- Entry:
- REQS
- VIT option:
- SMS
- Event:
- Request storage (Part 1)
- VIT processing module:
- ISTRACSM
- Control is returned to:
- ISTORMBA
This trace record provides the status of each REQSTORE request issued by VTAM® components to obtain fixed-length buffers from one of the predefined buffer pools. The storage obtained by REQSTORE is released by RELSTORE.
If this entry is associated with an event failure (that
is, the return code is nonzero), this entry is generated whether the
SMS option is in effect or not. It is treated as an exception condition
and is always traced, regardless of the VIT options specified, if
the VIT is active. 
- Byte (hex)
- Contents
- 00–03
- Record ID: C"REQS"
- 04
- ID is the primary address space ID (ASID). This field is 0 if the ASID is greater than X'FF'.
- 05
- Control block ID index value or 0. A 0 is returned if the buffer is not allocated for a specific control block or if the buffer allocation failed. For the index values and the control block IDs they represent, see z/OS® Communications Server: SNA Data Areas Volume 1.
- 08–0B
- Pointer to the PST, or 0
- 0C–0F
- Address of buffer obtained, or 0 if buffer not obtained
- 10–13
- Address of the issuer of the REQSTORE macro
- 14–15
- Number of buffers requested
- 16–17
- Return code from REQSTORE
- 00
- Successful.
- 04
- Storage obtained, but slowdown threshold exceeded.
- 06
- Storage request queued, but buffer pool has to be expanded before buffers can be allocated.
- 08
- The number of buffers requested could not be allocated immediately.
Depending on the conditions specified on the REQSTORE request and
the state of the buffer pool that is requested, the request may or
may not be queued for future processing. The request is queued for future processing if one of the following conditions is met:
- The REQSTORE request specifies that it can be queued for future processing regardless of the state of the buffer pool from which buffers are requested.
- The REQSTORE request specifies that it can be queued for future
processing if specific conditions are met. These conditions are as
follows:
- Number of buffers already allocated plus the number of buffers for which there are outstanding requests does not exceed the maximum size of the buffer pool.
- Buffer pool is defined to be expandable.
- Buffer pool expansion has never failed for the buffer pool or the buffer pool has contracted since it failed to expand.
The request is not queued for future processing if any of the following conditions apply:- The REQSTORE request specifies that it is not to be queued under any circumstances.
- The REQSTORE request specifies that it is to be queued according to one or more of the conditions described previously in this topic and the specified conditions are not met.
- 16
- This return code applies only to nonexpandable buffer pools. The number of buffers requested exceeds the maximum number which can be allocated in one request. This return code does not indicate that the number of buffers requested is not available; it indicates that the number of buffers exceeds the maximum allowed in one request.
- 18–1B
- Register 1 (normally RPH address)
- 1C–1F
- Number of available buffers in pool after this request is processed.