Difference between revisions of "love.thread"

(Pointless and ugly)
(Example: Removed outdated examples)
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{{#set:Description=Allows you to work with threads.}}
 
{{#set:Description=Allows you to work with threads.}}
 
{{#set:Since=070}}
 
{{#set:Since=070}}
== Example ==
+
== Examples ==
 
For 0.9.0: http://love2d.org/forums/viewtopic.php?f=4&t=76670
 
For 0.9.0: http://love2d.org/forums/viewtopic.php?f=4&t=76670
{{oldin|[[0.9.0]]|090|type=example}}
 
See: http://love2d.org/forums/viewtopic.php?f=4&t=2138&hilit=Thread#p22550
 
=== from http://love2d.org/forums/viewtopic.php?f=5&t=9934&p=60592&hilit=thread#p60592 ===
 
=== main.lua ===
 
<source lang="lua">
 
-- new thread
 
thread = love.thread.newThread('thread','thread.lua')
 
thread:start()
 
 
function love.update(dt)
 
  msg_table      = msg_table or {}
 
  -- process messages when other thread is "done"
 
  if thread:get('done') then
 
  msg_table[1]  = thread:get('number')
 
  msg_table[2]  = thread:get('string')
 
  msg_table[3]  = tostring(thread:get('condition'))
 
  -- concat our messages into a long string
 
  message        = table.concat(msg_table,'\n')
 
  -- get image data from the other thread
 
  imageData      = imageData or thread:get('image')
 
 
  -- initialize image
 
  image  = love.graphics.newImage(imageData)
 
  end
 
  if thread:get('hasCounter') then
 
  msg_table[4]  = thread:get('counter')
 
  message        = table.concat(msg_table,'\n')
 
  end
 
end
 
 
function love.draw()
 
  if image then
 
  love.graphics.draw(image,50,50)
 
  end
 
  if message then
 
  love.graphics.print(message,10,10)
 
  end
 
end
 
</source>
 
=== thread.lua ===
 
<source lang="lua">
 
-- load modules b/c new thread
 
require 'love.filesystem'
 
require 'love.image'
 
require 'love.timer'
 
 
-- get this thread's id
 
thisThread  = love.thread.getThread()
 
-- load image file, userdata can be sent also!
 
file      = love.image.newImageData('love.png')
 
 
-- send messages to this thread's inbox
 
thisThread:set('image',file)
 
thisThread:set('number',1337)
 
thisThread:set('string','a string message')
 
thisThread:set('condition',true)
 
thisThread:set('done',true)
 
 
time0 = love.timer.getTime()
 
counter = 0
 
 
-- count per second and send counter to inbox
 
while true do
 
  timeD = love.timer.getTime() - time0
 
  if timeD > 1 then
 
  counter = counter + 1
 
  thisThread:set('counter',counter)
 
  thisThread:set('hasCounter',true)
 
  time0 = love.timer.getTime()
 
  end
 
end
 
</source>
 
  
 
== See Also ==
 
== See Also ==

Revision as of 07:22, 13 February 2014

Available since LÖVE 0.7.0
This module is not supported in earlier versions.

Allows you to work with threads.

Threads are separate Lua environments, running in parallel to the main code. As their code runs separately, they can be used to compute complex operations without adversely affecting the frame rate of the main thread. However, as they are separate environments, they cannot access the variables and functions of the main thread, and communication between threads is limited.

All LOVE objects (userdata) are shared among threads so you'll only have to send their references across threads. You may run into concurrency issues if you manipulate an object on multiple threads at the same time.

When a Thread is started, it only loads the love.thread module. Every other module has to be loaded with require.

O.png The love.graphics and love.window modules have several restrictions and therefore should only be used in the main thread.  


Types

Channel An object which can be used to send and receive data between different threads. Added since 0.9.0
Thread A Thread represents a thread. Added since 0.7.0

Functions

love.thread.getChannel Creates or retrieves a named thread channel. Added since 0.9.0
love.thread.getThread Look for a thread and get its object. Added since 0.7.0 Removed in 0.9.0
love.thread.getThreads Get all threads. Added since 0.7.0 Removed in 0.9.0
love.thread.newChannel Creates a new unnamed thread channel. Added since 0.9.0
love.thread.newThread Creates a new Thread from a filename, string or FileData object containing Lua code. Added since 0.7.0


Examples

For 0.9.0: http://love2d.org/forums/viewtopic.php?f=4&t=76670

See Also

Other Languages