IOPERFORMANCE

Monitor Input/Output of data/index caching and count low-level file reads and writes.

Short Name

IOPERFORMANCE()

Type

Low-level function

Declaration

LONG IOPERFORMANCE(pVOID bufptr)

Description

IOPERFORMANCE() monitors the data and index cache as well as the low-level file reads and writes. On return, bufptr points to a structure of 8 unsigned long values, defined as follows:

ULONG     ct_dbrqs;          /* data buffer requests       */

ULONG     ct_dbhit;          /* data buffer hits           */

ULONG     ct_ibrqs;          /* index buffer requests      */

ULONG     ct_ibhit;          /* index buffer hits          */

ULONG     ct_rdops;          /* number of read operations  */

ULONG     ct_rdbyt;          /* bytes read                 */

ULONG     ct_wrops;          /* number of write operations */

ULONG     ct_wrbyt;          /* bytes written              */

Note the element defines used in the example below.

Return

IOPERFORMANCE() always returns a 0 (zero) value indicating NO_ERROR. See “c-tree Plus Error Codes” in the c-tree Plus Programmer’s Reference Guide for a complete listing of valid c-tree Plus error values.

Example

ULONG  ct[8]  /* array of 8 longs for performance value */


IOPERFORMANCE(ct)


printf("\n\n=================================================");

printf("\ndata buffer requests  = %ld",ct[DataBufferRequests]);

printf("\ndata buffer hits      = %ld",ct[DataBufferHits]);

printf("\nindex buffer requests = %ld",

                                      ct[IndexBufferRequests]);
printf("\nindex buffer hits     = %ld",ct[IndexBufferHits]);

printf("\n# of read operations  = %ld",ct[NbrReadOperations]);

printf("\nbytes read            = %ld",ct[NbrBytesRead]);

printf("\n# of write operations = %ld",ct[NbrWriteOperations]);

printf("\nbytes written         = %ld",ct[NbrBytesWritten]);

printf("\n===================================================");