pulse-server: handle if the module is destroyed while loading

Create a new event for modules ('destroy') which is emitted from
`module_free()`. It is used by the module loading logic, to handle
when a module is destroyed without properly loading first.

src/modules/module-protocol-pulse/module.c

@@ -92,6 +92,8 @@ void module_free(struct module *module)
 {
 	struct impl *impl = module->impl;
 
+	module_emit_destroy(module);
+
 	if (module->idx != SPA_ID_INVALID)
 		pw_map_remove(&impl->modules, module->idx & INDEX_MASK);
 

src/modules/module-protocol-pulse/module.h

@@ -45,6 +45,7 @@ struct module_events {
 	uint32_t version;
 
 	void (*loaded) (void *data, int result);
+	void (*destroy) (void *data);
 };
 
 struct module_methods {
@@ -68,6 +69,7 @@ struct module {
 };
 
 #define module_emit_loaded(m,r) spa_hook_list_call(&m->listener_list, struct module_events, loaded, 0, r)
+#define module_emit_destroy(m) spa_hook_list_call(&(m)->listener_list, struct module_events, destroy, 0)
 
 struct module *module_create(struct client *client, const char *name, const char *args);
 void module_free(struct module *module);

src/modules/module-protocol-pulse/pulse-server.c

@@ -4666,6 +4666,11 @@ static void on_module_loaded(void *data, int result)
 	free(pm);
 }
 
+static void on_module_destroy(void *data)
+{
+	on_module_loaded(data, -ECANCELED);
+}
+
 static void on_client_disconnect(void *data)
 {
 	struct pending_module *pm = data;
@@ -4679,6 +4684,7 @@ static int do_load_module(struct client *client, uint32_t command, uint32_t tag,
 	static const struct module_events module_events = {
 		VERSION_MODULE_EVENTS,
 		.loaded = on_module_loaded,
+		.destroy = on_module_destroy,
 	};
 	static const struct client_events client_events = {
 		VERSION_CLIENT_EVENTS,