Interlocked.Exchange Method
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Sets a variable to a specified value as an atomic operation.
Exchange(UInt16, UInt16) |
Sets a 16-bit signed integer to a specified value and returns the original value, as an atomic operation. |
Exchange(UInt32, UInt32) |
Sets a 32-bit unsigned integer to a specified value and returns the original value, as an atomic operation. |
Exchange(Single, Single) |
Sets a single-precision floating point number to a specified value and returns the original value, as an atomic operation. |
Exchange(UIntPtr, UIntPtr) |
Sets a platform-specific handle or pointer to a specified value and returns the original value, as an atomic operation. |
Exchange(UInt64, UInt64) |
Sets a 64-bit unsigned integer to a specified value and returns the original value, as an atomic operation. |
Exchange(SByte, SByte) |
Sets a 8-bit signed integer to a specified value and returns the original value, as an atomic operation. |
Exchange(Byte, Byte) |
Sets a 8-bit unsigned integer to a specified value and returns the original value, as an atomic operation. |
Exchange(IntPtr, IntPtr) |
Sets a platform-specific handle or pointer to a specified value and returns the original value, as an atomic operation. |
Exchange(Int64, Int64) |
Sets a 64-bit signed integer to a specified value and returns the original value, as an atomic operation. |
Exchange(Int32, Int32) |
Sets a 32-bit signed integer to a specified value and returns the original value, as an atomic operation. |
Exchange(Int16, Int16) |
Sets a 16-bit unsigned integer to a specified value and returns the original value, as an atomic operation. |
Exchange(Double, Double) |
Sets a double-precision floating point number to a specified value and returns the original value, as an atomic operation. |
Exchange(Object, Object) |
Sets an object to a specified value and returns a reference to the original object, as an atomic operation. |
Exchange<T>(T, T) |
Sets a variable of the specified type |
Important
This API is not CLS-compliant.
Sets a 16-bit signed integer to a specified value and returns the original value, as an atomic operation.
public:
static System::UInt16 Exchange(System::UInt16 % location1, System::UInt16 value);
[System.CLSCompliant(false)]
public static ushort Exchange (ref ushort location1, ushort value);
[<System.CLSCompliant(false)>]
static member Exchange : uint16 * uint16 -> uint16
Public Shared Function Exchange (ByRef location1 As UShort, value As UShort) As UShort
Parameters
- location1
- UInt16
The variable to set to the specified value.
- value
- UInt16
The value to which the location1
parameter is set.
Returns
The original value of location1
.
- Attributes
Exceptions
The address of location1 is a null
pointer.
Applies to
.NET 9
Product | Versions |
---|---|
.NET | 9 |
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
Important
This API is not CLS-compliant.
Sets a 32-bit unsigned integer to a specified value and returns the original value, as an atomic operation.
public:
static System::UInt32 Exchange(System::UInt32 % location1, System::UInt32 value);
[System.CLSCompliant(false)]
public static uint Exchange (ref uint location1, uint value);
[<System.CLSCompliant(false)>]
static member Exchange : uint32 * uint32 -> uint32
Public Shared Function Exchange (ByRef location1 As UInteger, value As UInteger) As UInteger
Parameters
- location1
- UInt32
The variable to set to the specified value.
- value
- UInt32
The value to which the location1
parameter is set.
Returns
The original value of location1
.
- Attributes
Exceptions
The address of location1
is a null
pointer.
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | 5, 6, 7, 8, 9 |
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
Sets a single-precision floating point number to a specified value and returns the original value, as an atomic operation.
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
Parameters
- location1
- Single
The variable to set to the specified value.
- value
- Single
The value to which the location1
parameter is set.
Returns
The original value of location1
.
Exceptions
The address of location1
is a null
pointer.
See also
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
Important
This API is not CLS-compliant.
