X-Git-Url: https://git.enpas.org/?a=blobdiff_plain;f=util%2Fasync.lua;h=968ec80495489b51b66a8e1e1ba6f8c201b7e14d;hb=a8958cbe5ebad3abc12efa7a76c8aedac8f21389;hp=c81f8639b490b30905af66ac3428e70fe6eedbe0;hpb=cb6f85d7c20eb0883135c6257c6ad87aaabab05b;p=prosody.git

diff --git a/util/async.lua b/util/async.lua
index c81f8639..968ec804 100644
--- a/util/async.lua
+++ b/util/async.lua
@@ -37,10 +37,48 @@ local function waiter(num)
 		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;
 
@@ -101,8 +139,12 @@ function runner_mt:run(input)
 		n = #q;
 	end
 	self.state = state;
-	if state ~= self.notified_state then
-		self.notified_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
@@ -113,4 +155,4 @@ function runner_mt:enqueue(input)
 	table.insert(self.queue, input);
 end
 
-return { waiter = waiter, runner = runner };
+return { waiter = waiter, guarder = guarder, runner = runner };