LIBPFM(3)						     Linux Programmer's Manual							 LIBPFM(3)

NAME

       pfm_get_event_next - iterate over events

SYNOPSIS

       #include <perfmon/pfmlib.h>

       int pfm_get_event_next(int idx);

DESCRIPTION

       Events  are  uniquely  identified  with opaque integer identifiers.  There is no guaranteed order within identifiers. Thus, to list all the
       events, it is necessary to use iterators.

       Events are grouped in tables within the libary. A table usually corresponds to a PMU model or family. The library contains support for mul-
       tiple  PMU models, thus it has multiple tables. Based on the host hardware and software environments, tables get activated when the library
       is initialized via pfm_initialize(). Events from activated tables are called active events. Events from	non-activated  tables  are  called
       supported events.

       Event identifiers are usually retrieved via pfm_find_event() or when encoding events.

       To iterate over a list of events for a given PMU model, all that is needed is an initial identifier for the PMU. The first event identifier
       is usually obainted via pfm_get_pmu_info().

       The pfm_get_event_next() function returns the identifier of next supported event after the one passed in idx. This iterator stops when  the
       last event for the PMU is passed as argument, in which case the function returns -1.

       void list_pmu_events(pfm_pmu_t pmu)
       {
	  struct pfm_event_info info;
	  struct pfm_pmu_info pinfo;
	  int i, ret;

	  memset(&info, 0, sizeof(info));
	  memset(&pinfo, 0, sizeof(pinfo));

	  info.size = sizeof(info);
	  pinfo.size = sizeof(pinfo);

	  ret = pfm_get_pmu_info(pmu, &pinfo);
	  if (ret != PFM_SUCCESS)
	     errx(1, "cannot get pmu info");

	  for (i = pinfo.first_event; i != -1; i = pfm_get_event_next(i)) {
	     ret = pfm_get_event_info(i, &info);
	     if (ret != PFM_SUCCESS)
	       errx(1, "cannot get event info");

	       printf("%s Event: %s::%s
",
		      pinfo.present ? "Active" : "Supported",
		      pinfo.name, info.name);
	 }
       }

RETURN

       The function returns the identifier of the next supported event. It returns -1 when the argument is already the last event for the PMU.

ERRORS

       No error code, besides -1, is returned by this function.

SEE ALSO

       pfm_find_event(3)

AUTHOR

       Stephane Eranian <eranian@gmail.com>

								  September, 2009							 LIBPFM(3)