public static HeapSnapshot Diff(HeapSnapshot baseline, HeapSnapshot current)
{
var result = new HeapSnapshot();
var baselineTypes = new HashSet <string>(baseline.SizeByType.Keys);
var currentTypes = new HashSet <string>(current.SizeByType.Keys);
baselineTypes.IntersectWith(currentTypes);
foreach (var type in baselineTypes) // In both baseline and current
{
result.SizeByType.Add(type, current.SizeByType[type] - baseline.SizeByType[type]);
result.CountByType.Add(type, current.CountByType[type] - baseline.CountByType[type]);
}
baselineTypes = new HashSet <string>(baseline.SizeByType.Keys);
baselineTypes.ExceptWith(currentTypes);
foreach (var type in baselineTypes) // Only in baseline
{
result.SizeByType.Add(type, -baseline.SizeByType[type]);
result.CountByType.Add(type, -baseline.CountByType[type]);
}
baselineTypes = new HashSet <string>(baseline.SizeByType.Keys);
currentTypes.ExceptWith(baselineTypes);
foreach (var type in currentTypes) // Only in current
{
result.SizeByType.Add(type, +current.SizeByType[type]);
result.CountByType.Add(type, +current.CountByType[type]);
}
return(result);
}
protected override void OnIntensiveSamplingStart()
{
var snapshots = new List <HeapSnapshot>();
for (int i = 0; i < SnapshotCount; ++i)
{
GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
using (var target = DataTarget.AttachToProcess(Process.GetCurrentProcess().Id, 1000, AttachFlag.Passive))
{
var runtime = target.ClrVersions[0].CreateRuntime();
snapshots.Add(new HeapSnapshot(runtime.Heap, TopTypes));
Thread.Sleep(SnapshotInterval);
}
}
for (int i = 0; i < SnapshotCount; ++i)
{
for (int j = i + 1; j < SnapshotCount; ++j)
{
var diff = HeapSnapshot.Diff(snapshots[i], snapshots[j]);
WriteTraceLine($"Diff between snapshot {i} (baseline) and snapshot {j}:");
foreach (var typeSize in diff.SizeByType.OrderBy(v => v.Value)) // Biggest offenders printed last
{
WriteTraceLine($" {typeSize.Key,10} {typeSize.Value,8} {diff.CountByType[typeSize.Key],8}");
}
}
}
}
