This is full dropin replacement for llthreads library.
- does not support Lua 5.0
- does not support ffi interface (use Lua C API for LuaJIT)
- returns nil instead of false on error
- start method returns self instead of true on success
- thread:join() method support zero timeout to check if thread alive (does not work on Windows with pthreads)
- thread:join() method support arbitrary timeout on Windows threads
- thread:alive() method return whether the thread is alive (does not work on Windows with pthreads)
- set_logger function allow logging errors (crash Lua VM) in current llthread's threads
- thread:start() has additional parameter which control in which thread child Lua VM will be destroyed
- allow pass cfunctions to child thread (e.g. to initialize Lua state)
detached |
joinable |
join returns | child state closes by | gc calls | detach on |
|---|---|---|---|---|---|
| false | false | true |
child | join | <NEVER> |
|  false(*) | true(*) | Lua values  |     parent    | join * | <NEVER> |
|  true   | false(*) | raise error |     child     | <NONE> |
 start  |
| true | true | true |
child | detach | gc |
In this example I use lua-log library.
-- This is child thread.
local llthreads = require "llthreads2"
-- Send logs using ZMQ
local LOG = require"log".new(
require "log.writer.net.zmq".new("tcp://127.0.0.1:5555")
)
llthread.set_logger(function(msg) LOG.error(msg) end)
-- This error with traceback will be passed to logger
error("SOME ERROR")-- This is main thread.
local thread = require "llthreads2".new[[
require "utils".sleep(5)
]]
-- We tell that we start attached thread but child Lua State shuld be close in child thread.
-- If `thread` became garbage in main thread then finallizer calls thread:join()
-- and main thread may hungup. But because of child state closes in child thread all objects
-- in this state can be destroyed and we can prevent deadlock.
thread:start(false, false)
-- We can call join.
-- Because of Lua state destroys in child thread we can not get
-- returned Lua values so we just returns `true`.
thread:join()-- This is main thread.
local thread = require "llthreads2".new[[
require "utils".sleep(5)
]]
-- We tell that we start detached joinable thread. In fact we start attached
-- thread but if `thread` became garbage in main thread then finallizer just
-- detach child thread and main thread may not hungup.
thread:start(true, true)
-- We can call join.
-- Because of Lua state destroys in child thread we can not get
-- returned Lua values so we just returns `true`.
thread:join()If you close parent Lua state then some dynamic library may be unloaded and cfunction in child Lua state (thread) became invalid.
-- `myhost.XXX` modules is built-in modules in host application
-- host application registers cfunction as module loader
local preload = {}
preload[ 'myhost.logger' ] = package.preload[ 'myhost.logger' ]
preload[ 'myhost.config' ] = package.preload[ 'myhost.config' ]
llthreads.new([[
-- registers preload
local preload = ...
for name, fn in pairs(preload) do package.preload[name] = fn end
local log = require 'myhost.logger'
]], preload):start(true)local thread = require "llthreads2".new[[
require "utils".sleep(5)
return 1
]]
thread:start()
-- we can not use `thread:join(0)` because we can not call it twice
-- so all returned values will be lost
while thread:alive() do
-- do some work
end
local ok, ret = thread:join() -- true, 1local Threads = require "llthreads2.ex"
local ok, v = Threads.new(function()
return 1
end):start():join()
assert(v == 1)
local thread = Threads.new({
-- this thread code gets changed arguments
function(a, b)
assert(1 == a)
assert(2 == b)
print("Done")
end;
-- prelude can change thread arguments
prelude = function(a, b)
assert("1" == a)
assert(nil == b)
return tonumber(a), 2
end;
}, "1")
thread:start():join()