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FMessageEndpoint

Implements a message endpoint for sending and receiving messages on a message bus.

API > API/Runtime > API/Runtime/MessagingCommon

Implements a message endpoint for sending and receiving messages on a message bus.

This class provides a convenient implementation of the IMessageReceiver and IMessageSender interfaces, which allow consumers to send and receive messages on a message bus. The endpoint allows for receiving messages asynchronously as they arrive, as well as synchronously through an inbox that can be polled.

By default, messages are received synchronously on the thread that the endpoint was created on. If the message consumer is thread-safe, a more efficient message dispatch can be enabled by calling the SetRecipientThread() method with ENamedThreads::AnyThread.

Endpoints that are destroyed or receive messages on non-Game threads should use the static function FMessageEndpoint::SafeRelease() to dispose of the endpoint. This will ensure that there are no race conditions between endpoint destruction and the receiving of messages.

The underlying message bus will take ownership of all sent and published message objects. The memory held by the messages must therefore NOT be freed by the caller.

   
Name FMessageEndpoint
Type class
Header File /Engine/Source/Runtime/MessagingCommon/Public/MessageEndpoint.h
Include Path #include "MessageEndpoint.h"

Syntax

class FMessageEndpoint :  
    public TSharedFromThis< FMessageEndpoint, ESPMode::ThreadSafe > ,  
    public IMessageReceiver,  
    public IMessageSender,  
    public IBusListener

Inheritance Hierarchy

Implements Interfaces

Constructors

Name Remarks Include Path Unreal Specifiers

FMessageEndpoint ( const FName& InName,
const TSharedRef< IMessageBus, ESPMode::ThreadSafe >& InBus,
const TArray< TSharedPtr< IMessageHandler, ESPMode::ThreadSafe > >& InHandlers,
const FOnBusNotification InNotificationDelegate
)

 Creates and initializes a new instance. MessageEndpoint.h  

Destructors

Name Remarks Include Path Unreal Specifiers

~FMessageEndpoint()

 Destructor. MessageEndpoint.h  

Typedefs

Name Type Remarks Include Path
Builder struct FMessageEndpointBuilder Type definition for the endpoint builder. MessageEndpoint.h

Variables

Protected

Name Type Remarks Include Path Unreal Specifiers
Address const FMessageAddress Holds the endpoint's identifier. MessageEndpoint.h  
BusPtr TWeakPtr< IMessageBus, ESPMode::ThreadSafe > Holds a weak pointer to the message bus. MessageEndpoint.h  
Enabled bool Hold a flag indicating whether this endpoint is active. MessageEndpoint.h  
ErrorDelegate FOnMessageEndpointError Holds a delegate that is invoked in case of messaging errors. MessageEndpoint.h  
Handlers TArray< TSharedPtr< IMessageHandler, ESPMode::ThreadSafe > > Holds the registered message handlers. MessageEndpoint.h  
HandlersCS FCriticalSection Sigfnifies that the handler array is being accessed and other threads should wait or skip MessageEndpoint.h  
Id const FGuid Holds the endpoint's unique identifier (for debugging purposes). MessageEndpoint.h  
Inbox TQueue< TSharedPtr< IMessageContext, ESPMode::ThreadSafe >, EQueueMode::Mpsc > Holds the endpoint's message inbox. MessageEndpoint.h  
InboxEnabled bool Holds a flag indicating whether the inbox is enabled. MessageEndpoint.h  
Name const FName Holds the endpoint's name (for debugging purposes). MessageEndpoint.h  
NotificationDelegate FOnBusNotification Holds a delegate that is invoked on disconnection events. MessageEndpoint.h  
RecipientThread ENamedThreads::Type Holds the name of the thread on which to receive messages. MessageEndpoint.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

void Defer ( const TSharedRef< IMessageContext, ESPMode::ThreadSafe >& Context,
const FTimespan& Delay
)

 Defers processing of the given message by the specified time delay. MessageEndpoint.h  

void Disable ()

 Disables this endpoint. MessageEndpoint.h  

void DisableInbox ()

 Disables the inbox for unhandled messages.The inbox is disabled by default. MessageEndpoint.h  

void Enable ()

 Enables this endpoint. MessageEndpoint.h  

void EnableInbox ()

 Enables the inbox for unhandled messages. MessageEndpoint.h  

void Forward ( const TSharedRef< IMessageContext, ESPMode::ThreadSafe >& Context,
const TArray< FMessageAddress >& Recipients,
const FTimespan& Delay
)

 Forwards a previously received message. MessageEndpoint.h  

void Forward ( const TSharedRef< IMessageContext, ESPMode::ThreadSafe >& Context,
const FMessageAddress& Recipient,
const FTimespan& Delay
)

 Forwards a previously received message to the specified recipient after a given delay. MessageEndpoint.h  

void Forward ( const TSharedRef< IMessageContext, ESPMode::ThreadSafe >& Context,
const FMessageAddress& Recipient
)

 Immediately forwards a previously received message to the specified recipient. MessageEndpoint.h  

void Forward ( const TSharedRef< IMessageContext, ESPMode::ThreadSafe >& Context,
const TArray< FMessageAddress >& Recipients
)

