Lua-Love program not closing devices as I expect it to

Question

I have the lua love program:

conf-nogui.lua (is called within the conf.lua to not display a GUI):

function love.conf(t)
  print("Switch GUI window off")
  t.window = nil
end

main.lua:

-- UDP Server
local socket = require("socket")
require("utils")
require("globals")

-- Module Scoped Variables (or as I like to call them local-globals)
local udp

-- Startup
function love.load()
  print("load")
  udp = socket.udp()
  udp:setsockname("*", SERVER_PORT)
  udp:settimeout(0)
  print("load done")
end

-- Scheduler 
function love.update()
  -- Check for Rx packets
  local rxDataPacket, ip, port = udp:receivefrom()
  if rxDataPacket then
    -- print the packet as hex
    printStringAsHex("Rx from " .. ip .. ":" .. port .. " ", rxDataPacket)    
    -- Turn string into an array for editing
    local rxByteArray = stringToArray(rxDataPacket)
    -- Edit values
    rxByteArray[5] = 0x66 
    -- Turn back into string
    local txDataPacket = arrayToString(rxByteArray)  
    -- Reply with the result
    udp:sendto(txDataPacket, ip, port)
  end
end

-- shutdown
function love.quit()
  print("Closing connection...")
  -- done with client, close the object
  udp:close()
  print("connection close done")
end

There are some other files that are included, but I don't think are necessary for this question.

I run the program on the command line like this: love . --console I am in the correct directory so "." is the current dir.

This little program runs exactly as expected until I close it. It is running on the windows command line, so I use ctrl+c to terminate the program (It is not running a GUI - see the conf file).

When the program closes this is what I see on in the command prompt:

AL lib: (EE) alc_cleanup: 1 device not closed

So what I don't understand is why my function love.quit() is not called. I don't see my debug Closing connection.... Is it because ctrl+C terminates the program too "harshly"? - is there another way to terminate the program?

score 1 · Accepted Answer · edited May 23 '17 at 12:08

1

It appears to me that love.quit is only called when the quit event is raised (i.e. love.event.quit())

When Ctrl+c is pressed, cmd is given a SIGINT, which causes the current program(s) running in the instance to stop.

What technically happens when you press Control-C is that all programs running in the foreground in your current terminal (or virtual terminal) get the signal SIGINT sent.¹

So, I guess LOVE catches that input, and doesn't choose to raise the quit event, but forcefully shuts down instead.

Check this question out for more help.

edited May 23 '17 at 12:08

Community

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answered Aug 17 '16 at 14:05

Liam Mueller

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hmm.... damn, that is what I feared. I hoped the love framework somehow handled that. Do you know how I can handle a SIGINT in lua? – code_fodder Aug 17 '16 at 14:06
ok, thanks - I understood that from your first post, what I want to know how to handle this, or how to end the program "correctly" - bearing in mind I have no GUI.... I tried reading the stdin, but that appears to be a blocking call, and I don't want my program to block.. – code_fodder Aug 17 '16 at 14:19
@code_fodder As far as I can tell, there isn't a way to, at least without editing LOVE's C files and rewriting their behavior when encountering SIGINT's. – Liam Mueller Aug 17 '16 at 14:30
ok fair enough. Its not a big issue for me since it appears to get "garbage collected" anyway : ) Thanks for the info. – code_fodder Aug 17 '16 at 14:44

Lua-Love program not closing devices as I expect it to

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