ChaosVDContextProvider.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "ChaosVDOptionalDataChannel.h"
#include "Containers/Array.h"
#include "Containers/ContainerAllocationPolicies.h"
#include "HAL/ThreadSingleton.h"
#include "Templates/SharedPointer.h"
 
#if WITH_CHAOS_VISUAL_DEBUGGER
 
#include "ChaosVDRuntimeModule.h"
 
enum class EChaosVDContextType : int32
{
    Any,
    Solver,
    Query,
    SubTraceQuery,
};
 
enum class EChaosVDContextAttributes : int32
{
    None = 0,
    Resimulated = 1 << 0
};
ENUM_CLASS_FLAGS(EChaosVDContextAttributes)
 
 
struct FChaosVDContext
{
    int32 OwnerID = INDEX_NONE;
    int32 Id = INDEX_NONE;
    int32 Type = INDEX_NONE;
    int32 Attributes = 0;
 
    FORCEINLINE void SetDataChannel(const TSharedRef<Chaos::VisualDebugger::FChaosVDOptionalDataChannel>& NewDataChannel)
    {
        CurrentDataChannel = NewDataChannel;
    }
 
    FORCEINLINE bool IsDataChannelEnabled() const { return CurrentDataChannel->IsChannelEnabled(); }
 
private:
    TSharedRef<Chaos::VisualDebugger::FChaosVDOptionalDataChannel> CurrentDataChannel = CVDDC_Default;
};
 
UE_DECLARE_THREAD_SINGLETON_TLS(class FChaosVDThreadContext, CHAOS_API)
 
 
class FChaosVDThreadContext : public TThreadSingleton<FChaosVDThreadContext>
{
public:
 
    virtual ~FChaosVDThreadContext() override
    {
        if (RecordingStoppedHandle.IsValid())
        {
            FChaosVDRuntimeModule::RemoveRecordingStopCallback(RecordingStoppedHandle);
        }
    }
 
    CHAOS_API bool GetCurrentContext(FChaosVDContext& OutContext);
    
    CHAOS_API const FChaosVDContext* GetCurrentContext(EChaosVDContextType Type);
    
    CHAOS_API const FChaosVDContext* GetCurrentContext();
    
    CHAOS_API void PushContext(const FChaosVDContext& InContext);
    
    CHAOS_API void PopContext();
 
protected:
    TArray<FChaosVDContext, TInlineAllocator<16>> LocalContextStack;
 
    TArray<uint8>& GetTLSDataBufferRef()
    {
        checkf(BufferAccessCounter == 0, TEXT("The CVD buffer is already in use!"));
 
        if (!RecordingStoppedHandle.IsValid())
        {
            // If we access the buffer, make sure we subscribe to the recording stop callback
            // So we free any memory we keep allocated
            RecordingStoppedHandle = FChaosVDRuntimeModule::RegisterRecordingStopCallback(FChaosVDRecordingStateChangedDelegate::FDelegate::CreateLambda([this](){ CVDDataBuffer.Empty(); }));
        }
        
        return CVDDataBuffer;
    }
 
    FDelegateHandle RecordingStoppedHandle;
 
    int32 BufferAccessCounter = 0;
    TArray<uint8> CVDDataBuffer;
 
    friend struct FChaosVDScopedTLSBufferAccessor;
};
 
namespace Chaos::VisualDebugger::Utils
{
    FORCEINLINE bool IsContextEnabledAndValid(const FChaosVDContext* Context)
    {
        if (!ensure(Context))
        {
            return false;
        }
 
        return Context->IsDataChannelEnabled();
    }
}
 
struct FChaosVDScopeContext
{
    FChaosVDScopeContext(const FChaosVDContext& InCVDContext)
    {
        FChaosVDThreadContext::Get().PushContext(InCVDContext);
    }
 
