output/Timer: use std::chrono

src/output/Timer.cxx

@@ -33,7 +33,7 @@ Timer::Timer(const AudioFormat af)
 
 void Timer::Start()
 {
-	time = MonotonicClockUS();
+	time = Now();
 	started = true;
 }
 
@@ -49,19 +49,17 @@ Timer::Add(size_t size)
 
 	// (size samples) / (rate samples per second) = duration seconds
 	// duration seconds * 1000000 = duration us
-	time += ((uint64_t)size * 1000000) / rate;
+	time += Time(((uint64_t)size * Time::period::den) / (Time::period::num * rate));
 }
 
-unsigned Timer::GetDelay() const
+std::chrono::steady_clock::duration
+Timer::GetDelay() const
 {
 	assert(started);
 
-	int64_t delay = (int64_t)(time - MonotonicClockUS()) / 1000;
-	if (delay < 0)
-		return 0;
+	const auto delay = time - Now();
+	if (delay < Time::zero())
+		return Time::zero();
 
-	if (delay > std::numeric_limits<int>::max())
-		delay = std::numeric_limits<int>::max();
-
-	return delay;
+	return std::chrono::duration_cast<std::chrono::steady_clock::duration>(delay);
 }

src/output/Timer.hxx

@@ -20,13 +20,14 @@
 #ifndef MPD_TIMER_HXX
 #define MPD_TIMER_HXX
 
-#include <stdint.h>
-#include <stddef.h>
+#include <chrono>
 
 struct AudioFormat;
 
 class Timer {
-	uint64_t time;
+	typedef std::chrono::microseconds Time;
+
+	Time time;
 	bool started = false;
 	const int rate;
 public:
@@ -40,9 +41,14 @@ public:
 	void Add(size_t size);
 
 	/**
-	 * Returns the number of milliseconds to sleep to get back to sync.
+	 * Returns the duration to sleep to get back to sync.
 	 */
-	unsigned GetDelay() const;
+	std::chrono::steady_clock::duration GetDelay() const;
+
+private:
+	static Time Now() {
+		return std::chrono::duration_cast<Time>(std::chrono::steady_clock::now().time_since_epoch());
+	}
 };
 
 #endif

src/output/plugins/FifoOutputPlugin.cxx

@@ -208,7 +208,7 @@ inline std::chrono::steady_clock::duration
 FifoOutput::Delay() const
 {
 	return timer->IsStarted()
-		? std::chrono::milliseconds(timer->GetDelay())
+		? timer->GetDelay()
 		: std::chrono::steady_clock::duration::zero();
 }
 

src/output/plugins/NullOutputPlugin.cxx

@@ -51,7 +51,7 @@ public:
 
 	std::chrono::steady_clock::duration Delay() const {
 		return sync && timer->IsStarted()
-			? std::chrono::milliseconds(timer->GetDelay())
+			? timer->GetDelay()
 			: std::chrono::steady_clock::duration::zero();
 	}
 

src/output/plugins/httpd/HttpdOutputPlugin.cxx

@@ -361,7 +361,7 @@ HttpdOutput::Delay() const
 	}
 
 	return timer->IsStarted()
-		? std::chrono::milliseconds(timer->GetDelay())
+		? timer->GetDelay()
 		: std::chrono::steady_clock::duration::zero();
 }