# SystemTarget Methods [Type overview](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/) ## Activate(Dictionary<string, object>, CancellationToken) {#activate-system-collections-generic-dictionary-string-object-nullable-system-thr-dd952eeb} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/activate-system-collections-generic-dictionary-string-object-nullable-system-thr-dd952eeb/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L381) ```csharp public void Activate(Dictionary? requestContext, CancellationToken cancellationToken) ``` Start activating this instance. ### Parameters - `requestContext` (`Dictionary`): The request context of the request which is causing this instance to be activated, if any. - `cancellationToken` (`CancellationToken`): A cancellation token which, when canceled, indicates that the process should complete promptly. ## Deactivate(DeactivationReason, CancellationToken) {#deactivate-orleans-deactivationreason-system-threading-cancellationtoken-00ee150f} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/deactivate-orleans-deactivationreason-system-threading-cancellationtoken-00ee150f/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L384) ```csharp public void Deactivate(DeactivationReason deactivationReason, CancellationToken cancellationToken) ``` Start deactivating this instance. ### Parameters - `deactivationReason` (`DeactivationReason`): The reason for deactivation, for informational purposes. - `cancellationToken` (`CancellationToken`): A cancellation token which, when canceled, indicates that the process should complete promptly. ## Dispose {#dispose-edaeeb0a} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/dispose-edaeeb0a/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L391-L397) ```csharp public void Dispose() ``` Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources. ## GetComponent {#getcomponent-1-90c7c395} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/getcomponent-1-90c7c395/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L107-L128) ```csharp public TComponent? GetComponent() ``` Gets the component with the specified type. ### Returns The component with the specified type. ## GetExtension {#getextension-1-7a25ae0c} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/getextension-1-7a25ae0c/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L335-L347) ```csharp public TExtensionInterface GetExtension() ``` Returns the grain extension registered for the provided `TExtensionInterface`. ### Returns The implementation of the extension which is bound to this grain. ## GetOrSetExtension(Func<TExtension>) {#getorsetextension-2-system-func-textension-d5b9a5ee} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/getorsetextension-2-system-func-textension-d5b9a5ee/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L275-L293) ```csharp public (TExtension, TExtensionInterface) SystemTarget.GetOrSetExtension(Func newExtensionFunc) ``` Binds an extension to an addressable object, if not already done. ### Parameters - `newExtensionFunc` (`Func`): A factory function that constructs a new extension object. ### Returns A tuple, containing first the extension and second an addressable reference to the extension's interface. ## GetTarget {#gettarget-6971be98} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/gettarget-6971be98/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L378) ```csharp public object? GetTarget() ``` Gets the target instance. ### Returns The target. ## Migrate(Dictionary<string, object>, CancellationToken) {#migrate-system-collections-generic-dictionary-string-object-nullable-system-thre-f2378ca7} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/migrate-system-collections-generic-dictionary-string-object-nullable-system-thre-f2378ca7/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L408) ```csharp public void Migrate(Dictionary? requestContext, CancellationToken cancellationToken) ``` Starts an attempt to migrating this instance to another location. Migration captures the current [RequestContext](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/orleans.runtime.requestcontext/), making it available to the activation's placement director so that it can consider it when selecting a new location. Migration will occur asynchronously, when no requests are executing, and will not occur if the activation's placement director does not select an alternative location. ### Parameters - `requestContext` (`Dictionary`): The request context, which is provided to the placement director so that it can be examined when selecting a new location. - `cancellationToken` (`CancellationToken`): A cancellation token which, when canceled, indicates that the process should complete promptly. ## ReceiveMessage(object) {#receivemessage-object-b980162f} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/receivemessage-object-b980162f/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L353-L375) ```csharp public void