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Thread.FreeNamedDataSlot Method

Eliminates the association between a name and a slot, for all threads in the process.

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

public static void FreeNamedDataSlot (
	string name
)
public static void FreeNamedDataSlot (
	String name
)
public static function FreeNamedDataSlot (
	name : String
)

Parameters

name

The name of the data slot to be freed.

NoteNote

The HostProtectionAttribute attribute applied to this method has the following Resources property value: SharedState | ExternalThreading. 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.

After any thread calls FreeNamedDataSlot, any other thread that calls GetNamedDataSlot with the same name will allocate a new slot associated with the name. Subsequent calls to GetNamedDataSlot by any thread will return the new slot. However, any thread that still has a System.LocalDataStoreSlot returned by an earlier call to GetNamedDataSlot can continue to use the old slot.

A slot that has been associated with a name is released only when every LocalDataStoreSlot that was obtained prior to the call to FreeNamedDataSlot has been released and garbage-collected.

Threads use a local store memory mechanism to store thread-specific data. The common language runtime allocates a multi-slot data store array to each process when it is created. The thread can allocate a data slot in the data store, store and retrieve a data value in the slot, and free the slot for reuse after the thread expires. Data slots are unique per thread. No other thread (not even a child thread) can get that data.

The following code example demonstrates how to use a named data slot to store thread-specific information.

using System;
using System.Threading;

class Test
{
    static void Main()
    {
        Thread[] newThreads = new Thread[4];
        for(int i = 0; i < newThreads.Length; i++)
        {
            newThreads[i] = 
                new Thread(new ThreadStart(Slot.SlotTest));
            newThreads[i].Start();
        }
    }
}

class Slot
{
    static Random randomGenerator = new Random();

    public static void SlotTest()
    {
        // Set different data in each thread's data slot.
        Thread.SetData(
            Thread.GetNamedDataSlot("Random"), 
            randomGenerator.Next(1, 200));

        // Write the data from each thread's data slot.
        Console.WriteLine("Data in thread_{0}'s data slot: {1,3}", 
            AppDomain.GetCurrentThreadId().ToString(),
            Thread.GetData(
            Thread.GetNamedDataSlot("Random")).ToString());

        // Allow other threads time to execute SetData to show
        // that a thread's data slot is unique to the thread.
        Thread.Sleep(1000);

        Console.WriteLine("Data in thread_{0}'s data slot is still: {1,3}", 
            AppDomain.GetCurrentThreadId().ToString(),
            Thread.GetData(
            Thread.GetNamedDataSlot("Random")).ToString());

        // Allow time for other threads to show their data,
        // then demonstrate that any code a thread executes
        // has access to the thread's named data slot.        
        Thread.Sleep(1000);

        Other o = new Other();
        o.ShowSlotData();
    }
}

public class Other
{
    public void ShowSlotData()
    {
        // This method has no access to the data in the Slot
        // class, but when executed by a thread it can obtain
        // the thread's data from a named slot.
        Console.WriteLine("Other code displays data in thread_{0}'s data slot: {1,3}", 
            AppDomain.GetCurrentThreadId().ToString(), 
            Thread.GetData( 
            Thread.GetNamedDataSlot("Random")).ToString());
    }
}

import System.*;
import System.Threading.*;
import System.Threading.Thread;

class Test
{
    public static void main(String[] args)
    {
        Thread newThreads[] = new Thread[4];

        for (int i = 0; i < newThreads.length; i++) {
            newThreads[i] = new Thread(new ThreadStart(Slot.SlotTest));
            newThreads[i].Start();
        }
    } //main
} //Test

class Slot
{
    private static Random randomGenerator = new Random();

    public static void SlotTest()
    {
        // Set different data in each thread's data slot.
        Thread.SetData(Thread.GetNamedDataSlot("Random"), 
            new Integer(randomGenerator.Next(1, 200)));

        // Write the data from each thread's data slot.
        Console.WriteLine("Data in thread_{0}'s data slot: {1,3}", 
            String.valueOf(AppDomain.GetCurrentThreadId()),
            Thread.GetData(Thread.GetNamedDataSlot("Random")).toString());

        // Allow other threads time to execute SetData to show
        // that a thread's data slot is unique to the thread.
        Thread.Sleep(1000);
        Console.WriteLine("Data in thread_{0}'s data slot is still: {1,3}",
            String.valueOf(AppDomain.GetCurrentThreadId()), 
            Thread.GetData(Thread.GetNamedDataSlot("Random")).toString());

        // Allow time for other threads to show their data,
        // then demonstrate that any code a thread executes
        // has access to the thread's named data slot.        
        Thread.Sleep(1000);

        Other o = new Other();

        o.ShowSlotData();
    } //SlotTest
} //Slot

public class Other
{
    public void ShowSlotData()
    {
        // This method has no access to the data in the Slot
        // class, but when executed by a thread it can obtain
        // the thread's data from a named slot.
        Console.WriteLine("Other code displays data in "
            + "thread_{0}'s data slot: {1,3}", 
            String.valueOf(AppDomain.GetCurrentThreadId()),
            Thread.GetData(Thread.GetNamedDataSlot("Random")).ToString());
    } //ShowSlotData
} //Other

Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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