Repository : ssh://darcs.haskell.org//srv/darcs/ghc On branch : ghc-7.6
http://hackage.haskell.org/trac/ghc/changeset/d71d19731f593d6d09d7cb982f0cde46d07787d1 >--------------------------------------------------------------- commit d71d19731f593d6d09d7cb982f0cde46d07787d1 Author: Ian Lynagh <i...@well-typed.com> Date: Thu Jan 3 22:34:21 2013 +0000 Revert "MERGED: Fix a bug in the handling of nested orElse" This reverts commit 5ea49271f793ed0f872342bf6a1cb0de10a48d94. >--------------------------------------------------------------- rts/STM.c | 24 +++--------------------- 1 files changed, 3 insertions(+), 21 deletions(-) diff --git a/rts/STM.c b/rts/STM.c index b988358..f8f56a2 100644 --- a/rts/STM.c +++ b/rts/STM.c @@ -1447,28 +1447,10 @@ StgBool stmCommitNestedTransaction(Capability *cap, StgTRecHeader *trec) { StgTVar *s; s = e -> tvar; - - // Careful! We might have a read entry here that we don't want - // to spam over the update entry in the enclosing TRec. e.g. in - // - // t <- newTVar 1 - // writeTVar t 2 - // ((readTVar t >> retry) `orElse` return ()) `orElse` return () - // - // - the innermost txn first aborts, giving us a read-only entry - // with e->expected_value == e->new_value == 1 - // - the inner orElse commits into the outer orElse, which - // lands us here. If we unconditionally did - // merge_update_into(), then we would overwrite the outer - // TRec's update, so we must check whether the entry is an - // update or not, and if not, just do merge_read_into. - // - if (entry_is_update(e)) { + if (entry_is_update(e)) { unlock_tvar(trec, s, e -> expected_value, FALSE); - merge_update_into(cap, et, s, e -> expected_value, e -> new_value); - } else { - merge_read_into(cap, et, s, e -> expected_value); - } + } + merge_update_into(cap, et, s, e -> expected_value, e -> new_value); ACQ_ASSERT(s -> current_value != (StgClosure *)trec); }); } else { _______________________________________________ Cvs-ghc mailing list Cvs-ghc@haskell.org http://www.haskell.org/mailman/listinfo/cvs-ghc
