Files
UnrealEngine/Engine/Source/Runtime/Messaging/Private/Bus/MessageRouter.cpp
2025-05-18 13:04:45 +08:00

458 lines
12 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#include "Bus/MessageRouter.h"
#include "IMessagingModule.h"
#include "HAL/PlatformProcess.h"
#include "Bus/MessageDispatchTask.h"
#include "IMessageBus.h"
#include "IMessageSubscription.h"
#include "IMessageReceiver.h"
#include "IMessageInterceptor.h"
#include "IMessageBusListener.h"
#include "Misc/ConfigCacheIni.h"
/* FMessageRouter structors
*****************************************************************************/
FMessageRouter::FMessageRouter()
: DelayedMessagesSequence(0)
, Stopping(false)
, Tracer(MakeShared<FMessageTracer, ESPMode::ThreadSafe>())
, bAllowDelayedMessaging(false)
{
ActiveSubscriptions.FindOrAdd(IMessageBus::PATHNAME_All);
WorkEvent = FPlatformProcess::GetSynchEventFromPool();
GConfig->GetBool(TEXT("Messaging"), TEXT("bAllowDelayedMessaging"), bAllowDelayedMessaging, GEngineIni);
}
FMessageRouter::~FMessageRouter()
{
FPlatformProcess::ReturnSynchEventToPool(WorkEvent);
WorkEvent = nullptr;
}
/* FRunnable interface
*****************************************************************************/
FSingleThreadRunnable* FMessageRouter::GetSingleThreadInterface()
{
return this;
}
bool FMessageRouter::Init()
{
return true;
}
uint32 FMessageRouter::Run()
{
while (!Stopping)
{
CurrentTime = FDateTime::UtcNow();
ProcessCommands();
ProcessDelayedMessages();
WorkEvent->Wait(CalculateWaitTime());
}
return 0;
}
void FMessageRouter::Stop()
{
Tracer->Stop();
Stopping = true;
WorkEvent->Trigger();
}
void FMessageRouter::Exit()
{
TArray<TWeakPtr<IMessageReceiver, ESPMode::ThreadSafe>> Recipients;
// gather all subscribed and registered recipients
for (const auto& RecipientPair : ActiveRecipients)
{
Recipients.AddUnique(RecipientPair.Value);
}
for (const auto& SubscriptionsPair : ActiveSubscriptions)
{
for (const auto& Subscription : SubscriptionsPair.Value)
{
Recipients.AddUnique(Subscription->GetSubscriber());
}
}
}
/* FMessageRouter implementation
*****************************************************************************/
FTimespan FMessageRouter::CalculateWaitTime()
{
FTimespan WaitTime = FTimespan::FromMilliseconds(100);
if (DelayedMessages.Num() > 0)
{
FTimespan DelayedTime = DelayedMessages.HeapTop().Context->GetTimeSent() - CurrentTime;
if (DelayedTime < WaitTime)
{
return DelayedTime;
}
}
return WaitTime;
}
void FMessageRouter::DispatchMessage(const TSharedRef<IMessageContext, ESPMode::ThreadSafe>& Context)
{
if (Context->IsValid())
{
TArray<TSharedPtr<IMessageReceiver, ESPMode::ThreadSafe>> Recipients;
int32 RecipientCount = Context->GetRecipients().Num();
// get recipients, either from the context...
if (RecipientCount > 0)
{
if (UE_GET_LOG_VERBOSITY(LogMessaging) >= ELogVerbosity::Verbose)
{
FString RecipientStr = FString::JoinBy(Context->GetRecipients(), TEXT("+"), &FMessageAddress::ToString);
UE_LOG(LogMessaging, Verbose, TEXT("Dispatching %s from %s to %s"), *Context->GetMessageTypePathName().ToString(), *Context->GetSender().ToString(), *RecipientStr);
}
FilterRecipients(Context, Recipients);
if (Recipients.Num() < RecipientCount)
{
UE_LOG(LogMessaging, Verbose, TEXT("%d recipients were filtered out"), RecipientCount - Recipients.Num());
}
}
// ... or from subscriptions
else
{
FilterSubscriptions(ActiveSubscriptions.FindOrAdd(Context->GetMessageTypePathName()), Context, Recipients);
FilterSubscriptions(ActiveSubscriptions.FindOrAdd(IMessageBus::PATHNAME_All), Context, Recipients);
if (UE_GET_LOG_VERBOSITY(LogMessaging) >= ELogVerbosity::Verbose)
{
FString RecipientStr = FString::JoinBy(Context->GetRecipients(), TEXT("+"), &FMessageAddress::ToString);
UE_LOG(LogMessaging, Verbose, TEXT("Dispatching %s from %s to %s subscribers"), *Context->GetMessageTypePathName().ToString(), *Context->GetSender().ToString(), *RecipientStr);
}
}
// dispatch the message
for (auto& Recipient : Recipients)
{
ENamedThreads::Type RecipientThread = Recipient->GetRecipientThread();
if (RecipientThread == ENamedThreads::AnyThread)
{
