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)

PAPI_start(3)							       PAPI							     PAPI_start(3)

NAME

       PAPI_start -

       Start counting hardware events in an event set.

SYNOPSIS

Detailed Description
       C Interface:
	   #include <papi.h>
	    int PAPI_start( int  EventSet );

       Parameters:
	   EventSet -- an integer handle for a PAPI event set as created by PAPI_create_eventset

       Return values:
	   PAPI_OK
	   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 EventSet specified does not exist.
	   PAPI_EISRUN -- The EventSet is currently counting events.
	   PAPI_ECNFLCT -- The underlying counter hardware can not count this event and other events in the EventSet simultaneously.
	   PAPI_ENOEVNT -- The PAPI preset is not available on the underlying hardware.

       PAPI_start starts counting all of the hardware events contained in the previously defined EventSet. All counters are implicitly set to zero
       before counting. Assumes an initialized PAPI library and a properly added event set.

       Example:

	   *  int EventSet = PAPI_NULL;
	   *  long long values[2];
	   *  int ret;
	   *
	   *  ret = PAPI_create_eventset(&EventSet);
	   *  if (ret != PAPI_OK) handle_error(ret);
	   *
	   *  // Add Total Instructions Executed to our EventSet
	   *  ret = PAPI_add_event(EventSet, PAPI_TOT_INS);
	   *  if (ret != PAPI_OK) handle_error(ret);
	   *
	   *  // Start counting
	   *  ret = PAPI_start(EventSet);
	   *  if (ret != PAPI_OK) handle_error(ret);
	   *  poorly_tuned_function();
	   *  ret = PAPI_stop(EventSet, values);
	   *  if (ret != PAPI_OK) handle_error(ret);
	   *  printf("%lld
",values[0]);
	   *

       See Also:
	   PAPI_create_eventset PAPI_add_event PAPI_stop

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

Version 5.2.0.0 						  Tue Jun 17 2014						     PAPI_start(3)