[patch] remove_wrong_dependencies.patch

remove_wrong_dependencies.patch (text/plain), 2.69 KB, created by iGentoo on 2011-12-01 22:03:22 UTC

 src/librc/librc-depend.c |   59 ++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 59 insertions(+), 0 deletions(-)

diff --git a/src/librc/librc-depend.c b/src/librc/librc-depend.c
index 3aa9457..1a4e15d 100644
--- a/src/librc/librc-depend.c
+++ b/src/librc/librc-depend.c
@@ -442,6 +442,61 @@ visit_service(const RC_DEPTREE *deptree,
 	}
 }
 
+static void
+remove_wrong_depends(RC_DEPTREE *deptree, const char *type)
+{
+	/* Remove wrong dependencies:
+	 *    svc1 > svc2 > svc3 > svc1
+	 *    svc1 < svc2 < svc3 < svc1
+	 * '>' means 'ibefore', '<' means 'iafter'.
+	 */
+
+	RC_DEPINFO *depinfo = NULL, *di, *di2;
+	RC_DEPTYPE *deptype = NULL, *dt, *dt2;
+	RC_STRING *s, *s_np, *s2, *s2_np, *s3, *s3_np;
+	char *svc1, *svc2, *svc3;
+
+	TAILQ_FOREACH(depinfo, deptree, entries) {
+		if ((deptype = get_deptype(depinfo, type))) {
+			svc1 = depinfo->service;
+			TAILQ_FOREACH_SAFE(s, deptype->services, entries, s_np) {
+				svc2 = s->value; // svc2 != svc1
+				if ((di = get_depinfo(deptree, svc2)) &&
+					(dt = get_deptype(di, type))) {
+					TAILQ_FOREACH_SAFE(s2, dt->services, entries, s2_np) {
+						svc3 = s2->value; // svc3 != svc2 && svc3 != svc1
+						if (strcmp(svc3, svc1) &&
+							(di2 = get_depinfo(deptree, svc3)) &&
+							(dt2 = get_deptype(di2, type))) {
+							TAILQ_FOREACH_SAFE(s3, dt2->services, entries, s3_np) {
+								if (!strcmp(s3->value, svc1)) {
+									/* svc1 > svc2 > svc3 > (s3->value) = svc1 */
+									// printf("Wrong deps: %s %s %s\n", svc1, svc2, svc3);
+
+									/* Remove svc3 > svc1, svc2 > svc3 and svc1 > svc2. */
+									rc_stringlist_delete(dt2->services, svc1);
+									rc_stringlist_delete(dt->services, svc3);
+									rc_stringlist_delete(deptype->services, svc2);
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+
+	/* 1. svc1 > svc2 > svc1 doesn't hang, so we check svc3 != svc1.
+	 * 2. Assume we have three wrong dependencies:
+	 *		crypto-loop	>	localmount	>	migrate-run
+	 *		hwclock		>	localmount	>	migrate-run
+	 *		localmount	>	migrate-run	>	modules
+	 *    Remove first one, second and third ones will not be wrong dependencies.
+	 * 3. We could remove wrong dependencies ( svc1 > svc2 > svc3 > svc4 > svc1 )
+	 *    in a similar way.
+	 */
+}
+
 RC_STRINGLIST *
 rc_deptree_depend(const RC_DEPTREE *deptree,
 		  const char *service, const char *type)
@@ -998,6 +1053,10 @@ rc_deptree_update(void)
 	}
 	rc_stringlist_free(types);
 
+	/* Phase 5.5 - wrong dependencies cause a hang in parallel mode */
+	remove_wrong_depends(deptree, "ibefore");
+	remove_wrong_depends(deptree, "iafter");
+
 	/* Phase 6 - save to disk
 	   Now that we're purely in C, do we need to keep a shell parseable file?
 	   I think yes as then it stays human readable