[Haskell-cafe] Threads freezing
Roel van Dijk
vandijk.roel at gmail.com
Sun Apr 25 10:45:26 EDT 2010
The problem could be in your use of forkIO.
To quote the documentation of forkOS :
>Like forkIO, this sparks off a new thread to run the IO computation passed as the first argument, and returns the ThreadId of the newly created thread.
>However, forkOS creates a bound thread, which is necessary if you need to call foreign (non-Haskell) libraries that make use of thread-local state, such as OpenGL (see Control.Concurrent).
So you have to make sure that all calls to OpenGL originate from a
bound thread and furthermore that all calls to OpenGL originate from
_the same_ thread.
1 - http://hackage.haskell.org/packages/archive/base/22.214.171.124/doc/html/Control-Concurrent.html#v%3AforkOS
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