File

util/watchdog.lua @ 10228:e77bf4222fae

net.server_epoll: Add support for opportunistic writes This tries to flush data to the underlying sockets when receiving writes. This should lead to fewer timer objects being around. On the other hand, this leads to more and smaller writes which may translate to more TCP/IP packets being sent, depending on how the kernel handles this. This trades throughput for lower latency.
author Kim Alvefur <zash@zash.se>
date Wed, 28 Aug 2019 01:41:00 +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;
};