uORB: add bitset for faster orb_exists check and remove uORB::Subscription lazy subscribe hack/optimization

- add PX4 bitset and atomic_bitset with testing
 - add uORB::Subscription constructor to take ORB_ID enum
 - move orb test messages into msg/

src/include/containers/Bitset.hpp

@@ -0,0 +1,88 @@
+/****************************************************************************
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+#pragma once
+
+namespace px4
+{
+
+template <size_t N>
+class Bitset
+{
+public:
+
+	size_t count() const
+	{
+		size_t total = 0;
+
+		for (auto x : _data) {
+			while (x) {
+				total += x & 1;
+				x >>= 1;
+			}
+		}
+
+		return total;
+	}
+
+	size_t size() const { return N; }
+
+	bool operator[](size_t position) const
+	{
+		return _data[array_index(position)] & element_mask(position);
+	}
+
+	void set(size_t pos, bool val = true)
+	{
+		const uint8_t bitmask = element_mask(pos);
+
+		if (val) {
+			_data[array_index(pos)] |= bitmask;
+
+		} else {
+			_data[array_index(pos)] &= ~bitmask;
+		}
+	}
+
+private:
+	static constexpr uint8_t BITS_PER_ELEMENT = 8;
+	static constexpr size_t ARRAY_SIZE = (N % BITS_PER_ELEMENT == 0) ? N / BITS_PER_ELEMENT : N / BITS_PER_ELEMENT + 1;
+	static constexpr size_t ALLOCATED_BITS = ARRAY_SIZE * BITS_PER_ELEMENT;
+
+	size_t array_index(size_t position) const { return position / BITS_PER_ELEMENT; }
+	uint8_t element_mask(size_t position) const { return (1 << position % BITS_PER_ELEMENT); }
+
+	uint8_t _data[ARRAY_SIZE] {};
+};
+
+} // namespace px4