fix: wait until the privious put is complete before trigger a new one.

Solves an issue when source and target field of the same exchange are
on the same process.

src/coyoteenv.cpp

@@ -90,6 +90,18 @@ namespace coyote {
                     int field_id = event->field.yac_source_field_id.value();
                     int info = -1, ierror = 0;
                     int collection_size = yac_cget_collection_size_from_field_id(field_id);
+
+                    // if the previous put is not completed yet, we
+                    // need to wait, because it might be that the
+                    // source and target field of the same exchange is
+                    // on this process. In this case YAC would trigger
+                    // an abort ( to avoid an deadlock in the
+                    // non-threaded case) if the put is not already
+                    // completed.
+                    int flag;
+                    do {
+                        yac_ctest(field_id, &flag);
+                    } while (!flag);
                     if (!event->field.frac_mask.empty()) {
                         yac_cput_frac_(
                             field_id,