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◆ main openmsx / src / utils / Poller.hh
1.2 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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#ifndef POLLER_HH
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#define POLLER_HH
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#include <array>
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#include <atomic>
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namespace openmsx {
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/** Polls for events on a given file descriptor.
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  * It is possible to abort this poll from another thread.
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  * This class exists because in POSIX there is no straightforward way to
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  * abort a blocking I/O operation.
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  */
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class Poller
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{
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public:
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	Poller();
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	Poller(const Poller&) = delete;
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	Poller(Poller&&) = delete;
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	Poller& operator=(const Poller&) = delete;
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	Poller& operator=(Poller&&) = delete;
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	~Poller();
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#ifndef _WIN32
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	/** Waits for an event to occur on the given file descriptor.
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	  * Returns true iff abort() was called or an error occurred.
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	  */
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	[[nodiscard]] bool poll(int fd);
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#endif
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	/** Returns true iff abort() was called.
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	  */
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	[[nodiscard]] bool aborted() const {
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		return abortFlag;
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	}
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	/** Aborts a poll in progress and any future poll attempts.
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	  */
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	void abort();
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	/** Reset aborted() to false. (Functionally the same, but more efficient
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	  * than destroying and recreating this object). */
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	void reset() {
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		abortFlag = false;
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	}
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private:
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#ifndef _WIN32
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	std::array<int, 2> wakeupPipe;
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#endif
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	std::atomic_bool abortFlag = false;
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};
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} // namespace openmsx
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#endif