Export (0) Print
Expand All

Stack.IsSynchronized Property

Gets a value indicating whether access to the Stack is synchronized (thread safe).

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

'Declaration
Public Overridable ReadOnly Property IsSynchronized As Boolean

Property Value

Type: System.Boolean
true, if access to the Stack is synchronized (thread safe); otherwise, false. The default is false.

Implements

ICollection.IsSynchronized

To guarantee the thread safety of the Stack, all operations must be done through the wrapper returned by the Synchronized method.

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.

Dim myCollection As New Stack()

SyncLock myCollection.SyncRoot
    For Each item As Object In myCollection
        ' Insert your code here. 
    Next item
End SyncLock

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

The following example shows how to synchronize a Stack, determine if a Stack is synchronized, and use a synchronized Stack.

Imports System
Imports System.Collections

Public Class SamplesStack    

    Public Shared Sub Main()

        ' Creates and initializes a new Stack. 
        Dim myStack As New Stack()
        myStack.Push("The")
        myStack.Push("quick")
        myStack.Push("brown")
        myStack.Push("fox")

        ' Creates a synchronized wrapper around the Stack. 
        Dim mySyncdStack As Stack = Stack.Synchronized(myStack)

        ' Displays the sychronization status of both Stacks. 
        Dim msg As String 
        If myStack.IsSynchronized Then
            msg = "synchronized" 
        Else
            msg = "not synchronized" 
        End If        
        Console.WriteLine("myStack is {0}.", msg)        
        If mySyncdStack.IsSynchronized Then
            msg = "synchronized" 
        Else
            msg = "not synchronized" 
        End If
        Console.WriteLine("mySyncdStack is {0}.", msg)
    End Sub 
End Class 

' This code produces the following output. 
'  
' myStack is not synchronized. 
' mySyncdStack is synchronized.
 

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

Show:
© 2014 Microsoft