Re: [Haskell-cafe] network-conduit proxy
Thanks for explaining the problem. I guess I have to ditch my preconceived notions (based on using Java/.Net) that killing a thread is dangerous. Thanks again, Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] network-conduit proxy
Sun, Mar 11, 2012 at 05:16:06PM +, grant wrote Thanks for explaining the problem. I guess I have to ditch my preconceived notions (based on using Java/.Net) that killing a thread is dangerous. Thanks again, Grant Don't know if it's a good way, but if you are afraid of killing thread you can use thread communication like you can use asynchronous exceptions or channels. So you can do smth like: (sourceClient $= CL.map Left) = (sourceTMChan communicationChannel $= CL.map Right) And have all data in Left and all commands in Right. This is really overkill for such a task but it can be usefull for more complicated ones, where there are communication between threads. -- Alexander V Vershilov signature.asc Description: Digital signature ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] network-conduit proxy
So you can do smth like: (sourceClient $= CL.map Left) = (sourceTMChan communicationChannel $= CL.map Right) Alexander V Vershilov That's a great idea, I'll give that a try. I was having an odd problem with killThread on windows where the first character would be lost in the next session straight after the killThread, so your idea looks more appealing. Thanks again, Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] network-conduit proxy
I think I missed something in this thread. What's the bug in network-conduit? I'd like to have it patched in the next release. On Sat, Mar 10, 2012 at 9:19 AM, grant the...@hotmail.com wrote: Excellent. registering killThread works great. Hopefully the library will be fixed correctly. Thanks a lot for your help, Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] network-conduit proxy
Unfortunately I don't have a solution to this. Here is some code and output that hopefully explains what is happening https://gist.github.com/2012723 The problem is that the clientSrc $$ serverSink appears to run and according to Alexander, the socket closes. But the thread seems to hang inside the clientSrc $$ serverSink command and then nothing after that command is run (until the process is terminated). I would have expected the register command to run and the statement END clientSrc serverSink to display. When I kill the process on Ubuntu all three exceptions are then thrown at once and the rest of the thread continue. Thanks for taking a look at this, Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] network-conduit proxy
Seems to work perfectly for me. The statement you're expecting to be printed won't be printed until the original server (running on 5000) closes its socket. If I connect it to Warp, this takes about 30 seconds, which is the slowloris timeout period. On Sat, Mar 10, 2012 at 10:01 PM, grant the...@hotmail.com wrote: Unfortunately I don't have a solution to this. Here is some code and output that hopefully explains what is happening https://gist.github.com/2012723 The problem is that the clientSrc $$ serverSink appears to run and according to Alexander, the socket closes. But the thread seems to hang inside the clientSrc $$ serverSink command and then nothing after that command is run (until the process is terminated). I would have expected the register command to run and the statement END clientSrc serverSink to display. When I kill the process on Ubuntu all three exceptions are then thrown at once and the rest of the thread continue. Thanks for taking a look at this, Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] network-conduit proxy
The problem is, how would I then go about creating a proxy like tcpmon? I was going to replace this code 'clientSrc $$ serverSink' with this 'clientSrc $$ (sinkFork (sinkFile randomname) serverSink' and the same for the 'serverSrc $$ clientSink' part. However, since the 'clientSrc $$ serverSink' part will be suspended until the process has ended, I would be holding on to open resources for the whole time. Is there a better way to create this proxy? Thanks, Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] network-conduit proxy
You're running `clientSrc $$ serverSink` in a separate thread. What it's doing is blocking for any kind of input from clientSrc before it can continue. That thread knows nothing about the rest of the program, including that serverSink is closed. This is inherent to the network functions involved here. It seems like this is a perfect time to pull out killThread, as Alexander mentioned. It's a way to send a signal to a blocked thread, which is what you have here. All of the conduit libraries have been designed from the ground up to work correctly with asynchronous exceptions, and all resources will be freed correctly. Is there a specific reason why this seems like the wrong approach here? Michael On Sat, Mar 10, 2012 at 11:12 PM, grant the...@hotmail.com wrote: The problem is, how would I then go about creating a proxy like tcpmon? I was going to replace this code 'clientSrc $$ serverSink' with this 'clientSrc $$ (sinkFork (sinkFile randomname) serverSink' and the same for the 'serverSrc $$ clientSink' part. However, since the 'clientSrc $$ serverSink' part will be suspended until the process has ended, I would be holding on to open resources for the whole time. Is there a better way to create this proxy? Thanks, Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] network-conduit proxy
Hello.
I'm not expert but first you should not use Network sockets, because everything
is included into Data.Conduit.Network, just use high level API.
