[TUHS] Re: Early supported UNIX manual

[Jonathan Gray <jsg@jsg.id.au>]

On Sat, Dec 24, 2022 at 08:58:06AM +0000, segaloco via TUHS wrote:
> Your reference to sema(2) in CB-UNIX prompted me to go check the source and curiously, that isn't in sysent.c:  https://www.tuhs.org/Archive/Distributions/USDL/CB_Unix/SourceCode/cbunix6.pdf (p. 50).  However, there is a sys5.c with some semaphore stuff in it.  Not how the code gets from the sigcall entry to that file, maybe there's a CB-specific syscall aggregator like the sys3b systemcall for 3B20-specific stuff.  It had never actually occurred to me that the semaphores in SVR1 weren't the ones from CB-UNIX, I thought they just forklifted all the IPC into 4.0 from CB.  That then means the semaphores that carried through in System V originated at least in UNIX/TS 4.0, but not by way of CB.  Minor trivia, but that's news to me.  Maybe the sysV modification request logs can shed some light, I remember seeing several IPC mentions in there.
> 
> - Matt G.

https://www.tuhs.org/Archive/Distributions/USDL/CB_Unix/cbunix_man2L_01.pdf
describes 'EVENT:O(2L), event - semaphore operations',
event() is system call 63 in cbunix6.pdf sysent

USG UNIX 4.0 and 4.1 IPC were not the same:
https://groups.google.com/g/net.unix/c/-H9x36DMOBQ/m/4mcL76lKbmMJ