Add basic scheduler structure

include/scheduler.hpp

@@ -0,0 +1,50 @@
+#pragma once
+#include <boost/container/flat_map.hpp>
+#include <boost/container/static_vector.hpp>
+#include <limits>
+#include <ranges>
+
+#include "helpers.hpp"
+
+struct Scheduler {
+	enum class EventType {
+		VBlank = 0,          // End of frame event
+		Panic = 1,           // Dummy event that is always pending and should never be triggered (Timestamp = UINT64_MAX)
+		TotalNumberOfEvents  // How many event types do we have in total?
+	};
+	static constexpr usize totalNumberOfEvents = static_cast<usize>(EventType::TotalNumberOfEvents);
+
+	template <typename Key, typename Val, usize size>
+	using EventMap = boost::container::flat_multimap<Key, Val, std::less<Key>, boost::container::static_vector<std::pair<Key, Val>, size>>;
+
+	EventMap<u64, EventType, totalNumberOfEvents> events;
+	u64 currentTimestamp = 0;
+	u64 nextTimestamp = 0;
+
+	// Set nextTimestamp to the timestamp of the next event
+	void updateNextTimestamp() { nextTimestamp = events.cbegin()->first; }
+	void addCycles(u64 cycles) { currentTimestamp += cycles; }
+
+	void addEvent(EventType type, u64 timestamp) {
+		events.emplace(timestamp, type);
+		updateNextTimestamp();
+	}
+
+	void removeEvent(EventType type) {
+		auto it = std::ranges::find_if(events, [type](decltype(events)::const_reference pair) { return pair.second == type; });
+
+		if (it != events.end()) {
+			events.erase(it);
+			updateNextTimestamp();
+		}
+	};
+
+	void reset() {
+		currentTimestamp = 0;
+
+		// Clear any pending events
+		events.clear();
+		// Add a dummy event to always keep the scheduler non-empty
+		addEvent(EventType::Panic, std::numeric_limits<u64>::max());
+	}
+};