Guardian Procedure Calls Reference Manual

FILE_READLOCK64_ Procedure
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Parameters
Returned Value
Considerations
OSS Considerations
Related Programming Manuals
Summary
The FILE_READLOCK64_ procedure sequentially locks and reads records in a disk file, exactly like
the combination of FILE_LOCKREC64_ and FILE_READ64_. FILE_READLOCK64_ is intended for
use with 64-bit extended addresses. The data buffer for FILE_READLOCK64_ can be either in the
caller's stack segment or any extended data segment.
FILE_READLOCK64_ extends the capabilities of READLOCKX in following ways:
• It permits the read buffer to reside outside of the 32-bit addressable range.
• It is callable from both 32-bit and 64-bit processes.
• It allows for a future capability to read more than 56kb in a single operation by widening the
read count to 32 bits.
• It allows the returned count-read argument to reside outside of the 32-bit addressable
range.
• It allows a 64-bit nowait I/O tag to be passed.
• Rather than returning a condition code status, the procedure returns a file management error.
A return value of zero indicates success.
NOTE: The FILE_READLOCK64_ procedure is supported on systems running H06.24 and later
H-series RVUs and J06.13 and later J-series RVUs. Its use is recommended for new code.
Syntax for C Programmers
#include <cextdecs(FILE_READLOCK64_)>
short FILE_READLOCK64_ ( short filenum
,char _ptr64 *buffer
,__int32_t read-count
,[ __int32_t _ptr64 *count-read ]
,[ long long tag ] );
Syntax for TAL Programmers
?SETTOG _64BIT_CALLS
?SOURCE EXTDECS(FILE_READLOCK64_)
error := FILE_READLOCK64_ ( filenum ! i
,buffer ! o
,read-count ! i
,[ count-read ] ! o
,[ tag ] ); ! i
482 Guardian Procedure Calls (F)