Fix actor ID collision in local mode (#5863)

* Fixed local mode actor id

* Update python/ray/actor.py

Co-Authored-By: Edward Oakes <ed.nmi.oakes@gmail.com>

* Added hyphen to match comments

* Added tests to test_local_mode

* Helloworld

* Better test naming

* lint

python/ray/actor.py

@@ -369,9 +369,7 @@ class ActorClass(object):
         # Instead, instantiate the actor locally and add it to the worker's
         # dictionary
         if worker.mode == ray.LOCAL_MODE:
-            actor_id = ActorID.of(worker.current_job_id,
-                                  worker.current_task_id,
-                                  worker.task_context.task_index + 1)
+            actor_id = ActorID.from_random()
             worker.actors[actor_id] = meta.modified_class(
                 *copy.deepcopy(args), **copy.deepcopy(kwargs))
             core_handle = ray._raylet.ActorHandle(

python/ray/includes/unique_ids.pxi

@@ -211,30 +211,35 @@ cdef class TaskID(BaseID):
 
     @classmethod
     def for_driver_task(cls, job_id):
-        return cls(CTaskID.ForDriverTask(CJobID.FromBinary(job_id.binary())).Binary())
+        return cls(CTaskID.ForDriverTask(
+            CJobID.FromBinary(job_id.binary())).Binary())
 
     @classmethod
     def for_actor_creation_task(cls, actor_id):
         assert isinstance(actor_id, ActorID)
-        return cls(CTaskID.ForActorCreationTask(CActorID.FromBinary(actor_id.binary())).Binary())
+        return cls(CTaskID.ForActorCreationTask(
+            CActorID.FromBinary(actor_id.binary())).Binary())
 
     @classmethod
-    def for_actor_task(cls, job_id, parent_task_id, parent_task_counter, actor_id):
+    def for_actor_task(cls, job_id, parent_task_id,
+                       parent_task_counter, actor_id):
         assert isinstance(job_id, JobID)
         assert isinstance(parent_task_id, TaskID)
         assert isinstance(actor_id, ActorID)
-        return cls(CTaskID.ForActorTask(CJobID.FromBinary(job_id.binary()),
-                                        CTaskID.FromBinary(parent_task_id.binary()),
-                                        parent_task_counter,
-                                        CActorID.FromBinary(actor_id.binary())).Binary())
+        return cls(CTaskID.ForActorTask(
+            CJobID.FromBinary(job_id.binary()),
+            CTaskID.FromBinary(parent_task_id.binary()),
+            parent_task_counter,
+            CActorID.FromBinary(actor_id.binary())).Binary())
 
     @classmethod
     def for_normal_task(cls, job_id, parent_task_id, parent_task_counter):
         assert isinstance(job_id, JobID)
         assert isinstance(parent_task_id, TaskID)
-        return cls(CTaskID.ForNormalTask(CJobID.FromBinary(job_id.binary()),
-                                         CTaskID.FromBinary(parent_task_id.binary()),
-                                         parent_task_counter).Binary())
+        return cls(CTaskID.ForNormalTask(
+            CJobID.FromBinary(job_id.binary()),
+            CTaskID.FromBinary(parent_task_id.binary()),
+            parent_task_counter).Binary())
 
 cdef class ClientID(UniqueID):
 
@@ -314,6 +319,10 @@ cdef class ActorID(BaseID):
     def nil(cls):
         return cls(CActorID.Nil().Binary())
 
+    @classmethod
+    def from_random(cls):
+        return cls(os.urandom(CActorID.Size()))
+
     @classmethod
     def size(cls):
         return CActorID.Size()

python/ray/tests/test_basic.py

@@ -1766,6 +1766,28 @@ def test_local_mode(shutdown_only):
     with pytest.raises(Exception, match=exception_str):
         ray.get(obj2)
 
+    # Check that Actors are not overwritten by remote calls from different
+    # classes.
+    @ray.remote
+    class RemoteActor1(object):
+        def __init__(self):
+            pass
+
+        def function1(self):
+            return 0
+
+    @ray.remote
+    class RemoteActor2(object):
+        def __init__(self):
+            pass
+
+        def function2(self):
+            return 1
+
+    actor1 = RemoteActor1.remote()
+    _ = RemoteActor2.remote()
+    assert ray.get(actor1.function1.remote()) == 0
+
 
 def test_resource_constraints(shutdown_only):
     num_workers = 20