Add support for immediate executors

Summary: related to T13767

Reviewers: ivica

Reviewed By: ivica

Subscribers: iljazovic, miljen

Differential Revision: https://repo.mireo.local/D30809

include/async_mqtt5/detail/cancellable_handler.hpp

@@ -11,8 +11,9 @@
 #include <boost/asio/associated_allocator.hpp>
 #include <boost/asio/associated_executor.hpp>
 #include <boost/asio/associated_cancellation_slot.hpp>
+#include <boost/asio/associated_immediate_executor.hpp>
 #include <boost/asio/cancellation_state.hpp>
-#include <boost/asio/post.hpp>
+#include <boost/asio/dispatch.hpp>
 #include <boost/asio/prepend.hpp>
 
 #include <async_mqtt5/detail/async_traits.hpp>
@@ -41,11 +42,6 @@ public:
 	cancellable_handler(cancellable_handler&&) = default;
 	cancellable_handler(const cancellable_handler&) = delete;
 
-	using executor_type = tracking_type<Handler, Executor>;
-	executor_type get_executor() const noexcept {
-		return _handler_ex;
-	}
-
 	using allocator_type = asio::associated_allocator_t<Handler>;
 	allocator_type get_allocator() const noexcept {
 		return asio::get_associated_allocator(_handler);
@@ -56,7 +52,20 @@ public:
 		return _cancellation_state.slot();
 	}
 
-	asio::cancellation_type_t cancelled() const noexcept {
+	using executor_type = tracking_type<Handler, Executor>;
+	executor_type get_executor() const noexcept {
+		return _handler_ex;
+	}
+	
+	using immediate_executor_type =
+		asio::associated_immediate_executor_t<Handler, Executor>;
+	immediate_executor_type get_immediate_executor() const noexcept {
+		// get_associated_immediate_executor will require asio::execution::blocking.never
+		// on the default executor.
+		return asio::get_associated_immediate_executor(_handler, _executor);
+	}
+
+	asio::cancellation_type_t cancelled() const {
 		return _cancellation_state.cancelled();
 	}
 
@@ -67,10 +76,11 @@ public:
 	}
 
 	template <typename... Args>
-	void complete_post(Args&&... args) {
+	void complete_immediate(Args&&... args) {
 		asio::get_associated_cancellation_slot(_handler).clear();
-		asio::post(
-			_executor,
+		auto ex = get_immediate_executor();
+		asio::dispatch(
+			ex,
 			asio::prepend(std::move(_handler), std::forward<Args>(args)...)
 		);
 	}

include/async_mqtt5/impl/disconnect_op.hpp

@@ -8,6 +8,9 @@
 #ifndef ASYNC_MQTT5_DISCONNECT_OP_HPP
 #define ASYNC_MQTT5_DISCONNECT_OP_HPP
 
+#include <boost/asio/associated_allocator.hpp>
+#include <boost/asio/associated_executor.hpp>
+#include <boost/asio/associated_cancellation_slot.hpp>
 #include <boost/asio/consign.hpp>
 #include <boost/asio/deferred.hpp>
 #include <boost/asio/prepend.hpp>
@@ -65,20 +68,23 @@ public:
 	disconnect_op(disconnect_op&&) = default;
 	disconnect_op(const disconnect_op&) = delete;
 
-	using executor_type = asio::associated_executor_t<handler_type>;
-	executor_type get_executor() const noexcept {
-		return asio::get_associated_executor(_handler);
-	}
+	disconnect_op& operator=(disconnect_op&&) noexcept = default;
+	disconnect_op& operator=(const disconnect_op&) = delete;
 
 	using allocator_type = asio::associated_allocator_t<handler_type>;
 	allocator_type get_allocator() const noexcept {
 		return asio::get_associated_allocator(_handler);
 	}
 
+	using executor_type = asio::associated_executor_t<handler_type>;
+	executor_type get_executor() const noexcept {
+		return asio::get_associated_executor(_handler);
+	}
+
 	void perform() {
 		error_code ec = validate_disconnect(_context.props);
 		if (ec)
-			return complete_post(ec);
+			return complete_immediate(ec);
 
 		auto disconnect = control_packet<allocator_type>::of(
 			no_pid, get_allocator(),
@@ -162,8 +168,8 @@ private:
 		_handler.complete(ec);
 	}
 
-	void complete_post(error_code ec) {
-		_handler.complete_post(ec);
+	void complete_immediate(error_code ec) {
+		_handler.complete_immediate(ec);
 	}
 };
 
@@ -194,10 +200,8 @@ public:
 	terminal_disconnect_op(terminal_disconnect_op&&) = default;
 	terminal_disconnect_op(const terminal_disconnect_op&) = delete;
 
