Controls the system garbage collector, a service that automatically reclaims unused memory. More...

Public Member Functions
static int	GetGeneration (object obj)
	Returns the current generation number of the specified object. More...

Static Public Member Functions
static void	AddMemoryPressure (long bytesAllocated)
	Informs the runtime of a large allocation of unmanaged memory that should be taken into account when scheduling garbage collection. More...

static void	RemoveMemoryPressure (long bytesAllocated)
	Informs the runtime that unmanaged memory has been released and no longer needs to be taken into account when scheduling garbage collection. More...

static void	Collect (int generation)
	Forces an immediate garbage collection from generation 0 through a specified generation. More...

static void	Collect ()
	Forces an immediate garbage collection of all generations. More...

static void	Collect (int generation, GCCollectionMode mode)
	Forces a garbage collection from generation 0 through a specified generation, at a time specified by a T:System.GCCollectionMode value. More...

static void	Collect (int generation, GCCollectionMode mode, bool blocking)
	Forces a garbage collection from generation 0 through a specified generation, at a time specified by a T:System.GCCollectionMode value, with a value specifying whether the collection should be blocking. More...

static void	Collect (int generation, GCCollectionMode mode, bool blocking, bool compacting)
	Forces a garbage collection from generation 0 through a specified generation, at a time specified by a T:System.GCCollectionMode value, with values that specify whether the collection should be blocking and compacting. More...

static int	CollectionCount (int generation)
	Returns the number of times garbage collection has occurred for the specified generation of objects. More...

static void	KeepAlive (object obj)
	References the specified object, which makes it ineligible for garbage collection from the start of the current routine to the point where this method is called. More...

static int	GetGeneration (WeakReference wo)
	Returns the current generation number of the target of a specified weak reference. More...

static void	WaitForPendingFinalizers ()
	Suspends the current thread until the thread that is processing the queue of finalizers has emptied that queue. More...

static void	SuppressFinalize (object obj)
	Requests that the common language runtime not call the finalizer for the specified object. More...

static void	ReRegisterForFinalize (object obj)
	Requests that the system call the finalizer for the specified object for which M:System.GC.SuppressFinalize(System.Object) has previously been called. More...

static long	GetTotalMemory (bool forceFullCollection)
	Retrieves the number of bytes currently thought to be allocated. A parameter indicates whether this method can wait a short interval before returning, to allow the system to collect garbage and finalize objects. More...

static void	RegisterForFullGCNotification (int maxGenerationThreshold, int largeObjectHeapThreshold)
	Specifies that a garbage collection notification should be raised when conditions favor full garbage collection and when the collection has been completed. More...

static void	CancelFullGCNotification ()
	Cancels the registration of a garbage collection notification. More...

static GCNotificationStatus	WaitForFullGCApproach ()
	Returns the status of a registered notification for determining whether a full, blocking garbage collection by the common language runtime is imminent. More...

static GCNotificationStatus	WaitForFullGCApproach (int millisecondsTimeout)
	Returns, in a specified time-out period, the status of a registered notification for determining whether a full, blocking garbage collection by the common language runtime is imminent. More...

static GCNotificationStatus	WaitForFullGCComplete ()
	Returns the status of a registered notification for determining whether a full, blocking garbage collection by the common language runtime has completed. More...

static GCNotificationStatus	WaitForFullGCComplete (int millisecondsTimeout)
	Returns, in a specified time-out period, the status of a registered notification for determining whether a full, blocking garbage collection by common language the runtime has completed. More...

static bool	TryStartNoGCRegion (long totalSize)
	Attempts to disallow garbage collection during the execution of a critical path if a specified amount of memory is available. More...

static bool	TryStartNoGCRegion (long totalSize, long lohSize)
	Attempts to disallow garbage collection during the execution of a critical path if a specified amount of memory is available for the large object heap and the small object heap. More...

static bool	TryStartNoGCRegion (long totalSize, bool disallowFullBlockingGC)
	Attempts to disallow garbage collection during the execution of a critical path if a specified amount of memory is available, and controls whether the garbage collector does a full blocking garbage collection if not enough memory is initially available. More...

static bool	TryStartNoGCRegion (long totalSize, long lohSize, bool disallowFullBlockingGC)
	Attempts to disallow garbage collection during the execution of a critical path if a specified amount of memory is available for the large object heap and the small object heap, and controls whether the garbage collector does a full blocking garbage collection if not enough memory is initially available. More...

static void	EndNoGCRegion ()
	Ends the no GC region latency mode. More...