Tracer->TraceDispatchedMessage(Context, Recipient.ToSharedRef(), false);
Recipient->ReceiveMessage(Context);
Tracer->TraceHandledMessage(Context, Recipient.ToSharedRef());
}
else
{
TGraphTask<FMessageDispatchTask>::CreateTask().ConstructAndDispatchWhenReady(RecipientThread, Context, Recipient, Tracer);
}
}
}
}
void FMessageRouter::FilterSubscriptions(
TArray<TSharedPtr<IMessageSubscription, ESPMode::ThreadSafe>>& Subscriptions,
const TSharedRef<IMessageContext, ESPMode::ThreadSafe>& Context,
TArray<TSharedPtr<IMessageReceiver, ESPMode::ThreadSafe>>& OutRecipients
)
{
EMessageScope MessageScope = Context->GetScope();
for (int32 SubscriptionIndex = 0; SubscriptionIndex < Subscriptions.Num(); ++SubscriptionIndex)
{
const auto Subscription = Subscriptions[SubscriptionIndex];
if (!Subscription->IsEnabled() || !Subscription->GetScopeRange().Contains(MessageScope))
{
continue;
}
auto Subscriber = Subscription->GetSubscriber().Pin();
if (Subscriber.IsValid())
{
if (MessageScope == EMessageScope::Thread)
{
ENamedThreads::Type RecipientThread = Subscriber->GetRecipientThread();
ENamedThreads::Type SenderThread = Context->GetSenderThread();
if (RecipientThread != SenderThread)
{
continue;
}
}
OutRecipients.AddUnique(Subscriber);
}
else
{
Subscriptions.RemoveAtSwap(SubscriptionIndex);
--SubscriptionIndex;
}
}
}
void FMessageRouter::FilterRecipients(
const TSharedRef<IMessageContext, ESPMode::ThreadSafe>& Context,
TArray<TSharedPtr<IMessageReceiver, ESPMode::ThreadSafe>>& OutRecipients)
{
FMessageScopeRange IncludeNetwork = FMessageScopeRange::AtLeast(EMessageScope::Network);
const TArray<FMessageAddress>& RecipientList = Context->GetRecipients();
for (const auto& RecipientAddress : RecipientList)
{
auto Recipient = ActiveRecipients.FindRef(RecipientAddress).Pin();
if (Recipient.IsValid())
{
// if the recipient is not local and the scope does not include network, filter it out of the recipient list
if (Recipient->IsLocal() || IncludeNetwork.Contains(Context->GetScope()))
{
OutRecipients.AddUnique(Recipient);
}
}
else
{
ActiveRecipients.Remove(RecipientAddress);
}
}
}
void FMessageRouter::ProcessCommands()
{
CommandDelegate Command;
while (Commands.Dequeue(Command))
{
Command.Execute();
}
}
void FMessageRouter::ProcessDelayedMessages()
{
FDelayedMessage DelayedMessage;
while ((DelayedMessages.Num() > 0) && (DelayedMessages.HeapTop().Context->GetTimeSent() <= CurrentTime))
{
DelayedMessages.HeapPop(DelayedMessage);
DispatchMessage(DelayedMessage.Context.ToSharedRef());
}
}
/* FSingleThreadRunnable interface
*****************************************************************************/
void FMessageRouter::Tick()
{
CurrentTime = FDateTime::UtcNow();
ProcessDelayedMessages();
ProcessCommands();
}
/* FMessageRouter callbacks
*****************************************************************************/
void FMessageRouter::HandleAddInterceptor(TSharedRef<IMessageInterceptor, ESPMode::ThreadSafe> Interceptor, FTopLevelAssetPath MessageType)
{
UE_LOG(LogMessaging, Verbose, TEXT("Adding %s as intereceptor for %s messages"), *Interceptor->GetDebugName().ToString(), *MessageType.ToString());
ActiveInterceptors.FindOrAdd(MessageType).AddUnique(Interceptor);
Tracer->TraceAddedInterceptor(Interceptor, MessageType);
}
void FMessageRouter::HandleAddRecipient(FMessageAddress Address, TWeakPtr<IMessageReceiver, ESPMode::ThreadSafe> RecipientPtr)
{
auto Recipient = RecipientPtr.Pin();
if (Recipient.IsValid())
{
UE_LOG(LogMessaging, Verbose, TEXT("Adding %s on %s as recipient"), *Recipient->GetDebugName().ToString(), *Address.ToString());
ActiveRecipients.FindOrAdd(Address) = Recipient;
Tracer->TraceAddedRecipient(Address, Recipient.ToSharedRef());
NotifyRegistration(Address, EMessageBusNotification::Registered);
}
}
void FMessageRouter::HandleAddSubscriber(TSharedRef<IMessageSubscription, ESPMode::ThreadSafe> Subscription)
{
auto Subscriber = Subscription->GetSubscriber().Pin();
if (Subscriber.IsValid())
{
UE_LOG(LogMessaging, Verbose, TEXT("Adding %s as a subscriber for %s messages"), *Subscriber->GetDebugName().ToString(), *Subscription->GetMessageTypePathName().ToString());
