Add and fix some comments regarding the reasons behind the pipe etc.
No code changes.
Signed-off-by: Pete Zaitcev <zaitcev@xxxxxxxxxx>
---
lib/cldc.c | 27 ++++++++++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)
commit e675f2f316bbb24ca84c1bc23e4d1c6d53b029de
Author: Master <zaitcev@xxxxxxxxxxxxxxxxxx>
Date: Sat Apr 17 19:14:30 2010 -0600
Fix commentary.
diff --git a/lib/cldc.c b/lib/cldc.c
index c1e8993..6ab2fe4 100644
--- a/lib/cldc.c
+++ b/lib/cldc.c
@@ -1372,7 +1372,7 @@ enum {
/*
* All the error printouts are likely to be lost for daemons, but it's
- * not a big deal. We abort instead of exist to indicate that something
+ * not a big deal. We abort instead in order to indicate that something
* went wrong, so system features should report it (usualy as a core).
* When debugging, strace or -F mode will capture the output.
*/
@@ -1503,13 +1503,29 @@ static void ncld_p_event(void *priv, struct cldc_session *csp,
if (!nsess->is_up)
return;
nsess->is_up = false;
- /* XXX wake up all I/O waiters here */
+
+ /*
+ * The cldc layer must deliver the callbacks for all pending
+ * CLD operations of the failed session. If we force-wake their
+ * waiters, all sorts of funny things happen with the lifetimes
+ * of related structures.
+ */
+ //
+ // g_cond_broadcast(nsess->cond);
+
/*
* This is a trick. As a direct callback from clcd layer,
* we are running under nsess->mutex, so we cannot call back
* into a user of ncld. If we do, it may invoke another
* ncld operation and deadlock. So, bump session callbacks
* into the part of the helper thread that runs unlocked.
+ *
+ * Notice that we are already running on the context of the
+ * thread that will deliver the event, so pipe really is not
+ * needed: could as well set a flag and test it right after
+ * the call to cldc_udp_receive_pkt(). But pipe also provides
+ * a queue of events, just in case. It's not like these events
+ * are super-performance critical.
*/
cmd = NCLD_CMD_SESEV;
write(nsess->to_thread[1], &cmd, 1);
@@ -1820,7 +1836,12 @@ int ncld_del(struct ncld_sess *nsess, const char *fname)
g_mutex_unlock(nsess->mutex);
return -rc;
}
- /* XXX A delete operation is not accounted for end-session */
+ /*
+ * A delete operation is not accounted for end-session (e.g. nios).
+ * This means: do not call ncld_del and ncld_close together.
+ * The ncld_close can be invoked by ncld_sess_close, so don't
+ * do that either.
+ */
g_mutex_unlock(nsess->mutex);
rc = ncld_wait_del(&dpb);
--
To unsubscribe from this list: send the line "unsubscribe hail-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
