.TH LIBPFM 3  "September, 2009" "" "Linux Programmer's Manual"

.SH NAME

pfm_get_event_next \- iterate over events

.SH SYNOPSIS

.nf

.B #include <perfmon/pfmlib.h>

.sp

.BI "int pfm_get_event_next(int "idx ");"

.sp

.SH 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 \fBpfm_initialize()\fR. Events from

activated tables are called active events. Events from

non-activated tables are called supported events.

Event identifiers are usually retrieved via \fBpfm_find_event()\fR 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 \fBpfm_get_pmu_info()\fR.

The \fBpfm_get_event_next()\fR function returns the identifier of

next supported event after the one passed in \fBidx\fR. This iterator

stops when the last event for the PMU is passed as argument, in which

case the function returns \-1.

.sp

.nf

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);

  }

}

.fi

.SH 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.

.SH ERRORS

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

.SH SEE ALSO

pfm_find_event(3)

.SH AUTHOR

Stephane Eranian <eranian@gmail.com>

.PP