1. 25 Mar, 2010 2 commits
  2. 24 Mar, 2010 1 commit
  3. 25 Mar, 2010 3 commits
    • Simon Marlow's avatar
      A sanity check · 18f1d72e
      Simon Marlow authored
      18f1d72e
    • Simon Marlow's avatar
      do_checks: do not set HpAlloc if the stack check fails · 5c3ea9fb
      Simon Marlow authored
      This fixes a very rare heap corruption bug, whereby
      
       - a context switch is requested, which sets HpLim to zero
         (contextSwitchCapability(), called by the timer signal or
         another Capability).
      
       - simultaneously a stack check fails, in a code fragment that has
         both a stack and a heap check.
      
      The RTS then assumes that a heap-check failure has occurred and
      subtracts HpAlloc from Hp, although in fact it was a stack-check
      failure and retreating Hp will overwrite valid heap objects.  The bug
      is that HpAlloc should only be set when Hp has been incremented by the
      heap check.  See comments in rts/HeapStackCheck.cmm for more details.
      
      This bug is probably incredibly rare in practice, but I happened to be
      working on a test that triggers it reliably:
      concurrent/should_run/throwto001, compiled with -O -threaded, args 30
      300 +RTS -N2, run repeatedly in a loop.
      5c3ea9fb
    • Simon Marlow's avatar
      comments and formatting only · 813f208a
      Simon Marlow authored
      813f208a
  4. 24 Mar, 2010 8 commits
  5. 23 Mar, 2010 1 commit
    • Ian Lynagh's avatar
      Tweak the Makefile code for making .a libs; fixes trac #3642 · 64c64a6e
      Ian Lynagh authored
      The main change is that, rather than using "xargs ar" we now put
      all the filenames into a file, and do "ar @file". This means that
      ar adds all the files at once, which works around a problem where
      files with the same basename in a later invocation were overwriting
      the existing file in the .a archive.
      64c64a6e
  6. 20 Mar, 2010 1 commit
  7. 21 Mar, 2010 2 commits
  8. 20 Mar, 2010 1 commit
  9. 19 Mar, 2010 2 commits
  10. 17 Mar, 2010 1 commit
  11. 16 Mar, 2010 1 commit
  12. 17 Mar, 2010 1 commit
  13. 16 Mar, 2010 2 commits
    • Simon Marlow's avatar
      copy_tag_nolock(): fix write ordering and add a write_barrier() · 1a050f3c
      Simon Marlow authored
      Fixes a rare crash in the parallel GC.
      
      If we copy a closure non-atomically during GC, as we do for all
      immutable values, then before writing the forwarding pointer we better
      make sure that the closure itself is visible to other threads that
      might follow the forwarding pointer.  I imagine this doesn't happen
      very often, but I just found one case of it: in scavenge_stack, the
      RET_FUN case, after evacuating ret_fun->fun we then follow it and look
      up the info pointer.
      1a050f3c
    • benl@ouroborus.net's avatar
      3a90968f
  14. 11 Mar, 2010 1 commit
  15. 15 Mar, 2010 2 commits
  16. 14 Mar, 2010 3 commits
  17. 13 Mar, 2010 3 commits
  18. 11 Mar, 2010 3 commits
    • Simon Marlow's avatar
    • Simon Marlow's avatar
      Use message-passing to implement throwTo in the RTS · 7408b392
      Simon Marlow authored
      This replaces some complicated locking schemes with message-passing
      in the implementation of throwTo. The benefits are
      
       - previously it was impossible to guarantee that a throwTo from
         a thread running on one CPU to a thread running on another CPU
         would be noticed, and we had to rely on the GC to pick up these
         forgotten exceptions. This no longer happens.
      
       - the locking regime is simpler (though the code is about the same
         size)
      
       - threads can be unblocked from a blocked_exceptions queue without
         having to traverse the whole queue now.  It's a rare case, but
         replaces an O(n) operation with an O(1).
      
       - generally we move in the direction of sharing less between
         Capabilities (aka HECs), which will become important with other
         changes we have planned.
      
      Also in this patch I replaced several STM-specific closure types with
      a generic MUT_PRIM closure type, which allowed a lot of code in the GC
      and other places to go away, hence the line-count reduction.  The
      message-passing changes resulted in about a net zero line-count
      difference.
      7408b392
    • Simon Marlow's avatar
      12cfec94
  19. 23 Nov, 2009 1 commit
  20. 09 Mar, 2010 1 commit