machine: introduce machine_hash_ops and use it

src/machine/machine.c

@@ -70,8 +70,9 @@ fail:
         return mfree(m);
 }
 
-void machine_free(Machine *m) {
-        assert(m);
+Machine* machine_free(Machine *m) {
+        if (!m)
+                return NULL;
 
         while (m->operations)
                 operation_free(m->operations);
@@ -98,7 +99,7 @@ void machine_free(Machine *m) {
         free(m->service);
         free(m->root_directory);
         free(m->netif);
-        free(m);
+        return mfree(m);
 }
 
 int machine_save(Machine *m) {

src/machine/machine.h

@@ -65,7 +65,7 @@ struct Machine {
 };
 
 Machine* machine_new(Manager *manager, MachineClass class, const char *name);
-void machine_free(Machine *m);
+Machine* machine_free(Machine *m);
 bool machine_may_gc(Machine *m, bool drop_not_started);
 void machine_add_to_gc_queue(Machine *m);
 int machine_start(Machine *m, sd_bus_message *properties, sd_bus_error *error);

src/machine/machined.c

@@ -25,6 +25,9 @@
 static Manager* manager_unref(Manager *m);
 DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_unref);
 
+DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(machine_hash_ops, void, trivial_hash_func, trivial_compare_func,
+                                              Machine, machine_free);
+
 static int manager_new(Manager **ret) {
         _cleanup_(manager_unrefp) Manager *m = NULL;
         int r;
@@ -37,7 +40,7 @@ static int manager_new(Manager **ret) {
 
         m->machines = hashmap_new(&string_hash_ops);
         m->machine_units = hashmap_new(&string_hash_ops);
-        m->machine_leaders = hashmap_new(NULL);
+        m->machine_leaders = hashmap_new(&machine_hash_ops);
 
         if (!m->machines || !m->machine_units || !m->machine_leaders)
                 return -ENOMEM;
@@ -61,8 +64,6 @@ static int manager_new(Manager **ret) {
 }
 
 static Manager* manager_unref(Manager *m) {
-        Machine *machine;
-
         if (!m)
                 return NULL;
 
@@ -71,9 +72,6 @@ static Manager* manager_unref(Manager *m) {
 
         assert(m->n_operations == 0);
 
-        while ((machine = hashmap_first(m->machines)))
-                machine_free(machine);
-
         hashmap_free(m->machines);
         hashmap_free(m->machine_units);
         hashmap_free(m->machine_leaders);