ZCOM Tables and Data Structures
ZCOM Header Structure
HCTOTAL - Total number of Dynamic System Configuration (DSC) requests
This field contains the number of DSC requests processed by the ZCOM subsystem since it was initialized and started up. It is incremented every time a DSC request is processed. This value is for information purposes only.
HCSTATE - Dynamic System Configuration (DSC) State
This field is used by the ZCOM subsystem as an indicator for controlling DSC functions. When the value is zero or positive, the DSC functions are enabled. The value represents the number of active DSC requests. When the value is negative, DSC functions are disabled. DSC requests are rejected until this field is set to zero. This field is initialized to zero by
TTGEN.
HCSWAIT - Number of DSC state waiters
This field contains the number of processes suspended, waiting for the DSC state to be set to zero. That is, the processes are waiting for the DSC functions to be enabled. A process will be suspended if it issues a DSC request while the DSC functions are disabled or if it issues a DSC disable request while other DSC requests are in progress.
HRDATAQ - Remote data queue (ZNODE Queue)
This is the data queue for remote ZCOM requests. All ZCOM API requests to a remote node or deferred remote request responses will be added to this queue by the LDM. The remote node request daemon, ZNODE, reads and processes the request from this queue. This special queue is sometimes referred to as the ZNODE queue or ZNODE data queue.
HNDPID - ZNODE
This field contains the process ID (PID) of the local ZNODE daemon to use for signalling the arrival of data on the ZNODE queue. If this value is positive, the LDM will send a signal to this process ID whenever new data is placed in the queue. If this value is negative, a signal will be sent to the process group. The group ID used is the absolute value of this field. This field is initialized to zero by TTGEN and is set up by the ZNODE program when it starts up.
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