Sets the data in the specified slot on the currently running thread, for that thread's current domain. For better performance, use fields marked with the ThreadStaticAttribute attribute instead.
(in mscorlib.dll)
Visual Basic (Declaration)
<HostProtectionAttribute(SecurityAction.LinkDemand, SharedState := True, ExternalThreading := True)> _
Public Shared Sub SetData ( _
slot As LocalDataStoreSlot, _
data As Object _
)
Dim slot As LocalDataStoreSlot
Dim data As Object
Thread.SetData(slot, data)
[HostProtectionAttribute(SecurityAction.LinkDemand, SharedState = true, ExternalThreading = true)]
public static void SetData(
LocalDataStoreSlot slot,
Object data
)
[HostProtectionAttribute(SecurityAction::LinkDemand, SharedState = true, ExternalThreading = true)]
public:
static void SetData(
LocalDataStoreSlot^ slot,
Object^ data
)
public static function SetData(
slot : LocalDataStoreSlot,
data : Object
)
.gif) Important Note: |
|---|
The .NET Framework provides two mechanisms for using thread local storage (TLS): thread-relative static fields (that is, fields that are marked with the ThreadStaticAttribute attribute) and data slots. Thread-relative static fields provide much better performance than data slots, and enable compile-time type checking. For more information about using TLS, see Thread Local Storage: Thread-Relative Static Fields and Data Slots. |
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 procedure ends and the Thread object has been reclaimed by garbage collection. Data slots are unique per thread. No other thread (not even a child thread) can get that data.
vb#.gif) Note: |
|---|
SetData is a Shared method that always applies to the currently executing thread, even if you call it using a variable that refers to another thread. To avoid confusion, use the class name when calling Shared methods: Thread.SetData(testSlot, "test data"). |
This section contains two code examples. The first example shows how to use a field that is marked with the ThreadStaticAttribute attribute to hold thread-specific information. The second example shows how to use a data slot to do the same thing.
First Example
The following example shows how to use a field that is marked with ThreadStaticAttribute to hold thread-specific information. This technique provides better performance than the technique that is shown in the second example.
Imports System
Imports System.Threading
Class Test
<MTAThread> _
Shared Sub Main()
For i As Integer = 1 To 3
Dim newThread As New Thread(AddressOf ThreadData.ThreadStaticDemo)
newThread.Start()
Next i
End Sub
End Class
Class ThreadData
<ThreadStaticAttribute> _
Shared threadSpecificData As Integer
Shared Sub ThreadStaticDemo()
' Store the managed thread id for each thread in the static
' variable.
threadSpecificData = Thread.CurrentThread.ManagedThreadId
' Allow other threads time to execute the same code, to show
' that the static data is unique to each thread.
Thread.Sleep( 1000 )
' Display the static data.
Console.WriteLine( "Data for managed thread {0}: {1}", _
Thread.CurrentThread.ManagedThreadId, threadSpecificData )
End Sub
End Class
' This code example produces output similar to the following:
'
'Data for managed thread 4: 4
'Data for managed thread 5: 5
'Data for managed thread 3: 3
using System;
using System.Threading;
class Test
{
static void Main()
{
for(int i = 0; i < 3; i++)
{
Thread newThread = new Thread(ThreadData.ThreadStaticDemo);
newThread.Start();
}
}
}
class ThreadData
{
[ThreadStaticAttribute]
static int threadSpecificData;
public static void ThreadStaticDemo()
{
// Store the managed thread id for each thread in the static
// variable.
threadSpecificData = Thread.CurrentThread.ManagedThreadId;
// Allow other threads time to execute the same code, to show
// that the static data is unique to each thread.
Thread.Sleep( 1000 );
// Display the static data.
Console.WriteLine( "Data for managed thread {0}: {1}",
Thread.CurrentThread.ManagedThreadId, threadSpecificData );
}
}
/* This code example produces output similar to the following:
Data for managed thread 4: 4
Data for managed thread 5: 5
Data for managed thread 3: 3
*/
using namespace System;
using namespace System::Threading;
ref class ThreadData
{
private:
[ThreadStaticAttribute]
static int threadSpecificData;
public:
static void ThreadStaticDemo()
{
// Store the managed thread id for each thread in the static
// variable.
threadSpecificData = Thread::CurrentThread->ManagedThreadId;
// Allow other threads time to execute the same code, to show
// that the static data is unique to each thread.
Thread::Sleep( 1000 );
// Display the static data.
Console::WriteLine( "Data for managed thread {0}: {1}",
Thread::CurrentThread->ManagedThreadId, threadSpecificData );
}
};
int main()
{
for ( int i = 0; i < 3; i++ )
{
Thread^ newThread =
gcnew Thread( gcnew ThreadStart( ThreadData::ThreadStaticDemo ));
newThread->Start();
}
}
/* This code example produces output similar to the following:
Data for managed thread 4: 4
Data for managed thread 5: 5
Data for managed thread 3: 3
*/
Second Example
The following example demonstrates how to use a named data slot to store thread-specific information.
Option Explicit
Option Strict
Imports System
Imports System.Threading
Class Test
<MTAThread> _
Shared Sub Main()
Dim newThreads(3) As Thread
For i As Integer = 0 To newThreads.Length - 1
newThreads(i) = New Thread(AddressOf SlotExample.SlotTest)
newThreads(i).Start()
Next i
End Sub
End Class
Public Class SlotExample
Shared randomGenerator As Random = New Random()
Shared Sub 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)
Dim o As New Other()
o.ShowSlotData()
End Sub
End Class
Public Class Other
Public Sub ShowSlotData()
' This method has no access to the data in the SlotExample
' 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())
End Sub
End Class
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());
}
}
using namespace System;
using namespace System::Threading;
ref 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(), Thread::GetData( Thread::GetNamedDataSlot( "Random" ) )->ToString() );
}
};
ref class Slot
{
private:
static Random^ randomGenerator = gcnew 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 = gcnew Other;
o->ShowSlotData();
}
};
int main()
{
array<Thread^>^newThreads = gcnew array<Thread^>(4);
for ( int i = 0; i < newThreads->Length; i++ )
{
newThreads[ i ] = gcnew Thread( gcnew ThreadStart( &Slot::SlotTest ) );
newThreads[ i ]->Start();
}
}
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
.NET Compact Framework
Supported in: 3.5, 2.0, 1.0
XNA Framework
Supported in: 3.0, 2.0, 1.0
Reference
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