Public ReadOnly Property SyncRoot As Object

public Object SyncRoot { get; }

public:
virtual property Object^ SyncRoot {
	Object^ get () sealed;
}

abstract SyncRoot : Object
override SyncRoot : Object

Implements

This property implements the System.Collections..::.ICollection interface.

.NET Framework classes based on Array provide their own synchronized version of the collection using the SyncRoot property.

Classes that use arrays can also implement their own synchronization using the SyncRoot property. The synchronizing code must perform operations on the SyncRoot of the collection, not directly on the collection. 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 collection. Note that some implementations of SyncRoot might return the Array itself.

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.

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

The following code example shows how to lock an array during the entire enumeration by using the SyncRoot property.

Dim myArray As Array = New Integer() { 1, 2, 4 }
SyncLock(myArray.SyncRoot) 
    For Each item As Object In myArray
        Console.WriteLine(item)
    Next
End SyncLock

Array myArray = new int[] { 1, 2, 4 };
lock(myArray.SyncRoot) 
{
    foreach (Object item in myArray)
        Console.WriteLine(item);
}

Array^ myArray = gcnew array<Int32> { 1, 2, 4 };
try
{
    Monitor::Enter(myArray->SyncRoot); 

    for each (Int32 item in myArray)
        Console::WriteLine(item);
}
finally
{
    Monitor::Exit(myArray->SyncRoot);
}

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference