Issue #12098: multiprocessing on Windows now starts child processes
using the same sys.flags as the current process.
Backport from default branch.
diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py
index 9b3f0a9..8091a9f 100644
--- a/Lib/test/test_multiprocessing.py
+++ b/Lib/test/test_multiprocessing.py
@@ -2400,11 +2400,43 @@
self.assertEqual('', err.decode('ascii'))
#
+# Issue 12098: check sys.flags of child matches that for parent
+#
+
+class TestFlags(unittest.TestCase):
+ @classmethod
+ def run_in_grandchild(cls, conn):
+ conn.send(tuple(sys.flags))
+
+ @classmethod
+ def run_in_child(cls):
+ import json
+ r, w = multiprocessing.Pipe(duplex=False)
+ p = multiprocessing.Process(target=cls.run_in_grandchild, args=(w,))
+ p.start()
+ grandchild_flags = r.recv()
+ p.join()
+ r.close()
+ w.close()
+ flags = (tuple(sys.flags), grandchild_flags)
+ print(json.dumps(flags))
+
+ def test_flags(self):
+ import json, subprocess
+ # start child process using unusual flags
+ prog = ('from test.test_multiprocessing import TestFlags; ' +
+ 'TestFlags.run_in_child()')
+ data = subprocess.check_output(
+ [sys.executable, '-E', '-S', '-O', '-c', prog])
+ child_flags, grandchild_flags = json.loads(data.decode('ascii'))
+ self.assertEqual(child_flags, grandchild_flags)
+#
#
#
testcases_other = [OtherTest, TestInvalidHandle, TestInitializers,
- TestStdinBadfiledescriptor, TestTimeouts, TestNoForkBomb]
+ TestStdinBadfiledescriptor, TestTimeouts, TestNoForkBomb,
+ TestFlags]
#
#
diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index 034a374..b3076c1 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -1344,22 +1344,7 @@
def args_from_interpreter_flags():
"""Return a list of command-line arguments reproducing the current
settings in sys.flags."""
- flag_opt_map = {
- 'bytes_warning': 'b',
- 'dont_write_bytecode': 'B',
- 'ignore_environment': 'E',
- 'no_user_site': 's',
- 'no_site': 'S',
- 'optimize': 'O',
- 'py3k_warning': '3',
- 'verbose': 'v',
- }
- args = []
- for flag, opt in flag_opt_map.items():
- v = getattr(sys.flags, flag)
- if v > 0:
- args.append('-' + opt * v)
- return args
+ return subprocess._args_from_interpreter_flags()
def strip_python_stderr(stderr):
"""Strip the stderr of a Python process from potential debug output