| |
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure IDSBK ISFC ID segment table
0000 0 Signed 4 IDSCOUNT Total count of IDs in this table
0004 4 Signed 4 IDSHMARK High water mark for this table
0008 8 Dbl-Word 8 * Reserved The value of
(IDSMAXSG*IDSEGBLN) for BLOCKMAP
is 64*8 = 512
0010 16 Bitstring 512 IDSSTART Reserve IDSEGENT space
00000042 IDSSIZE (*-IDSBK+7)/8 Size of IDSBK in
doublewords
FUNCTION :
This is the format for a single 'Segment Entry' in
the IDSBK.
LOCATED BY :
IDSSTART contains IDSEGENT entries.
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure IDSEGENT ISFC ID segment table
0000 0 Signed 4 IDSEGCNT Count of IDs in this segment
0004 4 Address 4 IDSEGADD Address of segment page
00000008 IDSEGBLN *-IDSEGENT Length of segment
entry in bytes
FUNCTION :
This is the format for a single 'Slot Entry' in
the IDSBK.
LOCATED BY :
IDSSTART contains IDSLTENT entries.
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure IDSLTENT ISFC ID segment table
0000 0 Address 4 IDSLTADD Address of slot entry
0=>available 1=>allocated,
not a pointer
>1=>allocated, pointer to
entry
00000004 IDSLTBLN *-IDSLTENT Length of slot entry
in bytes
IUCV is limited to 64K paths, so each of these tables
can only have 64K entries. Each "slot" in a segment
consists of a fullword, so each segment (4K page) can
hold 1K slots. Therefore, the maximum number of segment
entries per table is 64 and the maximum number of slots
per segment is 1024.
00000040 IDSMAXSG 64 Maximum segment entries per
table
00000400 IDSMAXSL 1024 Maximum slots per segment
00000001 IDSLTFUL 1 Zero implies slot available
Non-zero implies slot allocated
| |