ReceiveMessage(object message) ``` Submits an incoming message to this instance. ### Parameters - `message` (`object`): The message. ## RegisterGrainTimer(Func<CancellationToken, Task>, TimeSpan, TimeSpan) {#registergraintimer-system-func-system-threading-cancellationtoken-system-threadi-33f688fd} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/registergraintimer-system-func-system-threading-cancellationtoken-system-threadi-33f688fd/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L215-L219) ```csharp public IGrainTimer RegisterGrainTimer(Func callback, TimeSpan dueTime, TimeSpan period) ``` Registers a timer to send regular callbacks to this system target. ### Parameters - `callback` (`Func`): The timer callback, which will fire whenever the timer becomes due. - `dueTime` (`TimeSpan`): The amount of time to delay before the `callback` is invoked. Specify `System.Threading.Timeout.InfiniteTimeSpan` to prevent the timer from starting. Specify `System.TimeSpan.Zero` to invoke the callback promptly. - `period` (`TimeSpan`): The time interval between invocations of `callback`. Specify `System.Threading.Timeout.InfiniteTimeSpan` to disable periodic signaling. ### Returns An `System.IDisposable` object which will cancel the timer upon disposal. ## RegisterGrainTimer(Func<TState, CancellationToken, Task>, TState, TimeSpan, TimeSpan) {#registergraintimer-1-system-func-tstate-system-threading-cancellationtoken-syste-1f7ed765} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/registergraintimer-1-system-func-tstate-system-threading-cancellationtoken-syste-1f7ed765/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L242-L246) ```csharp public IGrainTimer RegisterGrainTimer(Func callback, TState state, TimeSpan dueTime, TimeSpan period) ``` Registers a timer to send regular callbacks to this grain. This timer will keep the current grain from being deactivated. ### Parameters - `callback` (`Func`): The timer callback, which will fire whenever the timer becomes due. - `state` (`TState`): The state object passed to the callback. - `dueTime` (`TimeSpan`): The amount of time to delay before the `callback` is invoked. Specify `System.Threading.Timeout.InfiniteTimeSpan` to prevent the timer from starting. Specify `System.TimeSpan.Zero` to invoke the callback promptly. - `period` (`TimeSpan`): The time interval between invocations of `callback`. Specify `System.Threading.Timeout.InfiniteTimeSpan` to disable periodic signaling. ### Returns An `System.IDisposable` object which will cancel the timer upon disposal. ## RegisterTimer(Func<object?, Task>, object?, TimeSpan, TimeSpan) {#registertimer-system-func-object-nullable-system-threading-tasks-task-object-nul-78cefed9} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/registertimer-system-func-object-nullable-system-threading-tasks-task-object-nul-78cefed9/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L191-L194) ```csharp public IGrainTimer RegisterTimer(Func callback, object? state, TimeSpan dueTime, TimeSpan period) ``` Registers a timer to send regular callbacks to this system target. ### Parameters - `callback` (`Func`): The timer callback, which will fire whenever the timer becomes due. - `state` (`object?`): The state object passed to the callback. - `dueTime` (`TimeSpan`): The amount of time to delay before the `callback` is invoked. Specify `System.Threading.Timeout.InfiniteTimeSpan` to prevent the timer from starting. Specify `System.TimeSpan.Zero` to invoke the callback promptly. - `period` (`TimeSpan`): The time interval between invocations of `callback`. Specify `System.Threading.Timeout.InfiniteTimeSpan` to disable periodic signaling. ### Returns An `System.IDisposable` object which will cancel the timer upon disposal. ## Rehydrate(IRehydrationContext) {#rehydrate-orleans-runtime-irehydrationcontext-7a09b31b} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/rehydrate-orleans-runtime-irehydrationcontext-7a09b31b/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L402-L403) ```csharp public void Rehydrate(IRehydrationContext context) ``` Start rehydrating this instance from the provided rehydration context. ### Parameters - `context` (`IRehydrationContext`) ## SetComponent(TComponent?) {#setcomponent-1-tcomponent-nullable-5383c46a} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/setcomponent-1-tcomponent-nullable-5383c46a/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L134-L146) ```csharp public void SetComponent(TComponent? instance) ``` Sets the provided value as the component for type `TComponent`. ### Parameters - `instance` (`TComponent?`): The component instance. ## ToString {#tostring-b40d0f00} [Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.systemtarget/methods/tostring-b40d0f00/) [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Core/SystemTarget.cs#L250) ```csharp public sealed override string ToString() ``` Returns a string that represents the current object. ### Returns A string that represents the current object.