System.Posix.Semaphore shouldn't create finalizers with Foreign.newForeignPtr
Running this program
import System.Posix.Semaphore
main = do
s <- semOpen "c" (OpenSemFlags True False) 0666 1
semThreadWait s
v <- semGetValue s
putStrLn "Type!"
a <- getLine
putStrLn $ "OK, " ++ a
semPost s
fails like this:
Type!
abc
OK, abc
sem: error: a C finalizer called back into Haskell.
This was previously allowed, but is disallowed in GHC 6.10.2 and later.
To create finalizers that may call back into Haskll, use
Foreign.Concurrent.newForeignPtr instead of Foreign.newForeignPtr.
The attached patch for libraries/unix/System/Posix/Semaphore.hsc should fix this.
Trac metadata
Trac field | Value |
---|---|
Version | 6.10.4 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | libraries/unix |
Test case | |
Differential revisions | |
BlockedBy | |
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Blocking | |
CC | |
Operating system | |
Architecture |