The System.Threading namespace provides classes and interfaces that enable multithreaded programming. In addition to classes for synchronizing thread activities and access to data ( Mutex, Monitor, Interlocked, AutoResetEvent, and so on), this namespace includes a ThreadPool class that allows you to use a pool of system-supplied threads, and a Timer class that executes callback methods on thread pool threads.

 Classes

	Class	Description
	AbandonedMutexException	The exception that is thrown when one thread acquires a Mutex object that another thread has abandoned by exiting without releasing it.
	AutoResetEvent	Notifies a waiting thread that an event has occurred. This class cannot be inherited.
	CompressedStack	Provides methods for setting and capturing the compressed stack on the current thread. This class cannot be inherited.
	EventWaitHandle	Represents a thread synchronization event.
	ExecutionContext	Manages the execution context for the current thread. This class cannot be inherited.
	HostExecutionContext	Encapsulates and propagates the host execution context across threads.
	HostExecutionContextManager	Provides the functionality that allows a common language runtime host to participate in the flow, or migration, of the execution context.
	Interlocked	Provides atomic operations for variables that are shared by multiple threads.
	ManualResetEvent	Notifies one or more waiting threads that an event has occurred. This class cannot be inherited.
	Monitor	Provides a mechanism that synchronizes access to objects.
	Mutex	A synchronization primitive that can also be used for interprocess synchronization.
	Overlapped	Provides a managed representation of a Win32 OVERLAPPED structure, including methods to transfer information from an Overlapped instance to a NativeOverlapped structure.
	ReaderWriterLock	Defines a lock that supports single writers and multiple readers.
	RegisteredWaitHandle	Represents a handle that has been registered when calling RegisterWaitForSingleObject. This class cannot be inherited.
	Semaphore	Limits the number of threads that can access a resource or pool of resources concurrently.
	SemaphoreFullException	The exception that is thrown when the System.Threading.Semaphore.Release method is called on a semaphore whose count is already at the maximum.
	SynchronizationContext	Provides the basic functionality for propagating a synchronization context in various synchronization models.
	SynchronizationLockException	The exception that is thrown when a method requires the caller to own the lock on a given Monitor, and the method is invoked by a caller that does not own that lock.
	Thread	Creates and controls a thread, sets its priority, and gets its status.
	ThreadAbortException	The exception that is thrown when a call is made to the Abort method. This class cannot be inherited.
	ThreadExceptionEventArgs	Provides data for the ThreadException event.
	ThreadInterruptedException	The exception that is thrown when a Thread is interrupted while it is in a waiting state.
	ThreadPool	Provides a pool of threads that can be used to post work items, process asynchronous I/O, wait on behalf of other threads, and process timers.
	ThreadStartException	The exception that is thrown when a failure occurs in a managed thread after the underlying operating system thread has been started, but before the thread is ready to execute user code.
	ThreadStateException	The exception that is thrown when a Thread is in an invalid ThreadState for the method call.
	Timeout	Contains a constant used to specify an infinite amount of time. This class cannot be inherited.
	Timer	Provides a mechanism for executing a method at specified intervals. This class cannot be inherited.
	WaitHandle	Encapsulates operating system–specific objects that wait for exclusive access to shared resources.
	WaitHandleCannotBeOpenedException	The exception that is thrown when an attempt is made to open a system mutex or semaphore that does not exist.

 Structures

	Structure	Description
	AsyncFlowControl	Provides the functionality to restore the migration, or flow, of the execution context between threads.
	LockCookie	Defines the lock that implements single-writer/multiple-reader semantics. This is a value type.
	NativeOverlapped	Provides an explicit layout that is visible from unmanaged code and that will have the same layout as the Win32 OVERLAPPED structure with additional reserved fields at the end.

 Delegates

	Delegate	Description
	ContextCallback	Represents a method to be called within a new context.
	IOCompletionCallback	Receives the error code, number of bytes, and overlapped value type when an I/O operation completes on the thread pool.
	ParameterizedThreadStart	Represents the method that executes on a Thread.
	SendOrPostCallback	Represents a method to be called when a message is to be dispatched to a synchronization context.
	ThreadExceptionEventHandler	Represents the method that will handle the ThreadException event of an Application.
	ThreadStart	Represents the method that executes on a Thread.
	TimerCallback	Represents the method that handles calls from a Timer.
	WaitCallback	Represents a callback method to be executed by a thread pool thread.
	WaitOrTimerCallback	Represents a method to be called when a WaitHandle is signaled or times out.

 Enumerations

	Enumeration	Description
	ApartmentState	Specifies the apartment state of a Thread.
	EventResetMode	Indicates whether an EventWaitHandle is reset automatically or manually after receiving a signal.
	ThreadPriority	Specifies the scheduling priority of a Thread.
	ThreadState	Specifies the execution states of a Thread.