bionic (3) pfm_get_event_next.3.gz

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 library. A table usually corresponds to a PMU  model  or  family.
       The  library  contains  support  for  multiple 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 obtained 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\n",
                      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)