papi_num_counters(3) [centos man page]

PAPI_num_counters(3)						       PAPI						      PAPI_num_counters(3)

NAME

       PAPI_num_counters -

       Get the number of hardware counters available on the system.

SYNOPSIS

Detailed Description
       @par C Interface:
       int PAPI_num_counters( void );

       Postcondition:
	   Initializes the library to PAPI_HIGH_LEVEL_INITED if necessary.

       Return values:
	   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);
	   *

       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 CPU component.

       Note:
	   This function only works for the CPU component. To determine the number of counters on another component, use the low level
	   PAPI_num_cmp_hwctrs().

Author
       Generated automatically by Doxygen for PAPI from the source code.

Version 5.2.0.0 						  Tue Jun 17 2014					      PAPI_num_counters(3)

PAPI_read_counters(3)						       PAPI						     PAPI_read_counters(3)

NAME

       PAPI_read_counters -

       Read and reset counters.

SYNOPSIS

Detailed Description
       @par C Interface:
       int PAPI_read_counters( long long *values, int array_len );

       Parameters:
	   *values an array to hold the counter values of the counting events
	   arry_len the number of items in the *events array

       Precondition:
	   These calls assume an initialized PAPI library and a properly added event set.

       Postcondition:
	   The counters are reset and left running after the call.

       Return values:
	   PAPI_EINVAL One or more of the arguments is invalid.
	   PAPI_ESYS A system or C library call failed inside PAPI, see the errno variable.

       PAPI_read_counters() copies the event counters into the array *values.

       do_100events();
       if ( PAPI_read_counters( values, num_hwcntrs ) != PAPI_OK )
	   handlw_error(1);
       // values[0] now equals 100
       do_100events();
       if ( PAPI_accum_counters( values, num_hwcntrs ) != PAPI_OK )
	   handle_error(1);
       // values[0] now equals 200
       values[0] = -100;
       do_100events();
       if ( PAPI_accum_counters(values, num_hwcntrs ) != PAPI_OK )
	   handle_error();
       // values[0] now equals 0
	*

       See Also:
	   PAPI_set_opt() PAPI_start_counters()

       Fortran Interface:
	   #include 'fpapi.h'
	    PAPIF_read_counters( C_LONG_LONG(*) values, C_INT array_len, C_INT check )

       See Also:
	   PAPI_read_counters

Author
       Generated automatically by Doxygen for PAPI from the source code.

Version 5.2.0.0 						  Tue Jun 17 2014					     PAPI_read_counters(3)