Added Message Suppression flag for status values, including providing a -Q option to the RETURN command to return with a message suppressed status
Added Do command file default extension of .sim (from Dave Bryan)
Added -O option to DO command file invocation which causes the caller's ON state and actions to be inherited in the newly called DO command file
Added Command Line expansion to include a %* which expands to the whole set of arguments (%1 ... %9)
Relaxed Command Line argument substitution (delimited by %'s) which cause environment variable lookups to first lookup the literal name provided and if that fails, lookup the name upcased.
Added a SIM_VERIFY special Command Line expansion variable which expands to "-V" when command echoing is active
Added a SIM_MESSAGE special Command Line expansion variable which expands to "-Q" when error message display is suppressed
Added Command Aliasing, which causes the initial token on a command line to be looked up in the environment variable table, and if it exists to substitute the expansion for the initial token.
Changed environment variable defining (with SET ENV variable=value) to always upcase the variable name.
Added SHIFT command which shifts the numbered argument variables %1 ... %9 to the left by one (%1 becomes what was %2, etc.)
Added CALL command which will call a routine (label) in the currently executing command file
Added SET VERIFY and SET NOVERIFY commands which enable or disable DO command echoing
Added SET MESSAGE and SET NOMESSAGE commands which globally enable or disable the display of status messages when commands (or Do Commands) return with unsuccessful status
Added SET ON INHERIT and SET ON NOINHERIT to globally enable inheritance of ON state and actions when DO commands are invoked
Added PROCEED and IGNORE commands which are do nothing but return success. These can be used in specific ON actions to possibly ignore particular return status values
Added DO command file line number to error messages which are displayed while processing DO command files
Expanded the DO command nesting level to 20 to potentially allow for more nesting due to the extensive use of CALL commands are used
- Removed flawed logic which assumed that sim_interval was meaningful when referenced by an asynchronous thread.
- Adjust the event_time of events removed from the asynch queue to account for the average time spent on the queue before the event was noticed by the instruction execution thread.
- Added a sim_activate_notbefore function which specifies an rtime which is the earliest time the event should fire.
- Changed the 'wakeup from idle' logic to force an immediate asynch queue check if the wakeup was not due to a timeout (i.e. it was due to an asynch queue insertion).
- Fixed the descrip.mms to build asynchronous support on AXP and IA64 VMS with kernel threads enabled
Fixed OS/X build issues from Tony Nickolson
Fixed OS/X tap networking startup
Added cygwin host NIC hardware address determination
Made *nix host NIC hardware address determination more robust
VMS engineers designed the address conflict strategy when essentially all LANs were single collision domains (i.e. ALL nodes which might be affected by an address conflict were physically present on a single Ethernet cable which might have been extended by a couple of repeaters). Since that time, essentially no networks are single collision domains. Thick and thinwire Ethernet cables don’t exist and very few networks even have hubs. Today, essentially all LANs are deployed using one or more layers of network switches. In a switched LAN environment, the switches on the LAN ‘learn’ which ports on the LAN source traffic from which MAC addresses and then forward traffic destined for particular MAC address to the appropriate ports. If a particular MAC address is already in use somewhere on the LAN, then the switches ‘know’ where it is. The host based test using the loopback protocol is poorly designed to detect this condition. This test is performed by the host first changing the device’s Physical MAC address to the address which is to be tested, and then sending a loopback packet FROM AND TO this MAC address with a loopback reply to be sent by a system which may be currently using the MAC address. If no reply is received, then the MAC address is presumed to be unused. The sending of this packet will result in its delivery to the right system since the switch port/MAC address tables know where to deliver packets destined to this MAC address, however the response it generates won’t be delivered to the system performing the test since the switches on the LAN won’t know about the local port being the right target for packets with this MAC address. A better test design to detect these conflicts would be for the testing system to send a loopback packet FROM the current physical MAC address (BEFORE changing it) TO the MAC address being tested with the loopback response coming to the current physical MAC address of the device. If a response is received, then the address is in use and the attempt to change the device’s MAC address should fail. Since we can’t change the software running in these simulators to implement this better conflict detection approach, we can still ‘do the right thing’ in the sim_ether layer. We’re already handling the loopback test packets specially since we always had to avoid receiving the packets which were being sent, but needed to allow for the incoming loopback packets to be properly dealt with. We can extend this current special handling to change outgoing ‘loopback to self’ packets to have source AND loopback destination addresses in the packets to be the host NIC’s physical address. The switch network will already know the correct MAC/port relationship for the host NIC’s physical address, so loopback response packets will be delivered as needed.
