trampoline

Performs trampoline execution within the adapted executor, establishing the trampoline from inside that executor's own execution.

template<
    typename Executor,
    typename Blocking = execution::blocking_t::possibly_t,
    typename InlineExceptionHandling = execution::inline_exception_handling_t::propagate_t>
class trampoline

Types

Name	Description
inner_executor_type	The type of the underlying executor.

Member Functions

Name	Description
context	Obtain the underlying execution context.
defer	Request the executor to invoke the given function object.
dispatch	Request the executor to invoke the given function object.
execute	Request the executor to invoke the given function object.
get_inner_executor	Obtain the underlying executor.
max_inline_depth	Obtain the deepest a blocking.possibly execute() made from inside this trampoline's own frame may run immediately rather than queue.
max_trampolined_calls	Obtain the number of calls that may be queued to a trampoline this executor installs.
on_work_finished	Inform the executor that some work is no longer outstanding.
on_work_started	Inform the executor that it has some outstanding work.
operator=	Assignment operator. — Converting assignment operator. — Move assignment operator. — Converting move assignment operator.
post	Request the executor to invoke the given function object.
prefer	Forward a preference to the underlying executor.
query	Forward a query to the underlying executor.
query [static]	Query the current value of the blocking property. — Query the current value of the relationship property. — Query the current value of the inline_exception_handling property.
require	Obtain an executor with the blocking.possibly property. — Obtain an executor with the blocking.never property. — Obtain an executor with the inline_exception_handling.propagate property. — Obtain an executor with the inline_exception_handling.terminate property. — Forward a requirement to the underlying executor. —
running_in_this_thread	Determine whether a trampoline with this executor's identity is running in the current thread.
trampoline [constructor]	Default constructor. — Construct an executor for the specified target executor. — Copy constructor. — Converting copy constructor. — Move constructor. — Converting move constructor.
~trampoline [destructor]	Destructor.

Friends

Name	Description
operator!=	Compare two executors for inequality.
operator==	Compare two executors for equality.

The trampoline class template adapts an existing executor such that:

Posted function objects (or when the blocking property is set to blocking.never) are submitted to the target executor, unless a trampoline with this executor's identity and with sufficient capacity is already installed on the current thread, in which case they are queued on it.
Dispatched function objects (or when blocking is blocking.possibly) are submitted to the target executor if there is already a trampoline with this executor's identity on the current thread, but it has already reached its maximum number of calls. If there is such a trampoline with sufficient capacity, the function object is queued to it. Otherwise the target executor is given a wrapper that installs a new trampoline, and the function object runs within it.

A trampoline's identity is assigned once, when it is constructed directly or via make_trampoline(). This identity is carried through copies, conversions and require/prefer results. The identity is used to determine whether a submitted function object is permitted to join an already-installed trampoline.

Requirements

Header: boost/asio/trampoline.hpp

Convenience header: boost/asio.hpp