kvikio::StreamFuture Class Reference

Future of an asynchronous IO operation. More...

#include <stream.hpp>

Public Member Functions
	StreamFuture (void *devPtr_base, std::size_t size, off_t file_offset, off_t devPtr_offset, CUstream stream)
	StreamFuture (const StreamFuture &)=delete
	StreamFuture support move semantic but isn't copyable.
StreamFuture &	operator= (StreamFuture &o)=delete
	StreamFuture (StreamFuture &&o) noexcept
StreamFuture &	operator= (StreamFuture &&o) noexcept
std::tuple< void *, std::size_t *, off_t *, off_t *, ssize_t *, CUstream >	get_args () const
	Return the arguments of the future call. More...
std::size_t	check_bytes_done ()
	Return the number of bytes read or written by the future operation. More...
	~StreamFuture () noexcept
	Free the by-value arguments and make sure the associated CUDA stream has been synchronized.

Detailed Description

Future of an asynchronous IO operation.

This class shouldn't be used directly, instead some stream operations such as FileHandle.read_async and FileHandle.write_async returns an instance of this class. Use .check_bytes_done() to synchronize the associated CUDA stream and return the number of bytes read or written by the operation.

The goal of this class is twofold:

• Have read_async and write_async return an object that clearly associates the function arguments with the CUDA stream used. This is useful because the current validity of the arguments depends on the stream.
• Support of by-value arguments. In many cases, a user will use read_async and write_async like most other asynchronous CUDA functions that take by-value arguments.

To support by-value arguments, we allocate the arguments on the heap (malloc ArgByVal) and have the by-reference arguments points into ArgByVal. This way, the read_async and write_async can call .get_args() to get the by-reference arguments required by cuFile's stream API.

Definition at line 47 of file stream.hpp.

Member Function Documentation

check_bytes_done()

std::size_t kvikio::StreamFuture::check_bytes_done ( )

inline

Return the number of bytes read or written by the future operation.

Synchronize the associated CUDA stream.

Returns

Number of bytes read or written by the future operation.

Definition at line 124 of file stream.hpp.

get_args()

std::tuple<void*, std::size_t*, off_t*, off_t*, ssize_t*, CUstream> kvikio::StreamFuture::get_args ( ) const

inline

Return the arguments of the future call.

Returns

Tuple of the arguments in the order matching FileHandle.read() and FileHandle.write()

Definition at line 104 of file stream.hpp.

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

• stream.hpp