Messages in this thread | | | Date | Sun, 27 Aug 2000 21:54:51 -0600 | From | yodaiken@fsmlabs ... | Subject | Re: SCO: "thread creation is about a thousand times faster than on |
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On Mon, Aug 28, 2000 at 12:37:06AM -0400, Albert D. Cahalan wrote: > > It's silly to expect to "fork" or to "exec" via a file system > > in a minimal realtime environment. These are complex activities > > however you cut it. > > The "exec" is very easy. You don't need a real filesystem. > Your executable names can be a compiled-in table that maps > from string to function pointer.
That's why I wrote: " "exec" via a file system". But exec without a real fs is a pointless feature-- if you have pthread_create and the code in memory already, the only possible use of exec is to do something with file type resources and we just said we didn't have them.
> The "fork" is easy with your choice of position-independent > code, real swapping, x86-style segments, or a real MMU. > You'd use whatever works fastest on the available hardware. > Don't have a COW.
Again, it's a possible, but pointless feature. You want fork/exec in the presence of a file system and memory protection. But since RTLinux has all that nice stuff available from Linux, there is little point in duplicating it in the RT environment.
All that said, I reserve the right to add fork/exec to RTLinux sometime if we see applications that really could make use of it. But my original point remains: the 1003.13 spec allow us to take a coherent subset of POSIX that makes sense in the minimal RT environment.
-- --------------------------------------------------------- Victor Yodaiken Finite State Machine Labs: The RTLinux Company. www.fsmlabs.com www.rtlinux.com
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