Limits the number of threads that can access a resource or pool of resources concurrently. More...

Inheritance diagram for System.Threading.Semaphore:

Collaboration diagram for System.Threading.Semaphore:

Public Member Functions
	Semaphore (int initialCount, int maximumCount)
	Initializes a new instance of the T:System.Threading.Semaphore class, specifying the initial number of entries and the maximum number of concurrent entries. More...

	Semaphore (int initialCount, int maximumCount, string name)
	Initializes a new instance of the T:System.Threading.Semaphore class, specifying the initial number of entries and the maximum number of concurrent entries, and optionally specifying the name of a system semaphore object. More...

	Semaphore (int initialCount, int maximumCount, string name, out bool createdNew)
	Initializes a new instance of the T:System.Threading.Semaphore class, specifying the initial number of entries and the maximum number of concurrent entries, optionally specifying the name of a system semaphore object, and specifying a variable that receives a value indicating whether a new system semaphore was created. More...

unsafe	Semaphore (int initialCount, int maximumCount, string name, out bool createdNew, SemaphoreSecurity semaphoreSecurity)
	Initializes a new instance of the T:System.Threading.Semaphore class, specifying the initial number of entries and the maximum number of concurrent entries, optionally specifying the name of a system semaphore object, specifying a variable that receives a value indicating whether a new system semaphore was created, and specifying security access control for the system semaphore. More...

int	Release ()
	Exits the semaphore and returns the previous count. More...

int	Release (int releaseCount)
	Exits the semaphore a specified number of times and returns the previous count. More...

SemaphoreSecurity	GetAccessControl ()
	Gets the access control security for a named system semaphore. More...

void	SetAccessControl (SemaphoreSecurity semaphoreSecurity)
	Sets the access control security for a named system semaphore. More...

Public Member Functions inherited from System.Threading.WaitHandle
virtual bool	WaitOne (int millisecondsTimeout, bool exitContext)
	Blocks the current thread until the current T:System.Threading.WaitHandle receives a signal, using a 32-bit signed integer to specify the time interval and specifying whether to exit the synchronization domain before the wait. More...

virtual bool	WaitOne (TimeSpan timeout, bool exitContext)
	Blocks the current thread until the current instance receives a signal, using a T:System.TimeSpan to specify the time interval and specifying whether to exit the synchronization domain before the wait. More...

virtual bool	WaitOne ()
	Blocks the current thread until the current T:System.Threading.WaitHandle receives a signal. More...

virtual bool	WaitOne (int millisecondsTimeout)
	Blocks the current thread until the current T:System.Threading.WaitHandle receives a signal, using a 32-bit signed integer to specify the time interval in milliseconds. More...

virtual bool	WaitOne (TimeSpan timeout)
	Blocks the current thread until the current instance receives a signal, using a T:System.TimeSpan to specify the time interval. More...

virtual void	Close ()
	Releases all resources held by the current T:System.Threading.WaitHandle. More...

void	Dispose ()
	Releases all resources used by the current instance of the T:System.Threading.WaitHandle class. More...

Public Member Functions inherited from System.MarshalByRefObject
object	GetLifetimeService ()
	Retrieves the current lifetime service object that controls the lifetime policy for this instance. More...

virtual object	InitializeLifetimeService ()
	Obtains a lifetime service object to control the lifetime policy for this instance. More...

virtual ObjRef	CreateObjRef (Type requestedType)
	Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. More...

Static Public Member Functions
static Semaphore	OpenExisting (string name)
	Opens the specified named semaphore, if it already exists. More...

static Semaphore	OpenExisting (string name, SemaphoreRights rights)
	Opens the specified named semaphore, if it already exists, with the desired security access. More...

static bool	TryOpenExisting (string name, out Semaphore result)
	Opens the specified named semaphore, if it already exists, and returns a value that indicates whether the operation succeeded. More...

static bool	TryOpenExisting (string name, SemaphoreRights rights, out Semaphore result)
	Opens the specified named semaphore, if it already exists, with the desired security access, and returns a value that indicates whether the operation succeeded. More...

