Variables.Unlock Method

Definition

Namespace:

Microsoft.SqlServer.Dts.Runtime

Assembly:

Microsoft.SqlServer.ManagedDTS.dll

Releases the locks on the variables collection and flags the state of the variables collection as invalid or unknown.

public:
 void Unlock();

public void Unlock ();

member this.Unlock : unit -> unit

Public Sub Unlock ()

Examples

The following code example locks the variable collection when GetVariables is called. The example then checks if the collection is locked and, if so, calls Unlock.

using System;  
using System.Collections.Generic;  
using System.Text;  
using Microsoft.SqlServer.Dts.Runtime;  

namespace Microsoft.SqlServer.SSIS.Sample  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            Package pkg = new Package();  
            Variables vars = null;  
            VariableDispenser variableDispenser = pkg.VariableDispenser;  
            variableDispenser.LockForRead("System::PackageName");  
            variableDispenser.LockForRead("System::OfflineMode");  
            variableDispenser.LockForWrite("System::InteractiveMode");  
            variableDispenser.GetVariables(ref vars);             
            // Determine whether the variable collection is locked before unlocking.  
            Boolean isLocked = vars.Locked;  

            // Verify the value of vars.Locked. If the lock failed,  
            // call Reset.  
            if (isLocked)  
            {  
                vars.Unlock();  
            }  
            else  
            {  
                variableDispenser.Reset();  
            }  
        }  
    }  
}  

Imports System  
Imports System.Collections.Generic  
Imports System.Text  
Imports Microsoft.SqlServer.Dts.Runtime  

Namespace Microsoft.SqlServer.SSIS.Sample  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
            Dim pkg As Package =  New Package()   
            Dim vars As Variables =  Nothing   
            Dim variableDispenser As VariableDispenser =  pkg.VariableDispenser   
            variableDispenser.LockForRead("System::PackageName")  
            variableDispenser.LockForRead("System::OfflineMode")  
            variableDispenser.LockForWrite("System::InteractiveMode")  
            variableDispenser.GetVariables( vars)  
            ' Determine whether the variable collection is locked before unlocking.  
            Dim isLocked As Boolean =  vars.Locked   

            ' Verify the value of vars.Locked. If the lock failed,  
            ' call Reset.  
            If isLocked = True Then  
                vars.Unlock()  
            Else   
                variableDispenser.Reset()  
            End If  
        End Sub  
    End Class  
End Namespace  

Remarks

This method is used to unlock variables that were locked by using the VariableDispenser class. When VariableDispenser dispenses a variables collection, it keeps track of the collection in a list. When the task that called the variable dispenser finishes executing, all dispensed collections are automatically unlocked. Therefore, if automatic unlocking is suitable for your purposes, and if automatic unlocking occurred when the task completed, you do not need to call the Unlock method. However, it is sometimes desirable to unlock variables as soon as possible for performance reasons. An explicit call to this Unlock method unlocks the variables.

The Locked property returns a value of false to indicate that a dispensed collection has already been unlocked. A value of true indicates that the variable collection is still locked. Calling Unlock twice causes an error; therefore, in certain situations you may have to check the value of this property before deciding whether to call Unlock.