Sets a platform-specific handle or pointer to a specified value and returns the original value, as an atomic operation.
public:
static UIntPtr Exchange(UIntPtr % location1, UIntPtr value);
[System.CLSCompliant(false)]
public static UIntPtr Exchange (ref UIntPtr location1, UIntPtr value);
[<System.CLSCompliant(false)>]
static member Exchange : unativeint * unativeint -> unativeint
Public Shared Function Exchange (ByRef location1 As UIntPtr, value As UIntPtr) As UIntPtr
Parameters
- location1
-
UIntPtr
unativeint
The variable to set to the specified value.
- value
-
UIntPtr
unativeint
The value to which the location1
parameter is set.
Returns
unativeint
The original value of location1
.
- Attributes
Exceptions
The address of location1
is a null
pointer.
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | 7, 8, 9 |
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
Important
This API is not CLS-compliant.
Sets a 64-bit unsigned integer to a specified value and returns the original value, as an atomic operation.
public:
static System::UInt64 Exchange(System::UInt64 % location1, System::UInt64 value);
[System.CLSCompliant(false)]
public static ulong Exchange (ref ulong location1, ulong value);
[<System.CLSCompliant(false)>]
static member Exchange : uint64 * uint64 -> uint64
Public Shared Function Exchange (ByRef location1 As ULong, value As ULong) As ULong
Parameters
- location1
- UInt64
The variable to set to the specified value.
- value
- UInt64
The value to which the location1
parameter is set.
Returns
The original value of location1
.
- Attributes
Exceptions
The address of location1
is a null
pointer.
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | 5, 6, 7, 8, 9 |
Important
This API is not CLS-compliant.
Sets a 8-bit signed integer to a specified value and returns the original value, as an atomic operation.
public:
static System::SByte Exchange(System::SByte % location1, System::SByte value);
[System.CLSCompliant(false)]
public static sbyte Exchange (ref sbyte location1, sbyte value);
[<System.CLSCompliant(false)>]
static member Exchange : sbyte * sbyte -> sbyte
Public Shared Function Exchange (ByRef location1 As SByte, value As SByte) As SByte
Parameters
- location1
- SByte
The variable to set to the specified value.
- value
- SByte
The value to which the location1
parameter is set.
Returns
The original value of location1
.
- Attributes
Exceptions
The address of location1 is a null
pointer.
Applies to
.NET 9
Product | Versions |
---|---|
.NET | 9 |
Sets a 8-bit unsigned integer to a specified value and returns the original value, as an atomic operation.
public:
static System::Byte Exchange(System::Byte % location1, System::Byte value);
public static byte Exchange (ref byte location1, byte value);
static member Exchange : byte * byte -> byte
Public Shared Function Exchange (ByRef location1 As Byte, value As Byte) As Byte
Parameters
- location1
- Byte
The variable to set to the specified value.
- value
- Byte
The value to which the location1
parameter is set.
Returns
The original value of location1
.
Exceptions
The address of location1 is a null
pointer.
Applies to
.NET 9
Product | Versions |
---|---|
.NET | 9 |
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
Sets a platform-specific handle or pointer to a specified value and returns the original value, as an atomic operation.
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
Parameters
- location1
-
IntPtr
nativeint
The variable to set to the specified value.
- value
-
IntPtr
nativeint
The value to which the location1
parameter is set.
Returns
nativeint
The original value of location1
.
Exceptions
The address of location1
is a null
pointer.
See also
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
- Source:
- Interlocked.CoreCLR.cs
Sets a 64-bit signed integer to a specified value and returns the original value, as an atomic operation.
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
Parameters
- location1
- Int64
The variable to set to the specified value.
- value
- Int64
The value to which the location1
parameter is set.
Returns
The original value of location1
.
Exceptions
The address of location1
is a null
pointer.
See also
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
- Source:
- Interlocked.CoreCLR.cs
Sets a 32-bit signed integer to a specified value and returns the original value, as an atomic operation.
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
Parameters
- location1
- Int32
The variable to set to the specified value.
- value
- Int32
The value to which the location1
parameter is set.
Returns
The original value of location1
.
Exceptions
The address of location1
is a null
pointer.
The address of location1
is a null
pointer.