}
ActiveSubscriptions.FindOrAdd(Subscription->GetMessageTypePathName()).AddUnique(Subscription);
Tracer->TraceAddedSubscription(Subscription);
}
void FMessageRouter::HandleRemoveInterceptor(TSharedRef<IMessageInterceptor, ESPMode::ThreadSafe> Interceptor, FTopLevelAssetPath MessageType)
{
UE_LOG(LogMessaging, Verbose, TEXT("Removing %s as intereceptor for %s messages"), *Interceptor->GetDebugName().ToString(), *MessageType.ToString());
if (MessageType == IMessageBus::PATHNAME_All)
{
for (auto& InterceptorsPair : ActiveInterceptors)
{
InterceptorsPair.Value.Remove(Interceptor);
}
}
else
{
auto& Interceptors = ActiveInterceptors.FindOrAdd(MessageType);
Interceptors.Remove(Interceptor);
}
Tracer->TraceRemovedInterceptor(Interceptor, MessageType);
}
void FMessageRouter::HandleRemoveRecipient(FMessageAddress Address)
{
auto Recipient = ActiveRecipients.FindRef(Address).Pin();
if (Recipient.IsValid())
{
UE_LOG(LogMessaging, Verbose, TEXT("Removing %s on %s as recipient"), *Recipient->GetDebugName().ToString(), *Address.ToString());
ActiveRecipients.Remove(Address);
Tracer->TraceRemovedRecipient(Address);
NotifyRegistration(Address, EMessageBusNotification::Unregistered);
}
}
void FMessageRouter::HandleRemoveSubscriber(TWeakPtr<IMessageReceiver, ESPMode::ThreadSafe> SubscriberPtr, FTopLevelAssetPath MessageType)
{
auto Subscriber = SubscriberPtr.Pin();
if (!Subscriber.IsValid())
{
return;
}
for (auto& SubscriptionsPair : ActiveSubscriptions)
{
if ((MessageType != IMessageBus::PATHNAME_All) && (MessageType != SubscriptionsPair.Key))
{
continue;
}
TArray<TSharedPtr<IMessageSubscription, ESPMode::ThreadSafe>>& Subscriptions = SubscriptionsPair.Value;
for (int32 SubscriptionIndex = 0; SubscriptionIndex < Subscriptions.Num(); ++SubscriptionIndex)
{
const auto Subscription = Subscriptions[SubscriptionIndex];
if (Subscription->GetSubscriber().Pin() == Subscriber)
{
UE_LOG(LogMessaging, Verbose, TEXT("Removing %s as a subscriber for %s messages"), *Subscriber->GetDebugName().ToString(), *Subscription->GetMessageTypePathName().ToString());
Subscriptions.RemoveAtSwap(SubscriptionIndex);
Tracer->TraceRemovedSubscription(Subscription.ToSharedRef(), MessageType);
break;
}
}
}
}
void FMessageRouter::HandleRouteMessage(TSharedRef<IMessageContext, ESPMode::ThreadSafe> Context)
{
UE_LOG(LogMessaging, Verbose, TEXT("Routing %s message from %s"), *Context->GetMessageTypePathName().ToString(), *Context->GetSender().ToString());
Tracer->TraceRoutedMessage(Context);
// intercept routing
auto& Interceptors = ActiveInterceptors.FindOrAdd(Context->GetMessageTypePathName());
for (auto& Interceptor : Interceptors)
{
if (Interceptor->InterceptMessage(Context))
{
UE_LOG(LogMessaging, Verbose, TEXT("Message was intercepted by %s"), *Interceptor->GetDebugName().ToString());
Tracer->TraceInterceptedMessage(Context, Interceptor.ToSharedRef());
return;
}
}
// dispatch the message
if (bAllowDelayedMessaging && (Context->GetTimeSent() > CurrentTime))
{
UE_LOG(LogMessaging, Verbose, TEXT("Queued message for dispatch"));
DelayedMessages.HeapPush(FDelayedMessage(Context, ++DelayedMessagesSequence));
}
else
{
DispatchMessage(Context);
}
}
void FMessageRouter::HandleAddListener(TWeakPtr<IBusListener, ESPMode::ThreadSafe> ListenerPtr)
{
ActiveRegistrationListeners.AddUnique(ListenerPtr);
}
void FMessageRouter::HandleRemoveListener(TWeakPtr<IBusListener, ESPMode::ThreadSafe> ListenerPtr)
{
ActiveRegistrationListeners.Remove(ListenerPtr);
}
void FMessageRouter::NotifyRegistration(const FMessageAddress& Address, EMessageBusNotification Notification)
{
for (auto It = ActiveRegistrationListeners.CreateIterator(); It; ++It)
{
auto Listener = It->Pin();
if (Listener.IsValid())
{
ENamedThreads::Type ListenerThread = Listener->GetListenerThread();
if (ListenerThread == ENamedThreads::AnyThread)
{
Listener->NotifyRegistration(Address, Notification);
}
else
{
TGraphTask<FBusNotificationDispatchTask>::CreateTask().ConstructAndDispatchWhenReady(ListenerThread, Listener, Address, Notification);
}
}
else
{
It.RemoveCurrent();
}
}
}