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List<T>.ICollection.SyncRoot Property

  • Reference

Definition

Namespace:
System.Collections.Generic
Assembly:
System.Collections.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll
Source:
List.cs
Source:
List.cs
Source:
List.cs

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

property System::Object ^ System::Collections::ICollection::SyncRoot { System::Object ^ get(); };
object System.Collections.ICollection.SyncRoot { get; }
member this.System.Collections.ICollection.SyncRoot : obj
 ReadOnly Property SyncRoot As Object Implements ICollection.SyncRoot

Property Value

Object

An object that can be used to synchronize access to the ICollection. In the default implementation of List<T>, this property always returns the current instance.

Implements

SyncRoot

Remarks

Default implementations of collections in the System.Collections.Generic namespace are not synchronized.

Enumerating through a collection is intrinsically not a thread-safe procedure. To guarantee thread safety during enumeration, you can lock the collection during the entire enumeration. To allow the collection to be accessed by multiple threads for reading and writing, you must implement your own synchronization.

SyncRoot returns an object that can be used to synchronize access to the ICollection. Synchronization is effective only if all threads lock this object before accessing the collection. The following code shows the use of the SyncRoot property for C#, C++, and Visual Basic.

ICollection ic = ...;
lock (ic.SyncRoot)
{
    // Access the collection.
}

Dim ic As ICollection = ...
SyncLock ic.SyncRoot
    ' Access the collection.
End SyncLock

ICollection^ ic = ...;
try
{
    Monitor::Enter(ic->SyncRoot);
    // Access the collection.
}
finally
{
    Monitor::Exit(ic->SyncRoot);
}

Retrieving the value of this property is an O(1) operation.

Applies to

See also