Resolve outer promises getting blocked waiting on inner promises to complete.

promise/async_.py

@@ -1,5 +1,6 @@
 # Based on https://github.com/petkaantonov/bluebird/blob/master/src/promise.js
 import collections
+from threading import Thread
 
 
 class Async(object):
@@ -67,10 +68,10 @@ def drain_queue(self, queue):
         from .promise import Promise
         while queue:
             fn = queue.popleft()
-            if (isinstance(fn, Promise)):
+            if isinstance(fn, Promise):
                 fn._settle_promises()
                 continue
-            fn()
+            Thread(target=fn).start()
 
     def drain_queues(self):
         assert self.is_tick_used

tests/test_extra.py

@@ -677,9 +677,20 @@ def test_promises_promisify_still_works_but_deprecated_for_non_callables():
 #     values = Promise.resolve([1, None, 2])
 #     def on_error(error):
 #         error
-
 #     def executor(resolve, reject):
 #         resolve(Promise.resolve(values).then(lambda values: Promise.all([Promise.resolve(values[0])]).catch(on_error)))
-
 #     p = Promise(executor)
 #     assert p.get(.1) == 2
+
+
+def test_get_after_get_in_promise():
+    expected_value = "ok"
+
+    def do(_):
+        def then_fn(y):
+            return y
+        completed_promise_value = Promise.resolve(expected_value).then(then_fn).get()
+        return completed_promise_value
+
+    p = Promise.resolve(None).then(do)
+    assert p.get() == expected_value