input testing

apps/RenderCadenceCompositor/frames/InputFrameMailbox.cpp

@@ -1,6 +1,7 @@
 #include "InputFrameMailbox.h"
 
 #include <algorithm>
+#include <chrono>
 #include <cstring>
 
 namespace
@@ -102,6 +103,8 @@ bool InputFrameMailbox::SubmitFrame(const void* bytes, unsigned rowBytes, uint64
 	mReadyIndices.push_back(slotIndex);
 	++mCounters.submittedFrames;
 	mCounters.latestFrameIndex = frameIndex;
+	mCounters.hasSubmittedFrame = true;
+	mLatestSubmitTime = std::chrono::steady_clock::now();
 	return true;
 }
 
@@ -170,6 +173,11 @@ InputFrameMailboxMetrics InputFrameMailbox::Metrics() const
 	std::lock_guard<std::mutex> lock(mMutex);
 	InputFrameMailboxMetrics metrics = mCounters;
 	metrics.capacity = mSlots.size();
+	if (metrics.hasSubmittedFrame)
+	{
+		metrics.latestFrameAgeMilliseconds = std::chrono::duration_cast<std::chrono::duration<double, std::milli>>(
+			std::chrono::steady_clock::now() - mLatestSubmitTime).count();
+	}
 
 	for (const Slot& slot : mSlots)
 	{