Programming Interface Information:
This information is NOT intended to be used as Programming Interfaces of z/VM. |
MSDBK
Control Block Contents
MSDBK DSECT
Cross Reference (Contains links to field and bit definitions)
MSDBK Prolog
NAME : HCPMSDBK DESCRIPTION: Monitor Send Block DSECT : MSDBK FUNCTION : To represent a monitor broadcast (IUCV Sends of the same information to one or more users). The counts contained in an MSDBK are used to determine when the DCSS pages corresponding to that broadcast can be released for reuse. Data structure Field location MNDI_EV_TOSEND MNDI_EV_TOSEND_HEAD MNDI_EV_TOSEND_TAIL MNDI_EV_SENT MNDI_EV_SENT.MND_HEAD MNDI_EV_SENT.MND_TAIL MNDI_SAM_SENT MNDI_SAM_SENT.MND_HEAD MNDI_SAM_SENT.MND_TAIL LOCATED BY : CREATED BY : HCPMOISS HCPMNXAE DELETED BY : HCPMOISR HCPMOIER HCPMOVPM REFERENCES : none SERIALIZED : The appropriate lock must be obtained for any manipulations to the list. NOTES : The MSDBK is used to link Monitor broadcasts in a circular list. As a result of this circular list implentation, it is a requirement that MSDFWDPT and MSDBCKPT are the first two words in the list. This is necessary, because the code thinks that the head and tail pointers to the list are 'another element of the list'.
MSDBK Control Block Content
MSDBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure MSDBK Monitor Send Block 0000 0 Address 4 MSDFWDPT Pointer to the next MDSBK on the list 0004 4 Address 4 MSDBCKPT Pointer to the previous MSDBK on the list 0008 8 Signed 4 MSD_SENT_CT Count of outstanding messages 000C 12 Signed 4 MSD_PEND_CT Count of pending messages 0010 16 Bitstring 4 MSD_TRGCL Target class of this message. This field fill be used to assign the TRGCLS parameter of the IUCV macro when sending data. 0014 20 Bitstring 8 MSD_CTL_ADDR (0) Control area addresses. This level exists so that the control area addressess remain together. It is necessary they be together because the data is used as the PRMMSG for the IUCV SEND. 0014 20 Address 4 MSD_CTLST_GRA Monitor control area starting address - guest real address 0018 24 Address 4 MSD_CTLEN_GRA Monitor control area ending address - guest real address 0000001C MSD$END * End of MSDBK 00000004 MSDSIZE (MSD$END-MSDBK+7)/8 MSDBK size in doublewords
MSDBK Storage Layout
*** MSDBK - Monitor Send Block * * +---------------------------+---------------------------+ * 0 | MSDFWDPT | MSDBCKPT | * +---------------------------+---------------------------+ * 8 | MSD_SENT_CT | MSD_PEND_CT | * +---------------------------+---------------------------+ * 10 | MSD_TRGCL | MSD_CTLST_GRA | * +---------------------------+---------------------------+ * 18 | MSD_CTLEN_GRA | 1C * +---------------------------+ * *** MSDBK - Monitor Send Block
MSDBK Cross Reference
Symbol Dspl Value -------------- ---- ----- MSD$END 0018 0000001C MSD_CTL_ADDR 0014 MSD_CTLEN_GRA 0018 MSD_CTLST_GRA 0014 MSD_PEND_CT 000C MSD_SENT_CT 0008 MSD_TRGCL 0010 MSDBCKPT 0004 MSDFWDPT 0000 MSDSIZE 0018 00000004
Copyright IBM Corporation, 1990, 2001