GC.MaxGeneration 屬性

定義

命名空間:

System

組件:

System.Runtime.dll

來源:

GC.CoreCLR.cs

取得系統目前支援的最大層代編號。

public:
 static property int MaxGeneration { int get(); };

public static int MaxGeneration { get; }

static member MaxGeneration : int

Public Shared ReadOnly Property MaxGeneration As Integer

屬性值

Int32

範圍從零至所支援最大層代編號的值。

範例

下列範例示範如何使用 MaxGeneration 屬性來顯示目前使用中的最大世代數目。

using namespace System;
const long maxGarbage = 1000;
ref class MyGCCollectClass
{
public:
   void MakeSomeGarbage()
   {
      Version^ vt;
      for ( int i = 0; i < maxGarbage; i++ )
      {
         
         // Create objects and release them to fill up memory
         // with unused objects.
         vt = gcnew Version;

      }
   }

};

int main()
{
   MyGCCollectClass^ myGCCol = gcnew MyGCCollectClass;
   
   // Determine the maximum number of generations the system
   // garbage collector currently supports.
   Console::WriteLine( "The highest generation is {0}", GC::MaxGeneration );
   myGCCol->MakeSomeGarbage();
   
   // Determine which generation myGCCol object is stored in.
   Console::WriteLine( "Generation: {0}", GC::GetGeneration( myGCCol ) );
   
   // Determine the best available approximation of the number
   // of bytes currently allocated in managed memory.
   Console::WriteLine( "Total Memory: {0}", GC::GetTotalMemory( false ) );
   
   // Perform a collection of generation 0 only.
   GC::Collect( 0 );
   
   // Determine which generation myGCCol object is stored in.
   Console::WriteLine( "Generation: {0}", GC::GetGeneration( myGCCol ) );
   Console::WriteLine( "Total Memory: {0}", GC::GetTotalMemory( false ) );
   
   // Perform a collection of all generations up to and including 2.
   GC::Collect( 2 );
   
   // Determine which generation myGCCol object is stored in.
   Console::WriteLine( "Generation: {0}", GC::GetGeneration( myGCCol ) );
   Console::WriteLine( "Total Memory: {0}", GC::GetTotalMemory( false ) );
}

using System;

namespace GCCollectIntExample
{
    class MyGCCollectClass
    {
        private const long maxGarbage = 1000;

        static void Main()
        {
            MyGCCollectClass myGCCol = new MyGCCollectClass();

            // Determine the maximum number of generations the system
        // garbage collector currently supports.
            Console.WriteLine("The highest generation is {0}", GC.MaxGeneration);

            myGCCol.MakeSomeGarbage();

            // Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol));

            // Determine the best available approximation of the number
        // of bytes currently allocated in managed memory.
            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(false));

            // Perform a collection of generation 0 only.
            GC.Collect(0);

            // Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol));

            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(false));

            // Perform a collection of all generations up to and including 2.
            GC.Collect(2);

            // Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol));
            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(false));
            Console.Read();
        }

        void MakeSomeGarbage()
        {
            Version vt;

            for(int i = 0; i < maxGarbage; i++)
            {
                // Create objects and release them to fill up memory
        // with unused objects.
                vt = new Version();
            }
        }
    }
}

open System

let maxGarbage = 1000

type MyGCCollectClass() =
    member _.MakeSomeGarbage() =
        for _ = 1 to maxGarbage do
            // Create objects and release them to fill up memory with unused objects.
            Version() |> ignore

[<EntryPoint>]
let main _ =
    let myGCCol = MyGCCollectClass()

    // Determine the maximum number of generations the system
    // garbage collector currently supports.
    printfn $"The highest generation is {GC.MaxGeneration}"

    myGCCol.MakeSomeGarbage()

    // Determine which generation myGCCol object is stored in.
    printfn $"Generation: {GC.GetGeneration myGCCol}"

    // Determine the best available approximation of the number
    // of bytes currently allocated in managed memory.
    printfn $"Total Memory: {GC.GetTotalMemory false}"

    // Perform a collection of generation 0 only.
    GC.Collect 0

    // Determine which generation myGCCol object is stored in.
    printfn $"Generation: {GC.GetGeneration myGCCol}"

    printfn $"Total Memory: {GC.GetTotalMemory false}"

    // Perform a collection of all generations up to and including 2.
    GC.Collect 2

    // Determine which generation myGCCol object is stored in.
    printfn $"Generation: {GC.GetGeneration myGCCol}"
    printfn $"Total Memory: {GC.GetTotalMemory false}"

    0

Namespace GCCollectInt_Example
    Class MyGCCollectClass
        Private maxGarbage As Long = 10000

        Public Shared Sub Main()
            Dim myGCCol As New MyGCCollectClass

            'Determine the maximum number of generations the system
            'garbage collector currently supports.
            Console.WriteLine("The highest generation is {0}", GC.MaxGeneration)

            myGCCol.MakeSomeGarbage()

            'Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol))

            'Determine the best available approximation of the number 
            'of bytes currently allocated in managed memory.
            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(False))

            'Perform a collection of generation 0 only.
            GC.Collect(0)

            'Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol))

            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(False))

            'Perform a collection of all generations up to and including 2.
            GC.Collect(2)

            'Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol))
            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(False))
            Console.Read()

        End Sub


        Sub MakeSomeGarbage()
            Dim vt As Version

            Dim i As Integer
            For i = 0 To maxGarbage - 1
                'Create objects and release them to fill up memory
                'with unused objects.
                vt = New Version
            Next i
        End Sub
    End Class
End Namespace

備註

物件的世代號碼或年齡是物件生命週期的實作定義相對量值。 最近建立的物件位於層代 0 中，而最舊的物件則位於小於或等於 屬性所傳回的世代中 MaxGeneration 。

垃圾收集行程假設較新的記憶體比較舊的記憶體更可能符合垃圾收集的資格。 因此，垃圾收集行程會藉由在每次回收記憶體時調整世代號碼來改善其效能，而 MaxGeneration 屬性值可能會隨著時間成長。

如果實作物件過時， MaxGeneration 屬性會傳回系統所使用的最大世代數目，否則這個屬性會傳回零。

針對這個實作，屬性所 MaxGeneration 傳回的值保證會在執行中應用程式的存留期維持不變。

MaxGeneration使用 屬性來判斷呼叫採用產生參數的方法時 Collect(Int32) 可以指定的最大值。

另請參閱

• GetGeneration(Object)