System.Threading Namespace Reference

Classes
class	AbandonedMutexException
	The exception that is thrown when one thread acquires a T:System.Threading.Mutex object that another thread has abandoned by exiting without releasing it. More...
struct	AsyncFlowControl
	Provides the functionality to restore the migration, or flow, of the execution context between threads. More...
class	AsyncLocal
	Represents ambient data that is local to a given asynchronous control flow, such as an asynchronous method. More...
struct	AsyncLocalValueChangedArgs
	The class that provides data change information to T:System.Threading.AsyncLocal`1 instances that register for change notifications. More...
class	AutoResetEvent
	Notifies a waiting thread that an event has occurred. This class cannot be inherited. More...
class	Barrier
	Enables multiple tasks to cooperatively work on an algorithm in parallel through multiple phases. More...
class	BarrierPostPhaseException
	The exception that is thrown when the post-phase action of a T:System.Threading.Barrier fails More...
struct	CancellationToken
	Propagates notification that operations should be canceled. More...
struct	CancellationTokenRegistration
	Represents a callback delegate that has been registered with a T:System.Threading.CancellationToken. More...
class	CancellationTokenSource
	Signals to a T:System.Threading.CancellationToken that it should be canceled. More...
class	CompressedStack
	Provides methods for setting and capturing the compressed stack on the current thread. This class cannot be inherited. More...
class	CountdownEvent
	Represents a synchronization primitive that is signaled when its count reaches zero. More...
class	EventWaitHandle
	Represents a thread synchronization event. More...
class	ExecutionContext
	Manages the execution context for the current thread. This class cannot be inherited. More...
class	HostExecutionContext
	Encapsulates and propagates the host execution context across threads. More...
class	HostExecutionContextManager
	Provides the functionality that allows a common language runtime host to participate in the flow, or migration, of the execution context. More...
class	Interlocked
	Provides atomic operations for variables that are shared by multiple threads. More...
class	LazyInitializer
	Provides lazy initialization routines. More...
struct	LockCookie
	Defines the lock that implements single-writer/multiple-reader semantics. This is a value type. More...
class	LockRecursionException
	The exception that is thrown when recursive entry into a lock is not compatible with the recursion policy for the lock. More...
class	ManualResetEvent
	Notifies one or more waiting threads that an event has occurred. This class cannot be inherited. More...
class	ManualResetEventSlim
	Provides a slimmed down version of T:System.Threading.ManualResetEvent. More...
class	Monitor
	Provides a mechanism that synchronizes access to objects. More...
class	Mutex
	A synchronization primitive that can also be used for interprocess synchronization. More...
struct	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. More...
class	Overlapped
	Provides a managed representation of a Win32 OVERLAPPED structure, including methods to transfer information from an T:System.Threading.Overlapped instance to a T:System.Threading.NativeOverlapped structure. More...
class	PreAllocatedOverlapped
	Represents pre-allocated state for native overlapped I/O operations. More...
class	ReaderWriterLock
	Defines a lock that supports single writers and multiple readers. More...
class	ReaderWriterLockSlim
	Represents a lock that is used to manage access to a resource, allowing multiple threads for reading or exclusive access for writing. More...
class	RegisteredWaitHandle
	Represents a handle that has been registered when calling M:System.Threading.ThreadPool.RegisterWaitForSingleObject(System.Threading.WaitHandle,System.Threading.WaitOrTimerCallback,System.Object,System.UInt32,System.Boolean). This class cannot be inherited. More...
class	Semaphore
	Limits the number of threads that can access a resource or pool of resources concurrently. More...
class	SemaphoreFullException
	The exception that is thrown when the Overload:System.Threading.Semaphore.Release method is called on a semaphore whose count is already at the maximum. More...
class	SemaphoreSlim
	Represents a lightweight alternative to T:System.Threading.Semaphore that limits the number of threads that can access a resource or pool of resources concurrently. More...
struct	SpinLock
	Provides a mutual exclusion lock primitive where a thread trying to acquire the lock waits in a loop repeatedly checking until the lock becomes available. More...
struct	SpinWait
	Provides support for spin-based waiting. More...
class	SynchronizationContext
	Provides the basic functionality for propagating a synchronization context in various synchronization models. More...
class	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. More...
class	Thread
	Creates and controls a thread, sets its priority, and gets its status. More...
class	ThreadAbortException
	The exception that is thrown when a call is made to the M:System.Threading.Thread.Abort(System.Object) method. This class cannot be inherited. More...
class	ThreadExceptionEventArgs
	Provides data for the E:System.Windows.Forms.Application.ThreadException event. More...
class	ThreadInterruptedException
	The exception that is thrown when a T:System.Threading.Thread is interrupted while it is in a waiting state. More...
class	ThreadLocal
	Provides thread-local storage of data. More...
class	ThreadPool
	Provides a pool of threads that can be used to execute tasks, post work items, process asynchronous I/O, wait on behalf of other threads, and process timers. More...
class	ThreadPoolBoundHandle
	Represents an I/O handle that is bound to the system thread pool and enables low-level components to receive notifications for asynchronous I/O operations. More...
class	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. More...
class	ThreadStateException
	The exception that is thrown when a T:System.Threading.Thread is in an invalid P:System.Threading.Thread.ThreadState for the method call. More...
class	Timeout
	Contains constants that specify infinite time-out intervals. This class cannot be inherited. More...
class	Timer
	Provides a mechanism for executing a method on a thread pool thread at specified intervals. This class cannot be inherited.To browse the .NET Framework source code for this type, see the Reference Source. More...
class	Volatile
	Contains methods for performing volatile memory operations. More...
class	WaitHandle
	Encapsulates operating system–specific objects that wait for exclusive access to shared resources. More...
class	WaitHandleCannotBeOpenedException
	The exception that is thrown when an attempt is made to open a system mutex, semaphore, or event wait handle that does not exist. More...
class	WaitHandleExtensions
	Provides convenience methods to for working with a safe handle for a wait handle. More...

