uORB: introduce SubscriptionMultiArray for working with multi-instances

src/modules/uORB/CMakeLists.txt

@@ -49,6 +49,7 @@ if(NOT PX4_BOARD MATCHES "px4_io") # TODO: fix this hack (move uORB to platform
 			Subscription.hpp
 			SubscriptionCallback.hpp
 			SubscriptionInterval.hpp
+			SubscriptionMultiArray.hpp
 			uORB.cpp
 			uORB.h
 			uORBCommon.hpp

src/modules/uORB/Subscription.hpp

@@ -112,7 +112,7 @@ public:
 
 	/**
 	 * Check if there is a new update.
-	 * */
+	 */
 	bool updated() { return advertised() && (_node->published_message_count() != _last_generation); }
 
 	/**

src/modules/uORB/SubscriptionInterval.hpp

@@ -86,6 +86,7 @@ public:
 	~SubscriptionInterval() = default;
 
 	bool subscribe() { return _subscription.subscribe(); }
+	void unsubscribe() { _subscription.unsubscribe(); }
 
 	bool advertised() { return _subscription.advertised(); }
 

src/modules/uORB/SubscriptionMultiArray.hpp

@@ -0,0 +1,128 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2020 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file SubscriptionMultiArray.hpp
+ *
+ */
+
+#pragma once
+
+#include <uORB/uORB.h>
+
+#include <px4_platform_common/defines.h>
+#include <lib/mathlib/mathlib.h>
+
+#include "SubscriptionInterval.hpp"
+
+namespace uORB
+{
+
+/**
+ * An array of uORB::Subscriptions of the same topic
+ */
+template<typename T, uint8_t SIZE = ORB_MULTI_MAX_INSTANCES>
+class SubscriptionMultiArray
+{
+public:
+	static_assert(SIZE <= ORB_MULTI_MAX_INSTANCES, "size must be <= uORB max instances");
+
+	static constexpr uint8_t size() { return SIZE; }
+
+	/**
+	 * Constructor
+	 *
+	 * @param id The uORB ORB_ID enum for the topic.
+	 */
+	explicit SubscriptionMultiArray(ORB_ID id)
+	{
+		for (uint8_t i = 0; i < SIZE; i++) {
+			_subscriptions[i] = SubscriptionInterval{id, i};
+			_subscriptions[i].subscribe();
+		}
+	}
+
+	~SubscriptionMultiArray() = default;
+
+	SubscriptionInterval &operator [](int i) { return _subscriptions[i]; }
+	const SubscriptionInterval &operator [](int i) const { return _subscriptions[i]; }
+
+	SubscriptionInterval *begin() { return &_subscriptions[0]; }
+	SubscriptionInterval *end() { return &_subscriptions[SIZE - 1]; }
+
+	const SubscriptionInterval *begin() const { return &_subscriptions[0]; }
+	const SubscriptionInterval *end() const { return &_subscriptions[SIZE - 1]; }
+
+	// true if any instance is advertised
+	bool advertised()
+	{
+		for (auto &s : _subscriptions) {
+			if (s.advertised()) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	// return the number of instances currently advertised
+	uint8_t advertised_count()
+	{
+		uint8_t count = 0;
+
+		for (auto &s : _subscriptions) {
+			if (s.advertised()) {
+				count++;
+			}
+		}
+
+		return count;
+	}
+
+	// true if any instance is updated
+	bool updated()
+	{
+		for (auto &s : _subscriptions) {
+			if (s.updated()) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+private:
+	SubscriptionInterval _subscriptions[SIZE];
+};
+
+} // namespace uORB