Public Member Functions
	device_buffer ()
	Default constructor creates an empty `device_buffer`

	device_buffer (std::size_t size, cuda_stream_view stream=cuda_stream_view{}, mr::device_memory_resource *mr=mr::get_current_device_resource())
	Constructs a new device buffer of `size` uninitialized bytes. More...

	device_buffer (void const source_data, std::size_t size, cuda_stream_view stream=cuda_stream_view{}, mr::device_memory_resource mr=mr::get_current_device_resource())
	Construct a new device buffer by copying from a raw pointer to an existing host or device memory allocation. More...

	device_buffer (device_buffer const &other, cuda_stream_view stream=cuda_stream_view{}, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Construct a new `device_buffer` by deep copying the contents of another `device_buffer`, optionally using the specified stream and memory resource. More...

	device_buffer (device_buffer &&other) noexcept
	Constructs a new `device_buffer` by moving the contents of another `device_buffer` into the newly constructed one. More...

device_buffer &	operator= (device_buffer const &other)
	Copies the contents of `other` into this `device_buffer`. More...

device_buffer &	operator= (device_buffer &&other) noexcept
	Move assignment operator moves the contents from `other`. More...

	~device_buffer () noexcept
	Destroy the device buffer object. More...

void	resize (std::size_t new_size, cuda_stream_view stream=cuda_stream_view{})
	Resize the device memory allocation. More...

void	shrink_to_fit (cuda_stream_view stream=cuda_stream_view{})
	Forces the deallocation of unused memory. More...

void const *	data () const noexcept
	Returns raw pointer to underlying device memory allocation.

void *	data () noexcept
	Returns raw pointer to underlying device memory allocation.

std::size_t	size () const noexcept
	Returns size in bytes that was requested for the device memory allocation.

bool	is_empty () const noexcept
	Returns whether the size in bytes of the `device_buffer` is zero. More...

std::size_t	capacity () const noexcept
	Returns actual size in bytes of device memory allocation. More...

cuda_stream_view	stream () const noexcept
	Returns stream most recently specified for allocation/deallocation.

void	set_stream (cuda_stream_view stream) noexcept
	Sets the stream to be used for deallocation. More...

mr::device_memory_resource *	memory_resource () const noexcept
	Returns pointer to the memory resource used to allocate and deallocate the device memory.

Constructor & Destructor Documentation

◆ device_buffer() [1/4]

rmm::device_buffer::device_buffer	(	std::size_t	size,
		cuda_stream_view	stream = `cuda_stream_view{}`,
		mr::device_memory_resource *	mr = `mr::get_current_device_resource()`
	)

inlineexplicit

Constructs a new device buffer of size uninitialized bytes.

Exceptions

rmm::bad_alloc If allocation fails.

Parameters

size	Size in bytes to allocate in device memory.
stream	CUDA stream on which memory may be allocated if the memory resource supports streams.
mr	Memory resource to use for the device memory allocation.

◆ device_buffer() [2/4]

rmm::device_buffer::device_buffer	(	void const *	source_data,
		std::size_t	size,
		cuda_stream_view	stream = `cuda_stream_view{}`,
		mr::device_memory_resource *	mr = `mr::get_current_device_resource()`
	)

inline

Construct a new device buffer by copying from a raw pointer to an existing host or device memory allocation.

Exceptions

rmm::bad_alloc	If creating the new allocation fails.
rmm::logic_error	If `source_data` is null, and `size != 0`.
rmm::cuda_error	if copying from the device memory fails.

Parameters

source_data	Pointer to the host or device memory to copy from.
size	Size in bytes to copy.
stream	CUDA stream on which memory may be allocated if the memory resource supports streams.
mr	Memory resource to use for the device memory allocation

◆ device_buffer() [3/4]

rmm::device_buffer::device_buffer	(	device_buffer const &	other,
		cuda_stream_view	stream = `cuda_stream_view{}`,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

inline

Construct a new device_buffer by deep copying the contents of another device_buffer, optionally using the specified stream and memory resource.

Note: Only copies other.size() bytes from other, i.e., if other.size() != other.capacity(), then the size and capacity of the newly constructed device_buffer will be equal to other.size().

Exceptions

rmm::bad_alloc	If creating the new allocation fails.
rmm::cuda_error	if copying from `other` fails.

Parameters

other	The `device_buffer` whose contents will be copied
stream	The stream to use for the allocation and copy
mr	The resource to use for allocating the new `device_buffer`

◆ device_buffer() [4/4]

rmm::device_buffer::device_buffer ( device_buffer && other )

inlinenoexcept

Constructs a new device_buffer by moving the contents of another device_buffer into the newly constructed one.