Enumerations
enum	ApartmentState { ApartmentState.STA, ApartmentState.MTA, ApartmentState.Unknown }
	Specifies the apartment state of a T:System.Threading.Thread. More...
enum	EventResetMode { EventResetMode.AutoReset, EventResetMode.ManualReset }
	Indicates whether an T:System.Threading.EventWaitHandle is reset automatically or manually after receiving a signal. More...
enum	LazyThreadSafetyMode { LazyThreadSafetyMode.None, LazyThreadSafetyMode.PublicationOnly, LazyThreadSafetyMode.ExecutionAndPublication }
	Specifies how a T:System.Lazy`1 instance synchronizes access among multiple threads. More...
enum	LockRecursionPolicy { LockRecursionPolicy.NoRecursion, LockRecursionPolicy.SupportsRecursion }
	Specifies whether a lock can be entered multiple times by the same thread. More...
enum	StackCrawlMark { LookForMe, LookForMyCaller, LookForMyCallersCaller, LookForThread }
enum	SynchronizationContextProperties { None = 0x0, RequireWaitNotification = 0x1 }
enum	ThreadPriority {   ThreadPriority.Lowest, ThreadPriority.BelowNormal, ThreadPriority.Normal, ThreadPriority.AboveNormal,   ThreadPriority.Highest }
	Specifies the scheduling priority of a T:System.Threading.Thread. More...
enum	ThreadState {   ThreadState.Running = 0x0, ThreadState.StopRequested = 0x1, ThreadState.SuspendRequested = 0x2, ThreadState.Background = 0x4,   ThreadState.Unstarted = 0x8, ThreadState.Stopped = 0x10, ThreadState.WaitSleepJoin = 0x20, ThreadState.Suspended = 0x40,   ThreadState.AbortRequested = 0x80, ThreadState.Aborted = 0x100 }
	Specifies the execution states of a T:System.Threading.Thread. More...

Functions
delegate void	ContextCallback (object state)
	Represents a method to be called within a new context. More...
internal delegate object	InternalCrossContextDelegate (object[] args)
unsafe delegate void	IOCompletionCallback (uint errorCode, uint numBytes, NativeOverlapped *pOVERLAP)
	Receives the error code, number of bytes, and overlapped value type when an I/O operation completes on the thread pool. More...
delegate void	ParameterizedThreadStart (object obj)
	Represents the method that executes on a T:System.Threading.Thread. More...
delegate void	SendOrPostCallback (object state)
	Represents a method to be called when a message is to be dispatched to a synchronization context. More...
delegate void	ThreadExceptionEventHandler (object sender, ThreadExceptionEventArgs e)
	Represents the method that will handle the E:System.Windows.Forms.Application.ThreadException event of an T:System.Windows.Forms.Application. More...
delegate void	ThreadStart ()
	Represents the method that executes on a T:System.Threading.Thread. More...
delegate void	TimerCallback (object state)
	Represents the method that handles calls from a T:System.Threading.Timer. More...
delegate void	WaitCallback (object state)
	Represents a callback method to be executed by a thread pool thread. More...
delegate void	WaitOrTimerCallback (object state, bool timedOut)
	Represents a method to be called when a T:System.Threading.WaitHandle is signaled or times out. More...

