GC.WaitForPendingFinalizers Metoda

Definice

Obor názvů:

System

Sestavení:

netstandard.dll, System.Runtime.dll

Zdroj:

GC.CoreCLR.cs

Pozastaví aktuální vlákno, dokud vlákno, které zpracovává frontu finalizačních metod, nevyprázdní tuto frontu.

public:
 static void WaitForPendingFinalizers();

public static void WaitForPendingFinalizers();

static member WaitForPendingFinalizers : unit -> unit

Public Shared Sub WaitForPendingFinalizers ()

Příklady

Následující příklad ukazuje, jak pomocí WaitForPendingFinalizers metody pozastavit aktuální vlákno do dokončení dokončení všech shromážděných objektů.

using System;

namespace WaitForPendingFinalizersExample
{
   class MyWaitForPendingFinalizersClass
   {
    // You can increase this number to fill up more memory.
    const int numMfos = 1000;
    // You can increase this number to cause more
    // post-finalization work to be done.
    const int maxIterations = 100;

    static void Main(string[] args)
    {
       MyFinalizeObject mfo = null;

       // Create and release a large number of objects
       // that require finalization.
       for(int j = 0; j < numMfos; j++)
       {
          mfo = new MyFinalizeObject();
       }

       //Release the last object created in the loop.
       mfo = null;

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

       // Wait for all finalizers to complete before continuing.
       // Without this call to GC.WaitForPendingFinalizers,
       // the worker loop below might execute at the same time
       // as the finalizers.
       // With this call, the worker loop executes only after
       // all finalizers have been called.
       GC.WaitForPendingFinalizers();

       // Worker loop to perform post-finalization code.
       for(int i = 0; i < maxIterations; i++)
       {
          Console.WriteLine("Doing some post-finalize work");
       }
    }
   }

   class MyFinalizeObject
   {
    // Make this number very large to cause the finalizer to
    // do more work.
    private const int maxIterations = 10000;

    ~MyFinalizeObject()
    {
       Console.WriteLine("Finalizing a MyFinalizeObject");
            
       // Do some work.
       for(int i = 0; i < maxIterations; i++)
       {
          // This method performs no operation on i, but prevents
          // the JIT compiler from optimizing away the code inside
          // the loop.
          GC.KeepAlive(i);
       }
        }
    }
}

open System

// You can increase this number to fill up more memory.
let numMfos = 1000

// You can increase this number to cause more
// post-finalization work to be done.
let maxIterations = 100

[<AllowNullLiteral>]
type MyFinalizeObject() =
    // Make this number very large to cause the finalizer todo more work.
    let maxIterations = 10000

    override _.Finalize() =
        printfn "Finalizing a MyFinalizeObject"
        
        // Do some work.
        for i = 1 to maxIterations do
            // This method performs no operation on i, but prevents
            // the JIT compiler from optimizing away the code inside
            // the loop.
            GC.KeepAlive i

let mutable mfo = null

// Create and release a large number of objects
// that require finalization.
for j = 1 to numMfos do
    mfo <- MyFinalizeObject()

//Release the last object created in the loop.
mfo <- null

//Force garbage collection.
GC.Collect()

// Wait for all finalizers to complete before continuing.
// Without this call to GC.WaitForPendingFinalizers,
// the worker loop below might execute at the same time
// as the finalizers.
// With this call, the worker loop executes only after
// all finalizers have been called.
GC.WaitForPendingFinalizers()

// Worker loop to perform post-finalization code.
for _ = 1 to maxIterations do
    printfn "Doing some post-finalize work"

Namespace WaitForPendingFinalizersExample
   Class MyWaitForPendingFinalizersClass
  
    ' You can increase this number to fill up more memory.
      Private Const numMfos As Integer = 1000
      ' You can increase this number to cause more
      ' post-finalization work to be done.
      Private Const maxIterations As Integer = 100
     
      Overloads Shared Sub Main()
         Dim mfo As MyFinalizeObject = Nothing
      
         ' Create and release a large number of objects
         ' that require finalization.
         Dim j As Integer
         For j = 0 To numMfos - 1
            mfo = New MyFinalizeObject()
         Next j
      
         'Release the last object created in the loop.
         mfo = Nothing
      
         'Force garbage collection.
         GC.Collect()
      
         ' Wait for all finalizers to complete before continuing.
         ' Without this call to GC.WaitForPendingFinalizers, 
         ' the worker loop below might execute at the same time 
         ' as the finalizers.
         ' With this call, the worker loop executes only after
         ' all finalizers have been called.
         GC.WaitForPendingFinalizers()
      
         ' Worker loop to perform post-finalization code.
         Dim i As Integer
         For i = 0 To maxIterations - 1
            Console.WriteLine("Doing some post-finalize work")
         Next i
      End Sub
   End Class


   Class MyFinalizeObject
      ' Make this number very large to cause the finalizer to
      ' do more work.
      Private maxIterations As Integer = 10000
      
      Protected Overrides Sub Finalize()
         Console.WriteLine("Finalizing a MyFinalizeObject")
      
         ' Do some work.
         Dim i As Integer
         For i = 0 To maxIterations - 1
            ' This method performs no operation on i, but prevents 
            ' the JIT compiler from optimizing away the code inside 
            ' the loop.
            GC.KeepAlive(i)
         Next i
         MyBase.Finalize()
      End Sub
   End Class
End Namespace

Poznámky

Když systém uvolňování paměti najde objekty, které je možné uvolnit, zkontroluje každý objekt, aby určil požadavky na dokončení objektu. Pokud objekt implementuje finalizační metodu a nezablokuje finalizaci voláním SuppressFinalize, objekt se umístí do seznamu objektů, které jsou označené jako připravené k dokončení. Systém uvolňování paměti volá Finalize metody pro objekty v tomto seznamu a odebere položky ze seznamu. Tato metoda blokuje, dokud se všechny finalizační metody nespustí do dokončení.

Vlákno, na kterém jsou finalizační metody spuštěny, není zadáno, takže neexistuje žádná záruka, že tato metoda ukončí. Toto vlákno však může být přerušeno jiným vláknem, zatímco WaitForPendingFinalizers probíhá metoda. Můžete například spustit jiné vlákno, které počká po určitou dobu, a pak přeruší toto vlákno, pokud je toto vlákno stále pozastaveno.