Interlocked.Exchange Méthode

public:
 static float Exchange(float % location1, float value);

public static float Exchange(ref float location1, float value);

static member Exchange : single * single -> single

Public Shared Function Exchange (ByRef location1 As Single, value As Single) As Single

Paramètres

Retours

Valeur d’origine de location1.

Exceptions

Voir aussi

• Threading managé
• Vue d’ensemble des primitives de synchronisation

public:
 static System::Object ^ Exchange(System::Object ^ % location1, System::Object ^ value);

public static object Exchange(ref object location1, object value);

static member Exchange : obj * obj -> obj

Public Shared Function Exchange (ByRef location1 As Object, value As Object) As Object

Paramètres

Retours

Valeur d’origine de location1.

Exceptions

Remarques

Voir aussi

• Threading managé
• Vue d’ensemble des primitives de synchronisation

public:
 static IntPtr Exchange(IntPtr % location1, IntPtr value);

public static IntPtr Exchange(ref IntPtr location1, IntPtr value);

static member Exchange : nativeint * nativeint -> nativeint

Public Shared Function Exchange (ByRef location1 As IntPtr, value As IntPtr) As IntPtr

Paramètres

Retours

Valeur d’origine de location1.

Exceptions

Voir aussi

• Threading managé
• Vue d’ensemble des primitives de synchronisation

public:
 static double Exchange(double % location1, double value);

public static double Exchange(ref double location1, double value);

static member Exchange : double * double -> double

Public Shared Function Exchange (ByRef location1 As Double, value As Double) As Double

Paramètres

Retours

Valeur d’origine de location1.

Exceptions

Voir aussi

• Threading managé
• Vue d’ensemble des primitives de synchronisation

public:
 static int Exchange(int % location1, int value);

public static int Exchange(ref int location1, int value);

static member Exchange : int * int -> int

Public Shared Function Exchange (ByRef location1 As Integer, value As Integer) As Integer

Paramètres

Retours

Valeur d’origine de location1.

Exceptions

Exemples

L’exemple de code suivant montre un mécanisme de verrouillage de ressources thread-safe.

using System;
using System.Threading;

namespace InterlockedExchange_Example
{
    class MyInterlockedExchangeExampleClass
    {
        //0 for false, 1 for true.
        private static int usingResource = 0;

        private const int numThreadIterations = 5;
        private const int numThreads = 10;

        static void Main()
        {
            Thread myThread;
            Random rnd = new Random();

            for(int i = 0; i < numThreads; i++)
            {
                myThread = new Thread(new ThreadStart(MyThreadProc));
                myThread.Name = String.Format("Thread{0}", i + 1);
            
                //Wait a random amount of time before starting next thread.
                Thread.Sleep(rnd.Next(0, 1000));
                myThread.Start();
            }
        }

        private static void MyThreadProc()
        {
            for(int i = 0; i < numThreadIterations; i++)
            {
                UseResource();
            
                //Wait 1 second before next attempt.
                Thread.Sleep(1000);
            }
        }

        //A simple method that denies reentrancy.
        static bool UseResource()
        {
            //0 indicates that the method is not in use.
            if(0 == Interlocked.Exchange(ref usingResource, 1))
            {
                Console.WriteLine("{0} acquired the lock", Thread.CurrentThread.Name);
            
                //Code to access a resource that is not thread safe would go here.
            
                //Simulate some work
                Thread.Sleep(500);

                Console.WriteLine("{0} exiting lock", Thread.CurrentThread.Name);
            
                //Release the lock
                Interlocked.Exchange(ref usingResource, 0);
                return true;
            }
            else
            {
                Console.WriteLine("   {0} was denied the lock", Thread.CurrentThread.Name);
                return false;
            }
        }
    }
}

Imports System.Threading

Namespace InterlockedExchange_Example
    Class MyInterlockedExchangeExampleClass
        '0 for false, 1 for true.
        Private Shared usingResource As Integer = 0

        Private Const numThreadIterations As Integer = 5
        Private Const numThreads As Integer = 10

        <MTAThread> _
        Shared Sub Main()
            Dim myThread As Thread
            Dim rnd As New Random()

            Dim i As Integer
            For i = 0 To numThreads - 1
                myThread = New Thread(AddressOf MyThreadProc)
                myThread.Name = String.Format("Thread{0}", i + 1)

                'Wait a random amount of time before starting next thread.
                Thread.Sleep(rnd.Next(0, 1000))
                myThread.Start()
            Next i
        End Sub

        Private Shared Sub MyThreadProc()
            Dim i As Integer
            For i = 0 To numThreadIterations - 1
                UseResource()

                'Wait 1 second before next attempt.
                Thread.Sleep(1000)
            Next i
        End Sub 

        'A simple method that denies reentrancy.
        Shared Function UseResource() As Boolean
            '0 indicates that the method is not in use.
            If 0 = Interlocked.Exchange(usingResource, 1) Then
                Console.WriteLine("{0} acquired the lock", Thread.CurrentThread.Name)

                'Code to access a resource that is not thread safe would go here.
                'Simulate some work
                Thread.Sleep(500)

                Console.WriteLine("{0} exiting lock", Thread.CurrentThread.Name)

                'Release the lock
                Interlocked.Exchange(usingResource, 0)
                Return True
            Else
                Console.WriteLine("   {0} was denied the lock", Thread.CurrentThread.Name)
                Return False
            End If
        End Function 
    End Class 
End Namespace

Voir aussi

• Threading managé
• Vue d’ensemble des primitives de synchronisation

public:
 static long Exchange(long % location1, long value);

public static long Exchange(ref long location1, long value);

static member Exchange : int64 * int64 -> int64

Public Shared Function Exchange (ByRef location1 As Long, value As Long) As Long

Paramètres

Retours

Valeur d’origine de location1.

Exceptions

Voir aussi

• Threading managé
• Vue d’ensemble des primitives de synchronisation

public:
generic <typename T>
 where T : class static T Exchange(T % location1, T value);

public static T Exchange<T>(ref T location1, T value) where T : class;

[System.Runtime.InteropServices.ComVisible(false)]
public static T Exchange<T>(ref T location1, T value) where T : class;

static member Exchange : 'T * 'T -> 'T (requires 'T : null)

[<System.Runtime.InteropServices.ComVisible(false)>]
static member Exchange : 'T * 'T -> 'T (requires 'T : null)

Public Shared Function Exchange(Of T As Class) (ByRef location1 As T, value As T) As T

Paramètres de type

Paramètres

Retours

Valeur d’origine de location1.

Attributs

ComVisibleAttribute

Exceptions