How works love.threads?

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NoAim91
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Location: Germany

How works love.threads?

Post by NoAim91 »

Hey, the love.thread thing really need a bit more description at the wiki. I like to input a variable in the thread and get a return after a function call. In this case I put 10 in, the function should add 3 and the return should be 13. But the function inside the thread doesn´t get called. and in generell I have no clue what is going on.

main.lua

Code: Select all

function love.load()
  t  = love.thread.newThread("thread.lua")
  c1 = love.thread.newChannel()

  
  input = 10
 
  t:start(c1:push(input))
  
  table = c1:demand()
  print(table)
end
thread.lua

Code: Select all

function test(input)
  a = 3
  a = a + input
  print(a)
  return a
end

input = c1:demand()
c1:push(test(input))
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zorg
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Re: How works love.threads?

Post by zorg »

Anything you pass into Thread:start will be available as a "file-level" vararg that you can access by doing this:

Code: Select all

local stuff = {...}
for example; you can also use the select function too.

Haven't tested the following, but it may or may not work:

Code: Select all

-- main.lua
function love.load()
  t  = love.thread.newThread("thread.lua")
  c1 = love.thread.newChannel()

  
  input = 10
 
  t:start(c1)
  c1:push(input)
  table = c1:demand()
  print(table)
end

Code: Select all

--thread.lua
local c1 = {...}[1]

function test(input)
  a = 3
  a = a + input
  print(a)
  return a
end

input = c1:demand()
c1:push(test(input))

Me and my stuff :3True Neutral Aspirant. Why, yes, i do indeed enjoy sarcastically correcting others when they make the most blatant of spelling mistakes. No bullying or trolling the innocent tho.
NoAim91
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Posts: 38
Joined: Mon Feb 20, 2017 10:28 am
Location: Germany

Re: How works love.threads?

Post by NoAim91 »

@zorg: nope, doesn´t work.

Maybe I don´t need channels for this.

I tryed this

Code: Select all

--main.lua
function love.load()
  t     = love.thread.newThread("thread.lua")

  input = 10
  
  output = t:start( input )

  print(output)
  
end

Code: Select all

--thread.lua
local input = input

function test(input)
  a = 3
  a = a + input
  print(a)
  return a
end

test(input)
and this did not work.

print(output) --> true
print(a) --> doesn´t print anything
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Nixola
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Posts: 1949
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Location: Italy

Re: How works love.threads?

Post by Nixola »

wiki wrote:Unless you define the love.threaderror callback or call Thread:getError you won't see any errors your thread code throws.
lf = love.filesystem
ls = love.sound
la = love.audio
lp = love.physics
lt = love.thread
li = love.image
lg = love.graphics
NoAim91
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Posts: 38
Joined: Mon Feb 20, 2017 10:28 am
Location: Germany

Re: How works love.threads?

Post by NoAim91 »

Code: Select all

local input = input

function test(input)
  a = input
  a = a + 3
  print(a)
  return a
end

test(input)
Thread error!
thread.lua:5: attempt to perform arithmetic on global 'a' (a nil value)

line 5 is a = a + 3

so what?! define a = input is fine but after that a is unknown?! o.O
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bartbes
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Re: How works love.threads?

Post by bartbes »

Yes, because input is nil, change your first line to

Code: Select all

local input = ...
NoAim91
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Location: Germany

Re: How works love.threads?

Post by NoAim91 »

thank you! :-)

Ok, now how I get the resault ( a ) out of the thread? XD
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bartbes
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Re: How works love.threads?

Post by bartbes »

The easiest way is using a channel, so if we take your initial code again...

Code: Select all

-- main.lua
function love.load()
  t  = love.thread.newThread("thread.lua")
  c1 = love.thread.newChannel()

  
  input = 10
  c1:push(input)
  t:start(c1)
  
  table = c1:demand()
  print(table)
end

-- thread.lua
local c1 = ...

function test(input)
  a = 3
  a = a + input
  print(a)
  return a
end

input = c1:demand()
c1:push(test(input))
Of course you probably don't want to use threads for this, but it should work.
NoAim91
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Posts: 38
Joined: Mon Feb 20, 2017 10:28 am
Location: Germany

Re: How works love.threads?

Post by NoAim91 »

@bartbes: this code doesn´t work :-/

I changed something that it work, but it is not finaly right:

Code: Select all

 
main.lua

function love.load()
  t     = love.thread.newThread("thread.lua")
  c1    = love.thread.newChannel()

  input = 10
  
  c1:push(input)
  t:start(c1)

end

Code: Select all

thread.lua

local c1 = ...
input = c1:demand()
print("thread/ input: "..input) -- print 10

function test(input)
  a = input
  a = a + 3
  print("thread/ a: "..a) -- print 13
  return a
end

c1:push(test(input))


and the strange thing is, when I write this:

Code: Select all

function love.load()
  t     = love.thread.newThread("thread.lua")
  c1    = love.thread.newChannel()

  input = 10
  
  c1:push(input)
  t:start(c1)
  
  output = c1:demand()
  print("main/ output: "..output) --print 10
  
end
it only print 10 ... and nothing from the thread ... and the thread gives no error
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zorg
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Re: How works love.threads?

Post by zorg »

So your issue is that the print command doesn't work in the thread? Because it seems like the thread did return 10 to the main thread, and it was printed...
Me and my stuff :3True Neutral Aspirant. Why, yes, i do indeed enjoy sarcastically correcting others when they make the most blatant of spelling mistakes. No bullying or trolling the innocent tho.
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