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Struct `core.memory.GC`

This struct encapsulates all garbage collection functionality for the D programming language.


						
				struct GC
				;

Methods

Name	Description
`addRange`	Adds `p[0 .. sz]` to the list of memory ranges to be scanned for pointers during a collection. If p is null, no operation is performed.
`addrOf`	Returns the base address of the memory block containing p. This value is useful to determine whether p is an interior pointer, and the result may be passed to routines such as sizeOf which may otherwise fail. If p references memory not originally allocated by this garbage collector, if p is null, or if the garbage collector does not support this operation, null will be returned.
`addRoot`	Adds an internal root pointing to the GC memory block referenced by p. As a result, the block referenced by p itself and any blocks accessible via it will be considered live until the root is removed again.
`calloc`	Requests an aligned block of managed memory from the garbage collector, which is initialized with all bits set to zero. This memory may be deleted at will with a call to free, or it may be discarded and cleaned up automatically during a collection run. If allocation fails, this function will call onOutOfMemory which is expected to throw an OutOfMemoryError.
`clrAttr`	Clears the specified bits for the memory references by p. If p references memory not originally allocated by this garbage collector, points to the interior of a memory block, or if p is null, no action will be performed.
`collect`	Begins a full collection. While the meaning of this may change based on the garbage collector implementation, typical behavior is to scan all stack segments for roots, mark accessible memory blocks as alive, and then to reclaim free space. This action may need to suspend all running threads for at least part of the collection process.
`disable`	Disables automatic garbage collections performed to minimize the process footprint. Collections may continue to occur in instances where the implementation deems necessary for correct program behavior, such as during an out of memory condition. This function is reentrant, but enable must be called once for each call to disable.
`enable`	Enables automatic garbage collection behavior if collections have previously been suspended by a call to disable. This function is reentrant, and must be called once for every call to disable before automatic collections are enabled.
`extend`	Requests that the managed memory block referenced by p be extended in place by at least mx bytes, with a desired extension of sz bytes. If an extension of the required size is not possible or if p references memory not originally allocated by this garbage collector, no action will be taken.
`free`	Deallocates the memory referenced by p. If p is null, no action occurs. If p references memory not originally allocated by this garbage collector, if p points to the interior of a memory block, or if this method is called from a finalizer, no action will be taken. The block will not be finalized regardless of whether the FINALIZE attribute is set. If finalization is desired, use delete instead.
`getAttr`	Returns a bit field representing all block attributes set for the memory referenced by p. If p references memory not originally allocated by this garbage collector, points to the interior of a memory block, or if p is null, zero will be returned.
`malloc`	Requests an aligned block of managed memory from the garbage collector. This memory may be deleted at will with a call to free, or it may be discarded and cleaned up automatically during a collection run. If allocation fails, this function will call onOutOfMemory which is expected to throw an OutOfMemoryError.
`minimize`	Indicates that the managed memory space be minimized by returning free physical memory to the operating system. The amount of free memory returned depends on the allocator design and on program behavior.
`qalloc`	Requests an aligned block of managed memory from the garbage collector. This memory may be deleted at will with a call to free, or it may be discarded and cleaned up automatically during a collection run. If allocation fails, this function will call onOutOfMemory which is expected to throw an OutOfMemoryError.
`query`	Returns aggregate information about the memory block containing p. If p references memory not originally allocated by this garbage collector, if p is null, or if the garbage collector does not support this operation, BlkInfo.init will be returned. Typically, support for this operation is dependent on support for addrOf.
`realloc`	If sz is zero, the memory referenced by p will be deallocated as if by a call to free. A new memory block of size sz will then be allocated as if by a call to malloc, or the implementation may instead resize the memory block in place. The contents of the new memory block will be the same as the contents of the old memory block, up to the lesser of the new and old sizes. Note that existing memory will only be freed by realloc if sz is equal to zero. The garbage collector is otherwise expected to later reclaim the memory block if it is unused. If allocation fails, this function will call onOutOfMemory which is expected to throw an OutOfMemoryError. If p references memory not originally allocated by this garbage collector, or if it points to the interior of a memory block, no action will be taken. If ba is zero (the default) and p references the head of a valid, known memory block then any bits set on the current block will be set on the new block if a reallocation is required. If ba is not zero and p references the head of a valid, known memory block then the bits in ba will replace those on the current memory block and will also be set on the new block if a reallocation is required.
`removeRange`	Removes the memory range starting at p from an internal list of ranges to be scanned during a collection. If p is null or does not represent a value previously passed to addRange() then no operation is performed.
`removeRoot`	Removes the memory block referenced by p from an internal list of roots to be scanned during a collection. If p is null or is not a value previously passed to addRoot() then no operation is performed.
`reserve`	Requests that at least sz bytes of memory be obtained from the operating system and marked as free.
`runFinalizers`	Runs any finalizer that is located in address range of the given code segment. This is used before unloading shared libraries. All matching objects which have a finalizer in this code segment are assumed to be dead, using them while or after calling this method has undefined behavior.
`setAttr`	Sets the specified bits for the memory references by p. If p references memory not originally allocated by this garbage collector, points to the interior of a memory block, or if p is null, no action will be performed.
`sizeOf`	Returns the true size of the memory block referenced by p. This value represents the maximum number of bytes for which a call to realloc may resize the existing block in place. If p references memory not originally allocated by this garbage collector, points to the interior of a memory block, or if p is null, zero will be returned.
`stats`	Returns runtime stats for currently active GC implementation See `GC.Stats` for list of available metrics.

Inner structs

Name	Description
`Stats`	Aggregation of GC stats to be exposed via public API

Enums

Name	Description
`BlkAttr`	Elements for a bit field representing memory block attributes. These are manipulated via the getAttr, setAttr, clrAttr functions.

Aliases

Name	Description
`BlkInfo`	Contains aggregate information about a block of managed memory. The purpose of this struct is to support a more efficient query style in instances where detailed information is needed.

Authors

Sean Kelly, Alex Rønne Petersen

License

Boost License 1.0