Enumeration Type Documentation

ApartmentState

enum System.Threading.ApartmentState

strong

Specifies the apartment state of a T:System.Threading.Thread.

Enumerator
STA	The T:System.Threading.Thread will create and enter a single-threaded apartment.
MTA	The T:System.Threading.Thread will create and enter a multithreaded apartment.
Unknown	The P:System.Threading.Thread.ApartmentState property has not been set.

Definition at line 8 of file ApartmentState.cs.

EventResetMode

enum System.Threading.EventResetMode

strong

Indicates whether an T:System.Threading.EventWaitHandle is reset automatically or manually after receiving a signal.

Enumerator
AutoReset	When signaled, the T:System.Threading.EventWaitHandle resets automatically after releasing a single thread. If no threads are waiting, the T:System.Threading.EventWaitHandle remains signaled until a thread blocks, and resets after releasing the thread.
ManualReset	When signaled, the T:System.Threading.EventWaitHandle releases all waiting threads and remains signaled until it is manually reset.

Definition at line 8 of file EventResetMode.cs.

LazyThreadSafetyMode

enum System.Threading.LazyThreadSafetyMode

strong

Specifies how a T:System.Lazy`1 instance synchronizes access among multiple threads.

Enumerator
None	The T:System.Lazy`1 instance is not thread safe; if the instance is accessed from multiple threads, its behavior is undefined. Use this mode only when high performance is crucial and the T:System.Lazy`1 instance is guaranteed never to be initialized from more than one thread. If you use a T:System.Lazy`1 constructor that specifies an initialization method (valueFactory parameter), and if that initialization method throws an exception (or fails to handle an exception) the first time you call the P:System.Lazy`1.Value property, then the exception is cached and thrown again on subsequent calls to the P:System.Lazy`1.Value property. If you use a T:System.Lazy`1 constructor that does not specify an initialization method, exceptions that are thrown by the default constructor for T are not cached. In that case, a subsequent call to the P:System.Lazy`1.Value property might successfully initialize the T:System.Lazy`1 instance. If the initialization method recursively accesses the P:System.Lazy`1.Value property of the T:System.Lazy`1 instance, an T:System.InvalidOperationException is thrown.
PublicationOnly	When multiple threads try to initialize a T:System.Lazy`1 instance simultaneously, all threads are allowed to run the initialization method (or the default constructor, if there is no initialization method). The first thread to complete initialization sets the value of the T:System.Lazy`1 instance. That value is returned to any other threads that were simultaneously running the initialization method, unless the initialization method throws exceptions on those threads. Any instances of T that were created by the competing threads are discarded. If the initialization method throws an exception on any thread, the exception is propagated out of the P:System.Lazy`1.Value property on that thread. The exception is not cached. The value of the P:System.Lazy`1.IsValueCreated property remains false, and subsequent calls to the P:System.Lazy`1.Value property, either by the thread where the exception was thrown or by other threads, cause the initialization method to run again. If the initialization method recursively accesses the P:System.Lazy`1.Value property of the T:System.Lazy`1 instance, no exception is thrown.
ExecutionAndPublication	Locks are used to ensure that only a single thread can initialize a T:System.Lazy`1 instance in a thread-safe manner. If the initialization method (or the default constructor, if there is no initialization method) uses locks internally, deadlocks can occur. If you use a T:System.Lazy`1 constructor that specifies an initialization method (valueFactory parameter), and if that initialization method throws an exception (or fails to handle an exception) the first time you call the P:System.Lazy`1.Value property, then the exception is cached and thrown again on subsequent calls to the P:System.Lazy`1.Value property. If you use a T:System.Lazy`1 constructor that does not specify an initialization method, exceptions that are thrown by the default constructor for T are not cached. In that case, a subsequent call to the P:System.Lazy`1.Value property might successfully initialize the T:System.Lazy`1 instance. If the initialization method recursively accesses the P:System.Lazy`1.Value property of the T:System.Lazy`1 instance, an T:System.InvalidOperationException is thrown.

Definition at line 5 of file LazyThreadSafetyMode.cs.

LockRecursionPolicy

enum System.Threading.LockRecursionPolicy

strong

Specifies whether a lock can be entered multiple times by the same thread.

Enumerator
NoRecursion	If a thread tries to enter a lock recursively, an exception is thrown. Some classes may allow certain recursions when this setting is in effect.
SupportsRecursion	A thread can enter a lock recursively. Some classes may restrict this capability.

Definition at line 5 of file LockRecursionPolicy.cs.

ThreadPriority

enum System.Threading.ThreadPriority

strong

Specifies the scheduling priority of a T:System.Threading.Thread.

