Diff

--- a/util/watchdog.lua	Mon Dec 12 20:40:23 2022 +0100
+++ b/util/watchdog.lua	Mon Dec 12 07:10:54 2022 +0100
@@ -1,6 +1,5 @@
 local timer = require "util.timer";
 local setmetatable = setmetatable;
-local os_time = os.time;
 
 local _ENV = nil;
 -- luacheck: std none
@@ -9,27 +8,35 @@
 local watchdog_mt = { __index = watchdog_methods };
 
 local function new(timeout, callback)
-	local watchdog = setmetatable({ timeout = timeout, last_reset = os_time(), callback = callback }, watchdog_mt);
-	timer.add_task(timeout+1, function (current_time)
-		local last_reset = watchdog.last_reset;
-		if not last_reset then
-			return;
-		end
-		local time_left = (last_reset + timeout) - current_time;
-		if time_left < 0 then
-			return watchdog:callback();
-		end
-		return time_left + 1;
-	end);
+	local watchdog = setmetatable({
+		timeout = timeout;
+		callback = callback;
+		timer_id = nil;
+	}, watchdog_mt);
+
+	watchdog:reset(); -- Kick things off
+
 	return watchdog;
 end
 
-function watchdog_methods:reset()
-	self.last_reset = os_time();
+function watchdog_methods:reset(new_timeout)
+	if new_timeout then
+		self.timeout = new_timeout;
+	end
+	if self.timer_id then
+		timer.reschedule(self.timer_id, self.timeout+1);
+	else
+		self.timer_id = timer.add_task(self.timeout+1, function ()
+			return self:callback();
+		end);
+	end
 end
 
 function watchdog_methods:cancel()
-	self.last_reset = nil;
+	if self.timer_id then
+		timer.stop(self.timer_id);
+		self.timer_id = nil;
+	end
 end
 
 return {