After the new device_buffer is constructed, other is modified to be a valid, empty device_buffer, i.e., data() returns nullptr, and size() and capacity() are zero.

Exceptions

Nothing

Parameters

other The device_buffer whose contents will be moved into the newly constructed one.

◆ ~device_buffer()

rmm::device_buffer::~device_buffer ( )

inlinenoexcept

Destroy the device buffer object.

Note: If the memory resource supports streams, this destructor deallocates using the stream most recently passed to any of this device buffer's methods.

Member Function Documentation

◆ capacity()

std::size_t rmm::device_buffer::capacity ( ) const

inlinenoexcept

Returns actual size in bytes of device memory allocation.

The invariant size() <= capacity() holds.

◆ is_empty()

bool rmm::device_buffer::is_empty ( ) const

inlinenoexcept

Returns whether the size in bytes of the device_buffer is zero.

If is_empty() == true, the device_buffer may still hold an allocation if capacity() > 0.

◆ operator=() [1/2]

device_buffer& rmm::device_buffer::operator= ( device_buffer && other )

inlinenoexcept

Move assignment operator moves the contents from other.

This device_buffer's current device memory allocation will be deallocated on stream().

If a different stream is required, call set_stream() on the instance before assignment. After assignment, this instance's stream is replaced by the other.stream().

Parameters

other The device_buffer whose contents will be moved.

◆ operator=() [2/2]

device_buffer& rmm::device_buffer::operator= ( device_buffer const & other )

inline

Copies the contents of other into this device_buffer.

All operations on the data in this device_buffer on all streams must be complete before using this operator, otherwise behavior is undefined.

If the existing capacity is large enough, and the memory resources are compatible, then this device_buffer's existing memory will be reused and others contents will simply be copied on other.stream(). I.e., if capcity() > other.size() and memory_resource()->is_equal(*other.memory_resource()).

Otherwise, the existing memory will be deallocated using memory_resource() on stream() and new memory will be allocated using other.memory_resource() on other.stream().

Exceptions

rmm::bad_alloc	if allocation fails
rmm::cuda_error	if the copy from `other` fails

Parameters

other The device_buffer to copy.

◆ resize()

void rmm::device_buffer::resize	(	std::size_t	new_size,
		cuda_stream_view	stream = `cuda_stream_view{}`
	)

inline

Resize the device memory allocation.

If the requested new_size is less than or equal to capacity(), no action is taken other than updating the value that is returned from size(). Specifically, no memory is allocated nor copied. The value capacity() remains the actual size of the device memory allocation.

Note: shrink_to_fit() may be used to force the deallocation of unused capacity().

If new_size is larger than capacity(), a new allocation is made on stream to satisfy new_size, and the contents of the old allocation are copied on stream to the new allocation. The old allocation is then freed. The bytes from [old_size, new_size) are uninitialized.

The invariant size() <= capacity() holds.

Exceptions

rmm::bad_alloc	If creating the new allocation fails
rmm::cuda_error	if the copy from the old to new allocation fails

Parameters

new_size	The requested new size, in bytes
stream	The stream to use for allocation and copy

◆ set_stream()

void rmm::device_buffer::set_stream ( cuda_stream_view stream )

inlinenoexcept

Sets the stream to be used for deallocation.

If no other rmm::device_buffer method that allocates or copies memory is called after this call with a different stream argument, then stream will be used for deallocation in the `rmm::device_buffer destructor. Otherwise, if another rmm::device_buffer method with a stream parameter is called after this, the later stream parameter will be stored and used in the destructor.

◆ shrink_to_fit()

void rmm::device_buffer::shrink_to_fit ( cuda_stream_view stream = cuda_stream_view{} )

inline

Forces the deallocation of unused memory.

Reallocates and copies on stream stream the contents of the device memory allocation to reduce capacity() to size().

If size() == capacity(), no allocations nor copies occur.

Exceptions

rmm::bad_alloc	If creating the new allocation fails
rmm::cuda_error	If the copy from the old to new allocation fails

Parameters

stream The stream on which the allocation and copy are performed

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

device_buffer.hpp

Public Member Functions

Constructor & Destructor Documentation

◆ device_buffer() [1/4]

◆ device_buffer() [2/4]

◆ device_buffer() [3/4]

◆ device_buffer() [4/4]

◆ ~device_buffer()

Member Function Documentation

◆ capacity()

◆ is_empty()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ resize()

◆ set_stream()

◆ shrink_to_fit()