Created the drift and ghost tasks for the black holes.

src/cell.h

@@ -606,6 +606,13 @@ struct cell {
     /*! The drift task for bparts */
     struct task *drift;
 
+    /*! Implicit tasks marking the entry of the BH physics block of tasks
+     */
+    struct task *black_holes_in;
+
+    /*! Implicit tasks marking the exit of the BH physics block of tasks */
+    struct task *black_holes_out;
+
     /*! The star ghost task itself */
     struct task *ghost;
 

src/engine_maketasks.c

@@ -729,6 +729,7 @@ void engine_make_hierarchical_tasks_hydro(struct engine *e, struct cell *c) {
   const int with_feedback = (e->policy & engine_policy_feedback);
   const int with_cooling = (e->policy & engine_policy_cooling);
   const int with_star_formation = (e->policy & engine_policy_star_formation);
+  const int with_black_holes = (e->policy & engine_policy_black_holes);
 
   /* Are we in a super-cell ? */
   if (c->hydro.super == c) {
@@ -775,6 +776,13 @@ void engine_make_hierarchical_tasks_hydro(struct engine *e, struct cell *c) {
         scheduler_addunlock(s, c->stars.drift, c->super->kick2);
       }
 
+      /* Black holes */
+      if (with_black_holes) {
+        c->black_holes.drift = scheduler_addtask(
+            s, task_type_drift_bpart, task_subtype_none, 0, 0, c, NULL);
+        scheduler_addunlock(s, c->black_holes.drift, c->super->kick2);
+      }
+
       /* Subgrid tasks: cooling */
       if (with_cooling) {
 
@@ -810,6 +818,25 @@ void engine_make_hierarchical_tasks_hydro(struct engine *e, struct cell *c) {
                               c->stars.stars_in);
         }
       }
+
+      /* Subgrid tasks: black hole feedback */
+      if (with_black_holes) {
+
+        c->black_holes.black_holes_in =
+            scheduler_addtask(s, task_type_bh_in, task_subtype_none, 0,
+                              /* implicit = */ 1, c, NULL);
+
+        c->black_holes.black_holes_out =
+            scheduler_addtask(s, task_type_bh_out, task_subtype_none, 0,
+                              /* implicit = */ 1, c, NULL);
+
+        c->black_holes.ghost = scheduler_addtask(
+            s, task_type_bh_ghost, task_subtype_none, 0, 0, c, NULL);
+
+        scheduler_addunlock(s, c->super->kick2, c->black_holes.black_holes_in);
+        scheduler_addunlock(s, c->black_holes.black_holes_out,
+                            c->super->timestep);
+      }
     }
   } else { /* We are above the super-cell so need to go deeper */
 

src/task.c

@@ -89,6 +89,8 @@ const char *taskID_names[task_type_count] = {"none",
                                              "stars_ghost",
                                              "stars_ghost_out",
                                              "stars_sort",
+                                             "bh_in",
+                                             "bh_out",
                                              "bh_ghost"};
 
 /* Sub-task type names. */

src/task.h

@@ -84,6 +84,8 @@ enum task_types {
   task_type_stars_ghost,
   task_type_stars_ghost_out, /* Implicit */
   task_type_stars_sort,
+  task_type_bh_in,  /* Implicit */
+  task_type_bh_out, /* Implicit */
   task_type_bh_ghost,
   task_type_count
 } __attribute__((packed));