test: add support for checking for TSAN

 - Skip some unsupported tests in test_threading
 - Skip some unsupported tests in test_concurrent_futures

Author: colesbury

Lib/test/support/__init__.py

@@ -396,9 +396,9 @@ def skip_if_buildbot(reason=None):
         isbuildbot = False
     return unittest.skipIf(isbuildbot, reason)
 
-def check_sanitizer(*, address=False, memory=False, ub=False):
+def check_sanitizer(*, address=False, memory=False, ub=False, thread=False):
     """Returns True if Python is compiled with sanitizer support"""
-    if not (address or memory or ub):
+    if not (address or memory or ub or thread):
         raise ValueError('At least one of address, memory, or ub must be True')
 
 
@@ -416,10 +416,15 @@ def check_sanitizer(*, address=False, memory=False, ub=False):
         '-fsanitize=undefined' in _cflags or
         '--with-undefined-behavior-sanitizer' in _config_args
     )
+    thread_sanitizer = (
+        '-fsanitize=thread' in _cflags or
+        '--with-thread-sanitizer' in _config_args
+    )
     return (
         (memory and memory_sanitizer) or
         (address and address_sanitizer) or
-        (ub and ub_sanitizer)
+        (ub and ub_sanitizer) or
+        (thread and thread_sanitizer)
     )
 
 

Lib/test/test_concurrent_futures.py

@@ -161,6 +161,8 @@ def get_context(self):
             self.skipTest("ProcessPoolExecutor unavailable on this system")
         if sys.platform == "win32":
             self.skipTest("require unix system")
+        if support.check_sanitizer(thread=True):
+            self.skipTest("TSAN doesn't support threads after fork")
         return super().get_context()
 
 
@@ -187,6 +189,8 @@ def get_context(self):
             self.skipTest("ProcessPoolExecutor unavailable on this system")
         if sys.platform == "win32":
             self.skipTest("require unix system")
+        if support.check_sanitizer(thread=True):
+            self.skipTest("TSAN doesn't support threads after fork")
         return super().get_context()
 
 

Lib/test/test_threading.py

@@ -562,6 +562,7 @@ def exit_handler():
         self.assertEqual(err.rstrip(), b'child process ok')
 
     @support.requires_fork()
+    @unittest.skipIf(support.check_sanitizer(thread=True), "TSAN doesn't support threads after fork")
     def test_dummy_thread_after_fork(self):
         # Issue #14308: a dummy thread in the active list doesn't mess up
         # the after-fork mechanism.
@@ -653,6 +654,7 @@ def test_main_thread_after_fork(self):
     @unittest.skipIf(sys.platform in platforms_to_skip, "due to known OS bug")
     @support.requires_fork()
     @unittest.skipUnless(hasattr(os, 'waitpid'), "test needs os.waitpid()")
+    @unittest.skipIf(support.check_sanitizer(thread=True), "TSAN doesn't support threads after fork")
     def test_main_thread_after_fork_from_nonmain_thread(self):
         code = """if 1:
             import os, threading, sys, warnings
@@ -1071,6 +1073,7 @@ def test_2_join_in_forked_process(self):
 
     @support.requires_fork()
     @unittest.skipIf(sys.platform in platforms_to_skip, "due to known OS bug")
+    @unittest.skipIf(support.check_sanitizer(thread=True), "TSAN doesn't support threads after fork")
     def test_3_join_in_forked_from_thread(self):
         # Like the test above, but fork() was called from a worker thread
         # In the forked process, the main Thread object must be marked as stopped.