open cookie db unshared and exclusive - bug 449987. r=dwitte

netwerk/cookie/src/nsCookieService.cpp

@@ -467,13 +467,13 @@ nsCookieService::InitDB()
     return NS_ERROR_UNEXPECTED;
 
   // cache a connection to the cookie database
-  rv = storage->OpenDatabase(cookieFile, getter_AddRefs(mDBConn));
+  rv = storage->OpenUnsharedDatabase(cookieFile, getter_AddRefs(mDBConn));
   if (rv == NS_ERROR_FILE_CORRUPTED) {
     // delete and try again
     rv = cookieFile->Remove(PR_FALSE);
     NS_ENSURE_SUCCESS(rv, rv);
 
-    rv = storage->OpenDatabase(cookieFile, getter_AddRefs(mDBConn));
+    rv = storage->OpenUnsharedDatabase(cookieFile, getter_AddRefs(mDBConn));
   }
   NS_ENSURE_SUCCESS(rv, rv);
 
@@ -553,6 +553,9 @@ nsCookieService::InitDB()
   // make operations on the table asynchronous, for performance
   mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("PRAGMA synchronous = OFF"));
 
+  // open in exclusive mode for performance
+  mDBConn->ExecuteSimpleSQL(NS_LITERAL_CSTRING("PRAGMA locking_mode = EXCLUSIVE"));
+
   // cache frequently used statements (for insertion, deletion, and updating)
   rv = mDBConn->CreateStatement(NS_LITERAL_CSTRING(
     "INSERT INTO moz_cookies "