Standards Update, IEEE 1003.4: Real-time Extensions
Chuck.Phillips
Chuck.Phillips at FtCollins.NCR.COM
Thu Aug 30 00:01:44 AEST 1990
From: Chuck.Phillips at FtCollins.NCR.COM (Chuck.Phillips)
>>>>> On 28 Aug 90 11:58:40 GMT, sp at mysteron.osf.org (Simon Patience) said:
>> Finally, the group accepted abandoning the use of
>> file descriptors for semaphore handles, but some participants
>> wanted to keep semaphore names pathnames.
>>
>Aargh! Almost everyone realizes that System V IPC is a botch, largely
>because it doesn't live in the filesystem. So what does IEEE do?
>They take IPC out of the filesystem!
>
>What sane reason could there be to introduce Yet Another Namespace?
Simon> The reason for semaphores not being in the file system is twofold.
Simon> Some realtime embedded systems do not have a file system but do want
Simon> semaphores...
Simon> A good reason for *not* having IPC handles in the file system is to
Simon> allow network IPC to use the same interfaces.
How about adding non-file-system-based "handles" to an mmap-like interface?
(e.g. shmmap(host,porttype,portnum,addr,len,prot,flags)?) This could
allow the same interface to be used for network and non-network IPC,
without the overhead of a trap for every non-network IPC transaction.
`Scuse me while I don my flame retardant suit... :-)
#include <std/disclaimer.h>
--
Chuck Phillips MS440
NCR Microelectronics Chuck.Phillips%FtCollins.NCR.com
2001 Danfield Ct.
Ft. Collins, CO. 80525 uunet!ncrlnk!ncr-mpd!bach!chuckp
Volume-Number: Volume 21, Number 72
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