Re: [Luarocks-developers] [ANN] lua-llthreads 1.0

["Robert G. Jakabosky" <bobby@...>]

On Sunday 10, Benoit Germain wrote:
> 2011/4/10 Robert G. Jakabosky <bobby@sharedrealm.com>:
> > Announcing lua-llthreads 1.0 release.
> 
> Hello,
> 
> Since I maintain Lanes, I can't help but reflect that this is some
> sort of a Lanes subset where the inter-thread communication lindas are
> gone. But I suppose that zeromq would be usable with Lanes threads?

Originally this module had been part of my lua-zmq project, but the first 
person I showed it to said that it would be interesting to see it as s 
separate module (since it wasn't dependent on zmq).

> Also your documentation seems to show that the thread function must be
> provided as unparsed Lua code that will be compiled in the target VM.

This is a Low-Level threads module.  People can use string.dump() or some 
other serialization library if they want to pass complex Lua values to the 
child thread.  I wanted to keep this module as simple as possible.

> Lanes also offers this possibility, but the only reason is to start
> the path toward LuaJIT compatibility, since the other way (using
> lua_dump to move the function proto) isn't available in LuaJIT. Is
> this why you have restricted to this solution?

lua-llthreads & lua-zmq work with LuaJIT2. Lua-zmq is also optimized to use 
LJ2's FFI support.

> Also, since you have
> felt the need for llthreads, there is probably some use case that is
> not properly adressed by Lanes. What would that be?

Lanes doesn't fit my needs like ZeroMQ does.  I need a message passing library 
that handles thread-to-thread & host-to-host communication and that supports 
multiple languages [1].  Also most of the programs I write are network 
services that use event loops for non-blocking network IO and ZeroMQ sockets 
can be used in an event loop like normal sockets.

I ported the latency & throughput benchmarks from lua-zmq to the Lanes 
interface (see the two attached lua scripts).  I wasn't able to get Lanes to 
work on LuaJIT2 even when using unparsed Lua code for the thread function.

Latency:
Message size: 512 bytes
roundtrip count: 1,000,000

Lanes 2.1 Lua 5.1.4:
mean latency: 10.318 microseconds.

ZeroMQ Lua 5.1.4:
mean latency: 7.027 microseconds

ZeroMQ LuaJIT2:
mean latency: 6.280 microseconds

Throughput for Lanes is much lower then ZeroMQ:
Message size: 512 bytes
message count: 1,000,000

Lanes 2.1 Lua 5.1.4:
mean throughput: 97,141 msg/second
mean throughput: 398 MBits/second

ZeroMQ Lua 5.1.4:
mean throughput: 1,275,092 msg/second
mean throughput: 5,223 MBits/second

ZeroMQ LuaJIT2:
mean throughput: 1,777,966 msg/second
mean throughput: 7,283 MBits/second

For Lanes I had to tweak the queue limit, since it was taking way to long with 
the default queue length.

For smaller messages (1-30 bytes) ZeroMQ+LuaJIT2 can get above 4Million 
message per second.

The above tests where run on Linux 2.6.36 x86_64 CPU: AMD Athlon II X2 250 
(Dual-core 3Ghz).

Also sometime the lanes_*.lua scripts would crash with a double free error 
(See the attached lanes_lat_errors.log for the output from valgrind).

1. http://www.zeromq.org/bindings:_start

-- 
Robert G. Jakabosky

-- Copyright (c) 2011 Robert G. Jakabosky <bobby@sharedrealm.com>
--
-- Permission is hereby granted, free of charge, to any person obtaining a copy
-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:
--
-- The above copyright notice and this permission notice shall be included in
-- all copies or substantial portions of the Software.
--
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-- THE SOFTWARE.

if #arg < 1 then
	print("usage: lua " .. arg[0] .. " [message-size] [roundtrip-count]")
end

local message_size = tonumber(arg[1] or 1)
local roundtrip_count = tonumber(arg[2] or 100000)

require "lanes"

local linda= lanes.linda()

local socket = require"socket"
local time = socket.gettime

local function child_code()
	local msg

	for i = 1, roundtrip_count do
		msg = assert(linda:receive("x"))
		assert(#msg == message_size, "Invalid message size")
		assert(linda:send("y", msg))
	end
end

local child_thread = lanes.gen("", child_code)()
print("child:", child_thread)

local msg = ("0"):rep(message_size)

print(string.format("message size: %i [B]", message_size))
print(string.format("roundtrip count: %i", roundtrip_count))

local start_time = time()

for i = 1, roundtrip_count do
	assert(linda:send("x", msg))
	msg = assert(linda:receive("y"))
	assert(#msg == message_size, "Invalid message size")
end

local end_time = time()

print("child.join:",child_thread:join())

local elapsed = end_time - start_time
local latency = elapsed * 1000000 / roundtrip_count / 2

print(string.format("mean latency: %.3f [us]", latency))

