File

util/watchdog.lua @ 12532:8e4033213c62

luacheck: Ignore new warning about using variables prefixed with '_' luacheck 0.26 considers the _ prefix as a hint that the variable or argument is unused, then warns if they are used despite this. We have several places where this prefix is used to avoid shadowing another similarly named variable, resulting in many instances of this warning.
author Kim Alvefur <zash@zash.se>
date Mon, 30 May 2022 16:49:52 +0200
parent 8555:4f0f5b49bb03
child 12545:5059a639f61e
line wrap: on
line source

local timer = require "util.timer";
local setmetatable = setmetatable;
local os_time = os.time;

local _ENV = nil;
-- luacheck: std none

local watchdog_methods = {};
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);
	return watchdog;
end

function watchdog_methods:reset()
	self.last_reset = os_time();
end

function watchdog_methods:cancel()
	self.last_reset = nil;
end

return {
	new = new;
};