 Immediately forwards a previously received message to the specified list of recipients. MessageEndpoint.h  

const FMessageAddress & GetAddress()

 Gets the endpoint's message address. MessageEndpoint.h  

virtual FName GetDebugName()

   MessageEndpoint.h  

virtual ENamedThreads::Type GetListenerThread()

   MessageEndpoint.h  

virtual const FGuid & GetRecipientId()

   MessageEndpoint.h  

virtual ENamedThreads::Type GetRecipientThread()

   MessageEndpoint.h  

virtual FMessageAddress GetSenderAddress()

   MessageEndpoint.h  

bool IsConnected ()

 Checks whether this endpoint is connected to the bus. MessageEndpoint.h  

bool IsEnabled ()

 Checks whether this endpoint is enabled. MessageEndpoint.h  

bool IsInboxEmpty ()

 Checks whether the inbox is empty. MessageEndpoint.h  

bool IsInboxEnabled ()

 Checks whether the inbox is enabled. MessageEndpoint.h  

virtual bool IsLocal()

   MessageEndpoint.h  

virtual void NotifyMessageError ( const TSharedRef< IMessageContext, ESPMode::ThreadSafe >& Context,
const FString& Error
)

   MessageEndpoint.h  

virtual void NotifyRegistration ( const FMessageAddress& InAddress,
EMessageBusNotification InNotification
)

   MessageEndpoint.h  

void ProcessInbox ()

 Calls the matching message handlers for all messages queued up in the inbox. MessageEndpoint.h  

void Publish ( void* Message,
UScriptStruct* TypeInfo,
EMessageScope Scope,
const TMap< FName, FString > Annotations,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Publishes a message to all subscribed recipients within the specified scope. MessageEndpoint.h  

void Publish ( MessageType* Message,
const TMap< FName, FString > Annotations,
EMessageScope Scope,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Publishes a message to all subscribed recipients within the specified scope. MessageEndpoint.h  

void Publish ( void* Message,
UScriptStruct* TypeInfo,
EMessageScope Scope,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Publishes a message to all subscribed recipients within the specified scope. MessageEndpoint.h  

void Publish ( MessageType* Message,
EMessageScope Scope,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Publishes a message to all subscribed recipients within the specified scope. MessageEndpoint.h  

void Publish ( MessageType* Message,
const TMap< FName, FString > Annotations,
EMessageScope Scope
)

 Immediately pa message to all subscribed recipients within the specified scope. MessageEndpoint.h  

void Publish ( MessageType* Message,
EMessageScope Scope,
const FTimespan& Delay
)

 Publishes a message to all subscribed recipients within the specified scope after a given delay. MessageEndpoint.h  

void Publish ( MessageType* Message,
const FTimespan& Delay
)

 Publishes a message to all subscribed recipients after a given delay. MessageEndpoint.h  

void Publish ( MessageType* Message
)

 Immediately publishes a message to all subscribed recipients. MessageEndpoint.h  

void Publish ( MessageType* Message,
EMessageScope Scope
)

 Immediately pa message to all subscribed recipients within the specified scope. MessageEndpoint.h  

void Publish ( MessageType* Message,
const TMap< FName, FString > Annotations
)

 Immediately publishes a message to all subscribed recipients. MessageEndpoint.h  

bool ReceiveFromInbox ( TSharedPtr< IMessageContext, ESPMode::ThreadSafe >& OutContext
)

 Receives a single message from the endpoint's inbox. MessageEndpoint.h  

virtual void ReceiveMessage ( const TSharedRef< IMessageContext, ESPMode::ThreadSafe >& Context
)

   MessageEndpoint.h  

void Send ( void* Message,
UScriptStruct* TypeInfo,
EMessageFlags Flags,
const TMap< FName, FString > Annotations,
const TSharedPtr< IMessageAttachment, ESPMode::ThreadSafe >& Attachment,
const TArray< FMessageAddress >& Recipients,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Sends a message to the specified list of recipients. MessageEndpoint.h  

void Send ( MessageType* Message,
EMessageFlags Flags,
const TMap< FName, FString > Annotations,
const TSharedPtr< IMessageAttachment, ESPMode::ThreadSafe >& Attachment,
const TArray< FMessageAddress >& Recipients,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Sends a message to the specified list of recipients. Allows to specify message flags MessageEndpoint.h  

void Send ( void* Message,
UScriptStruct* TypeInfo,
EMessageFlags Flags,
const TSharedPtr< IMessageAttachment, ESPMode::ThreadSafe >& Attachment,
const TArray< FMessageAddress >& Recipients,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Sends a message to the specified list of recipients. Allows to specify message flags MessageEndpoint.h  

void Send ( MessageType* Message,
EMessageFlags Flags,
const TSharedPtr< IMessageAttachment, ESPMode::ThreadSafe >& Attachment,
const TArray< FMessageAddress >& Recipients,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Sends a message to the specified list of recipients. Allows to specify message flags MessageEndpoint.h  

void Send ( MessageType* Message,
const TMap< FName, FString > Annotations,
const TSharedPtr< IMessageAttachment, ESPMode::ThreadSafe >& Attachment,
const FMessageAddress& Recipient,
const FDateTime& Expiration,
const FTimespan& Delay
)

