papi_num_counters(3) - Linux man page

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.

Return Values

On success, this function returns the number of hardware counters available. On error, a negative error code is returned.

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.0);

Bugs

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

Referenced By

papi_start_counters(3)