Properties
static int	MaxGeneration `[get]`
	Gets the maximum number of generations that the system currently supports. More...

Detailed Description

Controls the system garbage collector, a service that automatically reclaims unused memory.

Definition at line 11 of file GC.cs.

Member Function Documentation

◆ AddMemoryPressure()

static void System.GC.AddMemoryPressure ( long bytesAllocated )

static

Informs the runtime of a large allocation of unmanaged memory that should be taken into account when scheduling garbage collection.

Parameters

bytesAllocated The incremental amount of unmanaged memory that has been allocated.

Exceptions

T:System.ArgumentOutOfRangeException bytesAllocated is less than or equal to 0.-or-On a 32-bit computer, bytesAllocated is larger than F:System.Int32.MaxValue.

Definition at line 111 of file GC.cs.

◆ CancelFullGCNotification()

static void System.GC.CancelFullGCNotification ( )

static

Cancels the registration of a garbage collection notification.

Exceptions

T:System.InvalidOperationException This member is not available when concurrent garbage collection is enabled. See the <gcConcurrent> runtime setting for information about how to disable concurrent garbage collection.

Definition at line 402 of file GC.cs.

◆ Collect() [1/5]

static void System.GC.Collect ( int generation )

static

Forces an immediate garbage collection from generation 0 through a specified generation.

Parameters

generation The number of the oldest generation to be garbage collected.

Exceptions

T:System.ArgumentOutOfRangeException generation is not valid.

Definition at line 155 of file GC.cs.

◆ Collect() [2/5]

static void System.GC.Collect ( )

static

Forces an immediate garbage collection of all generations.

Definition at line 163 of file GC.cs.

◆ Collect() [3/5]

static void System.GC.Collect	(	int	generation,
		GCCollectionMode	mode
	)

static

Forces a garbage collection from generation 0 through a specified generation, at a time specified by a T:System.GCCollectionMode value.

Parameters

generation	The number of the oldest generation to be garbage collected.
mode	An enumeration value that specifies whether the garbage collection is forced (F:System.GCCollectionMode.Default or F:System.GCCollectionMode.Forced) or optimized (F:System.GCCollectionMode.Optimized).

Exceptions

T:System.ArgumentOutOfRangeException generation is not valid.-or- mode is not one of the T:System.GCCollectionMode values.

Definition at line 176 of file GC.cs.

◆ Collect() [4/5]

static void System.GC.Collect	(	int	generation,
		GCCollectionMode	mode,
		bool	blocking
	)

static

Forces a garbage collection from generation 0 through a specified generation, at a time specified by a T:System.GCCollectionMode value, with a value specifying whether the collection should be blocking.

Parameters

generation	The number of the oldest generation to be garbage collected.
mode	An enumeration value that specifies whether the garbage collection is forced (F:System.GCCollectionMode.Default or F:System.GCCollectionMode.Forced) or optimized (F:System.GCCollectionMode.Optimized).
blocking	`true` to perform a blocking garbage collection; `false` to perform a background garbage collection where possible.

Exceptions

T:System.ArgumentOutOfRangeException generation is not valid.-or- mode is not one of the T:System.GCCollectionMode values.

Definition at line 191 of file GC.cs.

◆ Collect() [5/5]

static void System.GC.Collect	(	int	generation,
		GCCollectionMode	mode,
		bool	blocking,
		bool	compacting
	)

static

Forces a garbage collection from generation 0 through a specified generation, at a time specified by a T:System.GCCollectionMode value, with values that specify whether the collection should be blocking and compacting.

Parameters

generation	The number of the oldest generation to be garbage collected.
mode	An enumeration value that specifies whether the garbage collection is forced (F:System.GCCollectionMode.Default or F:System.GCCollectionMode.Forced) or optimized (F:System.GCCollectionMode.Optimized).
blocking	`true` to perform a blocking garbage collection; `false` to perform a background garbage collection where possible. See the Remarks section for more information.
compacting	`true` to compact the small object heap; `false` to sweep only. See the Remarks section for more information.

