Do not start processSlotTx before it is ready to run.

Implement run-to-completion for processSlotTX. This is achieved by using a new
dynamic_barrier_t which allows to specify callback after the first join has been
made.

common/utils/barrier/barrier.c

@@ -31,6 +31,16 @@ void dynamic_barrier_init(dynamic_barrier_t* barrier)
   barrier->completed_jobs = 0;
 }
 
+void dynamic_barrier_reset(dynamic_barrier_t* barrier)
+{
+  barrier->callback = NULL;
+  if (barrier->callback_arg != NULL) {
+    free(barrier->callback_arg);
+  }
+  barrier->callback_arg = NULL;
+  barrier->completed_jobs = 0;
+}
+
 void dynamic_barrier_join(dynamic_barrier_t* barrier)
 {
   int ret = pthread_mutex_lock(&barrier->barrier_lock);

common/utils/barrier/barrier.h

@@ -39,6 +39,10 @@ typedef struct dynamic_barrier_t {
 /// @param barrier
 void dynamic_barrier_init(dynamic_barrier_t* barrier);
 
+/// @brief Reset the barrier
+/// @param barrier
+void dynamic_barrier_reset(dynamic_barrier_t* barrier);
+
 /// @brief Perform join on the barrier. May run callback if it is already set
 /// @param barrier
 void dynamic_barrier_join(dynamic_barrier_t* barrier);