Re: [Haskell-cafe] Re: all threads are blocked by recvFrom

Hi Adam, sorry for late answer. Here is my example [1], but yours doesn't work on my PC too. And it's strange it works on yours. According to documentation for Control.Concurrent module [2] every other thread should be blocked.

With the -threaded option, only foreign calls with the unsafe attribute will block all other threads. And after changing in the network package FFI declaration for c_recvfrom from unsafe to safe both examples start working. There are two solutions I see now. The first is to copy-paste definitions from the network package to mine with changing "unsafe" to "safe" for FFI declaration. The second is to use unblocking sockets. This by the way will help to get rid of hack-like solution of stopping server by closing listening socket, but it will get more effort.

[1] http://hpaste.org/6426 [2] http://haskell.org/ghc/docs/latest/html/libraries/base/Control-Concurrent.ht... 2008/3/14, Adam Langley :

On Fri, Mar 14, 2008 at 8:51 AM, Vitaliy Akimov

wrote:

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I assume that you're binding the libc function directly here:

I'm using Network.Socket. Sory if it's not clear from my previous posts.

Then everything should Just Work(tm). You might need to paste in code in order to figure out why this wouldn't be so.

See [1] for an example which works for me. It starts a thread which prints "working..." once a second and, in another thread, listens for UDP packets on port 4112. I can use `nc -u 127.0.0.1 4112` to get this: "working..." "working..." ("testing\n",8,127.0.0.1:36179) "working..." "working..." ("testing two\n",12,127.0.0.1:36179) "working..."

[1] http://hpaste.org/6362

-- Adam Langley agl@imperialviolet.org http://www.imperialviolet.org