Definition at line 204 of file GC.cs.

◆ CollectionCount()

static int System.GC.CollectionCount ( int generation )

static

Returns the number of times garbage collection has occurred for the specified generation of objects.

Parameters

generation The generation of objects for which the garbage collection count is to be determined.

Returns: The number of times garbage collection has occurred for the specified generation since the process was started.

Exceptions

T:System.ArgumentOutOfRangeException generation is less than 0.

Definition at line 242 of file GC.cs.

◆ EndNoGCRegion()

static void System.GC.EndNoGCRegion ( )

static

Ends the no GC region latency mode.

Exceptions

T:System.InvalidOperationException The garbage collector is not in no GC region latency mode. See the Remarks section for more information. -or-The no GC region latency mode was ended previously because a garbage collection was induced. -or-A memory allocation exceeded the amount specified in the call to the M:System.GC.TryStartNoGCRegion(System.Int64) method.

Definition at line 549 of file GC.cs.

◆ GetGeneration() [1/2]

static int System.GC.GetGeneration ( object obj )

Returns the current generation number of the specified object.

Parameters

obj	The object that generation information is retrieved for.

Returns: The current generation number of obj .

◆ GetGeneration() [2/2]

static int System.GC.GetGeneration ( WeakReference wo )

static

Returns the current generation number of the target of a specified weak reference.

Parameters

wo	A T:System.WeakReference that refers to the target object whose generation number is to be determined.

Returns: The current generation number of the target of wo .

Exceptions

T:System.ArgumentException Garbage collection has already been performed on wo .

Definition at line 276 of file GC.cs.

◆ GetTotalMemory()

static long System.GC.GetTotalMemory ( bool forceFullCollection )

static

Retrieves the number of bytes currently thought to be allocated. A parameter indicates whether this method can wait a short interval before returning, to allow the system to collect garbage and finalize objects.

Parameters

forceFullCollection true to indicate that this method can wait for garbage collection to occur before returning; otherwise, false.

Returns: A number that is the best available approximation of the number of bytes currently allocated in managed memory.

Definition at line 342 of file GC.cs.

◆ KeepAlive()

static void System.GC.KeepAlive ( object obj )

static

References the specified object, which makes it ineligible for garbage collection from the start of the current routine to the point where this method is called.

Parameters

obj	The object to reference.

Definition at line 267 of file GC.cs.

◆ RegisterForFullGCNotification()

static void System.GC.RegisterForFullGCNotification	(	int	maxGenerationThreshold,
		int	largeObjectHeapThreshold
	)

static

Specifies that a garbage collection notification should be raised when conditions favor full garbage collection and when the collection has been completed.

Parameters

maxGenerationThreshold	A number between 1 and 99 that specifies when the notification should be raised based on the objects allocated in generation 2.
largeObjectHeapThreshold	A number between 1 and 99 that specifies when the notification should be raised based on objects allocated in the large object heap.

Exceptions

T:System.ArgumentOutOfRangeException maxGenerationThreshold or largeObjectHeapThreshold is not between 1 and 99.

Definition at line 383 of file GC.cs.

◆ RemoveMemoryPressure()

static void System.GC.RemoveMemoryPressure ( long bytesAllocated )

static

Informs the runtime that unmanaged memory has been released and no longer needs to be taken into account when scheduling garbage collection.

Parameters

bytesAllocated The amount of unmanaged memory that has been released.

Exceptions

T:System.ArgumentOutOfRangeException bytesAllocated is less than or equal to 0. -or- On a 32-bit computer, bytesAllocated is larger than F:System.Int32.MaxValue.

Definition at line 130 of file GC.cs.

◆ ReRegisterForFinalize()

static void System.GC.ReRegisterForFinalize ( object obj )

static

Requests that the system call the finalizer for the specified object for which M:System.GC.SuppressFinalize(System.Object) has previously been called.

Parameters

obj	The object that a finalizer must be called for.

Exceptions

T:System.ArgumentNullException obj is null.

