private IEnumerable <PdhCounterHandle> DoRemoveCounters(IEnumerable <IPerfCounter> counters)
{
PdhCounterHandle hCounter = null;
List <PdhCounterHandle> removedCounters = new List <PdhCounterHandle>();
foreach (var counter in counters)
{
if (_counters.TryGetValue(counter, out hCounter))
{
_counters.Remove(counter);
removedCounters.Add(hCounter);
}
}
return(removedCounters);
}
public static extern UInt32 PdhGetRawCounterValue(
PdhCounterHandle phCounter,
IntPtr lpdwType,
out PDH_FMT_COUNTERVALUE pValue);
public static extern UInt32 PdhGetFormattedCounterValue(
PdhCounterHandle phCounter,
PdhFormat dwFormat,
IntPtr lpdwType,
out PDH_FMT_COUNTERVALUE pValue);
public static extern UInt32 PdhAddEnglishCounterW(
PdhQueryHandle hQuery,
string szFullCounterPath,
IntPtr dwUserData,
out PdhCounterHandle phCounter);
public async Task DoRefresh()
{
if (!NeedsRefresh)
{
return;
}
PDH_FMT_COUNTERVALUE value = default(PDH_FMT_COUNTERVALUE);
uint result = Pdh.PdhCollectQueryData(_query);
if (result == Pdh.PDH_NO_DATA)
{
throw new MissingCountersException(_counters.Keys);
}
if (result != 0)
{
throw new Win32Exception((int)result);
}
bool multiSample = false;
List <IPerfCounter> missingCounters = new List <IPerfCounter>();
foreach (KeyValuePair <IPerfCounter, PdhCounterHandle> counterInstance in _counters)
{
IPerfCounter counter = counterInstance.Key;
PdhCounterHandle handle = counterInstance.Value;
result = Pdh.PdhGetFormattedCounterValue(handle, PdhFormat.PDH_FMT_LARGE, IntPtr.Zero, out value);
if (result == Pdh.PDH_INVALID_DATA && value.CStatus == Pdh.PDH_CSTATUS_INVALID_DATA && !multiSample)
{
multiSample = true;
result = Pdh.PdhCollectQueryData(_query);
if (result != 0)
{
throw new Win32Exception((int)result);
}
result = Pdh.PdhGetFormattedCounterValue(handle, PdhFormat.PDH_FMT_LARGE, IntPtr.Zero, out value);
}
if ((result != 0 && value.CStatus == Pdh.PDH_CSTATUS_NO_INSTANCE) ||
result == Pdh.PDH_INVALID_HANDLE ||
result == Pdh.PDH_CALC_NEGATIVE_VALUE ||
result == Pdh.PDH_CALC_NEGATIVE_DENOMINATOR ||
(result == Pdh.PDH_INVALID_DATA && value.CStatus == Pdh.PDH_INVALID_DATA))
{
missingCounters.Add(counter);
continue;
}
else if (result != 0)
{
if (!_counterFinder.CounterExists(counter))
{
missingCounters.Add(counter);
continue;
}
throw new Win32Exception((int)result);
}
else if (value.CStatus != 0)
{
throw new Win32Exception((int)value.CStatus);
}
counter.Value = value.longLongValue;
}
if (missingCounters.Count > 0)
{
throw new MissingCountersException(missingCounters);
}
TimeSpan calculationDelta = DateTime.UtcNow - _lastCalculatedTime;
_lastCalculatedTime = DateTime.UtcNow;
}