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Queue::IsSynchronized Property

.NET Framework 4

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

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

public:
virtual property bool IsSynchronized {
	bool get ();
}

Property Value

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

Implements

ICollection::IsSynchronized

Remarks

To guarantee the thread safety of the Queue, 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.

Examples

The following code example shows how to lock the collection using the SyncRoot during the entire enumeration. Retrieving the value of this property is an O(1) operation.

C++


Queue^ myCollection = gcnew Queue();
bool lockTaken = false;
try
{
    Monitor::Enter(myCollection->SyncRoot, lockTaken);
    for each (Object^ item in myCollection);
    {
        // Insert your code here.
    }
}
finally
{
    if (lockTaken)
    {
        Monitor::Exit(myCollection->SyncRoot);
    }
}

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

C++


#using <system.dll>

using namespace System;
using namespace System::Collections;
int main()
{

   // Creates and initializes a new Queue.
   Queue^ myQ = gcnew Queue;
   myQ->Enqueue( "The" );
   myQ->Enqueue( "quick" );
   myQ->Enqueue( "brown" );
   myQ->Enqueue( "fox" );

   // Creates a synchronized wrapper around the Queue.
   Queue^ mySyncdQ = Queue::Synchronized( myQ );

   // Displays the sychronization status of both Queues.
   Console::WriteLine( "myQ is {0}.", myQ->IsSynchronized ? (String^)"synchronized" : "not synchronized" );
   Console::WriteLine( "mySyncdQ is {0}.", mySyncdQ->IsSynchronized ? (String^)"synchronized" : "not synchronized" );
}

/*
This code produces the following output.

myQ is not synchronized.
mySyncdQ is synchronized.
*/

Version Information

.NET Framework

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

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Platforms

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

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

Reference

Queue Class

System.Collections Namespace

SyncRoot

Synchronized

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