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papi_read(3) [centos man page]

PAPI_read(3)							       PAPI							      PAPI_read(3)

NAME

       PAPI_read -

       Read hardware counters from an event set.

SYNOPSIS

Detailed Description
       C Interface:
	   #include <papi.h>
	    int PAPI_read(int  EventSet, long_long * values );

       PAPI_read() copies the counters of the indicated event set into the provided array.

       The counters continue counting after the read.

       Note the differences between PAPI_read() and PAPI_accum(), specifically that PAPI_accum() resets the values array to zero.

       PAPI_read() assumes an initialized PAPI library and a properly added event set.

       Parameters:
	   EventSet -- an integer handle for a PAPI Event Set as created by PAPI_create_eventset()
	   *values -- an array to hold the counter values of the counting events

       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_ENOEVST The event set specified does not exist.

       Examples

	   * do_100events();
	   * if (PAPI_read(EventSet, values) != PAPI_OK)
	   *	handle_error(1);
	   * // values[0] now equals 100
	   * do_100events();
	   * if (PAPI_accum(EventSet, values) != PAPI_OK)
	   *	handle_error(1);
	   * // values[0] now equals 200
	   * values[0] = -100;
	   * do_100events();
	   * if (PAPI_accum(EventSet, values) != PAPI_OK)
	   *	 handle_error(1);
	   * // values[0] now equals 0
	   *

       See Also:
	   PAPI_accum

	   PAPI_start

	   PAPI_stop

	   PAPI_reset

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

Version 5.2.0.0 						  Tue Jun 17 2014						      PAPI_read(3)

Check Out this Related Man Page

PAPI_accum_counters(3)						       PAPI						    PAPI_accum_counters(3)

NAME

       PAPI_accum_counters -

       Accumulate and reset counters.

SYNOPSIS

Detailed Description
       @par C Interface:
       int PAPI_accum_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_accum_counters() adds 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()

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

Version 5.2.0.0 						  Tue Jun 17 2014					    PAPI_accum_counters(3)
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