Re: [Boost-users] [Boost.Asio] defer, dispatch and post differences?

Subject: Re: [Boost-users] [Boost.Asio] defer, dispatch and post differences?
From: Richard Hodges (hodges.r_at_[hidden])
Date: 2018-01-05 16:09:37

Aha: 13.2.2 table 4:

x1.defer(std::move(f), a)

Effects: Creates an object f1 initialized with DECAY_COPY(std::forward(f))
in the current thread of execution. Calls f1() at most once. The executor
shall not block forward progress of the caller pending completion of f1().
The executor should not begin f1’s progress before the call to defer
completes. [ Note: One use of defer is to convey the intention of the
caller that f1 is a continuation of the current call context. The executor
may use this information to optimize or otherwise adjust the way in which
f1 is invoked. — end note ] Executor implementations should use the
supplied allocator to allocate any memory required to store the function
object. Prior to invoking the function object, the executor shall
deallocate any memory allocated. [ Note: Executors defined in this
Technical Specification always use the supplied allocator unless otherwise
specified. — end note ] Synchronization: The invocation of defer
synchronizes with (C++ 2014 [intro.multithread]) the invocation of f1.

On 5 January 2018 at 17:02, Klaim - Joël Lamotte via Boost-users <
boost-users_at_[hidden]> wrote:

>
>
> On 5 January 2018 at 16:55, Vinnie Falco via Boost-users <
> boost-users_at_[hidden]> wrote:
>
>> On Fri, Jan 5, 2018 at 7:53 AM, Richard Hodges via Boost-users
>> <boost-users_at_[hidden]> wrote:
>> > Perhaps defer does a post
>> > unless the handler is a continuation? I think that would make sense.
>>
>> And how would it know if the handler is a continuation?
>>
>>
> I think defer imply that the provided handler is a continuation.
> There are similar mechanisms proposed in the Executor proposal:
> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0761r1.pdf
> (see page 6).
>
>
> Joël Lamotte
>
>
>
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>