From 271b2873566dd14d052e963ac75b3ccd64c62959 Mon Sep 17 00:00:00 2001
From: Max Kellermann <mk@cm4all.com>
Date: Thu, 4 Feb 2021 21:48:27 +0100
Subject: [PATCH] event/TimerEvent: assign `due` in Schedule()

---
 src/event/Loop.cxx       |  3 +--
 src/event/Loop.hxx       |  2 +-
 src/event/TimerEvent.cxx | 16 +++++++++++++---
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/event/Loop.cxx b/src/event/Loop.cxx
index ea19c2bd9..2260edead 100644
--- a/src/event/Loop.cxx
+++ b/src/event/Loop.cxx
@@ -152,11 +152,10 @@ EventLoop::AbandonFD(SocketEvent &event)  noexcept
 }
 
 void
-EventLoop::AddTimer(TimerEvent &t, Event::Duration d) noexcept
+EventLoop::Insert(TimerEvent &t) noexcept
 {
 	assert(IsInside());
 
-	t.due = SteadyNow() + d;
 	timers.insert(t);
 	again = true;
 }
diff --git a/src/event/Loop.hxx b/src/event/Loop.hxx
index 664ec1c77..d74550c5a 100644
--- a/src/event/Loop.hxx
+++ b/src/event/Loop.hxx
@@ -214,7 +214,7 @@ public:
 	 */
 	bool AbandonFD(SocketEvent &event) noexcept;
 
-	void AddTimer(TimerEvent &t, Event::Duration d) noexcept;
+	void Insert(TimerEvent &t) noexcept;
 
 	/**
 	 * Schedule a call to DeferEvent::RunDeferred().
diff --git a/src/event/TimerEvent.cxx b/src/event/TimerEvent.cxx
index 765e79174..dcb24d7b6 100644
--- a/src/event/TimerEvent.cxx
+++ b/src/event/TimerEvent.cxx
@@ -25,12 +25,22 @@ TimerEvent::Schedule(Event::Duration d) noexcept
 {
 	Cancel();
 
-	loop.AddTimer(*this, d);
+	due = loop.SteadyNow() + d;
+	loop.Insert(*this);
 }
 
 void
 TimerEvent::ScheduleEarlier(Event::Duration d) noexcept
 {
-	if (!IsPending() || loop.SteadyNow() + d < due)
-		Schedule(d);
+	const auto new_due = loop.SteadyNow() + d;
+
+	if (IsPending()) {
+		if (new_due >= due)
+			return;
+
+		Cancel();
+	}
+
+	due = new_due;
+	loop.Insert(*this);
 }