Definition at line 327 of file GC.cs.

◆ SuppressFinalize()

static void System.GC.SuppressFinalize ( object obj )

static

Requests that the common language runtime not call the finalizer for the specified object.

Parameters

obj	The object whose finalizer must not be executed.

Exceptions

T:System.ArgumentNullException obj is null.

Definition at line 308 of file GC.cs.

◆ TryStartNoGCRegion() [1/4]

static bool System.GC.TryStartNoGCRegion ( long totalSize )

static

Attempts to disallow garbage collection during the execution of a critical path if a specified amount of memory is available.

Parameters

totalSize The amount of memory in bytes to allocate without triggering a garbage collection. It must be less than or equal to the size of an ephemeral segment. For information on the size of an ephemeral segement, see the "Ephemeral generations and segments" section in the Fundamentals of Garbage Collection article.

Returns: true if the runtime was able to commit the required amount of memory and the garbage collector is able to enter no GC region latency mode; otherwise, false.

Exceptions

T:System.ArgumentOutOfRangeException	totalSize exceeds the ephemeral segment size.
T:System.InvalidOperationException	The process is already in no GC region latency mode.

Definition at line 480 of file GC.cs.

◆ TryStartNoGCRegion() [2/4]

static bool System.GC.TryStartNoGCRegion	(	long	totalSize,
		long	lohSize
	)

static

Attempts to disallow garbage collection during the execution of a critical path if a specified amount of memory is available for the large object heap and the small object heap.

Parameters

totalSize	The amount of memory in bytes to allocate without triggering a garbage collection. totalSize –lohSize must be less than or equal to the size of an ephemeral segment. For information on the size of an ephemeral segement, see the "Ephemeral generations and segments" section in the Fundamentals of Garbage Collection article.
lohSize	The number of bytes in totalSize to use for large object heap (LOH) allocations.

Returns: true if the runtime was able to commit the required amount of memory and the garbage collector is able to enter no GC region latency mode; otherwise, false.

Exceptions

T:System.ArgumentOutOfRangeException	totalSize – lohSize exceeds the ephemeral segment size.
T:System.InvalidOperationException	The process is already in no GC region latency mode.

Definition at line 494 of file GC.cs.

◆ TryStartNoGCRegion() [3/4]

static bool System.GC.TryStartNoGCRegion	(	long	totalSize,
		bool	disallowFullBlockingGC
	)

static

Attempts to disallow garbage collection during the execution of a critical path if a specified amount of memory is available, and controls whether the garbage collector does a full blocking garbage collection if not enough memory is initially available.

Parameters

totalSize	The amount of memory in bytes to allocate without triggering a garbage collection. It must be less than or equal to the size of an ephemeral segment. For information on the size of an ephemeral segement, see the "Ephemeral generations and segments" section in the Fundamentals of Garbage Collection article.
disallowFullBlockingGC	`true` to omit a full blocking garbage collection if the garbage collector is initially unable to allocate totalSize bytes; otherwise, `false`.

Returns: true if the runtime was able to commit the required amount of memory and the garbage collector is able to enter no GC region latency mode; otherwise, false.

Exceptions

T:System.ArgumentOutOfRangeException	totalSize exceeds the ephemeral segment size.
T:System.InvalidOperationException	The process is already in no GC region latency mode.

Definition at line 509 of file GC.cs.

◆ TryStartNoGCRegion() [4/4]

static bool System.GC.TryStartNoGCRegion	(	long	totalSize,
		long	lohSize,
		bool	disallowFullBlockingGC
	)

static

Attempts to disallow garbage collection during the execution of a critical path if a specified amount of memory is available for the large object heap and the small object heap, and controls whether the garbage collector does a full blocking garbage collection if not enough memory is initially available.

Parameters

totalSize	The amount of memory in bytes to allocate without triggering a garbage collection. totalSize –lohSize must be less than or equal to the size of an ephemeral segment. For information on the size of an ephemeral segement, see the "Ephemeral generations and segments" section in the Fundamentals of Garbage Collection article.
lohSize	The number of bytes in totalSize to use for large object heap (LOH) allocations.
disallowFullBlockingGC	`true` to omit a full blocking garbage collection if the garbage collector is initially unable to allocate the specified memory on the small object heap (SOH) and LOH; otherwise, `false`.

