import os import signal import sys import textwrap import unittest import warnings from unittest import mock import asyncio from asyncio import base_subprocess from asyncio import subprocess from test.test_asyncio import utils as test_utils from test import support from test.support import os_helper if not support.has_subprocess_support: raise unittest.SkipTest("test module requires subprocess") if support.MS_WINDOWS: import msvcrt else: from asyncio import unix_events if support.check_sanitizer(address=True): raise unittest.SkipTest("Exposes ASAN flakiness in GitHub CI") # Program blocking PROGRAM_BLOCKED = [sys.executable, '-c', 'import time; time.sleep(3600)'] # Program copying input to output PROGRAM_CAT = [ sys.executable, '-c', ';'.join(('import sys', 'data = sys.stdin.buffer.read()', 'sys.stdout.buffer.write(data)'))] def tearDownModule(): asyncio.set_event_loop_policy(None) class TestSubprocessTransport(base_subprocess.BaseSubprocessTransport): def _start(self, *args, **kwargs): self._proc = mock.Mock() self._proc.stdin = None self._proc.stdout = None self._proc.stderr = None self._proc.pid = -1 class SubprocessTransportTests(test_utils.TestCase): def setUp(self): super().setUp() self.loop = self.new_test_loop() self.set_event_loop(self.loop) def create_transport(self, waiter=None): protocol = mock.Mock() transport = TestSubprocessTransport( self.loop, protocol, ['test'], False, None, None, None, 0, waiter=waiter) return (transport, protocol) def test_proc_exited(self): waiter = self.loop.create_future() transport, protocol = self.create_transport(waiter) transport._process_exited(6) self.loop.run_until_complete(waiter) self.assertEqual(transport.get_returncode(), 6) self.assertTrue(protocol.connection_made.called) self.assertTrue(protocol.process_exited.called) self.assertTrue(protocol.connection_lost.called) self.assertEqual(protocol.connection_lost.call_args[0], (None,)) self.assertFalse(transport.is_closing()) self.assertIsNone(transport._loop) self.assertIsNone(transport._proc) self.assertIsNone(transport._protocol) # methods must raise ProcessLookupError if the process exited self.assertRaises(ProcessLookupError, transport.send_signal, signal.SIGTERM) self.assertRaises(ProcessLookupError, transport.terminate) self.assertRaises(ProcessLookupError, transport.kill) transport.close() def test_subprocess_repr(self): waiter = self.loop.create_future() transport, protocol = self.create_transport(waiter) transport._process_exited(6) self.loop.run_until_complete(waiter) self.assertEqual( repr(transport), "" ) transport._returncode = None self.assertEqual( repr(transport), "" ) transport._pid = None transport._returncode = None self.assertEqual( repr(transport), "" ) transport.close() class SubprocessMixin: def test_stdin_stdout(self): args = PROGRAM_CAT async def run(data): proc = await asyncio.create_subprocess_exec( *args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, ) # feed data proc.stdin.write(data) await proc.stdin.drain() proc.stdin.close() # get output and exitcode data = await proc.stdout.read() exitcode = await proc.wait() return (exitcode, data) task = run(b'some data') task = asyncio.wait_for(task, 60.0) exitcode, stdout = self.loop.run_until_complete(task) self.assertEqual(exitcode, 0) self.assertEqual(stdout, b'some data') def test_communicate(self): args = PROGRAM_CAT async def run(data): proc = await asyncio.create_subprocess_exec( *args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, ) stdout, stderr = await proc.communicate(data) return proc.returncode, stdout task = run(b'some data') task = asyncio.wait_for(task, support.LONG_TIMEOUT) exitcode, stdout = self.loop.run_until_complete(task) self.assertEqual(exitcode, 0) self.assertEqual(stdout, b'some data') def test_communicate_none_input(self): args = PROGRAM_CAT async def run(): proc = await asyncio.create_subprocess_exec( *args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, ) stdout, stderr = await proc.communicate() return proc.returncode, stdout task = run() task = asyncio.wait_for(task, support.LONG_TIMEOUT) exitcode, stdout = self.loop.run_until_complete(task) self.assertEqual(exitcode, 