util/gc.lua
author Kim Alvefur <zash@zash.se>
Sat, 23 Mar 2024 20:48:19 +0100
changeset 13465 c673ff1075bd
parent 12979 d10957394a3c
permissions -rw-r--r--
mod_posix: Move everything to util.startup This allows greater control over the order of events. Notably, the internal ordering between daemonization, initialization of libunbound and setup of signal handling is sensitive. libunbound starts a separate thread for processing DNS requests. If this thread is started before signal handling has been set up, it will not inherit the signal handlers and instead behave as it would have before signal handlers were set up, i.e. cause the whole process to immediately exit. libunbound is usually initialized on the first DNS request, usually triggered by an outgoing s2s connection attempt. If daemonization happens before signals have been set up, signals may not be processed at all.

local set = require "prosody.util.set";

local known_options = {
	incremental = set.new { "mode", "threshold", "speed", "step_size" };
	generational = set.new { "mode", "minor_threshold", "major_threshold" };
};

if _VERSION ~= "Lua 5.4" then
	known_options.generational = nil;
	known_options.incremental:remove("step_size");
end

local function configure(user, defaults)
	local mode = user.mode or defaults.mode or "incremental";
	if not known_options[mode] then
		return nil, "GC mode not supported on ".._VERSION..": "..mode;
	end

	for k, v in pairs(user) do
		if not known_options[mode]:contains(k) then
			return nil, "Unknown GC parameter: "..k;
		elseif k ~= "mode" and type(v) ~= "number" then
			return nil, "parameter '"..k.."' should be a number";
		end
	end

	if mode == "incremental" then
		if _VERSION == "Lua 5.4" then
			collectgarbage(mode,
				user.threshold or defaults.threshold,
				user.speed or defaults.speed,
				user.step_size or defaults.step_size
			);
		else
			collectgarbage("setpause", user.threshold or defaults.threshold);
			collectgarbage("setstepmul", user.speed or defaults.speed);
		end
	elseif mode == "generational" then
		collectgarbage(mode,
			user.minor_threshold or defaults.minor_threshold,
			user.major_threshold or defaults.major_threshold
		);
	end
	return true;
end

return {
	configure = configure;
};