hide the task 'rid' behind an ifdef, still need to add this to the configure script.

examples/main.c

@@ -551,6 +551,7 @@ int main(int argc, char *argv[]) {
 
     /* Dump the task data using the given frequency. */
     if (dump_tasks && (dump_tasks == 1 || j % dump_tasks == 1)) {
+#ifdef SWIFT_TASK_DUMP
 #ifdef WITH_MPI
 
       /* Make sure output file is empty, only on one rank. */
@@ -580,8 +581,8 @@ int main(int argc, char *argv[]) {
           for (int l = 0; l < e.sched.nr_tasks; l++) {
             if (!e.sched.tasks[l].implicit && e.sched.tasks[l].toc != 0) {
               fprintf(
-                  file_thread, " %03i %i %i %i %lli %lli %i %i %i %i %i\n",
-                  myrank, e.sched.tasks[l].type,
+                  file_thread, " %03i %i %i %i %i %lli %lli %i %i %i %i %i\n",
+                  myrank, e.sched.tasks[l].rid, e.sched.tasks[l].type,
                   e.sched.tasks[l].subtype, (e.sched.tasks[l].cj == NULL),
                   e.sched.tasks[l].tic, e.sched.tasks[l].toc,
                   (e.sched.tasks[l].ci != NULL) ? e.sched.tasks[l].ci->count
@@ -615,8 +616,8 @@ int main(int argc, char *argv[]) {
       for (int l = 0; l < e.sched.nr_tasks; l++) {
         if (!e.sched.tasks[l].implicit && e.sched.tasks[l].toc != 0) {
           fprintf(
-              file_thread, " %i %i %i %lli %lli %i %i %i %i\n",
-              e.sched.tasks[l].type,
+              file_thread, " %i %i %i %i %lli %lli %i %i %i %i\n",
+              e.sched.tasks[l].rid, e.sched.tasks[l].type,
               e.sched.tasks[l].subtype, (e.sched.tasks[l].cj == NULL),
               e.sched.tasks[l].tic, e.sched.tasks[l].toc,
               (e.sched.tasks[l].ci == NULL) ? 0 : e.sched.tasks[l].ci->count,
@@ -626,6 +627,9 @@ int main(int argc, char *argv[]) {
         }
       }
       fclose(file_thread);
+#endif
+#else
+      error("Task dumping not enabled at compile-time.");
 #endif
     }
   }

src/runner.c

@@ -1293,6 +1293,10 @@ void *runner_main(void *data) {
       /* Get the cells. */
       struct cell *ci = t->ci;
       struct cell *cj = t->cj;
+      
+#ifdef SWIFT_TASK_DUMP
+      t->rid = r->id;
+#endif
 
 /* Check that we haven't scheduled an inactive task */
 #ifdef SWIFT_DEBUG_CHECKS

src/scheduler.c

@@ -713,6 +713,9 @@ struct task *scheduler_addtask(struct scheduler *s, enum task_types type,
   t->tic = 0;
   t->toc = 0;
   t->nr_unlock_tasks = 0;
+#ifdef SWIFT_TASK_DUMP
+  t->rid = -1;
+#endif
 
   /* Add an index for it. */
   // lock_lock( &s->lock );

src/task.h

@@ -147,6 +147,11 @@ struct task {
 
   /*! Is this task implicit (i.e. does not do anything) ? */
   char implicit;
+  
+#ifdef SWIFT_TASK_DUMP
+  /* ID of the last thread to execute this task. */
+  short int rid;
+#endif  // SWIFT_TASK_DUMP
 
 } SWIFT_STRUCT_ALIGN;