How does forkIO and par interact?
Marcus D. Gabriel
marcus at gabriel.name
Sun Dec 20 08:17:26 EST 2009
How does forkIO (forkOS) and par interact with one another? Here is
why I ask.
I have a GUI application that has something like this:
th <- forkIO (guiCode + longRunningPureSerialCode)
Later, a user interaction invokes
and the guiCode plus the longRunningPureSerialCode suspends quite
nicely. Now I have
th <- forkIO (guiCode + longRunningPureParallelCode)
Later a user interaction invokes killThread th again but I have
observed under 6.10.4 that not all is suspended. From what I have
observed, I believe that if
longRunningPureParallelCode = ... 1stPart `par` 2ndPart ...
the 2ndPart is suspended by killThread th along with the guiCode, and
the 1stPart happily continues calcualting. (I believe this is correct
but it could be the other way around.)
For my little application, having everything suspend would have been
nice, but that's my app.
So, under ghc, how is forkIO (forkOS) and par supposed to operationally
interact with one another?
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