gtpn1m0v | Non-SNA Data Communications Reference |
The synchronous link control section of the core-resident CCP and receipt of information on a line, the control of LCB and message queues, the activating of the input LCB and message processing programs and the monitoring of time out situations.
The following members contain logic entirely associated with control of Synchronous Links.
Also, it contains keypoint D and translate tables used by SLC communications source and the output message handler.
When a data message block or ENQ is taken from either the input or ready (PI) list by the CPU loop, it is passed to this routine by means of the branch vector stored in the block. OPZO adds the blocks to the channel's input block queue and if input message handler is not already active, activates it.
These routines are used by other members. CLQG uses function (1) to add actual LCBs whilst CLQM uses it to add "pseudo LCBs" reflecting time out or TSI exhaustion situation. Function (2) is used by CLQG as part of its initialization logic.
These routines set up and control the channel command words (CCW) associated with reading information, and handle the queueing of input LCBs and data message blocks. Input LCBs, except for ENQ, are added to the Input LCB queue, and ENQs and all data message blocks are added either to the input or ready (PI) list, according to the setting of a system parameter (in CLQA).
These routines set up and control the channel command words associated with writing information and handle the queueing and dequeueing of output LCB and message blocks (PLONC macro support). Output initiate includes the assignment of TSIs.
Contains the code for handling application messages destined for transmission across a link, adding them to an AMQ and, if necessary, activating the appropriate output sender.
The following modules have been modified, to a greater or lesser extent, to cater to the link.