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PAPI_num_counters

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.);
 

BUGS

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

SEE ALSO

PAPI(3),PAPIF(3)