2021/07/25

stat gpu数据从何而来

• Stats2.h

//宏定义 函数
#define SET_CYCLE_COUNTER(Stat,Cycles) \
{\
	if (FThreadStats::IsCollectingData() || !GET_STATISEVERYFRAME(Stat)) \
		FThreadStats::AddMessage(GET_STATFNAME(Stat), EStatOperation::Set, int64(Cycles), true);\
}



template<typename TValue>
	static FORCEINLINE_STATS void AddMessage(FName InStatName, EStatOperation::Type InStatOperation, TValue Value, bool bIsCycle = false)
	{
   
		if (!InStatName.IsNone() && WillEverCollectData() && IsThreadingReady())
		{
   
			FThreadStats* ThreadStats = GetThreadStats();
			{
   
				FStatMessage temp(InStatName, InStatOperation, Value, bIsCycle);
				if (temp.NameAndInfo.GetShortName() == FName("Stat_GPU_RenderDeferredLighting")) 
				{
   
					UE_LOG(LogTemp, Warning, TEXT("stat name: %s, InStatOperate: %d, Value: %f, IsCycle: %d"), *InStatName.ToString(),InStatOperation,double(Value),bIsCycle);

				}
			}
			
			ThreadStats->AddStatMessage(FStatMessage(InStatName, InStatOperation, Value, bIsCycle));
			if(!ThreadStats->ScopeCount)
			{
   
				ThreadStats->Flush();
			}
			else if( bIsRawStatsActive )
			{
   
				ThreadStats->FlushRawStats();
			}
		}
	}

1. Stats 数据通常在Engine/Source/Runtime/Cores/Private/Stats 文件中
2. 上述代码获取stat数据名字，当前收集到的值等等
3. 宏定义中：SET_CYCLE_COUNTER，INC_DWORD_STAT，INC_MEMORY_STAT_BY等等都调用了AddMessage函数
4. FThreadStats* ThreadStats = GetThreadStats(); 获取Stats名字，如果没有创建一个

Stat GPU

1. RealtimeGPUProfiler.h: 单例
2. TArray<FRealtimeGPUProfilerFrame*> Frames: stat gpu 存储数据的容器
3. FRealtimeGPUProfilerFrame还有几个容器是存储数据时间的容器

UpdateStats函数

bool UpdateStats(FRHICommandListImmediate& RHICmdList)
{
   
	// Gather any remaining results and check all the results are ready
	const int32 NumEventsThisFramePlusOne = NextEventIdx;

	for (; NextResultPendingEventIdx < NumEventsThisFramePlusOne; ++NextResultPendingEventIdx)
	{
   
		FRealtimeGPUProfilerEvent& Event = GpuProfilerEvents[NextResultPendingEventIdx];

		if (!Event.GatherQueryResults(RHICmdList))
		{
   
#if !(UE_BUILD_SHIPPING || UE_BUILD_TEST)
			UE_LOG(LogRendererCore, Warning, TEXT(