ObjectiveCMarshal.CreateReferenceTrackingHandle Method

Definition

Namespace:

System.Runtime.InteropServices.ObjectiveC

Assembly:

System.Runtime.InteropServices.dll

Source:

ObjectiveCMarshal.PlatformNotSupported.cs

Request native reference tracking for the supplied object.

public:
 static System::Runtime::InteropServices::GCHandle CreateReferenceTrackingHandle(System::Object ^ obj, [Runtime::InteropServices::Out] Span<IntPtr> % taggedMemory);

public static System.Runtime.InteropServices.GCHandle CreateReferenceTrackingHandle (object obj, out Span<IntPtr> taggedMemory);

static member CreateReferenceTrackingHandle : obj * Span -> System.Runtime.InteropServices.GCHandle

Public Shared Function CreateReferenceTrackingHandle (obj As Object, ByRef taggedMemory As Span(Of IntPtr)) As GCHandle

Parameters

obj

Object

The object to track.

taggedMemory

Span<IntPtr>

Span<nativeint>

A pointer to memory tagged to the object.

Returns

GCHandle

Reference tracking GC handle.

Exceptions

InvalidOperationException

The ObjectiveCMarshal API has not been initialized.

Remarks

The Initialize() must be called prior to calling this function.

The obj must have a type in its hierarchy marked with ObjectiveCTrackedTypeAttribute.

The "Is Referenced" callback passed to Initialize() will be passed the taggedMemory returned from this function. The memory it points at is defined by the length in the Span<T> and will be zeroed out. It will be available until obj is collected by the GC. The memory pointed to by taggedMemory can be used for any purpose by the caller of this function and usable during the "Is Referenced" callback.

Calling this function multiple times with the same obj will return a new handle each time but the same tagged memory will be returned. The tagged memory is only guaranteed to be zero initialized on the first call.

The caller is responsible for freeing the returned GCHandle.