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◆ main openmsx / src / RTScheduler.hh
1.2 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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#ifndef RTSCHEDULER_HH
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#define RTSCHEDULER_HH
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#include "SchedulerQueue.hh"
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#include "Timer.hh"
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#include <cstdint>
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#include <optional>
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namespace openmsx {
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class RTSchedulable;
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struct RTSyncPoint
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{
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	uint64_t time;
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	RTSchedulable* schedulable;
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};
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class RTScheduler
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{
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public:
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	/** Execute all expired RTSchedulables. */
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	void execute() {
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		if (!queue.empty()) {
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			auto limit = Timer::getTime();
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			if (limit >= queue.front().time) [[unlikely]] {
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				scheduleHelper(limit); // slow path not inlined
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			}
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		}
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	}
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	/** Get the next scheduled time point (absolute, in microseconds).
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	  * @return The earliest scheduled time, or nullopt if queue is empty.
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	  */
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	[[nodiscard]] std::optional<uint64_t> getNextTime() const {
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		return queue.empty() ? std::nullopt
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		                     : std::optional(queue.front().time);
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	}
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private:
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	// These are called by RTSchedulable
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	friend class RTSchedulable;
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	void add(uint64_t delta, RTSchedulable& schedulable);
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	bool remove(RTSchedulable& schedulable);
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	[[nodiscard]] bool isPending(const RTSchedulable& schedulable) const;
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	void scheduleHelper(uint64_t limit);
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private:
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	SchedulerQueue<RTSyncPoint> queue;
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};
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} // namespace openmsx
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#endif