NAME

• PAPI_num_counters - PAPI High Level: return the number of hardware counters available on the system

Synopsis

C Interface

#include <papi.h>
int PAPI_num_counters( void );

Fortran Interface

#include "fpapi.h"
PAPIF_num_counters( C_INT  number )

Description

PAPI_num_counters() returns the optimal length of the values array for the high level functions. This value corresponds to the number of hardware counters supported by the current substrate. PAPI_num_counters() initializes the library to PAPI_HIGH_LEVEL_INITED if necessary.

Errors

PAPI_EINVAL papi.h is different from the version used to compile the PAPI library.

PAPI_ENOMEM Insufficient memory to complete the operation.

PAPI_ESYS A system or C library call failed inside PAPI, see the errno variable.

Examples

int num_hwcntrs;
/*  The installation does not support PAPI */
if ((num_hwcntrs = PAPI_num_counters()) < 0 )
handle_error(1);
/*  The installation supports PAPI, but has no counters */
if ((num_hwcntrs = PAPI_num_counters()) == 0 )
fprintf(stderr,"Info:: This machine does not provide hardware counters.\n");

Bugs

If you don't call this function, your application could core dump.

See Also

PAPI(3), PAPIF(3)