gtpg2m1qGeneral Macros

ENQC-Define and Enqueue Resource

This general macro is used to define to the control program a shared resource and to control access to the resource among ECBs. This macro is used with the DEQC macro.

Format




label
A symbolic name can be assigned to the macro statement.

BLOCK=address
If specified, it is the address of an 8-byte area which contains the ENQC resource name. BLOCK and LEVEL are mutually exclusive.

LEVEL=Dx
If specified, it is a file address reference word (D0-DF) which contains the name of resource. BLOCK and LEVEL are mutually exclusive.

WAIT=label1
The label of an instruction to be given control if the ECB waited before gaining control of the resource. Otherwise, the next sequential instruction will be given control on return from the execution of the macro. WAIT and NOWAIT parameters are mutually exclusive.

NOWAIT=label2
The label of an instruction to be given control if the named resource is already in use by another ECB. If specified and the resource is already in use control will be passed to the specified label without the ECB giving up control. NOWAIT and WAIT parameters are mutually exclusive.

QUAL
Subsystem qualification for the resource. The default value is U.

U
Subsystem qualification applies. The resource name is subsystem unique and is qualified by the Data Base Index (DBI) value for the subsystem.

S
System-wide qualification applies. The resource name is not subsystem unique. Any ECB issuing an ENQC with this system name and QUAL=S will be enqueued on the same named resource. If two ENQCs are issued with the same resource name but different QUAL values, then two different resource names are assumed to exist. The DEQC must have the same QUAL value as the ENQC.

TIMEOUT=n|(Rx)
The number of seconds that the ECB expects to hold the resource. The value may be specified by a self-defining value (from 0 to 4096) or by a value (from 0 to 32 768) in a register.

The timeout does not start until there is another ECB waiting. If the time elapses, the ECB will be exited with a system error. A default value of 180 seconds is used if none is specified. If 0 is specified, the timeout function is turned off.

Entry Requirements

Return Conditions

Programming Considerations

Examples

None.