fix test_flush_logs_fast_exit (#841)

Summary:
Pull Request resolved: #841

we got error "OS can't spawn worker thread: Resource temporarily
unavailable (os error 11)" under sandcastle stress test. There is no need to
manually create another 20 processes, which will cause 400 processes spawned.
Just use one pass to test and leave the rest to sandcastle.

Reviewed By: mariusae

Differential Revision: D80149544

fbshipit-source-id: d244b4739121f5199273957df6c5f7370a2f88a9

Author: James Sun

python/tests/python_actor_test_binary.py

@@ -40,7 +40,8 @@ async def _flush_logs() -> None:
     for _ in range(5):
         await am.print.call("has print streaming")
 
-    await pm.stop()
+    # TODO: will soon be removed by D80051803
+    await asyncio.sleep(2)
 
 
 @main.command("flush-logs")

python/tests/test_python_actors.py

@@ -727,25 +727,23 @@ async def test_flush_logs_fast_exit() -> None:
     # Run the binary in a separate process and capture stdout and stderr
     cmd = [str(test_bin), "flush-logs"]
 
-    # Stress test
-    for _ in range(20):
-        process = subprocess.run(cmd, capture_output=True, timeout=60, text=True)
-
-        # Check if the process ended without error
-        if process.returncode != 0:
-            raise RuntimeError(f"{cmd} ended with error code {process.returncode}. ")
-
-        # Assertions on the captured output, 160 = 32 procs * 5 logs per proc
-        # 32 and 5 are specified in the test_bin flush-logs.
-        assert (
-            len(
-                re.findall(
-                    r"160 similar log lines.*has print streaming",
-                    process.stdout,
-                )
+    process = subprocess.run(cmd, capture_output=True, timeout=60, text=True)
+
+    # Check if the process ended without error
+    if process.returncode != 0:
+        raise RuntimeError(f"{cmd} ended with error code {process.returncode}. ")
+
+    # Assertions on the captured output, 160 = 32 procs * 5 logs per proc
+    # 32 and 5 are specified in the test_bin flush-logs.
+    assert (
+        len(
+            re.findall(
+                r"160 similar log lines.*has print streaming",
+                process.stdout,
             )
-            == 1
-        ), process.stdout
+        )
+        == 1
+    ), process.stdout
 
 
 @pytest.mark.timeout(60)