Code Inspection: Thread static field has initializer
The
ThreadStaticAttribute
makes a field thread-local. This means that every thread has its own reference
corresponding to the field. Fields marked with
ThreadStaticAttribute
must be static and not initialized statically.
This attribute does not affect instance fields. If you need a thread-local instance field you can use the
ThreadLocal<>
type that has been introduced in .NET 4.0.
If a static field has an initializer, this initializer is invoked only once - on the thread that executes the static constructor. If initialization on all threads is needed, then the field can be encapsulated by a lazy-initialized property:
// C#
[ThreadStatic]
private static object myFoo;
public static object Foo
{
get
{
if (myFoo == null)
myFoo = new object();
return myFoo;
}
}' Visual Basic
<ThreadStatic>
Private Shared Dim myFoo As Object
Public Shared ReadOnly Property Foo As Object
Get
If (myFoo Is Nothing) Then myFoo = New Object()
Return myFoo
End Get
End Property
Alternatively, theThreadLocal<>class can be used (as of .NET 4.0):
// C#
private ThreadLocal<object> myFoo = new ThreadLocal<object>(() => new object());' Visual Basic
Dim myFoo As ThreadLocal(Of Object) = new ThreadLocal(Of Object)(Function() New Object())