SVECTORS MPXIOQ SELlOQ IOEXITQ Figure 1n IV. ASYNE ACTIVE IOE ASYNE ASYNE _____ n,-----, IIO Queues and Subqueues ACTIVE IOE Each link in RSCS is defined by a LINKTAEL DSECT. The LPOINTER field cf
the LINKTABL DSECT points to the link's TAG queue. This queue comprises those TAGs describing files that Rses has not yet transmitted. Only one TAG Fer link can be active at a time.
The queue of LINKTABLs (called the link table) is pointed to by the TLINKS field in SVECTORS. Transmitting VM/370 Files to an RSeS link When a VMj310 file is spooled to RSCS for a specific link, Rses accepts
tbe file and: Obtains a free TAG slot for the file. Builds a description of the file in the TAG slot. Enqueues the new TAG on the link's inactive TAG queue. When transmission to the remote station begins, the file's TAG is
dequeued from the inactive TAG queue and enqueued on the active input
file queue (TAGACIN in TAG AREA) When transmission of the file is
complete, the TAG is dequeued from the active input queue and its slct
is returned to the Free TAG Queue. R5CS Introduction 3-29 IOTABLE
PROCESSING FILES FRO! RE!OTE STATIONS As in the case of V!/310 spool files, when files are received fre.
re.ote stations, RSCS obtains a TAG slot and builds a description of the
file in that slot. However, files from reaote stations are enqueued on
the active cut put queue (TAGACOUT in TAGAREA) When the file is co.pletely trans.itted, its TAG is dequeued fro. the
active output queue, closed to the V!/370 spool systea, and its freed
slot returned to the free TAG queue.
Figure 11 shows the relationships between the DSECTs described above. TAG TAG TAG DUD I..i.!:l.!U Inactive TAG Queue
These are TAG's representing
files waiting for transmission;
that is,waiting to be enqueued
on the Active Input TAG Queue
described below.
TAG TAG TAG ,-----",TI Free TAG Queue All TAG "slots" which are
not in use to describe a file
are enqueued on the free
TAG queue.
Active TAG Queue ITDTI There may be only one active
input file for any given link on
this queue. Each file which is
being read from the VM!370 spool' system and transmitted to a
remote station is represented by
a TAG on this queue.
TAG L- __ ...1 '--"""IT
Active Output TAG Queue
Each file which is being writ. ten
to the VM'370 spool system is represented by a TAG on thiS queue, Figure 11. Chaining ,of Data Areas Required for File TAG 8anipulation 3-30 IB! V8/370: Syste. Logic and Proble. Deteraination--Volu.e 3
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