On 16/04/2007, at 12:30, Mitar wrote:
Hi!
On 4/16/07, Bertram Felgenhauer
<[EMAIL PROTECTED]> wrote:
> Since all the threads block on a single MVar how do they run in
> parallel?
The idea is that before the threads block on the MVar, they run their
action x to completion.
The rendering crashes. I will have to precompute the values in threads
someway and then sequentially draw it? Any suggestion how to do that?
Could it be that you are launching 400x300=120.000 new threads all at
once?
If you are not doing it already, it would be sensible to implement
some pooling of threads.
This is what I use myself, don't worry about the unsafeness IF you
know that the sequence of computations doesn't matter:
\begin{code}
unsafeParMapM :: (a -> IO b) -> [a] -> IO [b]
unsafeParMapM f = return . parMap rwhnf (unsafePerformIO . f)
unsafeParMapMn :: Integral bound => bound -> (a -> IO b) -> [a] -> IO
[b]
unsafeParMapMn max f xx = return (map (unsafePerformIO . f) xx
`using`
parListChunk (fromIntegral max) rwhnf)
unsafeParSeqn :: Integral bound => bound -> [IO a] -> IO [a]
unsafeParSeqn max cc = return ((map unsafePerformIO cc)
`using`
parListChunk (fromIntegral max) rwhnf)
\begin{code}
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