Programming .NET Components, 2nd Edition

Working with Threads

In .NET, a thread is the basic unit of execution. .NET threads are managed code representations of the underlying threads of the operating system. Under the current version of .NET on Windows, .NET threads map one-to-one to Win32 native threads. However, this mapping can be changed in other hosts. For example, SQL Server 2005 is a managed CLR host and is capable of using fibers for managed threads. Throughout this chapter, the underlying host is considered to be Windows unless otherwise specified. For each thread, the operating system allocates registers, a program counter, a stack, and a stack pointer, and assigns it a time slot and a priority. The operating system (presently) is the one responsible for thread scheduling and thread context switches, as well as thread-manipulation requests such as start and sleep. .NET exposes some of the native thread properties (such as priority). It also associates various managed-code properties with each thread, such as state, exception handlers, security principal (discussed in Chapter 12), name, unique ID, and culture (required for localization).

The .NET class Thread, defined in the System.Threading namespace, represents a managed thread. The Thread class provides various methods and properties to control the managed thread.

Tip

Calling the methods of the Thread class (be they static or instance methods) is always done on the stack of the calling thread, not on the stack of the thread represented by the Thread object. The ...