11 Jan
2019
11 Jan
'19
4:33 p.m.
1. First of all: I understand that early Unix version numbers and dates
mostly
refer to the manual editions, and that core users had
more frequent
snapshots of a constantly evolving code base.
Eh? They primarily refer to the distributions (Research V6, V7, PWB, the
various BSD tapes).
I'm not sure what "core users" are referring to. Most of us had many
versions as we hacked and merged the stock releasesx.
As Clem mentions, V7 had alarm (but simulated sleep in user mode). PWB
predated that slightly and had both sleep() and alarm() as system calls.
This propagated through to System III and V.
I suspect this all is the result of the philosophy of the guys responsible
for those separate kernel developments rather than an evolution of one or
the other.
As he mentions, I'm fairly sure this has nothing to do with networking
directly. Just too handy not to have.
A bigger networking issue was select() (or the like). It used to be an
interesting kludge of running two processes inorder to do simoultaneous
read/write before that.