connect timeout, see #611

lualib/http/httpc.lua

@@ -99,7 +99,7 @@ function httpc.request(method, host, url, recvheader, header, content)
 	if async_dns and not hostname:match(".*%d+$") then
 		hostname = dns.resolve(hostname)
 	end
-	local fd = socket.connect(hostname, port)
+	local fd = socket.connect(hostname, port, timeout)
 	local finish
 	if timeout then
 		skynet.timeout(timeout, function()

lualib/http/sockethelper.lua

@@ -1,4 +1,5 @@
 local socket = require "socket"
+local skynet = require "skynet"
 
 local readbytes = socket.read
 local writebytes = socket.write
@@ -66,8 +67,27 @@ function sockethelper.writefunc(fd)
 	end
 end
 
-function sockethelper.connect(host, port)
+function sockethelper.connect(host, port, timeout)
-	local fd = socket.open(host, port)
+	local fd
+	if timeout then
+		local drop_fd
+		-- asynchronous connect
+		skynet.fork(function()
+			fd = socket.open(host, port)
+			if drop_fd then
+				-- sockethelper.connect already return, and raise socket_error
+				socket.close(fd)
+			end
+		end)
+		skynet.sleep(timeout)
+		if not fd then
+			-- not connect yet
+			drop_fd = true
+		end
+	else
+		-- block connect
+		fd = socket.open(host, port)
+	end
 	if fd then
 		return fd
 	end

test/testhttp.lua

@@ -2,7 +2,7 @@ local skynet = require "skynet"
 local httpc = require "http.httpc"
 local dns = require "dns"
 
-skynet.start(function()
+local function main()
 	httpc.dns()	-- set dns server
 	httpc.timeout = 100	-- set timeout 1 second
 	print("GET baidu.com")
@@ -21,6 +21,9 @@ skynet.start(function()
 	print(string.format("GET %s (baidu.com)", ip))
 	local status, body = httpc.get("baidu.com", "/", respheader, { host = "baidu.com" })
 	print(status)
+end
 
+skynet.start(function()
+	print(pcall(main))
 	skynet.exit()
 end)