On Wed, 09 Apr 2008 07:51:50 -0400, "Ken Murchison" <[EMAIL PROTECTED]> said:
> Is there a bug somewhere in the rest of the code that causes this
> problem?
Yeah, folderlimit - another of my patches, but the interface is pretty
dangerous.
I haven't found any other paths yet, but a bug elsewhere could cause skiplist
corruption if it did a read while there was a transaction open - risky and bogus
interface.
The specific pattern is:
1) a transaction is started in WRITE mode (file locked EXCLUSIVE)
2) a read is done without a transaction being passed
2a) file gets re-locked in SHARED mode
2b) file gets unlocked
3) a different process writes to the end of the file
4) the first process believes it still has a lock, and seeks to the end of its
transaction offset and writes.
You get a file that might look something like this
|
v
ADD ADD
COMMIT COMMIT
<- ADD
DELETE COMMIT
ADD ->
COMMIT COMMIT
|
v
So there's junk between the commits that was part of the ADD from the
transaction
in item (3) above.
Bron.
--
Bron Gondwana
[EMAIL PROTECTED]