-	using executor_type = asio::associated_executor_t<handler_type>;
-	executor_type get_executor() const noexcept {
-		return asio::get_associated_executor(_handler);
-	}
+	terminal_disconnect_op& operator=(terminal_disconnect_op&&) noexcept = default;
+	terminal_disconnect_op& operator=(const terminal_disconnect_op&) = delete;
 
 	using allocator_type = asio::associated_allocator_t<handler_type>;
 	allocator_type get_allocator() const noexcept {
@@ -209,6 +213,11 @@ public:
 		return asio::get_associated_cancellation_slot(_handler);
 	}
 
+	using executor_type = asio::associated_executor_t<handler_type>;
+	executor_type get_executor() const noexcept {
+		return asio::get_associated_executor(_handler);
+	}
+
 	template <typename DisconnectContext>
 	void perform(DisconnectContext&& context) {
 		namespace asioex = boost::asio::experimental;

include/async_mqtt5/impl/publish_send_op.hpp

@@ -8,6 +8,8 @@
 #ifndef ASYNC_MQTT5_PUBLISH_SEND_OP_HPP
 #define ASYNC_MQTT5_PUBLISH_SEND_OP_HPP
 
+#include <boost/asio/associated_allocator.hpp>
+#include <boost/asio/associated_executor.hpp>
 #include <boost/asio/detached.hpp>
 #include <boost/asio/prepend.hpp>
 
@@ -86,19 +88,22 @@ public:
 			});
 	}
 
-	publish_send_op(publish_send_op&& other) = default;
+	publish_send_op(publish_send_op&&) = default;
 	publish_send_op(const publish_send_op&) = delete;
 
-	using executor_type = asio::associated_executor_t<handler_type>;
-	executor_type get_executor() const noexcept {
-		return asio::get_associated_executor(_handler);
-	}
+	publish_send_op& operator=(publish_send_op&&) noexcept = default;
+	publish_send_op& operator=(const publish_send_op&) = delete;
 
 	using allocator_type = asio::associated_allocator_t<handler_type>;
 	allocator_type get_allocator() const noexcept {
 		return asio::get_associated_allocator(_handler);
 	}
 
+	using executor_type = asio::associated_executor_t<handler_type>;
+	executor_type get_executor() const noexcept {
+		return asio::get_associated_executor(_handler);
+	}
+
 	void perform(
 		std::string topic, std::string payload,
 		retain_e retain, const publish_props& props
@@ -107,12 +112,12 @@ public:
 		if constexpr (qos_type != qos_e::at_most_once) {
 			packet_id = _svc_ptr->allocate_pid();
 			if (packet_id == 0)
-				return complete_post(client::error::pid_overrun, packet_id);
+				return complete_immediate(client::error::pid_overrun, packet_id);
 		}
 
 		auto ec = validate_publish(topic, payload, retain, props);
 		if (ec)
-			return complete_post(ec, packet_id);
+			return complete_immediate(ec, packet_id);
 
 		_serial_num = _svc_ptr->next_serial_num();
 
@@ -126,7 +131,7 @@ public:
 		auto max_packet_size = _svc_ptr->connack_property(prop::maximum_packet_size)
 				.value_or(default_max_send_size);
 		if (publish.size() > max_packet_size)
-			return complete_post(client::error::packet_too_large, packet_id);
+			return complete_immediate(client::error::packet_too_large, packet_id);
 
 		send_publish(std::move(publish));
 	}
@@ -429,8 +434,8 @@ private:
 		qos_e q = qos_type,
 		std::enable_if_t<q == qos_e::at_most_once, bool> = true
 	>
-	void complete_post(error_code ec, uint16_t) {
-		_handler.complete_post(ec);
+	void complete_immediate(error_code ec, uint16_t) {
+		_handler.complete_immediate(ec);
 	}
 
 	template <
@@ -457,10 +462,10 @@ private:
 			bool
 		> = true
 	>
-	void complete_post(error_code ec, uint16_t packet_id) {
+	void complete_immediate(error_code ec, uint16_t packet_id) {
 		if (packet_id != 0)
 			_svc_ptr->free_pid(packet_id, false);
-		_handler.complete_post(ec, reason_codes::empty, Props {});
+		_handler.complete_immediate(ec, reason_codes::empty, Props {});
 	}
 };
 

include/async_mqtt5/impl/subscribe_op.hpp

@@ -11,6 +11,8 @@
 #include <algorithm>
 #include <cstdint>
 
+#include <boost/asio/associated_allocator.hpp>
+#include <boost/asio/associated_executor.hpp>
 #include <boost/asio/detached.hpp>
 
 #include <async_mqtt5/error.hpp>
@@ -66,16 +68,19 @@ public:
 	subscribe_op(subscribe_op&&) = default;
 	subscribe_op(const subscribe_op&) = delete;
 
-	using executor_type = asio::associated_executor_t<handler_type>;
-	executor_type get_executor() const noexcept {
-		return asio::get_associated_executor(_handler);
-	}
+	subscribe_op& operator=(subscribe_op&&) noexcept = default;
+	subscribe_op& operator=(const subscribe_op&) = delete;
 
 	using allocator_type = asio::associated_allocator_t<handler_type>;
 	allocator_type get_allocator() const noexcept {
 		return asio::get_associated_allocator(_handler);
 	}
 
