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.NET Framework クラスライブラリリファレンス

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GC.ReRegisterForFinalize メソッド

SuppressFinalize が既に呼び出されている指定オブジェクトに対して、ファイナライザを呼び出すことをシステムに要求します。

名前空間: System
アセンブリ: mscorlib (mscorlib.dll 内)
構文

Visual Basic (宣言)

Public Shared Sub ReRegisterForFinalize
 ( _
    obj As Object _
)

Visual Basic (使用法)

Dim obj As Object

GC.ReRegisterForFinalize(obj)

public static void ReRegisterForFinalize
 (
    Object obj
)

C++

public:
static void ReRegisterForFinalize (
    Object^ obj
)

public static void ReRegisterForFinalize
 (
    Object obj
)

JScript

public static function ReRegisterForFinalize
 (
    obj : Object
)

パラメータ

obj: ファイナライザの呼び出しが必要なオブジェクト。

例外

例外の種類	条件
ArgumentNullException	obj が null 参照 (Visual Basic では Nothing) です。

解説

ReRegisterForFinalize メソッドは、ガベージコレクタがオブジェクトを解放する前に、終了操作を要求するオブジェクトのリストに obj を追加します。obj パラメータには、このメソッドの呼び出し元を指定する必要があります。

ReRegisterForFinalize メソッドを呼び出しても、ガベージコレクタがオブジェクトのファイナライザを呼び出すという保証はありません。

既定では、ファイナライザを実装するすべてのオブジェクトは、終了操作を要求をするオブジェクトのリストに追加されます。ただし、オブジェクトが既に終了されている場合や、SuppressFinalize メソッドを呼び出すことにより終了操作が無効にされている場合などがあります。

ファイナライザは、このメソッドを使用して、それ自身またはそれが参照するオブジェクトを復活させることができます。

使用例

Visual Basic

Imports System

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

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");
            }
        }
    }
}

C++

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();
}

package ReRegisterForFinalizeExample;

import System.* ;

class MyMainClass
{
    public static void main(String[]
 args)
    {
        // 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();
    } //main
} //MyMainClass

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

    public void finalize()
    {
        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");
        }

        try {
            super.finalize();
        }
        catch (System.Exception e) {
            Console.WriteLine(e.get_Message());
        }
    } //finalize
} //MyFinalizeObject