PAPIC:Error Handling
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PAPI Error Handling

This section discusses the various negative error codes that are returned by the PAPI functions. A table with the names, values, and descriptions of the return codes are given as well as a discussion of the PAPI function that can be used to convert error codes to error messages along with a code example with the corresponding output.

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
-16 PAPI_ENOINIT PAPI hasn't been initialized yet
-17 PAPI_ENOCMP Component Index isn't set
-18 PAPI_ENOSUPP Not supported
-19 PAPI_ENOIMPL Not implemented
-20 PAPI_EBUF Buffer size exceeded
-21 PAPI_EINVAL_DOM EventSet domain is not supported for the operation
-22 PAPI_EATTR Invalid or missing event attributes
-23 PAPI_ECOUNT Too many events or attributes
-24 PAPI_ECOMBO Bad combination of features

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 NULL or the error message string
length NULL 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 either destination or 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.

Example

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 event = 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 illegal PRESET event */
retval = PAPI_event_name_to_code(“PAPI_L4_DCM”, &event);
if ((retval = PAPI_add_event(&EventSet, event)) != 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.

Handling Errors

Throughout this Overview, the code snippets often reference a routine called handle_error. Feel free to implement this routine in whatever way makes sense for your circumstances. One possible implementation, based on the routines discussed above, is shown below.

void handle_error (int retval)
{
    /* print error to stderr and exit */
    PAPI_perror(retval,NULL,NULL);
    exit(1);
}