Static Public Member Functions inherited from System.Threading.WaitHandle
static bool	WaitAll (WaitHandle[] waitHandles, int millisecondsTimeout, bool exitContext)
	Waits for all the elements in the specified array to receive a signal, using an T:System.Int32 value to specify the time interval and specifying whether to exit the synchronization domain before the wait. More...

static bool	WaitAll (WaitHandle[] waitHandles, TimeSpan timeout, bool exitContext)
	Waits for all the elements in the specified array to receive a signal, using a T:System.TimeSpan value to specify the time interval, and specifying whether to exit the synchronization domain before the wait. More...

static bool	WaitAll (WaitHandle[] waitHandles)
	Waits for all the elements in the specified array to receive a signal. More...

static bool	WaitAll (WaitHandle[] waitHandles, int millisecondsTimeout)
	Waits for all the elements in the specified array to receive a signal, using an T:System.Int32 value to specify the time interval. More...

static bool	WaitAll (WaitHandle[] waitHandles, TimeSpan timeout)
	Waits for all the elements in the specified array to receive a signal, using a T:System.TimeSpan value to specify the time interval. More...

static int	WaitAny (WaitHandle[] waitHandles, int millisecondsTimeout, bool exitContext)
	Waits for any of the elements in the specified array to receive a signal, using a 32-bit signed integer to specify the time interval, and specifying whether to exit the synchronization domain before the wait. More...

static int	WaitAny (WaitHandle[] waitHandles, TimeSpan timeout, bool exitContext)
	Waits for any of the elements in the specified array to receive a signal, using a T:System.TimeSpan to specify the time interval and specifying whether to exit the synchronization domain before the wait. More...

static int	WaitAny (WaitHandle[] waitHandles, TimeSpan timeout)
	Waits for any of the elements in the specified array to receive a signal, using a T:System.TimeSpan to specify the time interval. More...

static int	WaitAny (WaitHandle[] waitHandles)
	Waits for any of the elements in the specified array to receive a signal. More...

static int	WaitAny (WaitHandle[] waitHandles, int millisecondsTimeout)
	Waits for any of the elements in the specified array to receive a signal, using a 32-bit signed integer to specify the time interval. More...

static bool	SignalAndWait (WaitHandle toSignal, WaitHandle toWaitOn)
	Signals one T:System.Threading.WaitHandle and waits on another. More...

static bool	SignalAndWait (WaitHandle toSignal, WaitHandle toWaitOn, TimeSpan timeout, bool exitContext)
	Signals one T:System.Threading.WaitHandle and waits on another, specifying the time-out interval as a T:System.TimeSpan and specifying whether to exit the synchronization domain for the context before entering the wait. More...

static bool	SignalAndWait (WaitHandle toSignal, WaitHandle toWaitOn, int millisecondsTimeout, bool exitContext)
	Signals one T:System.Threading.WaitHandle and waits on another, specifying a time-out interval as a 32-bit signed integer and specifying whether to exit the synchronization domain for the context before entering the wait. More...

Additional Inherited Members
Public Attributes inherited from System.Threading.WaitHandle
const int	WaitTimeout = 258
	Indicates that a M:System.Threading.WaitHandle.WaitAny(System.Threading.WaitHandle[],System.Int32,System.Boolean) operation timed out before any of the wait handles were signaled. This field is constant. More...

Protected Member Functions inherited from System.Threading.WaitHandle
	WaitHandle ()
	Initializes a new instance of the T:System.Threading.WaitHandle class. More...

virtual void	Dispose (bool explicitDisposing)
	When overridden in a derived class, releases the unmanaged resources used by the T:System.Threading.WaitHandle, and optionally releases the managed resources. More...

Protected Member Functions inherited from System.MarshalByRefObject
MarshalByRefObject	MemberwiseClone (bool cloneIdentity)
	Creates a shallow copy of the current T:System.MarshalByRefObject object. More...

Static Protected Attributes inherited from System.Threading.WaitHandle
static readonly IntPtr	InvalidHandle = GetInvalidHandle()
	Represents an invalid native operating system handle. This field is read-only. More...

Properties inherited from System.Threading.WaitHandle
virtual IntPtr	Handle `[get, set]`
	Gets or sets the native operating system handle. More...

SafeWaitHandle	SafeWaitHandle `[get, set]`
	Gets or sets the native operating system handle. More...

