mtapi_c: reuse main thread

mtapi_c/src/embb_mtapi_thread_context_t.c

@@ -54,6 +54,7 @@ mtapi_boolean_t embb_mtapi_thread_context_initialize_with_node_worker_and_core(
   that->core_num = core_num;
   that->priorities = node->attributes.max_priorities;
   that->is_initialized = MTAPI_FALSE;
+  that->is_main_thread = (worker_index == 0) ? MTAPI_TRUE : MTAPI_FALSE;
   embb_atomic_store_int(&that->run, 0);
 
   that->queue = (embb_mtapi_task_queue_t**)embb_mtapi_alloc_allocate(
@@ -121,6 +122,18 @@ mtapi_boolean_t embb_mtapi_thread_context_start(
   embb_core_set_add(&core_set, that->core_num);
 
   /* create thread */
+  if (that->is_main_thread) {
+    /* reuse main thread */
+    that->thread = embb_thread_current();
+    err = embb_tss_create(&that->tss_id);
+    if (EMBB_SUCCESS != err) {
+      /* report error to scheduler */
+      embb_atomic_store_int(&that->run, -1);
+      return MTAPI_FALSE;
+    }
+    embb_tss_set(&(that->tss_id), that);
+    embb_atomic_store_int(&that->run, 1);
+  } else {
     err = embb_thread_create(&that->thread, &core_set, worker_func, that);
     if (EMBB_SUCCESS != err) {
       embb_mtapi_log_error(
@@ -128,11 +141,11 @@ mtapi_boolean_t embb_mtapi_thread_context_start(
         "create thread %d on core %d\n", that->worker_index, that->core_num);
       return MTAPI_FALSE;
     }
-
     /* wait for worker to come up */
     while (0 == embb_atomic_load_int(&that->run)) {
       embb_thread_yield();
     }
+  }
 
   if (0 < embb_atomic_load_int(&that->run)) {
     return MTAPI_TRUE;
@@ -146,8 +159,10 @@ void embb_mtapi_thread_context_stop(embb_mtapi_thread_context_t* that) {
   if (0 < embb_atomic_load_int(&that->run)) {
     embb_atomic_store_int(&that->run, 0);
     embb_condition_notify_one(&that->work_available);
+    if (MTAPI_FALSE == that->is_main_thread) {
       embb_thread_join(&(that->thread), &result);
     }
+  }
 }
 
 void embb_mtapi_thread_context_finalize(embb_mtapi_thread_context_t* that) {
@@ -158,6 +173,9 @@ void embb_mtapi_thread_context_finalize(embb_mtapi_thread_context_t* that) {
   embb_mtapi_log_trace("embb_mtapi_thread_context_finalize() called\n");
 
   if (that->is_initialized) {
+    if (that->is_main_thread) {
+      embb_tss_delete(&that->tss_id);
+    }
     embb_condition_destroy(&that->work_available);
     embb_mutex_destroy(&that->work_available_mutex);
   }

mtapi_c/src/embb_mtapi_thread_context_t.h

@@ -68,6 +68,7 @@ struct embb_mtapi_thread_context_struct {
   embb_atomic_int run;
   mtapi_status_t status;
   mtapi_boolean_t is_initialized;
+  mtapi_boolean_t is_main_thread;
 };
 
 #include <embb_mtapi_thread_context_t_fwd.h>