// FIXME: there is a race condition here where two actors run Mailbox::byName
// on a non-existent mailbox during the same scheduling round. Both will be
// interrupted in the simcall creating the underlying simix mbox.
// Only one simix object will be created, but two S4U objects will be created.
// Only one S4U object will be stored in the hashmap and used, and the other
// one will be leaked.
// FIXME: there is a race condition here where two actors run Mailbox::byName
// on a non-existent mailbox during the same scheduling round. Both will be
// interrupted in the simcall creating the underlying simix mbox.
// Only one simix object will be created, but two S4U objects will be created.
// Only one S4U object will be stored in the hashmap and used, and the other
// one will be leaked.