Enumerator
Lowest	The T:System.Threading.Thread can be scheduled after threads with any other priority.
BelowNormal	The T:System.Threading.Thread can be scheduled after threads with Normal priority and before those with Lowest priority.
Normal	The T:System.Threading.Thread can be scheduled after threads with AboveNormal priority and before those with BelowNormal priority. Threads have Normal priority by default.
AboveNormal	The T:System.Threading.Thread can be scheduled after threads with Highest priority and before those with Normal priority.
Highest	The T:System.Threading.Thread can be scheduled before threads with any other priority.

Definition at line 8 of file ThreadPriority.cs.

ThreadState

enum System.Threading.ThreadState

strong

Specifies the execution states of a T:System.Threading.Thread.

Enumerator
Running	The thread has been started, it is not blocked, and there is no pending T:System.Threading.ThreadAbortException.
StopRequested	The thread is being requested to stop. This is for internal use only.
SuspendRequested	The thread is being requested to suspend.
Background	The thread is being executed as a background thread, as opposed to a foreground thread. This state is controlled by setting the P:System.Threading.Thread.IsBackground property.
Unstarted	The M:System.Threading.Thread.Start method has not been invoked on the thread.
Stopped	The thread has stopped.
WaitSleepJoin	The thread is blocked. This could be the result of calling M:System.Threading.Thread.Sleep(System.Int32) or M:System.Threading.Thread.Join, of requesting a lock — for example, by calling M:System.Threading.Monitor.Enter(System.Object) or M:System.Threading.Monitor.Wait(System.Object,System.Int32,System.Boolean) — or of waiting on a thread synchronization object such as T:System.Threading.ManualResetEvent.
Suspended	The thread has been suspended.
AbortRequested	The M:System.Threading.Thread.Abort(System.Object) method has been invoked on the thread, but the thread has not yet received the pending T:System.Threading.ThreadAbortException that will attempt to terminate it.
Aborted	The thread state includes F:System.Threading.ThreadState.AbortRequested and the thread is now dead, but its state has not yet changed to F:System.Threading.ThreadState.Stopped.

Definition at line 9 of file ThreadState.cs.

Function Documentation

ContextCallback()

delegate void System.Threading.ContextCallback

(

object

state

)

Represents a method to be called within a new context.

Parameters

state

An object containing information to be used by the callback method each time it executes.

IOCompletionCallback()

unsafe delegate void System.Threading.IOCompletionCallback	(	uint	errorCode,
		uint	numBytes,
		NativeOverlapped *	pOVERLAP
	)

Receives the error code, number of bytes, and overlapped value type when an I/O operation completes on the thread pool.

Parameters

errorCode	The error code.
numBytes	The number of bytes that are transferred.
pOVERLAP	A T:System.Threading.NativeOverlapped representing an unmanaged pointer to the native overlapped value type.

ParameterizedThreadStart()

delegate void System.Threading.ParameterizedThreadStart

(

object

obj

)

Represents the method that executes on a T:System.Threading.Thread.

Parameters

obj	An object that contains data for the thread procedure.

SendOrPostCallback()

delegate void System.Threading.SendOrPostCallback

(

object

state

)

Represents a method to be called when a message is to be dispatched to a synchronization context.

Parameters

state

The object passed to the delegate.

ThreadExceptionEventHandler()

delegate void System.Threading.ThreadExceptionEventHandler	(	object	sender,
		ThreadExceptionEventArgs	e
	)

Represents the method that will handle the E:System.Windows.Forms.Application.ThreadException event of an T:System.Windows.Forms.Application.

Parameters

sender	The source of the event.
e	A T:System.Threading.ThreadExceptionEventArgs that contains the event data.

ThreadStart()

delegate void System.Threading.ThreadStart

(

)

Represents the method that executes on a T:System.Threading.Thread.

TimerCallback()

delegate void System.Threading.TimerCallback

(

object

state

)

Represents the method that handles calls from a T:System.Threading.Timer.

Parameters

state

An object containing application-specific information relevant to the method invoked by this delegate, or null.

WaitCallback()

delegate void System.Threading.WaitCallback

(

object

state

)

Represents a callback method to be executed by a thread pool thread.

Parameters

state

An object containing information to be used by the callback method.

WaitOrTimerCallback()

delegate void System.Threading.WaitOrTimerCallback	(	object	state,
		bool	timedOut
	)

Represents a method to be called when a T:System.Threading.WaitHandle is signaled or times out.

Parameters

state	An object containing information to be used by the callback method each time it executes.
timedOut	true if the T:System.Threading.WaitHandle timed out; false if it was signaled.