Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Send a websocket ping control frame asynchronously.
template< class PingHandler = net::default_completion_token_t<executor_type>> DEDUCED async_ping( ping_data const& payload, PingHandler&& handler = net::default_completion_token_t< executor_type >{});
This function is used to asynchronously send a ping frame, which usually elicits an automatic pong control frame response from the peer.
The algorithm, known as a composed asynchronous operation,
is implemented in terms of calls to the next layer's async_write_some
function. The program must ensure that no other calls to ping, pong, async_ping, or async_pong are performed until
this operation completes.
If a close frame is sent or received before the ping frame is sent, the
error received by this completion handler will be net::error::operation_aborted.
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Name |
Description |
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The payload of the ping message, which may be empty. The implementation will not access the contents of this object after the initiating function returns. |
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The completion handler to invoke when the operation completes. The implementation takes ownership of the handler by performing a decay-copy. The equivalent function signature of the handler must be: void handler( error_code const & ec // Result of operation );
If the handler has an associated immediate executor, an immediate
completion will be dispatched to it. Otherwise, the handler will
not be invoked from within this function. Invocation of the handler
will be performed by dispatching to the immediate executor. If
no immediate executor is specified, this is equivalent to using
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This asynchronous operation supports cancellation for the following net::cancellation_type values:
net::cancellation_type::terminal
net::cancellation_type::total
totalcancellation succeeds
if the operation is suspended due to ongoing control operations such as
a ping/pong.
terminal cancellation succeeds
when supported by the underlying stream.
terminal cancellation leaves
the stream in an undefined state, so that only closing it is guaranteed
to succeed.