Abstract:
A data processing system executes a loop comprising a plurality of functional processes and at least one communications handler process. A temporary memory, referred to as the whiteboard, stores information indicating tasks to be performed by the communications handler. Whenever one of the functional processes requires to communicate externally of the system, it places information on the whiteboard indicating a task to be performed by the communications handler. Whenever the communications handler runs, it examines the whiteboard to determine what tasks it has to perform, and performs at least a part of those tasks. The whiteboard allows the communications handler to deal with communications traffic in a piecemeal fashion. This means that other processes running on the system need not be interrupted for a significant length of time when the communications handler runs.
Abstract:
A data processing system includes a control computer which controls and monitors a cooling subsystem. The control computer has a non-volatile memory holding two status logs for recording stautus data and fault information. One of the logs is selected as the current log. If a fault condition is detected, the control computer writes fault information into the current log and then, if the other log is unlocked, locks the current log and selects the other log as the current log. In response to a "request locked log" command, the control computer transmits the contents of the locked log. In response to an "unlock" command, the control computer unlocks the locked log and then, if the other log contains fault information, locks that other log. The system thus provides an efficient mechanism for ensuring that the fault information is maintained, even through system powerdown.
Abstract:
A data processing system includes a control computer which controls and monitors a cooling subsystem. The control computer has a non-volatile memory holding two status logs for recording stautus data and fault information. One of the logs is selected as the current log. If a fault condition is detected, the control computer writes fault information into the current log and then, if the other log is unlocked, locks the current log and selects the other log as the current log. In response to a "request locked log" command, the control computer transmits the contents of the locked log. In response to an "unlock" command, the control computer unlocks the locked log and then, if the other log contains fault information, locks that other log. The system thus provides an efficient mechanism for ensuring that the fault information is maintained, even through system powerdown.