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Stack.Synchronized Method

Returns a synchronized (thread safe) wrapper for the Stack.

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

static Stack^ Synchronized (
	Stack^ stack
public static Stack Synchronized (
	Stack stack
public static function Synchronized (
	stack : Stack
) : Stack
Not applicable.



The Stack to synchronize.

Return Value

A synchronized wrapper around the Stack.

Exception typeCondition


stack is a null reference (Nothing in Visual Basic).


The HostProtectionAttribute attribute applied to this method has the following Resources property value: Synchronization. The HostProtectionAttribute does not affect desktop applications, which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser. For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

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.

No code example is currently available or this language may not be supported.

This method 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.

#using <system.dll>

using namespace System;
using namespace System::Collections;
int main()
   // Creates and initializes a new Stack.
   Stack^ myStack = gcnew 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 ? (String^)"synchronized" : "not synchronized" );
   Console::WriteLine( "mySyncdStack is {0}.", mySyncdStack->IsSynchronized ? (String^)"synchronized" : "not synchronized" );

This code produces the following output.

myStack is not synchronized.
mySyncdStack is synchronized.

import System.*;
import System.Collections.*;

public class SamplesStack
    public static void main(String[] args)
        // Creates and initializes a new Stack.
        Stack myStack = new Stack();


        // 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.get_IsSynchronized()) ? 
            "synchronized" : "not synchronized");
        Console.WriteLine("mySyncdStack is {0}.", 
            (mySyncdStack.get_IsSynchronized()) ? 
            "synchronized" : "not synchronized");
    } //main

} //SamplesStack

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

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0