summaryrefslogtreecommitdiffstatshomepage
path: root/3rdparty/asio/include/asio/experimental/promise.hpp
diff options
context:
space:
mode:
Diffstat (limited to '3rdparty/asio/include/asio/experimental/promise.hpp')
-rw-r--r--3rdparty/asio/include/asio/experimental/promise.hpp224
1 files changed, 224 insertions, 0 deletions
diff --git a/3rdparty/asio/include/asio/experimental/promise.hpp b/3rdparty/asio/include/asio/experimental/promise.hpp
new file mode 100644
index 00000000000..2bcf66b4e30
--- /dev/null
+++ b/3rdparty/asio/include/asio/experimental/promise.hpp
@@ -0,0 +1,224 @@
+//
+// experimental/promise.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2021-2023 Klemens D. Morgenstern
+// (klemens dot morgenstern at gmx dot net)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_EXPERIMENTAL_PROMISE_HPP
+#define ASIO_EXPERIMENTAL_PROMISE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/any_io_executor.hpp"
+#include "asio/associated_cancellation_slot.hpp"
+#include "asio/associated_executor.hpp"
+#include "asio/bind_executor.hpp"
+#include "asio/cancellation_signal.hpp"
+#include "asio/dispatch.hpp"
+#include "asio/experimental/impl/promise.hpp"
+#include "asio/post.hpp"
+
+#include <algorithm>
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace experimental {
+
+template <typename T>
+struct is_promise : std::false_type {};
+
+template <typename ... Ts>
+struct is_promise<promise<Ts...>> : std::true_type {};
+
+template <typename T>
+constexpr bool is_promise_v = is_promise<T>::value;
+
+template <typename ... Ts>
+struct promise_value_type
+{
+ using type = std::tuple<Ts...>;
+};
+
+template <typename T>
+struct promise_value_type<T>
+{
+ using type = T;
+};
+
+template <>
+struct promise_value_type<>
+{
+ using type = std::tuple<>;
+};
+
+#if defined(GENERATING_DOCUMENTATION)
+/// A disposable handle for an eager operation.
+/**
+ * @tparam Signature The signature of the operation.
+ *
+ * @tparam Executor The executor to be used by the promise (taken from the
+ * operation).
+ *
+ * @tparam Allocator The allocator used for the promise. Can be set through
+ * use_allocator.
+ *
+ * A promise can be used to initiate an asynchronous option that can be
+ * completed later. If the promise gets destroyed before completion, the
+ * operation gets a cancel signal and the result is ignored.
+ *
+ * A promise fulfills the requirements of async_operation.
+ *
+ * @par Examples
+ * Reading and writing from one coroutine.
+ * @code
+ * awaitable<void> read_write_some(asio::ip::tcp::socket & sock,
+ * asio::mutable_buffer read_buf, asio::const_buffer to_write)
+ * {
+ * auto p = asio::async_read(read_buf, asio::use_awaitable);
+ * co_await asio::async_write_some(to_write, asio::deferred);
+ * co_await p;
+ * }
+ * @endcode
+ */
+template<typename Signature = void(),
+ typename Executor = asio::any_io_executor,
+ typename Allocator = std::allocator<void>>
+struct promise
+#else
+template <typename ... Ts, typename Executor, typename Allocator>
+struct promise<void(Ts...), Executor, Allocator>
+#endif // defined(GENERATING_DOCUMENTATION)
+{
+ /// The value that's returned by the promise.
+ using value_type = typename promise_value_type<Ts...>::type;
+
+ /// Cancel the promise. Usually done through the destructor.
+ void cancel(cancellation_type level = cancellation_type::all)
+ {
+ if (impl_ && !impl_->done)
+ {
+ asio::dispatch(impl_->executor,
+ [level, impl = impl_]{ impl->cancel.emit(level); });
+ }
+ }
+
+ /// Check if the promise is completed already.
+ bool completed() const noexcept
+ {
+ return impl_ && impl_->done;
+ }
+
+ /// Wait for the promise to become ready.
+ template <ASIO_COMPLETION_TOKEN_FOR(void(Ts...)) CompletionToken>
+ inline ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void(Ts...))
+ operator()(CompletionToken&& token)
+ {
+ assert(impl_);
+
+ return async_initiate<CompletionToken, void(Ts...)>(
+ initiate_async_wait{impl_}, token);
+ }
+
+ promise() = delete;
+ promise(const promise& ) = delete;
+ promise(promise&& ) noexcept = default;
+
+ /// Destruct the promise and cancel the operation.
+ /**
+ * It is safe to destruct a promise of a promise that didn't complete.
+ */
+ ~promise() { cancel(); }
+
+
+private:
+#if !defined(GENERATING_DOCUMENTATION)
+ template <typename, typename, typename> friend struct promise;
+ friend struct detail::promise_handler<void(Ts...), Executor, Allocator>;
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+ std::shared_ptr<detail::promise_impl<
+ void(Ts...), Executor, Allocator>> impl_;
+
+ promise(
+ std::shared_ptr<detail::promise_impl<
+ void(Ts...), Executor, Allocator>> impl)
+ : impl_(impl)
+ {
+ }
+
+ struct initiate_async_wait
+ {
+ std::shared_ptr<detail::promise_impl<
+ void(Ts...), Executor, Allocator>> self_;
+
+ template <typename WaitHandler>
+ void operator()(WaitHandler&& handler) const
+ {
+ const auto alloc = get_associated_allocator(
+ handler, self_->get_allocator());
+
+ auto cancel = get_associated_cancellation_slot(handler);
+
+ if (self_->done)
+ {
+ auto exec = asio::get_associated_executor(
+ handler, self_->get_executor());
+
+ asio::post(exec,
+ [self = std::move(self_),
+ handler = std::forward<WaitHandler>(handler)]() mutable
+ {
+ self->apply(std::move(handler));
+ });
+ }
+ else
+ {
+ if (cancel.is_connected())
+ {
+ struct cancel_handler
+ {
+ std::weak_ptr<detail::promise_impl<
+ void(Ts...), Executor, Allocator>> self;
+
+ cancel_handler(
+ std::weak_ptr<detail::promise_impl<
+ void(Ts...), Executor, Allocator>> self)
+ : self(std::move(self))
+ {
+ }
+
+ void operator()(cancellation_type level) const
+ {
+ if (auto p = self.lock())
+ {
+ p->cancel.emit(level);
+ p->cancel_();
+ }
+ }
+ };
+ cancel.template emplace<cancel_handler>(self_);
+ }
+
+ self_->set_completion(alloc, std::forward<WaitHandler>(handler));
+ }
+ }
+ };
+};
+
+} // namespace experimental
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_EXPERIMENTAL_PROMISE_HPP