// This event is used to figure out if a collection is compacting or not
// Note: last event for background GC (will be GCHeapStats for ephemeral (0/1) and non concurrent gen 2 collections)
private void OnGcGlobalHeapHistory(EventWrittenEventArgs e)
{
var currentGC = GetCurrentGC(_gcInfo);
// check unexpected event (we should have received a GCStart first)
if (currentGC == null)
{
return;
}
// check if the collection was compacting
var globalMask = (GCGlobalMechanisms)GetFieldValue <uint>(e, "GlobalMechanisms");
currentGC.IsCompacting =
(globalMask & GCGlobalMechanisms.Compaction) == GCGlobalMechanisms.Compaction;
// this is the last event for gen 2 background collections
if ((GetFieldValue <uint>(e, "CondemnedGeneration") == 2) && (currentGC.Type == GCType.BackgroundGC))
{
// check unexpected generation mismatch: should never occur
if (currentGC.Generation != GetFieldValue <uint>(e, "CondemnedGeneration"))
{
return;
}
GcEvents?.Invoke(this, BuildGcArgs(currentGC));
ClearCollections(_gcInfo);
}
}
// This event provides the size of each generation after the collection
// Note: last event for non background GC (will be GcGlobalHeapHistory for background gen 2)
private void OnGcHeapStats(EventWrittenEventArgs e)
{
var currentGC = GetCurrentGC(_gcInfo);
if (currentGC == null)
{
return;
}
currentGC.Heaps.Gen0Size = (long)GetFieldValue <ulong>(e, "GenerationSize0");
currentGC.Heaps.Gen1Size = (long)GetFieldValue <ulong>(e, "GenerationSize1");
currentGC.Heaps.Gen2Size = (long)GetFieldValue <ulong>(e, "GenerationSize2");
currentGC.Heaps.LOHSize = (long)GetFieldValue <ulong>(e, "GenerationSize3");
// this is the last event for a gen0/gen1 foreground collection during a background gen2 collections
if (
(_gcInfo.CurrentBGC != null) &&
(currentGC.Generation < 2)
)
{
Debug.Assert(_gcInfo.GCInProgress == currentGC);
GcEvents?.Invoke(this, BuildGcArgs(currentGC));
_gcInfo.GCInProgress = null;
}
}
private void OnGcRestartEEEnd(EventWrittenEventArgs e)
{
var currentGC = GetCurrentGC(_gcInfo);
if (currentGC == null)
{
// this should never happen, except if we are unlucky to have missed a GCStart event
return;
}
// compute suspension time
double suspensionDuration = 0;
if (_gcInfo.SuspensionStart.HasValue)
{
suspensionDuration = (e.TimeStamp - _gcInfo.SuspensionStart.Value).TotalMilliseconds;
_gcInfo.SuspensionStart = null;
}
else
{
// bad luck: a xxxBegin event has been missed
}
currentGC.PauseDuration += suspensionDuration;
// could be the end of a gen0/gen1 or of a non concurrent gen2 GC
if (
(currentGC.Generation < 2) ||
(currentGC.Type == GCType.NonConcurrentGC)
)
{
GcEvents?.Invoke(this, BuildGcArgs(currentGC));
_gcInfo.GCInProgress = null;
return;
}
// in case of background gen2, just need to sum the suspension time
// --> its end will be detected during GcGlobalHistory event
}