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Queue.SyncRoot Property

Gets an object that can be used to synchronize access to the Queue.

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

'Declaration
Public Overridable ReadOnly Property SyncRoot As Object
'Usage
Dim instance As Queue 
Dim value As Object 

value = instance.SyncRoot

Property Value

Type: System.Object
An object that can be used to synchronize access to the Queue.

Implements

ICollection.SyncRoot

To create a synchronized version of the Queue, use the Synchronized method. However, derived classes can provide their own synchronized version of the Queue using the SyncRoot property. The synchronizing code must perform operations on the SyncRoot of the Queue, not directly on the Queue. This ensures proper operation of collections that are derived from other objects. Specifically, it maintains proper synchronization with other threads that might be simultaneously modifying the Queue object.

Enumerating through a collection is intrinsically not a thread-safe procedure. Even when a collection is synchronized, other threads can still modify the collection, which causes the enumerator to throw an exception. To guarantee thread safety during enumeration, you can either lock the collection during the entire enumeration or catch the exceptions resulting from changes made by other threads.

The following code example shows how to lock the collection using the SyncRoot during the entire enumeration. Retrieving the value of this property is an O(1) operation.

Dim myCollection As New Queue()
 Dim item As Object
 SyncLock myCollection.SyncRoot
  For Each item In myCollection
  ' Insert your code here.
  Next item
 End SyncLock

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The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

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