from test import support

from test.support import os_helper

from test.support import threading_helper

from test.libregrtest.cmdline import Namespace

from test.libregrtest.save_env import saved_test_environment

from test.libregrtest.utils import clear_caches, format_duration, print_warning

output_on_failure = ns.verbose3

use_timeout = (ns.timeout is not None)

use_timeout = (

ns.timeout is not None and threading_helper.can_start_thread

)

if use_timeout:

faulthandler.dump_traceback_later(ns.timeout, exit=True)

del self.exc_value

del self.exc_traceback

del self.thread

def _can_start_thread() -> bool:

"""Detect if Python can start new threads.

Some WebAssembly platforms do not provide a working pthread

implementation. Thread support is stubbed and any attempt

to create a new thread fails.

- wasm32-wasi does not have threading.

- wasm32-emscripten can be compiled with or without pthread

support (-s USE_PTHREADS / __EMSCRIPTEN_PTHREADS__).

"""

if sys.platform == "emscripten":

try:

_thread.start_new_thread(lambda: None, ())

except RuntimeError:

return False

else:

return True

elif sys.platform == "wasi":

return False

else:

# assume all other platforms have working thread support.

return True

can_start_thread = _can_start_thread()