[Python-checkins] bpo-40280: Detect if WASM platform supports threading (GH-32243)
miss-islington
webhook-mailer at python.org
Sat Apr 2 04:12:52 EDT 2022
https://github.com/python/cpython/commit/59be9cd748728b03ac61287681c3010bcec5e558
commit: 59be9cd748728b03ac61287681c3010bcec5e558
branch: main
author: Christian Heimes <christian at python.org>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2022-04-02T01:12:44-07:00
summary:
bpo-40280: Detect if WASM platform supports threading (GH-32243)
Automerge-Triggered-By: GH:tiran
files:
M Lib/test/libregrtest/runtest.py
M Lib/test/support/threading_helper.py
diff --git a/Lib/test/libregrtest/runtest.py b/Lib/test/libregrtest/runtest.py
index 83c5f249841cc..62cf1a3f1175e 100644
--- a/Lib/test/libregrtest/runtest.py
+++ b/Lib/test/libregrtest/runtest.py
@@ -11,6 +11,7 @@
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
@@ -179,7 +180,9 @@ def _runtest(ns: Namespace, test_name: str) -> TestResult:
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)
diff --git a/Lib/test/support/threading_helper.py b/Lib/test/support/threading_helper.py
index 92a64e8354acb..2ae4577f41f7b 100644
--- a/Lib/test/support/threading_helper.py
+++ b/Lib/test/support/threading_helper.py
@@ -207,3 +207,30 @@ def __exit__(self, *exc_info):
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()
More information about the Python-checkins
mailing list