GC.ReRegisterForFinalize(Object) メソッド

定義

SuppressFinalize(Object) が事前に呼び出されている指定オブジェクトに対して、ファイナライザーを呼び出すことをシステムに要求します。Requests that the system call the finalizer for the specified object for which SuppressFinalize(Object) has previously been called.

public:
 static void ReRegisterForFinalize(System::Object ^ obj);
public static void ReRegisterForFinalize (object obj);
static member ReRegisterForFinalize : obj -> unit
Public Shared Sub ReRegisterForFinalize (obj As Object)

パラメーター

obj
Object

ファイナライザーの呼び出しが必要なオブジェクト。The object that a finalizer must be called for.

例外

objnull です。obj is null.

次の例では、ReRegisterForFinalize メソッドを使用して、ガベージコレクション後にオブジェクトを2回目に終了する方法を示します。The following example demonstrates how to use the ReRegisterForFinalize method to finalize an object a second time after garbage collection.

using namespace System;
ref class MyFinalizeObject
{
public:
   static MyFinalizeObject^ currentInstance = nullptr;

private:
   bool hasFinalized;

public:
   MyFinalizeObject()
   {
      hasFinalized = false;
   }

   ~MyFinalizeObject()
   {
      if ( hasFinalized == false )
      {
         Console::WriteLine( "First finalization" );
         
         // Put this object back into a root by creating
         // a reference to it.
         MyFinalizeObject::currentInstance = this;
         
         // Indicate that this instance has finalized once.
         hasFinalized = true;
         
         // Place a reference to this object back in the
         // finalization queue.
         GC::ReRegisterForFinalize( this );
      }
      else
      {
         Console::WriteLine( "Second finalization" );
      }
   }

};

int main()
{
   
   // Create a MyFinalizeObject.
   MyFinalizeObject^ mfo = gcnew MyFinalizeObject;
   
   // Release the reference to mfo.
   mfo = nullptr;
   
   // Force a garbage collection.
   GC::Collect();
   
   // At this point mfo will have gone through the first Finalize.
   // There should now be a reference to mfo in the static
   // MyFinalizeObject::currentInstance field.  Setting this value
   // to 0 and forcing another garbage collection will now
   // cause the object to Finalize permanently.
   MyFinalizeObject::currentInstance = nullptr;
   GC::Collect();
}

using System;

namespace ReRegisterForFinalizeExample
{
    class MyMainClass
    {
        static void Main()
        {
            // Create a MyFinalizeObject.
            MyFinalizeObject mfo = new MyFinalizeObject();

            // Release the reference to mfo.
            mfo = null;

            // Force a garbage collection.
            GC.Collect();

            // At this point mfo will have gone through the first Finalize.
            // There should now be a reference to mfo in the static
            // MyFinalizeObject.currentInstance field.  Setting this value
            // to null and forcing another garbage collection will now
            // cause the object to Finalize permanently.
            MyFinalizeObject.currentInstance = null;
            GC.Collect();
        }
    }

    class MyFinalizeObject
    {
        public static MyFinalizeObject currentInstance = null;
        private bool hasFinalized = false;

        ~MyFinalizeObject()
        {
            if(hasFinalized == false)
            {
                Console.WriteLine("First finalization");
            
                // Put this object back into a root by creating
                // a reference to it.
                MyFinalizeObject.currentInstance = this;
            
                // Indicate that this instance has finalized once.
                hasFinalized = true;

                // Place a reference to this object back in the
                // finalization queue.
                GC.ReRegisterForFinalize(this);
            }
            else
            {
                Console.WriteLine("Second finalization");
            }
        }
    }
}
Namespace ReRegisterForFinalizeExample
    Class MyMainClass
        Shared Sub Main()
            'Create a MyFinalizeObject.
            Dim mfo As New MyFinalizeObject()

            'Release the reference to mfo.
            mfo = Nothing

            'Force a garbage collection.
            GC.Collect()

            'At this point mfo will have gone through the first Finalize.
            'There should now be a reference to mfo in the static
            'MyFinalizeObject.currentInstance field.  Setting this value
            'to null and forcing another garbage collection will now
            'cause the object to Finalize permanently.
            MyFinalizeObject.currentInstance = Nothing
            GC.Collect()
        End Sub
    End Class

    Class MyFinalizeObject
        Public Shared currentInstance As MyFinalizeObject = Nothing
        Private hasFinalized As Boolean = False

        Protected Overrides Sub Finalize()
            If hasFinalized = False Then
                Console.WriteLine("First finalization")

                'Put this object back into a root by creating
                'a reference to it.
                MyFinalizeObject.currentInstance = Me

                'Indicate that this instance has finalized once.
                hasFinalized = True

                'Place a reference to this object back in the
                'finalization queue.
                GC.ReRegisterForFinalize(Me)
            Else
                Console.WriteLine("Second finalization")
            End If
            MyBase.Finalize()
        End Sub
    End Class
End Namespace

注釈

ReRegisterForFinalize メソッドは、ガベージコレクターがオブジェクトを解放する前に、終了を要求するオブジェクトのリストに obj パラメーターを追加します。The ReRegisterForFinalize method adds the obj parameter to the list of objects that request finalization before the garbage collector frees the object. obj パラメーターは、このメソッドの呼び出し元である必要があります。The obj parameter must be the caller of this method.

ReRegisterForFinalize メソッドを呼び出すと、ガベージコレクターがオブジェクトのファイナライザーを呼び出すことは保証されません。Calling the ReRegisterForFinalize method does not guarantee that the garbage collector will call an object's finalizer.

既定では、ファイナライザーを実装するすべてのオブジェクトが、終了を必要とするオブジェクトの一覧に追加されます。ただし、オブジェクトは既に完了しているか、SuppressFinalize メソッドを呼び出すことによって終了処理が無効になっている可能性があります。By default, all objects that implement finalizers are added to the list of objects that require finalization; however, an object might have already been finalized or might have disabled finalization by calling the SuppressFinalize method.

ファイナライザーは、このメソッドを使用して、自身またはそれが参照するオブジェクトをやり直すすることができます。A finalizer can use this method to resurrect itself or an object that it references.

適用対象

こちらもご覧ください