8 Nov
2021
8 Nov
'21
5:36 p.m.
At least for Tops-20, you have some sort of control on this because of
two JSYi, SOUT% (write a string) and SOUTR% (write a string record).?
This difference was originally largely for magnetic tape for writing a
'record' (my memory of what that meant is hazy).? It found its way into
DECnet and almost into TCP/IP.
On DECnet you can block on records, using a SINR% to read a SOUTR%,
which means you don't have to specify a length on read, which can speed
certain things up. VIKING does this.? I think DAP might use it to mark
end of stream.? The point is that a DECnet SINR% knows that a SOUTR% was
used.? You can really win knowing this kind of meta data.
On TCP/IP SOUTR% sets PSH (push the existing data) which may get
swallowed along the way, so it's not clear that a SINR% would wake up at
the right point.? I can't remember if I did tests on this.
On 11/8/21 11:09 AM, Robert Armstrong wrote:
"when do
you send the message". That's actually a question with TCP as
well...
You know about the Nagle algorithm, right?
Bob