 Sends a message with fields, attachment and expiration to the specified recipient after a given delay. MessageEndpoint.h  

void Send ( void* Message,
UScriptStruct* TypeInfo,
const TSharedPtr< IMessageAttachment, ESPMode::ThreadSafe >& Attachment,
const TArray< FMessageAddress >& Recipients,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Sends a message to the specified list of recipients. MessageEndpoint.h  

void Send ( MessageType* Message,
const TSharedPtr< IMessageAttachment, ESPMode::ThreadSafe >& Attachment,
const TArray< FMessageAddress >& Recipients,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Sends a message to the specified list of recipients. MessageEndpoint.h  

void Send ( MessageType* Message,
const TSharedPtr< IMessageAttachment, ESPMode::ThreadSafe >& Attachment,
const TArray< FMessageAddress >& Recipients,
const FTimespan& Delay
)

 Sends a message with fields and attachment to the specified list of recipients after a given delay. MessageEndpoint.h  

void Send ( MessageType* Message,
const TSharedPtr< IMessageAttachment, ESPMode::ThreadSafe >& Attachment,
const FMessageAddress& Recipient,
const FDateTime& Expiration,
const FTimespan& Delay
)

 Sends a message with fields, attachment and expiration to the specified recipient after a given delay. MessageEndpoint.h  

void Send ( MessageType* Message,
const TArray< FMessageAddress >& Recipients,
const FTimespan& Delay
)

 Sends a message to the specified list of recipients after a given delay after a given delay. MessageEndpoint.h  

void Send ( MessageType* Message,
const TSharedPtr< IMessageAttachment, ESPMode::ThreadSafe >& Attachment,
const FMessageAddress& Recipient
)

 Sends a message with fields and attachment to the specified recipient. MessageEndpoint.h  

void Send ( MessageType* Message,
const FMessageAddress& Recipient,
const FTimespan& Delay
)

 Sends a message to the specified recipient after a given delay. MessageEndpoint.h  

void Send ( MessageType* Message,
const TMap< FName, FString > Annotations,
const FMessageAddress& Recipient
)

 Immediately sends a message to the specified recipient. MessageEndpoint.h  

void Send ( MessageType* Message,
const TArray< FMessageAddress >& Recipients
)

 Immediately sends a message to the specified list of recipients. MessageEndpoint.h  

void Send ( MessageType* Message,
const FMessageAddress& Recipient
)

 Immediately sends a message to the specified recipient. MessageEndpoint.h  

void Send ( MessageType* Message,
const FMessageAddress& Recipient,
const FTimespan& Delay,
const FDateTime& Expiration
)

 Sends a message with fields and expiration to the specified recipient after a given delay. MessageEndpoint.h  

void SetRecipientThread ( const ENamedThreads::Type& NamedThread
)

 Sets the name of the thread to receive messages on. MessageEndpoint.h  

void Subscribe ()

 Template method to subscribe the message endpoint to the specified type of messages with the default message scope. MessageEndpoint.h  

void Subscribe ( const FMessageScopeRange& ScopeRange
)

 Template method to subscribe the message endpoint to the specified type and scope of messages. MessageEndpoint.h  

void Subscribe ( const FName& MessageType,
const FMessageScopeRange& ScopeRange
)

 Subscribes a message handler. MessageEndpoint.h  

void Subscribe ( const FTopLevelAssetPath& MessageType,
const FMessageScopeRange& ScopeRange
)

 Subscribes a message handler. MessageEndpoint.h  

void Unsubscribe ( const FName& MessageType
)

 Unsubscribes this endpoint from the specified message type. MessageEndpoint.h  

void Unsubscribe ()

 Unsubscribes this endpoint from all message types. MessageEndpoint.h  

void Unsubscribe ()

 Template method to unsubscribe the endpoint from the specified message type. MessageEndpoint.h  

void Unsubscribe ( const FTopLevelAssetPath& MessageType
)

 Unsubscribes this endpoint from the specified message type. MessageEndpoint.h  

Protected

Name Remarks Include Path Unreal Specifiers

void ClearHandlers ()

 Clears all handlers in a way that guarantees it won't overlap with message processing. MessageEndpoint.h  

TSharedPtr< IMessageBus, ESPMode::ThreadSafe > GetBusIfEnabled()

 Gets a shared pointer to the message bus if this endpoint is enabled. MessageEndpoint.h  

void ProcessMessage ( const TSharedRef< IMessageContext, ESPMode::ThreadSafe >& Context
)

 Forwards the given message context to matching message handlers. MessageEndpoint.h  

Static

Name Remarks Include Path Unreal Specifiers

static T * MakeMessage ( InArgTypes&&... Args
)

 Creates a message of the specified template type. MessageEndpoint.h  
Safely releases a message endpoint that is receiving messages on AnyThread. MessageEndpoint.h  

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