SortedList.Synchronized(SortedList) Method

Definition

Namespace:

System.Collections

Assembly:

System.Collections.NonGeneric.dll

Source:

SortedList.cs

Returns a synchronized (thread-safe) wrapper for a SortedList object.

public:
 static System::Collections::SortedList ^ Synchronized(System::Collections::SortedList ^ list);

public static System.Collections.SortedList Synchronized (System.Collections.SortedList list);

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

Public Shared Function Synchronized (list As SortedList) As SortedList

Parameters

list

SortedList

The SortedList object to synchronize.

Returns

SortedList

A synchronized (thread-safe) wrapper for the SortedList object.

Exceptions

ArgumentNullException

list is null.

Examples

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

SortedList^ myCollection = gcnew SortedList();
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);
    }
}

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

Dim myCollection As New SortedList()
SyncLock myCollection.SyncRoot
    For Each item In myCollection
        ' Insert your code here.
    Next item
End SyncLock

This method is an O(1) operation.

The following code example shows how to synchronize a SortedList object, determine whether a SortedList is synchronized, and use a synchronized SortedList.

#using <system.dll>

using namespace System;
using namespace System::Collections;
int main()
{
   
   // Creates and initializes a new SortedList.
   SortedList^ mySL = gcnew SortedList;
   mySL->Add( 2, "two" );
   mySL->Add( 3, "three" );
   mySL->Add( 1, "one" );
   mySL->Add( (int^)0, "zero" );
   mySL->Add( 4, "four" );
   
   // Creates a synchronized wrapper around the SortedList.
   SortedList^ mySyncdSL = SortedList::Synchronized( mySL );
   
   // Displays the sychronization status of both SortedLists.
   Console::WriteLine( "mySL is {0}.", mySL->IsSynchronized ? (String^)"synchronized" : "not synchronized" );
   Console::WriteLine( "mySyncdSL is {0}.", mySyncdSL->IsSynchronized ? (String^)"synchronized" : "not synchronized" );
}

/*
This code produces the following output.

mySL is not synchronized.
mySyncdSL is synchronized.
*/

using System;
using System.Collections;

public class SamplesSortedList
{
    public static void Main()
    {
        // Creates and initializes a new SortedList.
        SortedList mySL = new SortedList();
        mySL.Add(2, "two");
        mySL.Add(3, "three");
        mySL.Add(1, "one");
        mySL.Add(0, "zero");
        mySL.Add(4, "four");

        // Creates a synchronized wrapper around the SortedList.
        SortedList mySyncdSL = SortedList.Synchronized(mySL);

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

mySL is not synchronized.
mySyncdSL is synchronized.
*/

Imports System.Collections

Public Class SamplesSortedList
    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new SortedList.
        Dim mySL As New SortedList()
        mySL.Add(2, "two")
        mySL.Add(3, "three")
        mySL.Add(1, "one")
        mySL.Add(0, "zero")
        mySL.Add(4, "four")
        
        ' Creates a synchronized wrapper around the SortedList.
        Dim mySyncdSL As SortedList = SortedList.Synchronized(mySL)
        
        ' Displays the sychronization status of both SortedLists.
        Dim msg As String
        If mySL.IsSynchronized Then
            msg = "synchronized"
        Else
            msg = "not synchronized"
        End If
        Console.WriteLine("mySL is {0}.", msg)
        If mySyncdSL.IsSynchronized Then
            msg = "synchronized"
        Else
            msg = "not synchronized"
        End If
        Console.WriteLine("mySyncdSL is {0}.", msg)        
    End Sub
End Class

' This code produces the following output.
'
' mySL is not synchronized.
' mySyncdSL is synchronized.

Remarks

To guarantee the thread safety of a SortedList object, all operations must be done through this wrapper only.

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.

See also

• IsSynchronized
• SyncRoot