Interlocked.CompareExchange Method (IntPtr, IntPtr, IntPtr)


Compares two platform-specific handles or pointers for equality and, if they are equal, replaces the first one.

Namespace:   System.Threading
Assembly:  mscorlib (in mscorlib.dll)

Public Shared Function CompareExchange (
	ByRef location1 As IntPtr,
	value As IntPtr,
	comparand As IntPtr
) As IntPtr


Type: System.IntPtr

The destination IntPtr, whose value is compared with the value of comparand and possibly replaced by value.

Type: System.IntPtr

The IntPtr that replaces the destination value if the comparison results in equality.

Type: System.IntPtr

The IntPtr that is compared to the value at location1.

Return Value

Type: System.IntPtr

The original value in location1.

Exception Condition

The address of location1 is a null pointer.

If comparand and the value in location1 are equal, then value is stored in location1. Otherwise, no operation is performed. The compare and exchange operations are performed as an atomic operation. The return value of this method is the original value in location1, whether or not the exchange takes place.


IntPtr is a platform-specific type.

Universal Windows Platform
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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