Detailed Description

Limits the number of threads that can access a resource or pool of resources concurrently.

Definition at line 16 of file Semaphore.cs.

Constructor & Destructor Documentation

◆ Semaphore() [1/4]

System.Threading.Semaphore.Semaphore	(	int	initialCount,
		int	maximumCount
	)

Initializes a new instance of the T:System.Threading.Semaphore class, specifying the initial number of entries and the maximum number of concurrent entries.

Parameters

initialCount	The initial number of requests for the semaphore that can be granted concurrently.
maximumCount	The maximum number of requests for the semaphore that can be granted concurrently.

Exceptions

T:System.ArgumentException	initialCount is greater than maximumCount .
T:System.ArgumentOutOfRangeException	maximumCount is less than 1.-or- initialCount is less than 0.

Definition at line 38 of file Semaphore.cs.

◆ Semaphore() [2/4]

System.Threading.Semaphore.Semaphore	(	int	initialCount,
		int	maximumCount,
		string	name
	)

Initializes a new instance of the T:System.Threading.Semaphore class, specifying the initial number of entries and the maximum number of concurrent entries, and optionally specifying the name of a system semaphore object.

Parameters

initialCount	The initial number of requests for the semaphore that can be granted concurrently.
maximumCount	The maximum number of requests for the semaphore that can be granted concurrently.
name	The name of a named system semaphore object.

Exceptions

T:System.ArgumentException	initialCount is greater than maximumCount .-or- name is longer than 260 characters.
T:System.ArgumentOutOfRangeException	maximumCount is less than 1.-or- initialCount is less than 0.
T:System.IO.IOException	A Win32 error occurred.
T:System.UnauthorizedAccessException	The named semaphore exists and has access control security, and the user does not have F:System.Security.AccessControl.SemaphoreRights.FullControl.
T:System.Threading.WaitHandleCannotBeOpenedException	The named semaphore cannot be created, perhaps because a wait handle of a different type has the same name.

Definition at line 58 of file Semaphore.cs.

◆ Semaphore() [3/4]

System.Threading.Semaphore.Semaphore	(	int	initialCount,
		int	maximumCount,
		string	name,
		out bool	createdNew
	)

Initializes a new instance of the T:System.Threading.Semaphore class, specifying the initial number of entries and the maximum number of concurrent entries, optionally specifying the name of a system semaphore object, and specifying a variable that receives a value indicating whether a new system semaphore was created.

Parameters

initialCount	The initial number of requests for the semaphore that can be satisfied concurrently.
maximumCount	The maximum number of requests for the semaphore that can be satisfied concurrently.
name	The name of a named system semaphore object.
createdNew	When this method returns, contains `true` if a local semaphore was created (that is, if name is `null` or an empty string) or if the specified named system semaphore was created; `false` if the specified named system semaphore already existed. This parameter is passed uninitialized.

Exceptions

T:System.ArgumentException	initialCount is greater than maximumCount . -or- name is longer than 260 characters.
T:System.ArgumentOutOfRangeException	maximumCount is less than 1.-or- initialCount is less than 0.
T:System.IO.IOException	A Win32 error occurred.
T:System.UnauthorizedAccessException	The named semaphore exists and has access control security, and the user does not have F:System.Security.AccessControl.SemaphoreRights.FullControl.
T:System.Threading.WaitHandleCannotBeOpenedException	The named semaphore cannot be created, perhaps because a wait handle of a different type has the same name.

Definition at line 105 of file Semaphore.cs.

◆ Semaphore() [4/4]

unsafe System.Threading.Semaphore.Semaphore	(	int	initialCount,
		int	maximumCount,
		string	name,
		out bool	createdNew,
		SemaphoreSecurity	semaphoreSecurity
	)

Initializes a new instance of the T:System.Threading.Semaphore class, specifying the initial number of entries and the maximum number of concurrent entries, optionally specifying the name of a system semaphore object, specifying a variable that receives a value indicating whether a new system semaphore was created, and specifying security access control for the system semaphore.

