comment

2015-12-16 13:24:45 -04:00 · 2015-12-16 13:24:45 -04:00 · 1a051f4300
commit 1a051f4300
parent 1e016611de
1 changed files with 8 additions and 1 deletions
--- a/Database/Keys.hs
+++ b/Database/Keys.hs
@ -54,7 +54,14 @@ Content
  KeyCacheIndex key cache
 |]

-{- Opens the database, creating it if it doesn't exist yet. -}
+{- Opens the database, creating it if it doesn't exist yet.
+ -
+ - Multiple readers and writers can have the database open at the same
+ - time. Database.Handle deals with the concurrency issues.
+ - The lock is held while opening the database, so that when
+ - the database doesn't exist yet, one caller wins the lock and
+ - can create it undisturbed.
+ -}
 openDb :: Annex DbHandle
 openDb = withExclusiveLock gitAnnexKeysDbLock $ do
 	dbdir <- fromRepo gitAnnexKeysDb