About

A simple Lua wrapper for pthreads & WIN32 threads.

Each thread gets it's own lua_State and there is no shared global state. The parent thread can pass data to a child thread only as parameters when creating the child thread. The child threads can return data back to the parent thread only when it return (i.e. ends). The parent needs to call child:join() to get the return values from a child thread, this call will block until the child thread ends.

The design goals of this module is only provide support for creating new lua_State and running them in a different thread. This module will not provide any methods of thread-to-thread data passing between running threads (i.e. no locks, no shared state).

Thread to Thread communication methods

The recommend method of passing data between threads is to use ZeroMQ.
Another method is to use sockets library like LuaSocket or Nixio.

Installation

Release 1.2

lua-llthread 1.2 release:

$ sudo luarocks install lua-llthreads

Lastest Git Revision

With LuaRocks 2.0.4.1:

$ sudo luarocks install https://github.com/Neopallium/lua-llthreads/raw/master/rockspecs/lua-llthreads-scm-0.rockspec

With CMake:

$ git clone git://github.com/Neopallium/lua-llthreads.git
$ cd lua-llthreads ; mkdir build ; cd build
$ cmake ..
$ make
$ sudo make install

Example usage

local llthreads = require"llthreads"

local thread_code = [[
	-- print thread's parameter.
	print("CHILD: received params:", ...)
	-- return all thread's parameters back to the parent thread.
	return ...
]]

-- create detached child thread.
local thread = llthreads.new(thread_code, "number:", 1234, "nil:", nil, "bool:", true)
-- start non-joinable detached child thread.
assert(thread:start(true))
-- Use a detatched child thread when you don't care when the child finishes.

-- create child thread.
local thread = llthreads.new(thread_code, "number:", 1234, "nil:", nil, "bool:", true)
-- start joinable child thread.
assert(thread:start())
-- Warning: If you don't call thread:join() on a joinable child thread, it will be called
-- by the garbage collector, which may cause random pauses/freeze of the parent thread.
print("PARENT: child returned: ", thread:join())

local socket = require"socket"
socket.sleep(2) -- give detached thread some time to run.