Move tag locking within _starpu_notify_cg

We were already unlocking just after calling it anyway, and will allow
to drop a re-lock in the next commit.

src/core/dependencies/cg.c

@@ -169,7 +169,6 @@ int _starpu_list_tag_successors_in_cg_list(struct _starpu_cg_list *successors, u
 	return n;
 }
 
-/* Note: in case of a tag, it must be already locked */
 void _starpu_notify_cg(void *pred STARPU_ATTRIBUTE_UNUSED, struct _starpu_cg *cg)
 {
 	STARPU_ASSERT(cg);
@@ -208,6 +207,7 @@ void _starpu_notify_cg(void *pred STARPU_ATTRIBUTE_UNUSED, struct _starpu_cg *cg
 				struct _starpu_tag *tag;
 
 				tag = cg->succ.tag;
+				_starpu_spin_lock(&tag->lock);
 				tag_successors = &tag->tag_successors;
 
 				tag_successors->ndeps_completed++;
@@ -221,6 +221,7 @@ void _starpu_notify_cg(void *pred STARPU_ATTRIBUTE_UNUSED, struct _starpu_cg *cg
 					tag_successors->ndeps_completed = 0;
 					_starpu_tag_set_ready(tag);
 				}
+				_starpu_spin_unlock(&tag->lock);
 				break;
 			}
 
@@ -370,21 +371,7 @@ void _starpu_notify_cg_list(void *pred, struct _starpu_cg_list *successors)
 			successors->nsuccs--;
 		}
 		_starpu_spin_unlock(&successors->lock);
-
-		struct _starpu_tag *cgtag = NULL;
-
-		if (cg_type == STARPU_CG_TAG)
-		{
-			cgtag = cg->succ.tag;
-			STARPU_ASSERT(cgtag);
-			_starpu_spin_lock(&cgtag->lock);
-		}
-
 		_starpu_notify_cg(pred, cg);
-
-		if (cg_type == STARPU_CG_TAG)
-			_starpu_spin_unlock(&cgtag->lock);
-
 		_starpu_spin_lock(&successors->lock);
 	}
 	successors->terminated = 1;

src/core/dependencies/tags.c

@@ -245,7 +245,7 @@ void _starpu_tag_set_ready(struct _starpu_tag *tag)
 	STARPU_AYU_POSTRUNTASK(tag->id + STARPU_AYUDAME_OFFSET);
 }
 
-/* the lock must be taken ! */
+/* the lock of the tag must already be taken ! */
 static void _starpu_tag_add_succ(struct _starpu_tag *tag, struct _starpu_cg *cg)
 {
 	STARPU_ASSERT(tag);
@@ -396,12 +396,10 @@ void starpu_tag_declare_deps_array(starpu_tag_t id, unsigned ndeps, starpu_tag_t
 		struct _starpu_tag *tag_dep = gettag_struct(dep_id);
 		STARPU_ASSERT(tag_dep != tag_child);
 		_starpu_spin_lock(&tag_dep->lock);
-		_starpu_spin_lock(&tag_child->lock);
 		_starpu_tag_add_succ(tag_dep, cg);
 		STARPU_ASSERT(!STARPU_AYU_EVENT || dep_id < STARPU_AYUDAME_OFFSET);
 		STARPU_ASSERT(!STARPU_AYU_EVENT || id < STARPU_AYUDAME_OFFSET);
 		STARPU_AYU_ADDDEPENDENCY(dep_id+STARPU_AYUDAME_OFFSET, 0, id+STARPU_AYUDAME_OFFSET);
-		_starpu_spin_unlock(&tag_child->lock);
 		_starpu_spin_unlock(&tag_dep->lock);
 	}
 }
@@ -434,12 +432,10 @@ void starpu_tag_declare_deps(starpu_tag_t id, unsigned ndeps, ...)
 		struct _starpu_tag *tag_dep = gettag_struct(dep_id);
 		STARPU_ASSERT(tag_dep != tag_child);
 		_starpu_spin_lock(&tag_dep->lock);
-		_starpu_spin_lock(&tag_child->lock);
 		_starpu_tag_add_succ(tag_dep, cg);
 		STARPU_ASSERT(!STARPU_AYU_EVENT || dep_id < STARPU_AYUDAME_OFFSET);
 		STARPU_ASSERT(!STARPU_AYU_EVENT || id < STARPU_AYUDAME_OFFSET);
 		STARPU_AYU_ADDDEPENDENCY(dep_id+STARPU_AYUDAME_OFFSET, 0, id+STARPU_AYUDAME_OFFSET);
-		_starpu_spin_unlock(&tag_child->lock);
 		_starpu_spin_unlock(&tag_dep->lock);
 	}
 	va_end(pa);