File

util/watchdog.lua @ 11936:3f49c35607ca

mod_smacks: Fix timer lifetimes to follow session instead of module module:add_timer() creates a timer that stops working after the module is reloaded or unloaded, in order to prevent leaks. However, when the timers control vital session behavior, breakage occurs after reload. E.g. sessions would stop requesting acks and stop responding to acks.
author Kim Alvefur <zash@zash.se>
date Wed, 24 Nov 2021 21:27:45 +0100
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;
};