Fix LuCId behaviour if thread-limit is reached

libs/lucid/luasrc/lucid.lua

@@ -110,23 +110,26 @@ end
 -- This main function of LuCId will wait for events on given file descriptors.
 function run()
 	local pollint = tonumber((cursor:get(UCINAME, "main", "pollinterval")))
-	local threadlimit = tonumber(cursor:get(UCINAME, "main", "threadlimit"))
+	local threadlimit = tonumber((cursor:get(UCINAME, "main", "threadlimit")))
 
 	while true do
-		if not threadlimit or tcount < threadlimit then
 		local stat, code = nixio.poll(pollt, pollint)
 		
 		if stat and stat > 0 then
+			local ok = false
 			for _, polle in ipairs(pollt) do
 				if polle.revents ~= 0 and polle.handler then
-						polle.handler(polle)
+					ok = ok or polle.handler(polle)
 				end
 			end
+			if not ok then
+				-- Avoid high CPU usage if thread limit is reached
+				nixio.nanosleep(0, 100000000)
+			end
 		elseif stat == 0 then
 			ifaddrs = nixio.getifaddrs()
 			collectgarbage("collect")
 		end
-		end
 		
 		for _, cb in ipairs(tickt) do
 			cb()
@@ -200,6 +203,14 @@ function unregister_tick(cb)
 	return false
 end
 
+--- Tests whether a given number of processes can be created.
+-- @oaram num Processes to be created
+-- @return boolean status
+function try_process(num)
+	local threadlimit = tonumber((cursor:get(UCINAME, "main", "threadlimit")))
+	return not threadlimit or (threadlimit - tcount) >= (num or 1)
+end
+
 --- Create a new child process from a Lua function and assign a destructor.
 -- @param threadcb main function of the new process
 -- @param waitcb destructor callback

libs/lucid/luasrc/lucid/tcpserver.lua

@@ -111,6 +111,9 @@ end
 -- @param polle Poll descriptor
 -- @return handler process id or nil, error code, error message 
 function accept(polle)
+	if not lucid.try_process() then
+		return false
+	end
 	local socket, host, port = polle.fd:accept()
 	if not socket then
 		return nixio.syslog("warn", "accept() failed: " .. port)