PAPI_NOT_INITED Library has not been initialized
PAPI_LOW_LEVEL_INITED Low level has called library init
PAPI_HIGH_LEVEL_INITED High level has called library init
PAPI_THREAD_LEVEL_INITED
Threads have been inited

version upon initialization, PAPI checks the argument against the internal value of PAPI_VER_CURRENT when the library was compiled. This guards against portability problems when updating the PAPI shared libraries on your system.

int retval;
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 < 0)
handle_error(retval);
retval = PAPI_is_initialized();
if (retval != PAPI_LOW_LEVEL_INITED)
handle_error(retval);

PAPI_is_initialized() returns the status of the PAPI library. The PAPI library can be in one of four states, as described under RETURN VALUES.

PAPI

PAPI_thread_init