Second, you should use not server inside client but client inside server:
so you can make such a code [1]:
{-# OPTIONS -Wall #-}
import Data.Conduit
import Data.Conduit.Network
import Control.Monad.IO.Class (liftIO)
import Control.Concurrent.Lifted (fork)
main::IO ()
main =
runTCPServer (ServerSettings 5002 Nothing) $ \clientSrc clientSink - do
liftIO $ runTCPClient (ClientSettings 5000 localhost) $ \serverSrc
serverSink - do
_ - liftIO $ fork $ runResourceT $ serverSrc $$ clientSink
clientSrc $$ serverSink
tested and works
[1] https://gist.github.com/2008113
--
Alexander V Vershilov
Fri, Mar 09, 2012 at 05:44:29PM +, grant wrote
I am trying to get a proxy working using the network-conduit package on
windows.
So I send a request to port 5002 and that gets forwarded to another port 5000
where I have a simple echo server running.
I made a stab at it, but get intermittent send errors after the first
connection
Here is the code:
{-# OPTIONS -Wall #-}
import Data.Conduit
import Data.Conduit.Network
import Network (withSocketsDo)
import Control.Monad.IO.Class (liftIO)
import Control.Monad.Trans.Resource
main::IO ()
main =
withSocketsDo $ runTCPClient (ClientSettings 5000 localhost) $
\src1 sink1 - do
liftIO $ print in tcpclient section
liftIO $ withSocketsDo $ runTCPServer (ServerSettings 5002 Nothing) $
\src sink - do
liftIO $ print in tcpserver section
_ - liftIO $ runResourceT $ resourceForkIO $ do
src1 $$ sink
return ()
src $$ sink1
Thanks for any help,
Grant
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Re: [Haskell-cafe] network-conduit proxy
When I run the code you suggested on windows I get the following error: getAddrInfo: does not exist (error 10093) which probably refers to http://trac.haskell.org/network/ticket/32 After adding withSocketsDo I get a little further, but get the following error after sending data through the proxy: netproxy2: Network.Socket.ByteString.recv: failed (Unknown error) Any ideas? Thanks so much for your help with this. Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] network-conduit proxy
For first error it seems best way will be patching conduit-network as it done it warp [1]. I don't know how to deal with second error. [1] http://hackage.haskell.org/packages/archive/warp/1.1.0.1/doc/html/src/Network-Wai-Handler-Warp.html#runSettings -- Alexander V Vershilov Fri, Mar 09, 2012 at 07:52:39PM +, grant wrote When I run the code you suggested on windows I get the following error: getAddrInfo: does not exist (error 10093) which probably refers to http://trac.haskell.org/network/ticket/32 After adding withSocketsDo I get a little further, but get the following error after sending data through the proxy: netproxy2: Network.Socket.ByteString.recv: failed (Unknown error) Any ideas? Thanks so much for your help with this. Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe signature.asc Description: Digital signature ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] network-conduit proxy
I've tried running the code with runTCPServer first but I get
recv: invalid argument (Bad file descriptor) on ubuntu (virtualbox)
and when running on windows
I get Network.Socket.ByteString.recv: failed (Unknown error).
Also, it seems odd that when I run this code https://gist.github.com/2010354
that it doesn't print END serverSrc clientSink.
Is this the expected behaviour or are resources not being closed?
Again the same thing happens when running on Ubuntu.
{- here is the output ...
C:\haskellnetproxy4
START clientSrc serverSink
START serverSrc clientSink
END clientSrc serverSink
START serverSrc clientSink
START clientSrc serverSink
END clientSrc serverSink
-}
Thanks for any ideas.
Grant
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Re: [Haskell-cafe] network-conduit proxy
As it seems from code runTCPServer registers socket close
and TCPClient runs it in bracket so all open resources should be
closed. It my last try I add
_ - register $ killThread tId
after forking serverSrc $$ clientSink, to kill outter thread explicilty
otherwise it closes thread with error.
Is this the expected behaviour or are resources not being closed?
In 'strace' log it seems that both sockets is closed. So I think that
computation is closed before reaching the end because src $$ sink closed
with error. If you want to run action at the end you can register it
--
Alexander V Vershilov
Sat, Mar 10, 2012 at 05:43:12AM +, grant wrote
I've tried running the code with runTCPServer first but I get
recv: invalid argument (Bad file descriptor) on ubuntu (virtualbox)
and when running on windows
I get Network.Socket.ByteString.recv: failed (Unknown error).
Also, it seems odd that when I run this code
https://gist.github.com/2010354
that it doesn't print END serverSrc clientSink.
Is this the expected behaviour or are resources not being closed?
Again the same thing happens when running on Ubuntu.
{- here is the output ...
C:\haskellnetproxy4
START clientSrc serverSink
START serverSrc clientSink
END clientSrc serverSink
START serverSrc clientSink
START clientSrc serverSink
END clientSrc serverSink
-}
Thanks for any ideas.
Grant
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Re: [Haskell-cafe] network-conduit proxy
Excellent. registering killThread works great. Hopefully the library will be fixed correctly. Thanks a lot for your help, Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