Examples
The following code example shows a thread-safe resource locking mechanism.
using namespace System;
using namespace System::Threading;
const int numThreads = 10;
const int numThreadIterations = 5;
ref class MyInterlockedExchangeExampleClass
{
public:
static void MyThreadProc()
{
for ( int i = 0; i < numThreadIterations; i++ )
{
UseResource();
//Wait 1 second before next attempt.
Thread::Sleep( 1000 );
}
}
private:
//A simple method that denies reentrancy.
static bool UseResource()
{
//0 indicates that the method is not in use.
if ( 0 == Interlocked::Exchange( 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( usingResource, 0 );
return true;
}
else
{
Console::WriteLine( " {0} was denied the lock", Thread::CurrentThread->Name );
return false;
}
}
//0 for false, 1 for true.
static int usingResource;
};
int main()
{
Thread^ myThread;
Random^ rnd = gcnew Random;
for ( int i = 0; i < numThreads; i++ )
{
myThread = gcnew Thread( gcnew ThreadStart( MyInterlockedExchangeExampleClass::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();
}
}
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
See also
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
Sets a 16-bit unsigned integer to a specified value and returns the original value, as an atomic operation.
public:
static short Exchange(short % location1, short value);
public static short Exchange (ref short location1, short value);
static member Exchange : int16 * int16 -> int16
Public Shared Function Exchange (ByRef location1 As Short, value As Short) As Short
Parameters
- location1
- Int16
The variable to set to the specified value.
- value
- Int16
The value to which the location1
parameter is set.
Returns
The original value of location1
.
Exceptions
The address of location1 is a null
pointer.
Applies to
.NET 9
Product | Versions |
---|---|
.NET | 9 |
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
Sets a double-precision floating point number to a specified value and returns the original value, as an atomic operation.
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
Parameters
- location1
- Double
The variable to set to the specified value.
- value
- Double
The value to which the location1
parameter is set.
Returns
The original value of location1
.
Exceptions
The address of location1
is a null
pointer.
See also
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
- Source:
- Interlocked.cs
- Source:
- Interlocked.cs
- Source:
- Interlocked.CoreCLR.cs
Sets an object to a specified value and returns a reference to the original object, as an atomic operation.
public:
static System::Object ^ Exchange(System::Object ^ % location1, System::Object ^ value);
public static object Exchange (ref object location1, 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
Parameters
- location1
- Object
The variable to set to the specified value.
- value
- Object
The value to which the location1
parameter is set.
Returns
The original value of location1
.
Exceptions
The address of location1
is a null
pointer.
The address of location1
is a null
pointer.
Remarks
Important
Beginning with .NET Framework 2.0, the Exchange<T>(T, T) method overload provides a type-safe alternative for reference types. We recommend that you call it instead of this overload.
See also
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
- Source:
- Interlocked.CoreCLR.cs
- Source:
- Interlocked.CoreCLR.cs
- Source:
- Interlocked.CoreCLR.cs
Sets a variable of the specified type T
to a specified value and returns the original value, as an atomic operation.
public:
generic <typename T>
where T : class static T Exchange(T % location1, T value);
public:
generic <typename T>
static T Exchange(T % location1, T value);
public static T Exchange<T> (ref T location1, T value) where T : class;
public static T Exchange<T> (ref T location1, T value);
[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)
static member Exchange : 'T * 'T -> 'T
[<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
Public Shared Function Exchange(Of T) (ByRef location1 As T, value As T) As T
Type Parameters
- T
The type to be used for location1
and value
. This type must be a reference type.
Parameters
- location1
- T
The variable to set to the specified value. This is a reference parameter (ref
in C#, ByRef
in Visual Basic).
- value
- T
The value to which the location1
parameter is set.
Returns
The original value of location1
.
- Attributes
Exceptions
The address of location1
is a null
pointer.
An unsupported T
is specified.
Remarks
This method only supports reference types. There are overloads of the Exchange method for the Int32, Int64, IntPtr, Single, and Double value types, but there is no support for other value types.
Note
This method overload is preferable to the Exchange(Object, Object) method overload, because the latter requires late-bound access to the destination object .
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
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