pybricks.tools: Use new awaitable for pbio tasks.

This new awaitable is introduced so we can eventually drop queued tasks and safely await protothreads.

For now, just keep the pbio tasks compiling.

Author: laurensvalk

pybricks/tools/pb_module_tools.c

@@ -145,34 +145,20 @@ void pb_module_tools_pbio_task_do_blocking(pbio_task_t *task, mp_int_t timeout)
     }
 }
 
-// The awaitables associated with pbio tasks can originate from different
-// objects. At the moment, they are only associated with Bluetooth tasks, and
-// they cannot run at the same time. So we keep a single list of awaitables
-// here instead of with each Bluetooth-related MicroPython object.
-MP_REGISTER_ROOT_POINTER(mp_obj_t pbio_task_awaitables);
-
-static bool pb_module_tools_pbio_task_test_completion(mp_obj_t obj, uint32_t end_time) {
-    pbio_task_t *task = MP_OBJ_TO_PTR(obj);
-
-    // Keep going if not done yet.
-    if (task->status == PBIO_ERROR_AGAIN) {
-        return false;
-    }
-
-    // If done, make sure it was successful.
-    pb_assert(task->status);
-    return true;
+static pbio_error_t pb_module_tools_pbio_task_iterate_once(pbio_os_state_t *state, mp_obj_t parent_obj) {
+    pbio_task_t *task = MP_OBJ_TO_PTR(parent_obj);
+    return task->status;
 }
 
 mp_obj_t pb_module_tools_pbio_task_wait_or_await(pbio_task_t *task) {
-    return pb_type_awaitable_await_or_wait(
-        MP_OBJ_FROM_PTR(task),
-        MP_STATE_PORT(pbio_task_awaitables),
-        pb_type_awaitable_end_time_none,
-        pb_module_tools_pbio_task_test_completion,
-        pb_type_awaitable_return_none,
-        pb_type_awaitable_cancel_none,
-        PB_TYPE_AWAITABLE_OPT_RAISE_ON_BUSY);
+    pb_type_async_t config = {
+        .parent_obj = MP_OBJ_FROM_PTR(task),
+        .iter_once = pb_module_tools_pbio_task_iterate_once,
+    };
+
+    // REVISIT: pbio tasks will be deprecated. Instead, protothreads can now
+    // be safely awaited.
+    return pb_type_async_wait_or_await(&config, NULL);
 }
 
 /**
@@ -268,7 +254,6 @@ static MP_DEFINE_CONST_FUN_OBJ_KW(pb_module_tools_run_task_obj, 0, pb_module_too
 // Reset global awaitable state when user program starts.
 void pb_module_tools_init(void) {
     memset(waits, 0, sizeof(waits));
-    MP_STATE_PORT(pbio_task_awaitables) = mp_obj_new_list(0, NULL);
     run_loop_is_active = false;
 }