Parameters

initialCount	The initial number of requests for the semaphore that can be satisfied concurrently.
maximumCount	The maximum number of requests for the semaphore that can be satisfied concurrently.
name	The name of a named system semaphore object.
createdNew	When this method returns, contains `true` if a local semaphore was created (that is, if name is `null` or an empty string) or if the specified named system semaphore was created; `false` if the specified named system semaphore already existed. This parameter is passed uninitialized.
semaphoreSecurity	A T:System.Security.AccessControl.SemaphoreSecurity object that represents the access control security to be applied to the named system semaphore.

Exceptions

T:System.ArgumentException	initialCount is greater than maximumCount .-or- name is longer than 260 characters.
T:System.ArgumentOutOfRangeException	maximumCount is less than 1.-or- initialCount is less than 0.
T:System.UnauthorizedAccessException	The named semaphore exists and has access control security, and the user does not have F:System.Security.AccessControl.SemaphoreRights.FullControl.
T:System.IO.IOException	A Win32 error occurred.
T:System.Threading.WaitHandleCannotBeOpenedException	The named semaphore cannot be created, perhaps because a wait handle of a different type has the same name.

Definition at line 126 of file Semaphore.cs.

Member Function Documentation

◆ GetAccessControl()

SemaphoreSecurity System.Threading.Semaphore.GetAccessControl ( )

Gets the access control security for a named system semaphore.

Returns: A T:System.Security.AccessControl.SemaphoreSecurity object that represents the access control security for the named system semaphore.

Exceptions

T:System.UnauthorizedAccessException	The current T:System.Threading.Semaphore object represents a named system semaphore, and the user does not have F:System.Security.AccessControl.SemaphoreRights.ReadPermissions rights.-or-The current T:System.Threading.Semaphore object represents a named system semaphore and was not opened with F:System.Security.AccessControl.SemaphoreRights.ReadPermissions rights.
T:System.NotSupportedException	Not supported for Windows 98 or Windows Millennium Edition.

Definition at line 344 of file Semaphore.cs.

◆ OpenExisting() [1/2]

static Semaphore System.Threading.Semaphore.OpenExisting ( string name )

static

Opens the specified named semaphore, if it already exists.

Parameters

name	The name of the system semaphore to open.

Returns: An object that represents the named system semaphore.

Exceptions

T:System.ArgumentException	name is an empty string.-or- name is longer than 260 characters.
T:System.ArgumentNullException	name is `null`.
T:System.Threading.WaitHandleCannotBeOpenedException	The named semaphore does not exist.
T:System.IO.IOException	A Win32 error occurred.
T:System.UnauthorizedAccessException	The named semaphore exists, but the user does not have the security access required to use it.

Definition at line 193 of file Semaphore.cs.

◆ OpenExisting() [2/2]

static Semaphore System.Threading.Semaphore.OpenExisting	(	string	name,
		SemaphoreRights	rights
	)

static

Opens the specified named semaphore, if it already exists, with the desired security access.

Parameters

name	The name of the system semaphore to open.
rights	A bitwise combination of the enumeration values that represent the desired security access.

Returns: An object that represents the named system semaphore.

Exceptions

T:System.ArgumentException	name is an empty string.-or- name is longer than 260 characters.
T:System.ArgumentNullException	name is `null`.
T:System.Threading.WaitHandleCannotBeOpenedException	The named semaphore does not exist.
T:System.IO.IOException	A Win32 error occurred.
T:System.UnauthorizedAccessException	The named semaphore exists, but the user does not have the desired security access rights.

Definition at line 211 of file Semaphore.cs.

◆ Release() [1/2]

int System.Threading.Semaphore.Release ( )

Exits the semaphore and returns the previous count.

Returns: The count on the semaphore before the Overload:System.Threading.Semaphore.Release method was called.

Exceptions

T:System.Threading.SemaphoreFullException	The semaphore count is already at the maximum value.
T:System.IO.IOException	A Win32 error occurred with a named semaphore.
T:System.UnauthorizedAccessException	The current semaphore represents a named system semaphore, but the user does not have F:System.Security.AccessControl.SemaphoreRights.Modify.-or-The current semaphore represents a named system semaphore, but it was not opened with F:System.Security.AccessControl.SemaphoreRights.Modify.

Definition at line 312 of file Semaphore.cs.