0) self.assertEqual(stdout, b'') def test_shell(self): proc = self.loop.run_until_complete( asyncio.create_subprocess_shell('exit 7') ) exitcode = self.loop.run_until_complete(proc.wait()) self.assertEqual(exitcode, 7) def test_start_new_session(self): # start the new process in a new session proc = self.loop.run_until_complete( asyncio.create_subprocess_shell( 'exit 8', start_new_session=True, ) ) exitcode = self.loop.run_until_complete(proc.wait()) self.assertEqual(exitcode, 8) def test_kill(self): args = PROGRAM_BLOCKED proc = self.loop.run_until_complete( asyncio.create_subprocess_exec(*args) ) proc.kill() returncode = self.loop.run_until_complete(proc.wait()) if sys.platform == 'win32': self.assertIsInstance(returncode, int) # expect 1 but sometimes get 0 else: self.assertEqual(-signal.SIGKILL, returncode) def test_kill_issue43884(self): if sys.platform == 'win32': blocking_shell_command = f'"{sys.executable}" -c "import time; time.sleep(2)"' else: blocking_shell_command = 'sleep 1; sleep 1' creationflags = 0 if sys.platform == 'win32': from subprocess import CREATE_NEW_PROCESS_GROUP # On windows create a new process group so that killing process # kills the process and all its children. creationflags = CREATE_NEW_PROCESS_GROUP proc = self.loop.run_until_complete( asyncio.create_subprocess_shell(blocking_shell_command, stdout=asyncio.subprocess.PIPE, creationflags=creationflags) ) self.loop.run_until_complete(asyncio.sleep(1)) if sys.platform == 'win32': proc.send_signal(signal.CTRL_BREAK_EVENT) # On windows it is an alias of terminate which sets the return code proc.kill() returncode = self.loop.run_until_complete(proc.wait()) if sys.platform == 'win32': self.assertIsInstance(returncode, int) # expect 1 but sometimes get 0 else: self.assertEqual(-signal.SIGKILL, returncode) def test_terminate(self): args = PROGRAM_BLOCKED proc = self.loop.run_until_complete( asyncio.create_subprocess_exec(*args) ) proc.terminate() returncode = self.loop.run_until_complete(proc.wait()) if sys.platform == 'win32': self.assertIsInstance(returncode, int) # expect 1 but sometimes get 0 else: self.assertEqual(-signal.SIGTERM, returncode) @unittest.skipIf(sys.platform == 'win32', "Don't have SIGHUP") def test_send_signal(self): # bpo-31034: Make sure that we get the default signal handler (killing # the process). The parent process may have decided to ignore SIGHUP, # and signal handlers are inherited. old_handler = signal.signal(signal.SIGHUP, signal.SIG_DFL) try: code = 'import time; print("sleeping", flush=True); time.sleep(3600)' args = [sys.executable, '-c', code] proc = self.loop.run_until_complete( asyncio.create_subprocess_exec( *args, stdout=subprocess.PIPE, ) ) async def send_signal(proc): # basic synchronization to wait until the program is sleeping line = await proc.stdout.readline() self.assertEqual(line, b'sleeping\n') proc.send_signal(signal.SIGHUP) returncode = await proc.wait() return returncode returncode = self.loop.run_until_complete(send_signal(proc)) self.assertEqual(-signal.SIGHUP, returncode) finally: signal.signal(signal.SIGHUP, old_handler) def test_stdin_broken_pipe(self): # buffer large enough to feed the whole pipe buffer large_data = b'x' * support.PIPE_MAX_SIZE rfd, wfd = os.pipe() self.addCleanup(os.close, rfd) self.addCleanup(os.close, wfd) if support.MS_WINDOWS: handle = msvcrt.get_osfhandle(rfd) os.set_handle_inheritable(handle, True) code = textwrap.dedent(f''' import os, msvcrt handle = {handle} fd = msvcrt.open_osfhandle(handle, os.O_RDONLY) os.read(fd, 1) ''') from subprocess import STARTUPINFO startupinfo = STARTUPINFO() startupinfo.lpAttributeList = {"handle_list": [handle]} kwargs = dict(startupinfo=startupinfo) else: code = f'import os; fd = {rfd}; os.read(fd, 1)' kwargs = dict(pass_fds=(rfd,)) # the program ends before the stdin can be fed proc = self.loop.run_until_complete( asyncio.create_subprocess_exec( sys.executable, '-c', code, stdin=subprocess.PIPE, **kwargs ) ) async def write_stdin(proc, data): proc.stdin.write(data) # Only exit the child process once the write buffer is filled os.write(wfd, b'go') await proc.stdin.drain() coro = write_stdin(proc, large_data) # drain() must