This happens for example if a node is configured with a 1024-word
packet size and sends to a node with a 256-word packet size. In the
emulator PNC design, the packet has already been ACK'd at the sending
side, so there is no way to indicate a transmission error other than
taking down the connection. Since the error will just occur again,
the best course is to disable the node until the next reboot.
Primenet will disconnect the sending and receive nodes from each other
in about 30 seconds.
Also removed pnchexuid: useful in the beginning, not so much now.
1. Need 32-bit integer for dma address so newer Primos can use I/O
segments other than 0.
2. Ignore interrupted select()
3. Set fd to -1 after closing when not connected, to avoid bad
file descriptor error
work okay and not have the 30-second delay problem.
Over netlink, a prirun, l, displays a couple of medium-sized packets,
then '55' from PR0055 in a tiny packet, then one more reasonable-size
packet. The tiny packet seems odd, but I'm guessing it's a window
size or buffer size thing inside Primos / Primenet.
interrupts are enabled. This fixes the 30-second lag problem, but
also causes PNCDIM to get notified too many times. After an xmit,
devpnc causes an immediate interrupt. This is handled by the SEG4
phantom interrupt code by disabling PNC interrupts, then notifying
PNCDIM. (Remember, PNCDIM is still in the xmit OTA, or shortly
following). PNCDIM finishes its loop, enables interrupts, and does a
WAIT. When it enables interrupts before the WAIT, devpnc doesn't
remember that it has already interrupted, and interrupts again. I
think this is a bug - the other emulator controllers have a state
variable to remember whether they have already interrupted. But,
if I fix this "bug", we'll probably have 30-second delays again.
Hmmm...
problem with remote terminal sessions:
1. netlink to remote Prime
2. a prirun
3. l (list directory)
4. displays a little, then a longish pause up to 30 seconds, then the rest
Does a similar thing with stat us. Hitting Enter will cause it to
finish, while typing characters does not. I suspect this is a problem
with Prime's networking code, but not sure.
Also, if async I/O is used, the QUIT. OK, message doesn't appear after
ctrl-p. I think they are getting wiped out by Primenet's buffer
flushes.
All of this might be subtle timing problems because I changed the
default clock rate from 250/330/500/whatever times per sec to 20 times
per second in this rev 19 version of Primos.