◆ Release() [2/2]

int System.Threading.Semaphore.Release ( int releaseCount )

Exits the semaphore a specified number of times and returns the previous count.

Parameters

releaseCount The number of times to exit the semaphore.

Returns: The count on the semaphore before the Overload:System.Threading.Semaphore.Release method was called.

Exceptions

T:System.ArgumentOutOfRangeException	releaseCount is less than 1.
T:System.Threading.SemaphoreFullException	The semaphore count is already at the maximum value.
T:System.IO.IOException	A Win32 error occurred with a named semaphore.
T:System.UnauthorizedAccessException	The current semaphore represents a named system semaphore, but the user does not have F:System.Security.AccessControl.SemaphoreRights.Modify rights.-or-The current semaphore represents a named system semaphore, but it was not opened with F:System.Security.AccessControl.SemaphoreRights.Modify rights.

Definition at line 327 of file Semaphore.cs.

◆ SetAccessControl()

void System.Threading.Semaphore.SetAccessControl ( SemaphoreSecurity semaphoreSecurity )

Sets the access control security for a named system semaphore.

Parameters

semaphoreSecurity A T:System.Security.AccessControl.SemaphoreSecurity object that represents the access control security to be applied to the named system semaphore.

Exceptions

T:System.ArgumentNullException	semaphoreSecurity is `null`.
T:System.UnauthorizedAccessException	The user does not have F:System.Security.AccessControl.SemaphoreRights.ChangePermissions rights.-or-The semaphore was not opened with F:System.Security.AccessControl.SemaphoreRights.ChangePermissions rights.
T:System.NotSupportedException	The current T:System.Threading.Semaphore object does not represent a named system semaphore.

Definition at line 355 of file Semaphore.cs.

◆ TryOpenExisting() [1/2]

static bool System.Threading.Semaphore.TryOpenExisting	(	string	name,
		out Semaphore	result
	)

static

Opens the specified named semaphore, if it already exists, and returns a value that indicates whether the operation succeeded.

Parameters

name	The name of the system semaphore to open.
result	When this method returns, contains a T:System.Threading.Semaphore object that represents the named semaphore if the call succeeded, or `null` if the call failed. This parameter is treated as uninitialized.

Returns: true if the named semaphore was opened successfully; otherwise, false.

Exceptions

T:System.ArgumentException	name is an empty string.-or- name is longer than 260 characters.
T:System.ArgumentNullException	name is `null`.
T:System.IO.IOException	A Win32 error occurred.
T:System.UnauthorizedAccessException	The named semaphore exists, but the user does not have the security access required to use it.

Definition at line 242 of file Semaphore.cs.

◆ TryOpenExisting() [2/2]

static bool System.Threading.Semaphore.TryOpenExisting	(	string	name,
		SemaphoreRights	rights,
		out Semaphore	result
	)

static

Opens the specified named semaphore, if it already exists, with the desired security access, and returns a value that indicates whether the operation succeeded.

Parameters

name	The name of the system semaphore to open.
rights	A bitwise combination of the enumeration values that represent the desired security access.
result	When this method returns, contains a T:System.Threading.Semaphore object that represents the named semaphore if the call succeeded, or `null` if the call failed. This parameter is treated as uninitialized.

Returns: true if the named semaphore was opened successfully; otherwise, false.

Exceptions

T:System.ArgumentException	name is an empty string.-or- name is longer than 260 characters.
T:System.ArgumentNullException	name is `null`.
T:System.IO.IOException	A Win32 error occurred.
T:System.UnauthorizedAccessException	The named semaphore exists, but the user does not have the security access required to use it.

Definition at line 261 of file Semaphore.cs.

The documentation for this class was generated from the following file:

D:/All cs/System.Threading/Semaphore.cs

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Semaphore() [1/4]

◆ Semaphore() [2/4]

◆ Semaphore() [3/4]

◆ Semaphore() [4/4]

Member Function Documentation

◆ GetAccessControl()

◆ OpenExisting() [1/2]

◆ OpenExisting() [2/2]

◆ Release() [1/2]

◆ Release() [2/2]

◆ SetAccessControl()

◆ TryOpenExisting() [1/2]

◆ TryOpenExisting() [2/2]