Guardian Procedure Calls Reference Manual

operation
input
INT:value
defines the operation to be performed. (See Table 10: CONTROL Operation 1 (page 207) and
Table 11: CONTROL Operations 2 Through 27 (page 209) for the list of available operations.)
param
input
INT:value
is the value of the operation being performed (see Table 10: CONTROL Operation 1 (page 207)
and Table 11: CONTROL Operations 2 Through 27 (page 209) ).
tag
input
INT(64):value
is for nowait I/O only. The tag parameter is a value you define that uniquely identifies the
operation associated with this FILE_CONTROL64_ procedure call.
NOTE: The system stores the tag value until the I/O operation completes. It then returns the
tag information to the program in either the tag parameter of the call to FILE_AWAITIO64_
or the tag field of the completion-info parameter of the call to FILE_COMPLETEL_, thus
indicating that the operation finished.
Returned Value
INT
A file-system error code that indicates the outcome of the call.
Considerations
• EpTAL callers must set toggle
EpTAL callers must set the toggle _64BIT_CALLS before sourcing the FILE_CONTROL64_ section
from EXTDECS.
• Familiar semantics
Unless otherwise described, the semantic behavior of FILE_CONTROL64_ is the same as that
of CONTROL.
• Nowait and FILE_CONTROL64_
If FILE_CONTROL64_ is called on a file opened for nowait I/O, then the operation must be
completed by calling either FILE_AWAITIO64_ or FILE_COMPLETEL_.
• Disk files
Writing EOF to an unstructured file
Writing EOF to an unstructured disk file sets the EOF pointer to the relative byte address
indicated by the setting of the next-record pointer and writes the new EOF setting in the
file label on disk. Specifically, write:
◦
end-of-file pointer := next-record pointer;
(File pointer action for CONTROL operation 2, write EOF.)
380 Guardian Procedure Calls (F)