Add drift-->send dependency and update ti_old on reception

src/cell.c

@@ -99,6 +99,7 @@ int cell_unpack(struct pcell *pc, struct cell *c, struct space *s) {
   c->h_max = pc->h_max;
   c->ti_end_min = pc->ti_end_min;
   c->ti_end_max = pc->ti_end_max;
+  c->ti_old = pc->ti_old;
   c->count = pc->count;
   c->gcount = pc->gcount;
   c->tag = pc->tag;
@@ -127,6 +128,7 @@ int cell_unpack(struct pcell *pc, struct cell *c, struct space *s) {
       temp->dx_max = 0.f;
       temp->nodeID = c->nodeID;
       temp->parent = c;
+      temp->ti_old = c->ti_old;
       c->progeny[k] = temp;
       c->split = 1;
       count += cell_unpack(&pc[pc->progeny[k]], temp, s);
@@ -209,6 +211,7 @@ int cell_pack(struct cell *c, struct pcell *pc) {
   pc->h_max = c->h_max;
   pc->ti_end_min = c->ti_end_min;
   pc->ti_end_max = c->ti_end_max;
+  pc->ti_old = c->ti_old;
   pc->count = c->count;
   pc->gcount = c->gcount;
   c->tag = pc->tag = atomic_inc(&cell_next_tag) % cell_max_tag;
@@ -714,7 +717,7 @@ void cell_check_drift_point(struct cell *c, void *data) {
 
   const int ti_current = *(int *)data;
 
-  if (c->ti_old != ti_current)
+  if (c->ti_old != ti_current && c->nodeID == engine_rank)
     error("Cell in an incorrect time-zone! c->ti_old=%d ti_current=%d",
           c->ti_old, ti_current);
 }

src/cell.h

@@ -67,7 +67,7 @@ struct pcell {
 
   /* Stats on this cell's particles. */
   double h_max;
-  int ti_end_min, ti_end_max;
+  int ti_end_min, ti_end_max, ti_old;
 
   /* Number of particles in this cell. */
   int count, gcount;

src/engine.c

@@ -143,6 +143,7 @@ void engine_make_hierarchical_tasks(struct engine *e, struct cell *c) {
       c->kick = scheduler_addtask(s, task_type_kick, task_subtype_none, 0, 0, c,
                                   NULL, 0);
 
+      /* Add the drift task and dependency. */
       c->drift = scheduler_addtask(s, task_type_drift, task_subtype_none, 0, 0,
                                    c, NULL, 0);
 
@@ -673,6 +674,11 @@ void engine_addtasks_send(struct engine *e, struct cell *ci, struct cell *cj,
 
     /* Create the tasks and their dependencies? */
     if (t_xv == NULL) {
+      
+      if(ci->super->drift == NULL) 
+	ci->super->drift = scheduler_addtask(s, task_type_drift, task_subtype_none, 0, 0,
+					     ci->super, NULL, 0);
+
       t_xv = scheduler_addtask(s, task_type_send, task_subtype_none,
                                4 * ci->tag, 0, ci, cj, 0);
       t_rho = scheduler_addtask(s, task_type_send, task_subtype_none,
@@ -708,6 +714,8 @@ void engine_addtasks_send(struct engine *e, struct cell *ci, struct cell *cj,
 
       /* The send_xv task should unlock the super-cell's ghost task. */
       scheduler_addunlock(s, t_xv, ci->super->ghost);
+
+      scheduler_addunlock(s, ci->super->drift, t_xv);
 #endif
 
       /* The super-cell's kick task should unlock the send_ti task. */

src/runner.c

@@ -958,7 +958,7 @@ void runner_do_recv_cell(struct runner *r, struct cell *c, int timer) {
   const struct gpart *restrict gparts = c->gparts;
   const size_t nr_parts = c->count;
   const size_t nr_gparts = c->gcount;
-  // const int ti_current = r->e->ti_current;
+  const int ti_current = r->e->ti_current;
 
   TIMER_TIC;
 
@@ -1001,6 +1001,7 @@ void runner_do_recv_cell(struct runner *r, struct cell *c, int timer) {
   /* ... and store. */
   c->ti_end_min = ti_end_min;
   c->ti_end_max = ti_end_max;
+  c->ti_old = ti_current;
   c->h_max = h_max;
 
   if (timer) TIMER_TOC(timer_dorecv_cell);
@@ -1051,8 +1052,9 @@ void *runner_main(void *data) {
 
 /* Check that we haven't scheduled an inactive task */
 #ifdef SWIFT_DEBUG_CHECKS
+#ifndef WITH_MPI
       if (cj == NULL) { /* self */
-        if (!cell_is_active(ci, e) && t->type != task_type_sort)
+        if (!cell_is_active(ci, e) && t->type != task_type_sort && t->type != task_type_send && t->type != task_type_recv)
           error(
               "Task (type='%s/%s') should have been skipped ti_current=%d "
               "c->ti_end_min=%d",
@@ -1070,12 +1072,15 @@ void *runner_main(void *data) {
 
       } else { /* pair */
         if (!cell_is_active(ci, e) && !cell_is_active(cj, e))
+
+	  if(t->type != task_type_send && t->type != task_type_recv)
           error(
               "Task (type='%s/%s') should have been skipped ti_current=%d "
               "ci->ti_end_min=%d cj->ti_end_min=%d",
               taskID_names[t->type], subtaskID_names[t->subtype], e->ti_current,
               ci->ti_end_min, cj->ti_end_min);
       }
+#endif
 #endif
 
       /* Different types of tasks... */