Guardian Procedure Calls Reference Manual

Table 44 SETMODE Functions (continued)
Parameters and EffectFunction
The two words are combined to form a 32-bit integer for the timeout value. These values are reserved:
-2D = system default period (60 seconds)
-1D = infinite timeout period (timeout error is not returned)
0D = no timeout period (error is returned immediately if record cannot be read)
All other negative values are invalid. Note that SETMODE function 128 is valid for queue files only.
The purpose of the timeout period is to limit the time spent on dequeue operations, especially for audited
files. If the read operation is not completed within the timeout period, an error 162 (operation timed out)
is returned.
DP2 disk file: Enable/disable large transfers141
disable large transfers (this is the default value when the file is
opened.)
= 0param1
performs bulk reads without going through DP2 cache.= 1
performs bulk reads through DP2 cache. This value is supported only
on systems running H06.24 and later H-series RVUs and J06.13 and
later J-series RVUs.
= 3
param2 is used with param1 values of 1 and 3 and only on systems running H06.24 and later H-series
RVUs and J06.13 and later J-series RVUs.
if param1 = 1, does not provide any data prefetching. Works most
efficiently when data is aligned on 28K boundaries (that is, starting
address and read length are both multiples of 28K).
= 0param2
If param1 = 3, provides a single pin for prefetching data. Prefetch
may not be effective with multiple openers. Best performance is
obtained with 28K data alignment.
if param1 = 3, provides for up to 6 pins for prefetching data and
can achieve the highest throughput. Prefetch is not affected by the
= 1
number of opens as long as the file is accessed in consecutive file
addresses. Best performance is obtained with 28K data alignment.
NOTE: Because SETMODE function 141 uses multiple pins for prefetching, it will noticeably increase
the CPU requirements for DP2 reads on the file. HP recommends that this mode be tested to assess its
impact on other processes. All modes of prefetching will work with files opened Syncdepth 0 or 1.
However, best performance is achieved with Syncdepth 1.
contains the previous setting of the large transfer mode flag.last-params[0]
if param1 is 1, this contains the value of the file's broken flag after
the cache has been flushed; if param1 is 0, this contains a 0.
last-params[1]
SETMODE function 141 is valid only for DP2 disk files. When enabled by a SETMODE 141 (or
SETMODENOWAIT 141), a read or write operation can transfer up to 56K bytes of data to a DP2 disk
file. This setmode is in most cases now unnecessary for unstructured files (see READ or WRITE
Considerations).
If this SETMODE function is waited and any nowait I/O operations are outstanding at the time SETMODE
is called, the SETMODE is not done. The condition code is set to CCL and error 27 is returned.
When this SETMODE function is issued with param1 set to 1, DP2 flushes and removes all blocks for the
file from its cache. This ensures that any updates done by the user before the SETMODE are written to
disk.
The file must have been opened with the unstructured access option specified, even if the file is unstructured.
There is no support for alternate-key files or partitions. Because the file is opened for unstructured access,
secondary partitions and alternate-key files are not opened.
1336 Guardian Procedure Calls (S)