NAME

PAPI_start_counters - PAPI High Level: start counting hardware events

CONTENTS

Synopsis
Description
Arguments
Return Values
Errors
Examples
Authors
Bugs
See Also

C Interface

#include <papi.h> 

int PAPI_start_counters(int *events, int array_len); 

Fortran Interface

#include fpapi.h 

PAPIF_start_counters(C_INT(*) events, C_INT array_len, C_INT check) 

PAPI_start_counters() starts counting the events named in the events array. This function can’t be called if the events array is already running. The user must call PAPI_stop_counters to stop the events explicitly if he/she wants to call this function again. It is the user’s responsibility to choose events that can be counted simultaneously by reading the vendor’s documentation. The length of the event array should be no longer than the value returned by PAPI_num_counters (3).

*events -- an array of codes for events such as PAPI_INT_INS or a native event code

array_len -- the number of items in the *events array

On success, this function returns PAPI_OK.
On error, a non-zero error code is returned.

PAPI_EINVAL
	One or more of the arguments is invalid.
PAPI_EISRUN
	Counters already been started, you must call PAPI_stop_counters before you call this function again.
PAPI_ESYS
	A system or C library call failed inside PAPI, see the errno variable.
PAPI_ENOMEM
	Insufficient memory to complete the operation.
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.

  int Events[2] = { PAPI_TOT_CYC, PAPI_TOT_INS };
  int num_hwcntrs = 0;
        
  if ((num_hwcntrs = PAPI_num_counters()) != PAPI_OK)
    handle_error(1);

  if (num_hwcntrs > 2)
    num_hwcntrs = 2;

  /* Start counting events */

  if (PAPI_start_counters(Events, num_hwcntrs) != PAPI_OK)
    handle_error(1);

The PAPI Team. See them at the PAPI Web Site: http://icl.cs.utk.edu/projects/papi

This function has no known bugs.

PAPI_num_counters (3), PAPI_read_counters (3), PAPI_stop_counters (3)