raise BrokenPipeError or ConnectionResetError with test_utils.disable_logger(): self.assertRaises((BrokenPipeError, ConnectionResetError), self.loop.run_until_complete, coro) self.loop.run_until_complete(proc.wait()) def test_communicate_ignore_broken_pipe(self): # buffer large enough to feed the whole pipe buffer large_data = b'x' * support.PIPE_MAX_SIZE # the program ends before the stdin can be fed proc = self.loop.run_until_complete( asyncio.create_subprocess_exec( sys.executable, '-c', 'pass', stdin=subprocess.PIPE, ) ) # communicate() must ignore BrokenPipeError when feeding stdin self.loop.set_exception_handler(lambda loop, msg: None) self.loop.run_until_complete(proc.communicate(large_data)) self.loop.run_until_complete(proc.wait()) def test_pause_reading(self): limit = 10 size = (limit * 2 + 1) async def test_pause_reading(): code = '\n'.join(( 'import sys', 'sys.stdout.write("x" * %s)' % size, 'sys.stdout.flush()', )) connect_read_pipe = self.loop.connect_read_pipe async def connect_read_pipe_mock(*args, **kw): transport, protocol = await connect_read_pipe(*args, **kw) transport.pause_reading = mock.Mock() transport.resume_reading = mock.Mock() return (transport, protocol) self.loop.connect_read_pipe = connect_read_pipe_mock proc = await asyncio.create_subprocess_exec( sys.executable, '-c', code, stdin=asyncio.subprocess.PIPE, stdout=asyncio.subprocess.PIPE, limit=limit, ) stdout_transport = proc._transport.get_pipe_transport(1) stdout, stderr = await proc.communicate() # The child process produced more than limit bytes of output, # the stream reader transport should pause the protocol to not # allocate too much memory. return (stdout, stdout_transport) # Issue #22685: Ensure that the stream reader pauses the protocol # when the child process produces too much data stdout, transport = self.loop.run_until_complete(test_pause_reading()) self.assertEqual(stdout, b'x' * size) self.assertTrue(transport.pause_reading.called) self.assertTrue(transport.resume_reading.called) def test_stdin_not_inheritable(self): # asyncio issue #209: stdin must not be inheritable, otherwise # the Process.communicate() hangs async def len_message(message): code = 'import sys; data = sys.stdin.read(); print(len(data))' proc = await asyncio.create_subprocess_exec( sys.executable, '-c', code, stdin=asyncio.subprocess.PIPE, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE, close_fds=False, ) stdout, stderr = await proc.communicate(message) exitcode = await proc.wait() return (stdout, exitcode) output, exitcode = self.loop.run_until_complete(len_message(b'abc')) self.assertEqual(output.rstrip(), b'3') self.assertEqual(exitcode, 0) def test_empty_input(self): async def empty_input(): code = 'import sys; data = sys.stdin.read(); print(len(data))' proc = await asyncio.create_subprocess_exec( sys.executable, '-c', code, stdin=asyncio.subprocess.PIPE, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE, close_fds=False, ) stdout, stderr = await proc.communicate(b'') exitcode = await proc.wait() return (stdout, exitcode) output, exitcode = self.loop.run_until_complete(empty_input()) self.assertEqual(output.rstrip(), b'0') self.assertEqual(exitcode, 0) def test_devnull_input(self): async def empty_input(): code = 'import sys; data = sys.stdin.read(); print(len(data))' proc = await asyncio.create_subprocess_exec( sys.executable, '-c', code, stdin=asyncio.subprocess.DEVNULL, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE, close_fds=False, ) stdout, stderr = await proc.communicate() exitcode = await proc.wait() return (stdout, exitcode) output, exitcode = self.loop.run_until_complete(empty_input()) self.assertEqual(output.rstrip(), b'0') self.assertEqual(exitcode, 0) def test_devnull_output(self): async def empty_output(): code = 'import sys; data = sys.stdin.read(); print(len(data))' proc = await asyncio.create_subprocess_exec( sys.executable, '-c', code, stdin=asyncio.subprocess.PIPE, stdout=asyncio.subprocess.DEVNULL, stderr=asyncio.subprocess.PIPE, close_fds=False, ) stdout, stderr = await proc.communicate(b"abc") exitcode = await proc.wait() return (stdout, exitcode) output, exitcode = self.loop.run_until_complete(empty_output()) self.assertEqual(output, None) self.assertEqual(exitcode, 0) def test_devnull_error(self): async def empty_error(): code = 'import sys; data = sys.stdin.read(); print(len(data))' proc = await asyncio.create_subprocess_exec( sys.executable, '-c', code, stdin=asyncio.subprocess.PIPE, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.DEVNULL, close_fds=False, ) stdout, stderr = await proc.communicate(b"abc") exitcode = await proc.wait() return (stderr, exitcode) output, exitcode = self.loop.run_until_complete(empty_error()) self.assertEqual(output, None) self.assertEqual(exitcode, 0) @unittest.skipIf(sys.platform not in ('linux', 'android'), "Don't have /dev/stdin") def test_devstdin_input(self): async def devstdin_input(message): code = 'file = open("/dev/stdin"); data = file.read(); print(len(data))' proc = await asyncio.create_subprocess_exec( sys.executable, '-c', code, stdin=asyncio.subprocess.PIPE, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE, close_fds=False, ) stdout, stderr = await proc.communicate(message) exitcode = await proc.wait() return (stdout, exitcode) output, exitcode = self.loop.run_until_complete(devstdin_input(b'abc')) self.assertEqual(output.rstrip(), b'3') self.assertEqual(exitcode, 0) def test_cancel_process_wait(self): # Issue #23140: cancel Process.wait() async def cancel_wait(): proc = await asyncio.create_subprocess_exec(*PROGRAM_BLOCKED) # Create an internal future waiting on the process exit task = self.loop.create_task(proc.wait()) self.loop.call_soon(task.cancel) try: await task except asyncio.CancelledError: pass # Cancel the future task.cancel() # Kill the process and wait until it is done proc.kill() await proc.wait() self.loop.run_until_complete(cancel_wait()) def test_cancel_make_subprocess_transport_exec(self): async def cancel_make_transport(): coro = asyncio.create_subprocess_exec(*PROGRAM_BLOCKED) task = self.loop.create_task(coro) self.loop.call_soon(task.cancel) try: await task except asyncio.CancelledError: pass # ignore the log: # "Exception during subprocess creation, kill the subprocess" with test_utils.disable_logger(): self.loop.run_until_complete(cancel_make_transport()) def test_cancel_post_init(self): async def cancel_make_transport(): coro = self.loop.subprocess_exec(asyncio.SubprocessProtocol, *PROGRAM_BLOCKED) task = self.loop.create_task(coro) self.loop.call_soon(task.cancel) try: await task except asyncio.CancelledError: pass # ignore the log: # "Exception during subprocess creation, kill the subprocess" with test_utils.disable_logger(): self.loop.run_until_complete(cancel_make_transport()) test_utils.run_briefly(self.loop) def test_close_kill_running(self): async def kill_running(): create = self.loop.subprocess_exec(asyncio.SubprocessProtocol, *PROGRAM_BLOCKED) transport, protocol = await create kill_called = False def kill(): nonlocal kill_called kill_called = True orig_kill() proc = transport.get_extra_info('subprocess') orig_kill = proc.kill proc.kill = kill returncode = transport.get_returncode() transport.close() await asyncio.wait_for(transport._wait(), 5) return (returncode, kill_called) # Ignore "Close running child process: kill ..." log with test_utils.disable_logger(): try: returncode, killed = self.loop.run_until_complete( kill_running() ) except asyncio.TimeoutError: self.skipTest( "Timeout failure on waiting for subprocess stopping" ) self.assertIsNone(returncode) # transport.close() must kill the process if it is still running self.assertTrue(killed) test_utils.run_briefly(self.loop) def test_close_dont_kill_finished(self): async def kill_running(): create = self.loop.subprocess_exec(asyncio.SubprocessProtocol, *PROGRAM_BLOCKED) transport, protocol = await create proc = transport.get_extra_info('subprocess') # kill the process (but asyncio is not notified immediately) proc.kill() proc.wait() proc.kill = mock.Mock() proc_returncode = proc.poll() transport_returncode = transport.get_returncode() transport.close() return (proc_returncode, transport_returncode, proc.kill.called) # Ignore "Unknown child process pid ..." log of SafeChildWatcher, # emitted because the test already consumes the exit status: # proc.wait() with test_utils.disable_logger(): result = self.loop.run_until_complete(kill_running()) test_utils.run_briefly(self.loop) proc_returncode, transport_return_code, killed = result self.assertIsNotNone(proc_returncode) self.assertIsNone(transport_return_code) # transport.close() must not kill the process if it finished, even if # the transport was not notified yet self.assertFalse(killed) async def _test_popen_error(self, stdin): if sys.platform == 'win32': target = 'asyncio.windows_utils.Popen' else: target = 'subprocess.Popen' with mock.patch(target) as popen: exc = ZeroDivisionError popen.side_effect = exc with warnings.catch_warnings(record=True) as warns: with self.assertRaises(exc): await asyncio.create_subprocess_exec( sys.executable, '-c', 'pass', stdin=stdin ) self.assertEqual(warns, []) def test_popen_error(self): # Issue #24763: check that the subprocess transport is closed # when BaseSubprocessTransport fails self.loop.run_until_complete(self._test_popen_error(stdin=None)) def test_popen_error_with_stdin_pipe(self): # Issue #35721: check that newly created socket pair is closed when # Popen fails self.loop.run_until_complete( self._test_popen_error(stdin=subprocess.PIPE)) def test_read_stdout_after_process_exit(self): async def execute(): code = '\n'.join(['import sys', 'for _ in range(64):', ' sys.stdout.write("x" * 4096)', 'sys.stdout.flush()', 'sys.exit(1)']) process = await asyncio.create_subprocess_exec( sys.executable, '-c', code, stdout=asyncio.subprocess.PIPE, ) while True: data = await process.stdout.read(65536) if data: await asyncio.sleep(0.3) else: break self.loop.run_until_complete(execute()) def test_create_subprocess_exec_text_mode_fails(self): async def execute(): with self.assertRaises(ValueError): await subprocess.create_subprocess_exec(sys.executable, text=True) with self.assertRaises(ValueError): await subprocess.create_subprocess_exec(sys.executable, encoding="utf-8") with self.assertRaises(ValueError): await subprocess.create_subprocess_exec(sys.executable, errors="strict") self.loop.run_until_complete(execute()) def test_create_subprocess_shell_text_mode_fails(self): async def execute(): with self.assertRaises(ValueError): await subprocess.create_subprocess_shell(sys.executable, text=True) with self.assertRaises(ValueError): await subprocess.create_subprocess_shell(sys.executable, encoding="utf-8") with self.assertRaises(ValueError): await subprocess.create_subprocess_shell(sys.executable, errors="strict") self.loop.run_until_complete(execute()) def test_create_subprocess_exec_with_path(self): async def execute(): p = await subprocess.create_subprocess_exec( os_helper.FakePath(sys.executable), '-c', 'pass') await p.wait() p = await subprocess.create_subprocess_exec( sys.executable, '-c', 'pass', os_helper.FakePath('.')) await p.wait() self.assertIsNone(self.loop.run_until_complete(execute())) async def check_stdout_output(self, coro, output): proc = await coro stdout, _ = await proc.communicate() self.assertEqual(stdout, output) self.assertEqual(proc.returncode, 0) task = asyncio.create_task(proc.wait()) await asyncio.sleep(0) self.assertEqual(task.result(), proc.returncode) def test_create_subprocess_env_shell(self) -> None: async def main() -> None: executable = sys.executable if sys.platform == "win32": executable = f'"{executable}"' cmd = f'''{executable} -c "import os, sys; sys.stdout.write(os.getenv('FOO'))"''' env = os.environ.copy() env["FOO"] = "bar" proc = await asyncio.create_subprocess_shell( cmd, env=env, stdout=subprocess.PIPE ) return proc self.loop.run_until_complete(self.check_stdout_output(main(), b'bar')) def test_create_subprocess_env_exec(self) -> None: async def main() -> None: cmd = [sys.executable, "-c", "import os, sys; sys.stdout.write(os.getenv('FOO'))"] env = os.environ.copy() env["FOO"] = "baz" proc = await asyncio.create_subprocess_exec( *cmd, env=env, stdout=subprocess.PIPE ) return proc self.loop.run_until_complete(self.check_stdout_output(main(), b'baz')) def test_subprocess_concurrent_wait(self) -> None: async def main() -> None: proc = await asyncio.create_subprocess_exec( *PROGRAM_CAT, stdin=subprocess.PIPE, stdout=subprocess.PIPE, ) stdout, _ = await proc.communicate(b'some data') self.assertEqual(stdout, b"some data") self.assertEqual(proc.returncode, 0) self.assertEqual(await asyncio.gather(*[proc.wait() for _ in range(10)]), [proc.returncode] * 10) self.loop.run_until_complete(main()) def test_subprocess_protocol_events(self): # gh-108973: Test that all subprocess protocol methods are called. # The protocol methods are not called in a determistic order. # The order depends on the event loop and the operating system. events = [] fds = [1, 2] expected = [ ('pipe_data_received', 1, b'stdout'), ('pipe_data_received', 2, b'stderr'), ('pipe_connection_lost', 1), ('pipe_connection_lost', 2), 'process_exited', ] per_fd_expected = [ 'pipe_data_received', 'pipe_connection_lost', ] class MyProtocol(asyncio.SubprocessProtocol): def __init__(self, exit_future: asyncio.Future) -> None: self.exit_future = exit_future def pipe_data_received(self, fd, data) -> None: events.append(('pipe_data_received', fd, data)) self.exit_maybe() def pipe_connection_lost(self, fd, exc) -> None: events.append(('pipe_connection_lost', fd)) self.exit_maybe() def process_exited(self) -> None: events.append('process_exited') self.exit_maybe() def exit_maybe(self): # Only exit when we got all expected events if len(events) >= len(expected): self.exit_future.set_result(True) async def main() -> None: loop = asyncio.get_running_loop() exit_future = asyncio.Future() code = 'import sys; sys.stdout.write("stdout"); sys.stderr.write("stderr")' transport, _ = await loop.subprocess_exec(lambda: MyProtocol(exit_future), sys.executable, '-c', code, stdin=None) await exit_future transport.close() return events events = self.loop.run_until_complete(main()) # First, make sure that we received all events self.assertSetEqual(set(events), set(expected)) # Second, check order of pipe events per file descriptor per_fd_events = {fd: [] for fd in fds} for event in events: if event == 'process_exited': continue name, fd = event[:2] per_fd_events[fd].append(name) for fd in fds: self.assertEqual(per_fd_events[fd], per_fd_expected, (fd, events)) def test_subprocess_communicate_stdout(self): # See https://github.com/python/cpython/issues/100133 async def get_command_stdout(cmd, *args): proc = await asyncio.create_subprocess_exec( cmd, *args, stdout=asyncio.subprocess.PIPE, ) stdout, _ = await proc.communicate() return stdout.decode().strip() async def main(): outputs = [f'foo{i}' for i in range(10)] res = await asyncio.gather(*[get_command_stdout(sys.executable, '-c', f'print({out!r})') for out in outputs]) self.assertEqual(res, outputs) self.loop.run_until_complete(main()) @unittest.skipIf(sys.platform != 'linux', "Linux only") def test_subprocess_send_signal_race(self): # See https://github.com/python/cpython/issues/87744 async def main(): for _ in range(10): proc = await asyncio.create_subprocess_exec('sleep', '0.1') await asyncio.sleep(0.1) try: proc.send_signal(signal.SIGUSR1) except ProcessLookupError: pass self.assertNotEqual(await proc.wait(), 255) self.loop.run_until_complete(main()) if sys.platform != 'win32': # Unix class SubprocessWatcherMixin(SubprocessMixin): def setUp(self): super().setUp() policy = asyncio.get_event_loop_policy() self.loop = policy.new_event_loop() self.set_event_loop(self.loop) def test_watcher_implementation(self): loop = self.loop watcher = loop._watcher if unix_events.can_use_pidfd(): self.assertIsInstance(watcher, unix_events._PidfdChildWatcher) else: self.assertIsInstance(watcher, unix_events._ThreadedChildWatcher) class SubprocessThreadedWatcherTests(SubprocessWatcherMixin, test_utils.TestCase): def setUp(self): # Force the use of the threaded child watcher unix_events.can_use_pidfd = mock.Mock(return_value=False) super().setUp() @unittest.skipUnless( unix_events.can_use_pidfd(), "operating system does not support pidfds", ) class SubprocessPidfdWatcherTests(SubprocessWatcherMixin, test_utils.TestCase): pass else: # Windows class SubprocessProactorTests(SubprocessMixin, test_utils.TestCase): def setUp(self): super().setUp() self.loop = asyncio.ProactorEventLoop() self.set_event_loop(self.loop) if __name__ == '__main__': unittest.main()