 version of QNX did the message passing via shared memory.  This was stripped out from QNX4 (and probably later) because it turned out that it was SLOWER to share memory than to copy it between processes.

People who think message passing is slow have never used a realtime system.  Most RMXes are based on message passing for a reason.

--
"Perhaps people don't believe this, but throughout all of the discussions of entering China our focus has really been what's best for the Chinese people. It's not been about our revenue or profit or whatnot."
--Sergey Brin, demonstrating the emptiness of the "don't be evil" mantra.

I have no issue with message passing, I think either form of IPC can work -- my issue is with the message format.  I don't think serialization should be necessary -- it's slower to json some object than it is to just memcpy().  I'm saying Lua doesn't lend itself for avoiding marshalling/serialization altogether.