Segfault when lots of blocked MVar messages
I reduced the original problem I started with in #4835 (closed) to the following example, which spans 3 files. There is still further scope for reducing the test case - I have stopped now it's standalone without any data file or package dependencies. I have reproduced this bug on GHC 7.0.2-rc1.
The program does has some parallelism, and due to a bug in the parallel-io library (since fixed) it causes lots of MVar blocked messages. This program sometimes runs to completion, sometimes gives a blocked MVar, and sometimes segfaults. I see the segfault > 50% of the time.
The program is compiled and run with:
ghc --make Main.hs -threaded && Main.exe
Line 82 of Main.hs
does getDirectoryContents "C:/Windows"
. It seems to crash if I put file or directory operations here, but not if I put sleep or pure computation there. This line can be changed to any reasonably sized directory to get the same effects - there is nothing specific to that folder.
Trac metadata
Trac field | Value |
---|---|
Version | 7.0.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Runtime System |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |