event/Loop: move TimerRecord::due to class TimeoutMonitor

Prepare to eliminate the TimerRecord struct.

src/event/Loop.cxx

@@ -27,6 +27,18 @@
 
 #include <algorithm>
 
+inline std::chrono::steady_clock::time_point
+EventLoop::TimerRecord::GetDue() const noexcept
+{
+	return timer.due;
+}
+
+inline bool
+EventLoop::TimerRecord::operator<(const TimerRecord &other) const noexcept
+{
+	return timer.due < other.timer.due;
+}
+
 EventLoop::EventLoop(ThreadId _thread)
 	:SocketMonitor(*this), thread(_thread)
 {
@@ -93,7 +105,8 @@ EventLoop::AddTimer(TimeoutMonitor &t, std::chrono::steady_clock::duration d)
 {
 	assert(IsInside());
 
-	timers.insert(TimerRecord(t, now + d));
+	t.due = now + d;
+	timers.insert(TimerRecord(t));
 	again = true;
 }
 
@@ -150,7 +163,7 @@ EventLoop::Run()
 				break;
 			}
 
-			timeout = i->due - now;
+			timeout = i->GetDue() - now;
 			if (timeout > timeout.zero())
 				break;
 

src/event/Loop.hxx

@@ -51,21 +51,16 @@ class DeferredMonitor;
 class EventLoop final : SocketMonitor
 {
 	struct TimerRecord {
-		/**
-		 * Projected monotonic_clock_ms() value when this
-		 * timer is due.
-		 */
-		const std::chrono::steady_clock::time_point due;
-
 		TimeoutMonitor &timer;
 
-		constexpr TimerRecord(TimeoutMonitor &_timer,
+		explicit constexpr TimerRecord(TimeoutMonitor &_timer)
-				      std::chrono::steady_clock::time_point _due)
+			:timer(_timer) {}
-			:due(_due), timer(_timer) {}
 
-		bool operator<(const TimerRecord &other) const {
+		gcc_pure
-			return due < other.due;
+		std::chrono::steady_clock::time_point GetDue() const noexcept;
-		}
+
+		gcc_pure
+		bool operator<(const TimerRecord &other) const noexcept;
 	};
 
 	WakeFD wake_fd;

src/event/TimeoutMonitor.hxx

@@ -39,6 +39,12 @@ class TimeoutMonitor {
 
 	EventLoop &loop;
 
+	/**
+	 * When is this timer due?  This is only valid if #active is
+	 * true.
+	 */
+	std::chrono::steady_clock::time_point due;
+
 	bool active;
 
 public: