Method execute

3rd/asio-1.24.0/include/asio/impl/io_context.hpp:274–321

template <typename Allocator, uintptr_t Bits>
template <typename Function>
void io_context::basic_executor_type<Allocator, Bits>::execute(
    ASIO_MOVE_ARG(Function) f) const
{
  typedef typename decay<Function>::type function_type;

  // Invoke immediately if the blocking.possibly property is enabled and we are
  // already inside the thread pool.
  if ((bits() & blocking_never) == 0 && context_ptr()->impl_.can_dispatch())
  {
    // Make a local, non-const copy of the function.
    function_type tmp(ASIO_MOVE_CAST(Function)(f));

#if defined(ASIO_HAS_STD_EXCEPTION_PTR) \
  && !defined(ASIO_NO_EXCEPTIONS)
    try
    {
#endif // defined(ASIO_HAS_STD_EXCEPTION_PTR)
       //   && !defined(ASIO_NO_EXCEPTIONS)
      detail::fenced_block b(detail::fenced_block::full);
      asio_handler_invoke_helpers::invoke(tmp, tmp);
      return;
#if defined(ASIO_HAS_STD_EXCEPTION_PTR) \
  && !defined(ASIO_NO_EXCEPTIONS)
    }
    catch (...)
    {
      context_ptr()->impl_.capture_current_exception();
      return;
    }
#endif // defined(ASIO_HAS_STD_EXCEPTION_PTR)
       //   && !defined(ASIO_NO_EXCEPTIONS)
  }

  // Allocate and construct an operation to wrap the function.
  typedef detail::executor_op<function_type, Allocator, detail::operation> op;
  typename op::ptr p = {
      detail::addressof(static_cast<const Allocator&>(*this)),
      op::ptr::allocate(static_cast<const Allocator&>(*this)), 0 };
  p.p = new (p.v) op(ASIO_MOVE_CAST(Function)(f),
      static_cast<const Allocator&>(*this));

  ASIO_HANDLER_CREATION((*context_ptr(), *p.p,
        "io_context", context_ptr(), 0, "execute"));

  context_ptr()->impl_.post_immediate_completion(p.p,
      (bits() & relationship_continuation) != 0);
  p.v = p.p = 0;
}

#if !defined(ASIO_NO_TS_EXECUTORS)
template <typename Allocator, uintptr_t Bits>