From f9ab43954e0f6ee5ab40db26e3d7bcf47a92a0a6 Mon Sep 17 00:00:00 2001
From: Jialing He <burglarralgrub@gmail.com>
Date: Sat, 1 Jun 2024 00:18:37 +0800
Subject: [PATCH] [Core] Fix the GIL deadlock issue caused by
 `list_named_actors`. (#45582)

Signed-off-by: hejialing.hjl <hejialing.hjl@bytedance.com>
---
 python/ray/_raylet.pyx                 |  5 +++--
 python/ray/tests/test_list_actors_4.py | 31 ++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/python/ray/_raylet.pyx b/python/ray/_raylet.pyx
index 8437edaa01228..407db534b0138 100644
--- a/python/ray/_raylet.pyx
+++ b/python/ray/_raylet.pyx
@@ -4446,8 +4446,9 @@ cdef class CoreWorker:
         cdef:
             pair[c_vector[pair[c_string, c_string]], CRayStatus] result_pair
 
-        result_pair = CCoreWorkerProcess.GetCoreWorker().ListNamedActors(
-            all_namespaces)
+        with nogil:
+            result_pair = CCoreWorkerProcess.GetCoreWorker().ListNamedActors(
+                all_namespaces)
         check_status(result_pair.second)
         return [
             (namespace.decode("utf-8"),
diff --git a/python/ray/tests/test_list_actors_4.py b/python/ray/tests/test_list_actors_4.py
index 0f302e4280849..4bbbc819338de 100644
--- a/python/ray/tests/test_list_actors_4.py
+++ b/python/ray/tests/test_list_actors_4.py
@@ -1,5 +1,7 @@
+import asyncio
 import pytest
 import sys
+import time
 
 import ray
 from ray._private.test_utils import run_string_as_driver
@@ -52,6 +54,35 @@ class A:
     assert not ray.util.list_named_actors(all_namespaces=True)
 
 
+@pytest.mark.asyncio
+async def test_list_named_actors_with_normal_task(shutdown_only):
+    # The following parameters are all designed to increase the
+    # probability of reproducing the situation where
+    # `list_named_actors` gets hang.
+    # https://github.com/ray-project/ray/issues/45581 for more details.
+    TEST_RANGE = 10
+    NORMAL_TASK_PER_ITEM = 100
+    LIST_NAMED_ACTORS_PER_ITEM = 10
+    for _ in range(TEST_RANGE):
+        time.sleep(1)
+
+        @ray.remote
+        def test():
+            return True
+
+        res = []
+        for i in range(NORMAL_TASK_PER_ITEM):
+            res.append(test.remote())
+
+        async def run():
+            for i in range(LIST_NAMED_ACTORS_PER_ITEM):
+                await asyncio.sleep(0)
+                ray.util.list_named_actors(True)
+
+        res.append(run())
+        await asyncio.gather(*res)
+
+
 if __name__ == "__main__":
     import os