Interprocess Communication / Multitasking

[Warren Tucker]

In article <15345 at megatest.UUCP> djones at megatest.UUCP (Dave Jones) writes:
>From article <320 at n4hgf.Mt-Park.GA.US), by wht at n4hgf.Mt-Park.GA.US (Warren Tucker):
>) UNIX lacks "lightweight processes," threads which execute within
>) a single address space (alas) ...
>
>Sun's "release 4" Unix, (an amalgam of BSD and ATT flavors), comes with
>a lightweight process package. I've only looked at it long enough to
>speculate, "I wouldn't have done it that way," but it may be just the
>ticket for you. If you have a Sun workstation, say, "man lpw_create" to get
>started.

Here's a big plus for "non-standard UNIX!!"

I have only looked briefly myself, but the implementation appears
to be a very rich superset of rather classical in-process
multiprocessing, like what I used to use quite profitably on Data
General's RDOS and AOS, Interdata's OS-32MT and --oh well, I
betray my age if I go on.

Thanks for the pointer, Dave.  I thought it quite odd when I came
to UNIX and found that you HAVE to use shared memory and Ph.D.
class IPC to communicate among threads.  At least you can get by
with S5.  With BSD, ye be sucking wind.  Lightweight processes
are a very very big plus for communications programs dealing with
a full duplex line.  fork(2) may be elegant, but it has always
reminded me of the physicist joke that ends with "First, assume a
spherical horse."

Now, maybe in Sys V Release 5, when a possible reunification of
all the new deviants takes place (a la S5R4), hopest me that lpw
will be in there.
 
-----------------------------------------------------------------------
Warren Tucker, TuckerWare   gatech!n4hgf!wht or wht at n4hgf.Mt-Park.GA.US
Many [Nobel physics] prizes  have been given  to people for  telling us
the universe is not as simple as we thought it was. -Stephen Hawking in
A Brief History of Time     In computing, there are no such prizes. -me