[pacman-dev] logging output crazy

[Xavier]

On Fri, Jul 06, 2007 at 11:29:55PM +0200, Xavier wrote:
> There is a second problem (still unusual case) that I need to figure out :
> when first installing a package as root, then installing a package as user,
> I get the error and behavior as described here :
> http://www.archlinux.org/pipermail/pacman-dev/2007-April/008008.html
> ie pacman freezes and can't even be cancelled with ctrl+C.
> 
> It would be nicer if it exited cleanly instead :)

The problem is that when a transaction fails, trans->state isn't set
to STATE_COMMITED, but stays on STATE_COMMITING
(see _alpm_trans_commit function in libalm/trans.c).
Then when _alpm_trans_release is called, it does the following :

195   /* during a commit do not interrupt immediately, just after a target */
196   if(trans->state == STATE_COMMITING || trans->state == STATE_INTERRUPTED) {
197     if(trans->state == STATE_COMMITING) {
198       trans->state = STATE_INTERRUPTED;
199     }
200     pm_errno = PM_ERR_TRANS_COMMITING;
201     return(-1);
202   }

Does anyone understand the comment above?
Anyway, now the state is set to INTERRUPTED.
And the alpm_release function in libalpm/alpm.c :

77   while((dbs_left = alpm_list_count(handle->dbs_sync)) > 0) {
78     pmdb_t *db = (pmdb_t *)handle->dbs_sync->data;
79     _alpm_log(PM_LOG_DEBUG, _("removing DB %s, %d remaining..."), db->treename,
80     alpm_db_unregister(db);
81     db = NULL;
82   }

There is an infinite loop there when alpm_db_unregister (db.c) fails,
and it fails when handle->trans isn't NULL :
86   /* Do not unregister a database if a transaction is on-going */
87   ASSERT(handle->trans == NULL, RET_ERR(PM_ERR_TRANS_NOT_NULL, -1));

Could we consider that when trans is not NULL, but trans->state
is set to STATE_INTERRUPTED, then it isn't a on-going transaction anymore,
and so we can unregister the database safely ?


>From b130e08ed216e3a9caa0026bec213d9a0a5fa094 Mon Sep 17 00:00:00 2001
From: Chantry Xavier <shiningxc at gmail.com>
Date: Sat, 7 Jul 2007 21:24:30 +0200
Subject: [PATCH] libalpm/db.c : allow unregistering db for interrupted transaction.

This prevents alpm_release to loop infinitely in case of
an interrupted transaction, where the database wasn't
unregistered.
alpm_release should probably also be fixed, as it can
still loop if db_unregister fails for another reason.

Signed-off-by: Chantry Xavier <shiningxc at gmail.com>
---
 lib/libalpm/db.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/lib/libalpm/db.c b/lib/libalpm/db.c
index 95a1ecb..7cc9390 100644
--- a/lib/libalpm/db.c
+++ b/lib/libalpm/db.c
@@ -84,7 +84,8 @@ int SYMEXPORT alpm_db_unregister(pmdb_t *db)
 	ASSERT(handle != NULL, RET_ERR(PM_ERR_HANDLE_NULL, -1));
 	ASSERT(db != NULL, RET_ERR(PM_ERR_WRONG_ARGS, -1));
 	/* Do not unregister a database if a transaction is on-going */
-	ASSERT(handle->trans == NULL, RET_ERR(PM_ERR_TRANS_NOT_NULL, -1));
+	ASSERT(handle->trans == NULL || handle->trans->state == STATE_INTERRUPTED, 
+			RET_ERR(PM_ERR_TRANS_NOT_NULL, -1));
 
 	if(db == handle->db_local) {
 		handle->db_local = NULL;
-- 
1.5.2.2