Returns: true if the runtime was able to commit the required amount of memory and the garbage collector is able to enter no GC region latency mode; otherwise, false.

Exceptions

T:System.ArgumentOutOfRangeException	totalSize – lohSize exceeds the ephemeral segment size.
T:System.InvalidOperationException	The process is already in no GC region latency mode.

Definition at line 525 of file GC.cs.

◆ WaitForFullGCApproach() [1/2]

static GCNotificationStatus System.GC.WaitForFullGCApproach ( )

static

Returns the status of a registered notification for determining whether a full, blocking garbage collection by the common language runtime is imminent.

Returns: The status of the registered garbage collection notification.

Definition at line 413 of file GC.cs.

◆ WaitForFullGCApproach() [2/2]

static GCNotificationStatus System.GC.WaitForFullGCApproach ( int millisecondsTimeout )

static

Returns, in a specified time-out period, the status of a registered notification for determining whether a full, blocking garbage collection by the common language runtime is imminent.

Parameters

millisecondsTimeout The length of time to wait before a notification status can be obtained. Specify -1 to wait indefinitely.

Returns: The status of the registered garbage collection notification.

Exceptions

T:System.ArgumentOutOfRangeException millisecondsTimeout must be either non-negative or less than or equal to F:System.Int32.MaxValue or -1.

Definition at line 424 of file GC.cs.

◆ WaitForFullGCComplete() [1/2]

static GCNotificationStatus System.GC.WaitForFullGCComplete ( )

static

Returns the status of a registered notification for determining whether a full, blocking garbage collection by the common language runtime has completed.

Returns: The status of the registered garbage collection notification.

Definition at line 436 of file GC.cs.

◆ WaitForFullGCComplete() [2/2]

static GCNotificationStatus System.GC.WaitForFullGCComplete ( int millisecondsTimeout )

static

Returns, in a specified time-out period, the status of a registered notification for determining whether a full, blocking garbage collection by common language the runtime has completed.

Parameters

millisecondsTimeout The length of time to wait before a notification status can be obtained. Specify -1 to wait indefinitely.

Returns: The status of the registered garbage collection notification.

Exceptions

T:System.InvalidOperationException millisecondsTimeout must be either non-negative or less than or equal to F:System.Int32.MaxValue or -1.

Definition at line 447 of file GC.cs.

◆ WaitForPendingFinalizers()

static void System.GC.WaitForPendingFinalizers ( )

static

Suspends the current thread until the thread that is processing the queue of finalizers has emptied that queue.

Definition at line 291 of file GC.cs.

Property Documentation

◆ MaxGeneration

int System.GC.MaxGeneration

staticget

Gets the maximum number of generations that the system currently supports.

Returns: A value that ranges from zero to the maximum number of supported generations.

Definition at line 33 of file GC.cs.

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

D:/All cs/System/GC.cs

Public Member Functions

Static Public Member Functions

Properties

Detailed Description

Member Function Documentation

◆ AddMemoryPressure()

◆ CancelFullGCNotification()

◆ Collect() [1/5]

◆ Collect() [2/5]

◆ Collect() [3/5]

◆ Collect() [4/5]

◆ Collect() [5/5]

◆ CollectionCount()

◆ EndNoGCRegion()

◆ GetGeneration() [1/2]

◆ GetGeneration() [2/2]

◆ GetTotalMemory()

◆ KeepAlive()

◆ RegisterForFullGCNotification()

◆ RemoveMemoryPressure()

◆ ReRegisterForFinalize()

◆ SuppressFinalize()

◆ TryStartNoGCRegion() [1/4]

◆ TryStartNoGCRegion() [2/4]

◆ TryStartNoGCRegion() [3/4]

◆ TryStartNoGCRegion() [4/4]

◆ WaitForFullGCApproach() [1/2]

◆ WaitForFullGCApproach() [2/2]

◆ WaitForFullGCComplete() [1/2]

◆ WaitForFullGCComplete() [2/2]

◆ WaitForPendingFinalizers()

Property Documentation

◆ MaxGeneration