Stack.Synchronized(Stack) Method

public:
 static System::Collections::Stack ^ Synchronized(System::Collections::Stack ^ stack);

public static System.Collections.Stack Synchronized(System.Collections.Stack stack);

static member Synchronized : System.Collections.Stack -> System.Collections.Stack

Public Shared Function Synchronized (stack As Stack) As Stack

Parameters

Returns

A synchronized wrapper around the Stack.

Exceptions

Examples

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

using System;
using System.Collections;

public class SamplesStack
{
 public static void Main()
 {
 // Creates and initializes a new Stack.
 Stack myStack = new Stack();
 myStack.Push("The");
 myStack.Push("quick");
 myStack.Push("brown");
 myStack.Push("fox");

 // Creates a synchronized wrapper around the Stack.
 Stack mySyncdStack = Stack.Synchronized(myStack);

 // Displays the sychronization status of both Stacks.
 Console.WriteLine("myStack is {0}.",
 myStack.IsSynchronized ? "synchronized" : "not synchronized");
 Console.WriteLine("mySyncdStack is {0}.",
 mySyncdStack.IsSynchronized ? "synchronized" : "not synchronized");
 }
}
/*
This code produces the following output.

myStack is not synchronized.
mySyncdStack is synchronized.
*/

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.

Remarks

To guarantee the thread safety of the Stack, all operations must be done through this wrapper.

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.

Stack myCollection = new Stack();

lock (myCollection.SyncRoot)
{
 foreach (object item in myCollection)
 {
 // Insert your code here.
 }
}

Dim myCollection As New Stack()

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

This method is an O(1) operation.