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Prolog Control Block Contents DIOBK DSECT Storage Layout Cross Reference (Contains links to field and bit definitions) |
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DIOBK Prolog | Top of page |
NAME : HCPDIOBK DESCRIPTION: Dynamic I/O control block. DSECT : DIOBK FUNCTION : 1) Anchor the queue of pending CRW tasks for the corresponding RDEV. A CRW task, or queue element, can be one of the following: IPI - Subchannel Add CRW task, IPI - Subchannel Delete CRW task or IPM CRW task. 2) Maintain the count of currently executing CRW AND CRW - related tasks for the corresponding RDEV. CRW - related tasks are invoked by the CRW tasks (IPI - Subchannel Add/Delete CRW task, IPM CRW task). 3) Contains a flag field. LOCATED BY : RDEVDIO of the corresponding RDEV. CREATED BY : HCPRFCDC DELETED BY : HCPRFCET SERIALIZED : Access to the DIOBK is serialized with the RDEV lock of the corresponding RDEV. RELOCATION CONSIDERATIONS : None |
DIOBK Control Block Content | Top of page |
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DIOBK Storage Layout | Top of page |
*** DIOBK - Dynamic I/O control block. * * +---------------------------+------+--------------------+ * 0 | DIOQUEUE |:FLAGS|////////////////////| * +---------------------------+------+--------------------+ * 8 | DIOCOUNT |///////////////////////////| * +---------------------------+---------------------------+ * 10 | | * = DIOLOCK = * | | * +-------------------------------------------------------+ * 28 * *** DIOBK - Dynamic I/O control block. |
DIOBK Cross Reference | Top of page |
Symbol Dspl Value -------------- ---- ----- DIOAUTO 0004 40 DIOBKSIZ 0010 00000005 DIOCOUNT 0008 DIODISC 0004 20 DIOFLAGS 0004 DIOLOCK 0010 DIOQUEUE 0000 DIOREDRV 0004 80 DIORFCGD 0004 04 DIOSTCHG 0004 08 DIOTTY 0004 10 |
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