diff options
| -rw-r--r-- | src/manager.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/src/manager.c b/src/manager.c index 933dd5064f..a71150d0a9 100644 --- a/src/manager.c +++ b/src/manager.c @@ -964,20 +964,25 @@ static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned /* Does a recursive sweep through the ordering graph, looking * for a cycle. If we find cycle we try to break it. */ - /* Did we find a cycle? */ - if (j->marker && j->generation == generation) { + /* Have we seen this before? */ + if (j->generation == generation) { Job *k; - /* So, we already have been here. We have a - * cycle. Let's try to break it. We go backwards in - * our path and try to find a suitable job to - * remove. We use the marker to find our way back, - * since smart how we are we stored our way back in - * there. */ + /* If the marker is NULL we have been here already and + * decided the job was loop-free from here. Hence + * shortcut things and return right-away. */ + if (!j->marker) + return 0; + /* So, the marker is not NULL and we already have been + * here. We have a cycle. Let's try to break it. We go + * backwards in our path and try to find a suitable + * job to remove. We use the marker to find our way + * back, since smart how we are we stored our way back + * in there. */ log_debug("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type)); - for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) { + for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) { log_debug("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type)); @@ -1002,8 +1007,10 @@ static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned } /* Make the marker point to where we come from, so that we can - * find our way backwards if we want to break a cycle */ - j->marker = from; + * find our way backwards if we want to break a cycle. We use + * a special marker for the beginning: we point to + * ourselves. */ + j->marker = from ? from : j; j->generation = generation; /* We assume that the the dependencies are bidirectional, and @@ -1035,6 +1042,7 @@ static int transaction_verify_order(Manager *m, unsigned *generation) { Job *j; int r; Iterator i; + unsigned g; assert(m); assert(generation); @@ -1042,8 +1050,10 @@ static int transaction_verify_order(Manager *m, unsigned *generation) { /* Check if the ordering graph is cyclic. If it is, try to fix * that up by dropping one of the jobs. */ + g = (*generation)++; + HASHMAP_FOREACH(j, m->transaction_jobs, i) - if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0) + if ((r = transaction_verify_order_one(m, j, NULL, g)) < 0) return r; return 0; |