LuaSocket: asynchronous connect on Windows not behaving properly

[Jerome Vuarand <jerome.vuarand@...>]

Hi list,

I'm trying to write a copas-like module that handles both incoming and
outgoing connections. Since the socket:connect operation can take some
time, and I may have other sockets ready to do something, I'm setting
the timeout to zero, I call connect, but then select is not working as
expected on Windows.

Here is a test script:

#!/usr/bin/env lua

require 'socket'

function test(ip, port)
    local master = assert(socket.tcp())
    master:settimeout(0)
    print(master)
    local success,err = master:connect(ip, port)
    print(master, success, err)
    if not success and err=='timeout' then
        socket.select({}, {master})
        success,err = master:connect(ip, port)
        print(master, success,err)
    end
end

print("valid address 1")
test('127.0.0.1', 80)
print("valid address 2")
test('127.0.0.1', 2000)
print("invalid address")
test('127.0.0.1', 44444)

Note that I have a server on port 80 (Apache), and a custom LuaSocket
server on port 2000. There is nothing on port 44444.

On Linux, select returns as soon as the connection status is known. I
have to call connect again to determine if it succeeded or not, here
is the log:

doub@blimbox:~/test$ lua test
valid address 1
tcp{master}: 0x80738d4
tcp{client}: 0x80738d4  nil     timeout
tcp{client}: 0x80738d4  1       nil
valid address 2
tcp{master}: 0x8075b0c
connection on PIC
tcp{client}: 0x8075b0c  nil     timeout
tcp{client}: 0x8075b0c  1       nil
invalid address
tcp{master}: 0x8077d4c
tcp{client}: 0x8077d4c  nil     timeout
tcp{client}: 0x8077d4c  nil     connection refused
doub@blimbox:~/test$

On Windows however, when the connection succeeds, the socket is
already connected and calling connect again triggers an error. And if
the connection fails, select never returns. Note the Ctrl+C in the log
that I had to do to kill the program :

C:\test>lua test
valid address 1
tcp{master}: 00465008
tcp{client}: 00465008   nil     timeout
tcp{client}: 00465008   nil     already connected
valid address 2
tcp{master}: 00467078
tcp{client}: 00467078   nil     timeout
tcp{client}: 00467078   nil     already connected
invalid address
tcp{master}: 00469150
tcp{client}: 00469150   nil     timeout
^C
C:\test>

On both platforms I'm using LuaSocket 2.0.2.

Can anybody else reproduce the problem ? Is there a known workaround ?
I haven't tried the 2.0.3 beta, should I ? Any help would be
appreciated.

Doub.