Contents 1 PAPI ERROR HANDLING 1.1 ERROR CODES 1.1.1 CONVERTING ERROR CODES TO ERROR MESSAGES 1.1.1.1 ARGUMENTS 1.1.1.2 OUTPUT:

PAPI ERROR HANDLING

ERROR CODES

All of the functions contained in the PAPI library return standardized error codes in which the values that are greater than or equal to zero indicate success and those that are less than zero indicate failure, as shown in the table below:

VALUE	SYMBOL	DEFINITION
0	PAPI_OK	No error
-1	PAPI_EINVAL	Invalid argument
-2	PAPI_ENOMEM	Insufficient memory
-3	PAPI_ESYS	A system or C library call failed, please check errno
-4	PAPI_ESBSTR	Substrate returned an error, usually the result of an unimplemented feature
-5	PAPI_ECLOST	Access to the counters was lost or interrupted
-6	PAPI_EBUG	Internal error, please send mail to the developers
-7	PAPI_ENOEVNT	Hardware event does not exist
-8	PAPI_ECNFLCT	Hardware event exists, but cannot be counted due to counter resource limitations
-9	PAPI_ENOTRUN	No events or event sets are currently not counting
-10	PAPI_EISRUN	Event Set is currently running
-11	PAPI_ENOEVST	No such event set available
-12	PAPI_ENOTPRESET	Event is not a valid preset
-13	PAPI_ENOCNTR	Hardware does not support performance counters
-14	PAPI_EMISC	‘Unknown error’ code
-15	PAPI_EPERM	You lack the necessary permissions

CONVERTING ERROR CODES TO ERROR MESSAGES

Error codes can be converted to error messages by calling the following low-level functions:

C:

 
PAPI_perror(''code, destination, length'')
PAPI_strerror(''code'')

 

Fortan:

 
PAPIF_perror(''code'', ''destination'', check)

 

ARGUMENTS

 
''code'' -- the error code to interpret 
''*''''destination'' -- "the error message in quotes"  
''length'' -- either 0 or strlen(destination) 

 

PAPI_perror fills the string, destination', with the error message corresponding to the error code (code). The function copies length worth of the error description string corresponding to code into destination. The resulting string is always null terminated. If length is 0, then the string is printed to stderr.

PAPI_strerror returns a pointer to the error message corresponding to the error code (code). If the call fails, the function returns a NULL pointer. Otherwise, a non-NULL pointer is returned. Note that this function is not implemented in Fortran.

In the following code example, PAPI_perror is used to convert error codes to error messages:

 
#include <papi.h>
#include <stdio.h>

main()
{
int EventSet = PAPI_NULL;
int native = 0x0;
char error_str[PAPI_MAX_STR_LEN];
        
/* Initialize the PAPI library */
retval = PAPI_library_init(PAPI_VER_CURRENT);
 
if (retval != PAPI_VER_CURRENT && retval > 0) {
  fprintf(stderr,"PAPI library version mismatch!\n");
  exit(1);
}

if ((retval = PAPI_create_eventset(&EventSet)) != PAPI_OK) {
     fprintf(stderr, "PAPI error %d: %s\n",retval, 		PAPI_strerror(retval));
     exit(1);
}     

/* Add Total Instructions Executed to our EventSet */
if ((retval = PAPI_add_event(&EventSet, PAPI_TOT_INS)) != PAPI_OK) {
     PAPI_perror(retval,error_str,PAPI_MAX_STR_LEN);
     fprintf(stderr,"PAPI_error %d: %s\n",retval,error_str);
     exit(1);
}

/* Add POWER4 native event */
retval = PAPI_event_name_to_code(“PM_LD_MISS_L1”, &native);
if ((retval = PAPI_add_event(&EventSet, native)) != PAPI_OK) {
     /* Dump error string directly to stderr. */
      PAPI_perror(retval,NULL,NULL);
     exit(1);
}

/* Start counting */
if ((retval = PAPI_start(EventSet)) != PAPI_OK)
  handle_error(retval);
}
 

OUTPUT:

 
Invalid argument
 

Notice that the above output was generated from the last call to'PAPI_perror'.

On success, PAPI_perror returns PAPI_OK and on error, a non-zero error code is returned.