Cleaned up a couple of things here. Specifically:
1) scp_reading is only set when CmdThread is actually reading.
2) Avoid calling ResetEvent(hCmdReadEvent) since it has no effect.
3) Calling ReadFile directly rather than calling read_line which ultimately
calls fgets(stdin) and that ultimately calls ReadFile.
4) Added a cleanup mechanism to shutdown the CmdThread
and related open handles to Events and Thread when the program exits.
Remaining potential problems:
1) A user might have type a partial command (scp_reading) but not
completed it by hitting Enter, and then they perform some GUI
interaction which does other things. Some strange output will be
produced on top of the partially entered command line.
2) Whether or not a complete command has been entered, the original
CmdThread will have a read posted on stdin throughout any activity
initiated by GUI activities. It is not clear that the simulator’s console
will coherently be able to change the console’s mode from the line
oriented mode that SCP uses to the character oriented mode used
while instructions are executing with read pending on the input side.
These changes facilitate more robust parameter type checking and helps
to identify unexpected coding errors.
Most simulators can now also be compiled with a C++ compiler without
warnings.
Additionally, these changes have also been configured to facilitate easier
backporting of simulator and device simulation modules to run under the
simh v3.9+ SCP framework.
Cleanup/Simplification by:
1) removing irrelevant master flag variable from sim_close_sock and thus sim_err_sock
2) change previous boolean feature arguments (datagram, nodelay, reuseaddr) to flag bits in a single option argument. This allows for features to be added by new flag bits which don't change the calling signatures.
3) changed all status returns to be int (vs t_stat) with success being 0 and error being -1
4) removed unneeded simh specific type references to allow sim_sock to be used by n
Extended API by providing flags to influence socket setup/behavior:
SIM_SOCK_OPT_REUSEADDR Retains prior behavior when sim_switches had -U set
SIM_SOCK_OPT_DATAGRAM UDP socket setup provided for when prior datagram argument was specified
SIM_SOCK_OPT_NODELAY TCP Nagle disable provided for when prior nodelay argument was specified
SIM_SOCK_OPT_BLOCKING Blocking socket mode (detault is non blocking)
