Don't let total_queued go below zero.
diff --git a/main.c b/main.c
index ab686d0..8556c15 100644
--- a/main.c
+++ b/main.c
@@ -1191,7 +1191,8 @@ static void inc_queued(void)
static void dec_queued(void)
{
pthread_mutex_lock(&qd_lock);
- total_queued--;
+ if (total_queued > 0)
+ total_queued--;
pthread_mutex_unlock(&qd_lock);
dec_staged(1);
}