private void ClosePerfDataKey()
{
// System keys should never be closed. However, we want to call RegCloseKey
// on HKEY_PERFORMANCE_DATA when called from PerformanceCounter.CloseSharedResources
// (i.e. when disposing is true) so that we release the PERFLIB cache and cause it
// to be refreshed (by re-reading the registry) when accessed subsequently.
// This is the only way we can see the just installed perf counter.
// NOTE: since HKEY_PERFORMANCE_DATA is process wide, there is inherent race in closing
// the key asynchronously. While Vista is smart enough to rebuild the PERFLIB resources
// in this situation the down level OSes are not. We have a small window of race between
// the dispose below and usage elsewhere (other threads). This is By Design.
// This is less of an issue when OS > NT5 (i.e Vista & higher), we can close the perfkey
// (to release & refresh PERFLIB resources) and the OS will rebuild PERFLIB as necessary.
Interop.Advapi32.RegCloseKey(HKEY_PERFORMANCE_DATA);
}