    ~FChaosVDScopeContext()
    {
        FChaosVDThreadContext::Get().PopContext();
    }
};
 
struct FChaosCVDScopedDataChannelOverride
{
    FChaosCVDScopedDataChannelOverride(const TSharedRef<Chaos::VisualDebugger::FChaosVDOptionalDataChannel>& NewDataChannel)
    {
        if (const FChaosVDContext* CVDContextData = FChaosVDThreadContext::Get().GetCurrentContext())
        {
            FChaosVDContext NewContext = *CVDContextData;
            NewContext.SetDataChannel(NewDataChannel);
 
            FChaosVDThreadContext::Get().PushContext(MoveTemp(NewContext));
        }
    }
 
    ~FChaosCVDScopedDataChannelOverride()
    {
        FChaosVDThreadContext::Get().PopContext();
    }
};
 
struct FChaosVDScopedTLSBufferAccessor
{
    FChaosVDScopedTLSBufferAccessor() : BufferRef(FChaosVDThreadContext::Get().GetTLSDataBufferRef())
    {
        FChaosVDThreadContext::Get().BufferAccessCounter++;
 
        // This is close to the max amount of data we can Trace as a single trace event
        // Some times we will go over and some times this be more than we need
        // but keeping this amount allocated on average reduces the allocation cost when tracing.
        // TODO: There might be a better value for this, we need to do more testing
        constexpr uint32 MaxTraceChunkSize = TNumericLimits<uint16>::Max();
        BufferRef.Reserve(MaxTraceChunkSize);
    }
 
    ~FChaosVDScopedTLSBufferAccessor()
    {
        // Clear the buffer on exit but maintain allocated a minimum amount of memory
        constexpr uint32 MaxTraceChunkSize = TNumericLimits<uint16>::Max();
        BufferRef.Reset(MaxTraceChunkSize);
 
        FChaosVDThreadContext::Get().BufferAccessCounter--;
    }
    
    TArray<uint8>& BufferRef;
};
 
#ifndef CVD_GET_CURRENT_CONTEXT
    #define CVD_GET_CURRENT_CONTEXT(OutContext) \
        FChaosVDThreadContext::Get().GetCurrentContext(OutContext);
#endif
 
#ifndef CVD_GET_WRAPPED_CURRENT_CONTEXT
    #define CVD_GET_WRAPPED_CURRENT_CONTEXT(OutWrappedContext) \
        FChaosVDContext CurrentContext; \
        FChaosVDThreadContext::Get().GetCurrentContext(CurrentContext); \
        OutWrappedContext = FChaosVDContextWrapper(CurrentContext);
#endif
 
#ifndef CVD_SCOPE_CONTEXT
    #define CVD_SCOPE_CONTEXT(InContext) \
        FChaosVDScopeContext CVDScope(InContext);
#endif
 
#ifndef CVD_SCOPED_DATA_CHANNEL_OVERRIDE
    #define CVD_SCOPED_DATA_CHANNEL_OVERRIDE(DataChannel) \
    FChaosCVDScopedDataChannelOverride CVDDC_Scope_Override##DataChannel(DataChannel);
#endif
 
#else // WITH_CHAOS_VISUAL_DEBUGGER
 
#ifndef CVD_GET_CURRENT_CONTEXT
    #define CVD_GET_CURRENT_CONTEXT(OutContext)
#endif
 
#ifndef CVD_SCOPE_CONTEXT
    #define CVD_SCOPE_CONTEXT(InContext)
#endif
 
#ifndef CVD_GET_WRAPPED_CURRENT_CONTEXT
    #define CVD_GET_WRAPPED_CURRENT_CONTEXT(OutWrappedContext)
#endif
 
#ifndef CVD_SCOPED_CONTEXT_DATA_CHANNEL_OVERRIDE
    #define CVD_SCOPED_CONTEXT_DATA_CHANNEL_OVERRIDE(DataChannel)
#endif
 
#endif // WITH_CHAOS_VISUAL_DEBUGGER
 
struct FChaosVDContextWrapper
{
    FChaosVDContextWrapper()
    {
    }
    
#if WITH_CHAOS_VISUAL_DEBUGGER
    FChaosVDContextWrapper(const FChaosVDContext& InContext)
    : Context(InContext)
    {
    }
 
    FChaosVDContext Context;
#endif
};