System and Message Processing July 12, 2018
JANOS supplies a Message Pump wherein messages of various types may circulate between processes.
JANOS supplies a Message Pump wherein messages of various types may be circulated between processes or application. These messages may be user defined.
The following are the system defined message types.
This message is generated by the system prior to shutdown. When received applications MUST forward the message by returning it to the pump and exit in an expeditious fashion. The JNIOR is about to reboot.
This message is generated by the system periodically. When receive applications MUST forward the message by returning it to the pump. This is used to detect listeners that are no longer responding or that are not properly forwarding messages. The system expects to see this message return to it in a prompt fashion.
This message is generated by an application in response to a SM_PROTCMDMSG command message. It is intended for the JNIOR Protocol server. When received applications MUST forward the message by returning it to the pump.
Lowest allowed user defined message number. Applications that intend to exchange messages SHOULD attempt to define globally unique message identifiers. These must be values from 1024 and up. Message numbers below SM_USER are RESERVED by the system.