+	using executor_type = asio::associated_executor_t<handler_type>;
+	executor_type get_executor() const noexcept {
+		return asio::get_associated_executor(_handler);
+	}
+
 	void perform(
 		const std::vector<subscribe_topic>& topics,
 		const subscribe_props& props
@@ -84,14 +89,14 @@ public:
 
 		uint16_t packet_id = _svc_ptr->allocate_pid();
 		if (packet_id == 0)
-			return complete_post(client::error::pid_overrun, packet_id);
+			return complete_immediate(client::error::pid_overrun, packet_id);
 
 		if (_num_topics == 0)
-			return complete_post(client::error::invalid_topic, packet_id);
+			return complete_immediate(client::error::invalid_topic, packet_id);
 
 		auto ec = validate_subscribe(topics, props);
 		if (ec)
-			return complete_post(ec, packet_id);
+			return complete_immediate(ec, packet_id);
 
 		auto subscribe = control_packet<allocator_type>::of(
 			with_pid, get_allocator(),
@@ -102,7 +107,7 @@ public:
 		auto max_packet_size = _svc_ptr->connack_property(prop::maximum_packet_size)
 				.value_or(default_max_send_size);
 		if (subscribe.size() > max_packet_size)
-			return complete_post(client::error::packet_too_large, packet_id);
+			return complete_immediate(client::error::packet_too_large, packet_id);
 
 		send_subscribe(std::move(subscribe));
 	}
@@ -267,10 +272,10 @@ private:
 		);
 	}
 
-	void complete_post(error_code ec, uint16_t packet_id) {
+	void complete_immediate(error_code ec, uint16_t packet_id) {
 		if (packet_id != 0)
 			_svc_ptr->free_pid(packet_id);
-		_handler.complete_post(
+		_handler.complete_immediate(
 			ec, std::vector<reason_code>(_num_topics, reason_codes::empty),
 			suback_props {}
 		);

include/async_mqtt5/impl/unsubscribe_op.hpp

@@ -9,6 +9,7 @@
 #define ASYNC_MQTT5_UNSUBSCRIBE_OP_HPP
 
 #include <boost/asio/associated_allocator.hpp>
+#include <boost/asio/associated_executor.hpp>
 #include <boost/asio/detached.hpp>
 
 #include <async_mqtt5/error.hpp>
@@ -61,16 +62,19 @@ public:
 	unsubscribe_op(unsubscribe_op&&) = default;
 	unsubscribe_op(const unsubscribe_op&) = delete;
 
-	using executor_type = asio::associated_executor_t<handler_type>;
-	executor_type get_executor() const noexcept {
-		return asio::get_associated_executor(_handler);
-	}
+	unsubscribe_op& operator=(unsubscribe_op&&) noexcept = default;
+	unsubscribe_op& operator=(const unsubscribe_op&) = delete;
 
 	using allocator_type = asio::associated_allocator_t<handler_type>;
 	allocator_type get_allocator() const noexcept {
 		return asio::get_associated_allocator(_handler);
 	}
 
+	using executor_type = asio::associated_executor_t<handler_type>;
+	executor_type get_executor() const noexcept {
+		return asio::get_associated_executor(_handler);
+	}
+
 	void perform(
 		const std::vector<std::string>& topics,
 		const unsubscribe_props& props
@@ -79,14 +83,14 @@ public:
 
 		uint16_t packet_id = _svc_ptr->allocate_pid();
 		if (packet_id == 0)
-			return complete_post(client::error::pid_overrun, packet_id);
+			return complete_immediate(client::error::pid_overrun, packet_id);
 
 		if (_num_topics == 0)
-			return complete_post(client::error::invalid_topic, packet_id);
+			return complete_immediate(client::error::invalid_topic, packet_id);
 
 		auto ec = validate_unsubscribe(topics, props);
 		if (ec)
-			return complete_post(ec, packet_id);
+			return complete_immediate(ec, packet_id);
 
 		auto unsubscribe = control_packet<allocator_type>::of(
 			with_pid, get_allocator(),
@@ -97,7 +101,7 @@ public:
 		auto max_packet_size = _svc_ptr->connack_property(prop::maximum_packet_size)
 				.value_or(default_max_send_size);
 		if (unsubscribe.size() > max_packet_size)
-			return complete_post(client::error::packet_too_large, packet_id);
+			return complete_immediate(client::error::packet_too_large, packet_id);
 
 		send_unsubscribe(std::move(unsubscribe));
 	}
@@ -212,10 +216,10 @@ private:
 		);
 	}
 
-	void complete_post(error_code ec, uint16_t packet_id) {
+	void complete_immediate(error_code ec, uint16_t packet_id) {
 		if (packet_id != 0)
 			_svc_ptr->free_pid(packet_id);
-		_handler.complete_post(
+		_handler.complete_immediate(
 			ec, std::vector<reason_code>(_num_topics, reason_codes::empty),
 			unsuback_props {}
 		);