gh-84461: Add sys._emscripten_info, improve docs and build (gh-91781)

2 files changed, 9 insertions, 6 deletions

diff --git a/Lib/test/support/threading_helper.py b/Lib/test/support/threading_helper.py
index 7b636f0..26cbc6f 100644
--- a/Lib/test/support/threading_helper.py
+++ b/Lib/test/support/threading_helper.py
@@ -222,12 +222,7 @@ def _can_start_thread() -> bool:
       support (-s USE_PTHREADS / __EMSCRIPTEN_PTHREADS__).
     """
     if sys.platform == "emscripten":
-        try:
-            _thread.start_new_thread(lambda: None, ())
-        except RuntimeError:
-            return False
-        else:
-            return True
+        return sys._emscripten_info.pthreads
     elif sys.platform == "wasi":
         return False
     else:
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index b70871f..bbf01b6 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -629,6 +629,14 @@ class SysModuleTest(unittest.TestCase):
         self.assertIn(info.name, ('nt', 'pthread', 'solaris', None))
         self.assertIn(info.lock, ('semaphore', 'mutex+cond', None))
 
+    @unittest.skipUnless(support.is_emscripten, "only available on Emscripten")
+    def test_emscripten_info(self):
+        self.assertEqual(len(sys._emscripten_info), 4)
+        self.assertIsInstance(sys._emscripten_info.emscripten_version, tuple)
+        self.assertIsInstance(sys._emscripten_info.runtime, (str, type(None)))
+        self.assertIsInstance(sys._emscripten_info.pthreads, bool)
+        self.assertIsInstance(sys._emscripten_info.shared_memory, bool)
+
     def test_43581(self):
         # Can't use sys.stdout, as this is a StringIO object when
         # the test runs under regrtest.