cuda::stream Namespace Reference

Definitions and functionality related to CUDA streams (not including the device wrapper type stream_t itself) More...

Typedefs
using	handle_t = CUstream
	The CUDA driver's raw handle for streams.
using	priority_t = int
	CUDA streams have a scheduling priority, with lower values meaning higher priority. More...
using	callback_t = CUstreamCallback
	The CUDA driver's raw handle for a host-side callback function.

Enumerations
enum	: bool {   implicitly_synchronizes_with_default_stream = true,   no_implicit_synchronization_with_default_stream = false,   sync = implicitly_synchronizes_with_default_stream,   async = no_implicit_synchronization_with_default_stream,   blocking = sync,   nonblocking = async }
enum	wait_condition_t : unsigned {   greater_or_equal_to = CU_STREAM_WAIT_VALUE_GEQ,   geq = CU_STREAM_WAIT_VALUE_GEQ,   equality = CU_STREAM_WAIT_VALUE_EQ,   equals = CU_STREAM_WAIT_VALUE_EQ,   nonzero_after_applying_bitmask = CU_STREAM_WAIT_VALUE_AND,   one_bits_overlap = CU_STREAM_WAIT_VALUE_AND,   bitwise_and = CU_STREAM_WAIT_VALUE_AND,   zero_bits_overlap = CU_STREAM_WAIT_VALUE_NOR,   bitwise_nor = CU_STREAM_WAIT_VALUE_NOR }
	Kinds of conditions to apply to a value in GPU global memory when waiting on that value, i.e. More...
enum	: priority_t { default_priority = 0 }

Functions
stream_t	create (const device_t &device, bool synchronizes_with_default_stream, priority_t priority=stream::default_priority)
	Create a new stream (= queue) in the primary execution context of a CUDA device. More...
stream_t	create (const context_t &context, bool synchronizes_with_default_stream, priority_t priority=stream::default_priority, bool hold_pc_refcount_unit=false)
	Create a new stream (= queue) in a CUDA execution context. More...
stream_t	wrap (device::id_t device_id, context::handle_t context_handle, handle_t stream_handle, bool take_ownership=false, bool hold_pc_refcount_unit=false) noexcept
	Wrap an existing stream in a stream_t instance. More...

Variables
const stream::handle_t	default_stream_handle = nullptr
	The CUDA runtime provides a default stream on which work is scheduled when no stream is specified; for those API calls where you need to specify the relevant stream's ID, and want to specify the default, this is what you use.

Detailed Description

Definitions and functionality related to CUDA streams (not including the device wrapper type stream_t itself)

Typedef Documentation

priority_t

using cuda::stream::priority_t = typedef int

CUDA streams have a scheduling priority, with lower values meaning higher priority.

The types represents a larger range of values than those actually used; they can be obtained by device_t::stream_priority_range() .

Enumeration Type Documentation

anonymous enum

anonymous enum : priority_t

Enumerator
default_priority	the scheduling priority of a stream created without specifying any other priority value

wait_condition_t

enum cuda::stream::wait_condition_t : unsigned

Kinds of conditions to apply to a value in GPU global memory when waiting on that value, i.e.

on what condition to stop waiting.

Function Documentation

create() [1/2]

stream_t cuda::stream::create ( const device_t &  device, bool  synchronizes_with_default_stream, priority_t  priority = stream::default_priority  )

inline

Create a new stream (= queue) in the primary execution context of a CUDA device.

Parameters

device	the device on which a stream is to be created
synchronizes_with_default_stream	if true, no work on this stream will execute concurrently with work from the default stream (stream 0)
priority	priority of tasks on the stream, relative to other streams, for execution scheduling; lower numbers represent higher properties; each device has a range of priorities, which can be obtained using device_t::stream_priority_range()

Returns

The newly-created stream

create() [2/2]

stream_t cuda::stream::create ( const context_t &  context, bool  synchronizes_with_default_stream, priority_t  priority = stream::default_priority, bool  hold_pc_refcount_unit = false  )

inline

Create a new stream (= queue) in a CUDA execution context.

Parameters

context	the execution context in which to create the stream
synchronizes_with_default_stream	if true, no work on this stream will execute concurrently with work from the default stream (stream 0)
priority	priority of tasks on the stream, relative to other streams, for execution scheduling; lower numbers represent higher properties; each device has a range of priorities, which can be obtained using device_t::stream_priority_range()
hold_pc_refcount_unit	when the stream's context is a device's primary context, this controls whether that context must be kept active while the steam continues to exist

Returns

The newly-created stream

wrap()

stream_t cuda::stream::wrap ( device::id_t  device_id, context::handle_t  context_handle, stream::handle_t  stream_handle, bool  take_ownership = false, bool  hold_pc_refcount_unit = false  )

inlinenoexcept

Wrap an existing stream in a stream_t instance.

Note

This is a named constructor idiom, existing of direct access to the ctor of the same signature, to emphasize that a new stream is not created.

Parameters

device_id	ID of the device for which the stream is defined
context_handle	handle of the context in which the stream was created
stream_handle	handle of the pre-existing stream
take_ownership	When set to false, the stream will not be destroyed along with the wrapper; use this setting when temporarily working with a stream existing irrespective of the current context and outlasting it. When set to true, the proxy class will act as it does usually, destroying the stream when being destructed itself.
hold_pc_refcount_unit	when the stream's context is a device's primary context, this controls whether that context must be kept active while the stream continues to exist

Returns

an instance of the stream proxy class, with the specified device-stream combination.