refactor: always use multiprocess spawn

Author: hfudev

pytest-embedded/pytest_embedded/dut.py

@@ -1,6 +1,5 @@
 import functools
 import logging
-import multiprocessing
 import os.path
 import re
 from collections.abc import Callable
@@ -10,7 +9,7 @@
 import pexpect
 
 from .app import App
-from .log import PexpectProcess
+from .log import MessageQueue, PexpectProcess
 from .unity import UNITY_SUMMARY_LINE_REGEX, TestSuite
 from .utils import Meta, _InjectMixinCls, remove_asci_color_code, to_bytes, to_list
 
@@ -29,7 +28,7 @@ class Dut(_InjectMixinCls):
     def __init__(
         self,
         pexpect_proc: PexpectProcess,
-        msg_queue: multiprocessing.Queue,
+        msg_queue: MessageQueue,
         app: App,
         pexpect_logfile: str,
         test_case_name: str,

pytest-embedded/pytest_embedded/dut_factory.py

@@ -28,10 +28,7 @@ def _drop_none_kwargs(kwargs: dict[t.Any, t.Any]):
     return {k: v for k, v in kwargs.items() if v is not None}
 
 
-if sys.platform == 'darwin':
-    _ctx = multiprocessing.get_context('fork')
-else:
-    _ctx = multiprocessing.get_context()
+_ctx = multiprocessing.get_context('spawn')
 
 _stdout = sys.__stdout__
 
@@ -45,10 +42,6 @@ def _drop_none_kwargs(kwargs: dict[t.Any, t.Any]):
 PARAMETRIZED_FIXTURES_CACHE = {}
 
 
-def msg_queue_gn() -> MessageQueue:
-    return MessageQueue()
-
-
 def _listen(q: MessageQueue, filepath: str, with_timestamp: bool = True, count: int = 1, total: int = 1) -> None:
     shall_add_prefix = True
     while True:
@@ -741,10 +734,15 @@ def create(
         """
         layout = []
         try:
-            global PARAMETRIZED_FIXTURES_CACHE
-            msg_queue = msg_queue_gn()
+            from .plugin import _MP_MANAGER  # avoid circular import
+
+            if _MP_MANAGER is None:
+                raise SystemExit('The _MP_MANAGER is not initialized, please use this function under pytest.')
+
+            msg_queue = _MP_MANAGER.MessageQueue()
             layout.append(msg_queue)
 
+            global PARAMETRIZED_FIXTURES_CACHE
             _pexpect_logfile = os.path.join(
                 PARAMETRIZED_FIXTURES_CACHE['_meta'].logdir, f'custom-dut-{DUT_GLOBAL_INDEX}.txt'
             )

pytest-embedded/pytest_embedded/log.py

@@ -3,11 +3,11 @@
 import multiprocessing
 import os
 import subprocess
-import sys
 import tempfile
 import textwrap
 import uuid
 from multiprocessing import queues
+from multiprocessing.managers import BaseManager
 from typing import AnyStr
 
 import pexpect.fdpexpect
@@ -16,10 +16,11 @@
 
 from .utils import Meta, remove_asci_color_code, to_bytes, to_str, utcnow_str
 
-if sys.platform == 'darwin':
-    _ctx = multiprocessing.get_context('fork')
-else:
-    _ctx = multiprocessing.get_context()
+_ctx = multiprocessing.get_context('spawn')
+
+
+class MessageQueueManager(BaseManager):
+    pass
 
 
 class MessageQueue(queues.Queue):
@@ -40,7 +41,7 @@ def put(self, obj, **kwargs):
         _b = to_bytes(obj)
         try:
             super().put(_b, **kwargs)
-        except:  # noqa # queue might be closed
+        except Exception:  # queue might be closed
             pass
 
     def write(self, s: AnyStr):
@@ -53,6 +54,9 @@ def isatty(self):
         return True
 
 
+MessageQueueManager.register('MessageQueue', MessageQueue)
+
+
 class PexpectProcess(pexpect.fdpexpect.fdspawn):
     """
     Use a temp file to gather multiple inputs into one output, and do `pexpect.expect()` from one place.
@@ -146,16 +150,16 @@ def live_print_call(*args, msg_queue: MessageQueue | None = None, expect_returnc
 
 class _PopenRedirectProcess(_ctx.Process):
     def __init__(self, msg_queue: MessageQueue, logfile: str):
-        self._q = msg_queue
-
-        self.logfile = logfile
-
-        super().__init__(target=self._forward_io, daemon=True)  # killed by the main process
+        super().__init__(target=self._forward_io, args=(msg_queue, logfile), daemon=True)
 
-    def _forward_io(self) -> None:
-        with open(self.logfile) as fr:
+    @staticmethod
+    def _forward_io(msg_queue, logfile) -> None:
+        with open(logfile) as fr:
             while True:
-                self._q.put(fr.read())
+                try:
+                    msg_queue.put(fr.read())  # msg_queue may be closed
+                except Exception:
+                    break
 
 
 class DuplicateStdoutPopen(subprocess.Popen):

pytest-embedded/pytest_embedded/plugin.py

@@ -36,15 +36,14 @@
     app_fn,
     dut_gn,
     gdb_gn,
-    msg_queue_gn,
     openocd_gn,
     pexpect_proc_fn,
     qemu_gn,
     serial_gn,
     set_parametrized_fixtures_cache,
     wokwi_gn,
 )
-from .log import MessageQueue, PexpectProcess
+from .log import MessageQueue, MessageQueueManager, PexpectProcess
 from .unity import JunitMerger, UnityTestReportMode, escape_illegal_xml_chars
 from .utils import (
     SERVICE_LIB_NAMES,
@@ -300,6 +299,7 @@ def pytest_addoption(parser):
 # helpers #
 ###########
 _COUNT = 1
+_MP_MANAGER: MessageQueueManager | None = None
 
 
 def _gte_one_int(v) -> int:
@@ -630,6 +630,19 @@ def port_app_cache() -> dict[str, str]:
     return {}
 
 
+@pytest.fixture(scope='session', autouse=True)
+def _mp_manager():
+    manager = MessageQueueManager()
+    manager.start()
+
+    global _MP_MANAGER
+    _MP_MANAGER = manager
+
+    yield manager
+
+    manager.shutdown()
+
+
 @pytest.fixture
 def test_case_tempdir(test_case_name: str, session_tempdir: str) -> str:
     """Function scoped temp dir for pytest-embedded"""
@@ -668,8 +681,8 @@ def _pexpect_logfile(test_case_tempdir, logfile_extension, dut_index, dut_total)
 
 @pytest.fixture
 @multi_dut_generator_fixture
-def msg_queue() -> MessageQueue:  # kwargs passed by `multi_dut_generator_fixture()`
-    return msg_queue_gn()
+def msg_queue(_mp_manager) -> MessageQueue:  # kwargs passed by `multi_dut_generator_fixture()`
+    return _mp_manager.MessageQueue()
 
 
 @pytest.fixture

pytest-embedded/tests/test_base.py

@@ -290,7 +290,6 @@ def test_expect_all_failed(dut):
     result.assert_outcomes(passed=10)
 
 
-@pytest.mark.xfail(reason='unstable')
 def test_expect_from_timeout(testdir):
     testdir.makepyfile(r"""
         import threading