setNumCapabilities broken in HEAD
import GHC.Conc
import Control.Monad
main :: IO ()
main = do
n <- getNumCapabilities
when (n == 1) $ setNumCapabilities 2
print ()One would expect this program to print () just once, but when compiled with -O or -O2 it prints () repeatedly and indefinitely!
This doesn't happen on GHC 7.6.2 or 7.4.1, only on HEAD.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.7 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Runtime System |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |