From 3cd0dbda126b5cd4cbe32729f765231d53ecc2a3 Mon Sep 17 00:00:00 2001
From: Kim Alvefur <zash@zash.se>
Date: Thu, 17 Mar 2016 18:00:35 +0100
Subject: [PATCH] util.async: Remove to prevent blocking a stable release

---
 util/async.lua | 158 -------------------------------------------------
 1 file changed, 158 deletions(-)
 delete mode 100644 util/async.lua

diff --git a/util/async.lua b/util/async.lua
deleted file mode 100644
index 968ec804..00000000
--- a/util/async.lua
+++ /dev/null
@@ -1,158 +0,0 @@
-local log = require "util.logger".init("util.async");
-
-local function runner_continue(thread)
-	-- ASSUMPTION: runner is in 'waiting' state (but we don't have the runner to know for sure)
-	if coroutine.status(thread) ~= "suspended" then -- This should suffice
-		return false;
-	end
-	local ok, state, runner = coroutine.resume(thread);
-	if not ok then
-		local level = 0;
-		while debug.getinfo(thread, level, "") do level = level + 1; end
-		ok, runner = debug.getlocal(thread, level-1, 1);
-		local error_handler = runner.watchers.error;
-		if error_handler then error_handler(runner, debug.traceback(thread, state)); end
-	elseif state == "ready" then
-		-- If state is 'ready', it is our responsibility to update runner.state from 'waiting'.
-		-- We also have to :run(), because the queue might have further items that will not be
-		-- processed otherwise. FIXME: It's probably best to do this in a nexttick (0 timer).
-		runner.state = "ready";
-		runner:run();
-	end
-	return true;
-end
-
-local function waiter(num)
-	local thread = coroutine.running();
-	if not thread then
-		error("Not running in an async context, see http://prosody.im/doc/developers/async");
-	end
-	num = num or 1;
-	local waiting;
-	return function ()
-		if num == 0 then return; end -- already done
-		waiting = true;
-		coroutine.yield("wait");
-	end, function ()
-		num = num - 1;
-		if num == 0 and waiting then
-			runner_continue(thread);
-		elseif num < 0 then
-			error("done() called too many times");
-		end
-	end;
-end
-
-local function guarder()
-	local guards = {};
-	return function (id, func)
-		local thread = coroutine.running();
-		if not thread then
-			error("Not running in an async context, see http://prosody.im/doc/developers/async");
-		end
-		local guard = guards[id];
-		if not guard then
-			guard = {};
-			guards[id] = guard;
-			log("debug", "New guard!");
-		else
-			table.insert(guard, thread);
-			log("debug", "Guarded. %d threads waiting.", #guard)
-			coroutine.yield("wait");
-		end
-		local function exit()
-			local next_waiting = table.remove(guard, 1);
-			if next_waiting then
-				log("debug", "guard: Executing next waiting thread (%d left)", #guard)
-				runner_continue(next_waiting);
-			else
-				log("debug", "Guard off duty.")
-				guards[id] = nil;
-			end
-		end
-		if func then
-			func();
-			exit();
-			return;
-		end
-		return exit;
-	end;
-end
-
-local runner_mt = {};
-runner_mt.__index = runner_mt;
-
-local function runner_create_thread(func, self)
-	local thread = coroutine.create(function (self)
-		while true do
-			func(coroutine.yield("ready", self));
-		end
-	end);
-	assert(coroutine.resume(thread, self)); -- Start it up, it will return instantly to wait for the first input
-	return thread;
-end
-
-local empty_watchers = {};
-local function runner(func, watchers, data)
-	return setmetatable({ func = func, thread = false, state = "ready", notified_state = "ready",
-		queue = {}, watchers = watchers or empty_watchers, data = data }
-	, runner_mt);
-end
-
-function runner_mt:run(input)
-	if input ~= nil then
-		table.insert(self.queue, input);
-	end
-	if self.state ~= "ready" then
-		return true, self.state, #self.queue;
-	end
-
-	local q, thread = self.queue, self.thread;
-	if not thread or coroutine.status(thread) == "dead" then
-		thread = runner_create_thread(self.func, self);
-		self.thread = thread;
-	end
-
-	local n, state, err = #q, self.state, nil;
-	self.state = "running";
-	while n > 0 and state == "ready" do
-		local consumed;
-		for i = 1,n do
-			local input = q[i];
-			local ok, new_state = coroutine.resume(thread, input);
-			if not ok then
-				consumed, state, err = i, "ready", debug.traceback(thread, new_state);
-				self.thread = nil;
-				break;
-			elseif new_state == "wait" then
-				consumed, state = i, "waiting";
-				break;
-			end
-		end
-		if not consumed then consumed = n; end
-		if q[n+1] ~= nil then
-			n = #q;
-		end
-		for i = 1, n do
-			q[i] = q[consumed+i];
-		end
-		n = #q;
-	end
-	self.state = state;
-	if err or state ~= self.notified_state then
-		if err then
-			state = "error"
-		else
-			self.notified_state = state;
-		end
-		local handler = self.watchers[state];
-		if handler then handler(self, err); end
-	end
-	return true, state, n;
-end
-
-function runner_mt:enqueue(input)
-	table.insert(self.queue, input);
-end
-
-return { waiter = waiter, guarder = guarder, runner = runner };
-- 
2.30.2