folly::coro::Task< T > Class Template Reference

#include <Task.h>

Public Types
using	promise_type = detail::TaskPromise< T >

Public Member Functions
	Task (const Task &t)=delete
	Task (Task &&t) noexcept
	~Task ()
Task &	operator= (Task t) noexcept
void	swap (Task &t) noexcept
FOLLY_NODISCARD TaskWithExecutor< T >	scheduleOn (Executor *executor)&&noexcept

Private Types
using	handle_t = std::experimental::coroutine_handle< promise_type >

Private Member Functions
	Task (handle_t coro) noexcept

Private Attributes
handle_t	coro_

Friends
class	detail::TaskPromiseBase
class	detail::TaskPromise< T >

Detailed Description

template<typename T>
class folly::coro::Task< T >

Represents an allocated, but not-started coroutine, which is not yet been bound to an executor.

You can only co_await a Task from within another Task, in which case it is implicitly bound to the same executor as the parent Task.

Alternatively, you can explicitly provide an executor by calling the task.scheduleOn(executor) method, which will return a new not-yet-started TaskWithExecutor that can be co_awaited anywhere and that will automatically schedule the coroutine to start executing on the bound executor when it is co_awaited.

Within the body of a Task's coroutine, it will ensure that it always executes on the bound executor by implicitly transforming every 'co_await expr' expression into `co_await co_viaIfAsync(boundExecutor, expr)' to ensure that the coroutine always resumes on the executor.

Definition at line 38 of file Task.h.

Member Typedef Documentation

template<typename T>

using folly::coro::Task< T >::handle_t = std::experimental::coroutine_handle<promise_type>

private

Definition at line 267 of file Task.h.

template<typename T>

using folly::coro::Task< T >::promise_type = detail::TaskPromise<T>

Definition at line 264 of file Task.h.

Constructor & Destructor Documentation

template<typename T>

folly::coro::Task< T >::Task ( const Task< T > &  t )

delete

template<typename T>

folly::coro::Task< T >::Task ( Task< T > &&  t )

inlinenoexcept

Definition at line 272 of file Task.h.

: coro_(std::exchange(t.coro_, {})) {}

template<typename T>

folly::coro::Task< T >::~Task ( )

inline

Definition at line 274 of file Task.h.

          {
    if (coro_) {
      coro_.destroy();
    }
  }

template<typename T>

folly::coro::Task< T >::Task ( handle_t  coro )

inlineprivatenoexcept

Definition at line 303 of file Task.h.

: coro_(coro) {}

Member Function Documentation

template<typename T>

Task& folly::coro::Task< T >::operator= ( Task< T >  t )

inlinenoexcept

Definition at line 280 of file Task.h.

References folly::swap(), and folly::pushmi::detail::t.

                                   {
    swap(t);
    return *this;
  }

template<typename T>

FOLLY_NODISCARD TaskWithExecutor<T> folly::coro::Task< T >::scheduleOn ( Executor *  executor )

inlinenoexcept

Specify the executor that this task should execute on.

Returns a new task that when co_awaited will launch execution of this task on the specified executor.

Definition at line 294 of file Task.h.

References folly::exchange(), and folly::pushmi::executor.

                                                                 {
    coro_.promise().executor_ = executor;
    return TaskWithExecutor<T>{std::exchange(coro_, {})};
  }

template<typename T>

void folly::coro::Task< T >::swap ( Task< T > &  t )

inlinenoexcept

Definition at line 285 of file Task.h.

References FOLLY_NODISCARD, folly::f14::swap(), and folly::pushmi::detail::t.

                              {
    std::swap(coro_, t.coro_);
  }

Friends And Related Function Documentation

template<typename T>

friend class detail::TaskPromise< T >

friend

Definition at line 301 of file Task.h.

template<typename T>

friend class detail::TaskPromiseBase

friend

Definition at line 300 of file Task.h.

Member Data Documentation

template<typename T>

handle_t folly::coro::Task< T >::coro_

private

Definition at line 305 of file Task.h.

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

• proxygen/folly/folly/experimental/coro/Task.h