child:  userdata: 0x5b637c8
message size: 30 [B]
roundtrip count: 1000
child.join:
mean latency: 421.994 [us]
==19730== Thread 2:
==19730== Invalid read of size 8
==19730==    at 0x5ED8F12: lane_main (lanes.c:856)
==19730==    by 0x60E8D59: start_thread (pthread_create.c:301)
==19730==  Address 0x5b36be8 is 136 bytes inside a block of size 144 free'd
==19730==    at 0x4C278CD: free (vg_replace_malloc.c:366)
==19730==    by 0x5ED9323: selfdestruct_atexit (lanes.c:1004)
==19730==    by 0x552F8B4: __cxa_finalize (cxa_finalize.c:56)
==19730==    by 0x5ED6925: ??? (in /usr/lib64/lua/luarocks/lib/lua/5.1/lua51-lanes.so)
==19730==    by 0x5EDD420: ??? (in /usr/lib64/lua/luarocks/lib/lua/5.1/lua51-lanes.so)
==19730==    by 0x401378D: _dl_close (dl-close.c:747)
==19730==    by 0x400DA68: _dl_catch_error (dl-error.c:178)
==19730==    by 0x50B336C: _dlerror_run (dlerror.c:164)
==19730==    by 0x50B305E: dlclose (dlclose.c:48)
==19730==    by 0x42C4BF: gctm (loadlib.c:64)
==19730==    by 0x40B450: luaD_precall (ldo.c:319)
==19730==    by 0x40BA72: luaD_call (ldo.c:376)
==19730== 
==19730== Invalid free() / delete / delete[]
==19730==    at 0x4C278CD: free (vg_replace_malloc.c:366)
==19730==    by 0x5ED8F7D: lane_main (lanes.c:1329)
==19730==    by 0x60E8D59: start_thread (pthread_create.c:301)
==19730==  Address 0x5b36b60 is 0 bytes inside a block of size 144 free'd
==19730==    at 0x4C278CD: free (vg_replace_malloc.c:366)
==19730==    by 0x5ED9323: selfdestruct_atexit (lanes.c:1004)
==19730==    by 0x552F8B4: __cxa_finalize (cxa_finalize.c:56)
==19730==    by 0x5ED6925: ??? (in /usr/lib64/lua/luarocks/lib/lua/5.1/lua51-lanes.so)
==19730==    by 0x5EDD420: ??? (in /usr/lib64/lua/luarocks/lib/lua/5.1/lua51-lanes.so)
==19730==    by 0x401378D: _dl_close (dl-close.c:747)
==19730==    by 0x400DA68: _dl_catch_error (dl-error.c:178)
==19730==    by 0x50B336C: _dlerror_run (dlerror.c:164)
==19730==    by 0x50B305E: dlclose (dlclose.c:48)
==19730==    by 0x42C4BF: gctm (loadlib.c:64)
==19730==    by 0x40B450: luaD_precall (ldo.c:319)
==19730==    by 0x40BA72: luaD_call (ldo.c:376)
==19730== 
Killed 1 lane(s) at process end.

-- Copyright (c) 2011 Robert G. Jakabosky <bobby@sharedrealm.com>
--
-- Permission is hereby granted, free of charge, to any person obtaining a copy
-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:
--
-- The above copyright notice and this permission notice shall be included in
-- all copies or substantial portions of the Software.
--
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-- THE SOFTWARE.

if #arg < 1 then
    print("usage: lua " .. arg[0] .. " [message-size] [message-count]")
end

local message_size = tonumber(arg[1] or 1)
local message_count = tonumber(arg[2] or 100000)

require "lanes"

local linda= lanes.linda()

linda:limit("x", 100)

local socket = require"socket"
local time = socket.gettime

local function child_code()
	local socket = require"socket"
	local time = socket.gettime

	local msg = ("0"):rep(message_size)

	local start_time = time()

	for i = 1, message_count do
		linda:send("x", msg)
	end

	local end_time = time()

	local elapsed = end_time - start_time
	if elapsed == 0 then elapsed = 1 end
	
	local throughput = message_count / elapsed
	local megabits = throughput * message_size * 8 / 1000000
	
	print(string.format("Sender mean throughput: %i [msg/s]", throughput))
	print(string.format("Sender mean throughput: %.3f [Mb/s]", megabits))

	print("sending thread finished.")
end

local child_thread = lanes.gen("*", child_code)()
print("child:", child_thread)

print(string.format("message size: %i [B]", message_size))
print(string.format("message count: %i", message_count))

local msg

msg = linda:receive("x")

local start_time = time()

for i = 1, message_count - 1 do
	msg = linda:receive(3.0, "x")
	assert(#msg == message_size, "Invalid message size")
end

local end_time = time()

print("child.join:",child_thread:join())

local elapsed = end_time - start_time
if elapsed == 0 then elapsed = 1 end

local throughput = message_count / elapsed
local megabits = throughput * message_size * 8 / 1000000

print(string.format("mean throughput: %i [msg/s]", throughput))
print(string.format("mean throughput: %.3f [Mb/s]", megabits))