More multiprocessing & concurrent.futures disables when forkserver cannot work

Author: gpshead

Lib/test/_test_multiprocessing.py

@@ -1431,6 +1431,7 @@ def _acquire_event(lock, event):
         event.set()
         time.sleep(1.0)
 
+    @hashlib_helper.requires_hashdigest('sha256')  # Manager RPC connection auth
     def test_repr_lock(self):
         if self.TYPE != 'processes':
             self.skipTest('test not appropriate for {}'.format(self.TYPE))
@@ -1496,6 +1497,7 @@ def _acquire_release(lock, timeout, l=None, n=1):
         for _ in range(n):
             lock.release()
 
+    @hashlib_helper.requires_hashdigest('sha256')  # Manager RPC connection auth
     def test_repr_rlock(self):
         if self.TYPE != 'processes':
             self.skipTest('test not appropriate for {}'.format(self.TYPE))
@@ -3417,6 +3419,7 @@ def tearDown(self):
         self.mgr.shutdown()
         self.mgr.join()
 
+    @hashlib_helper.requires_hashdigest('sha256')  # multiprocessing.connection
     def test_queue_get(self):
         queue = self.mgr.Queue()
         if gc.isenabled():
@@ -3730,6 +3733,7 @@ def test_context(self):
         if self.TYPE == 'processes':
             self.assertRaises(OSError, l.accept)
 
+    @hashlib_helper.requires_hashdigest('sha256')  # connection auth
     def test_empty_authkey(self):
         # bpo-43952: allow empty bytes as authkey
         def handler(*args):
@@ -5782,9 +5786,11 @@ def test_get_all_start_methods(self):
             self.assertIn(methods[0], {'forkserver', 'spawn'},
                           msg='3.14+ default must not be fork')
             if methods[0] == 'spawn':
-                # Confirm that the current default selection logic prefers
-                # forkserver vs spawn when available.
-                self.assertNotIn('forkserver', methods)
+                if not hashlib_helper.in_openssl_fips_mode():
+                    # Confirm that the current default selection logic prefers
+                    # forkserver vs spawn when available.
+                    # OpenSSL FIPS mode can disable this by blocking sha256.
+                    self.assertNotIn('forkserver', methods)
 
     def test_preload_resources(self):
         if multiprocessing.get_start_method() != 'forkserver':
@@ -5805,7 +5811,11 @@ def test_mixed_startmethod(self):
         # Fork-based locks cannot be used with spawned process
         for process_method in ["spawn", "forkserver"]:
             queue = multiprocessing.get_context("fork").Queue()
-            process_ctx = multiprocessing.get_context(process_method)
+            try:
+                process_ctx = multiprocessing.get_context(process_method)
+            except ValueError as err:
+                self.skipTest(err)
+                continue
             p = process_ctx.Process(target=close_queue, args=(queue,))
             err_msg = "A SemLock created in a fork"
             with self.assertRaisesRegex(RuntimeError, err_msg):
@@ -5814,8 +5824,13 @@ def test_mixed_startmethod(self):
         # non-fork-based locks can be used with all other start methods
         for queue_method in ["spawn", "forkserver"]:
             for process_method in multiprocessing.get_all_start_methods():
-                queue = multiprocessing.get_context(queue_method).Queue()
-                process_ctx = multiprocessing.get_context(process_method)
+                try:
+                    queue_ctx = multiprocessing.get_context(queue_method)
+                    process_ctx = multiprocessing.get_context(process_method)
+                except ValueError as err:
+                    self.skipTest(err)
+                    continue
+                queue = queue_ctx.Queue()
                 p = process_ctx.Process(target=close_queue, args=(queue,))
                 p.start()
                 p.join()

Lib/test/support/hashlib_helper.py

@@ -8,6 +8,13 @@
     _hashlib = None
 
 
+def in_openssl_fips_mode() -> bool:
+    """Is OpenSSL based _hashlib is present & operating in FIPS mode?"""
+    if _hashlib and _hashlib.get_fips_mode() != 0:
+        return True
+    return False
+
+
 def requires_hashdigest(digestname, openssl=None, usedforsecurity=True):
     """Decorator raising SkipTest if a hashing algorithm is not available
 

Lib/test/test_concurrent_futures/test_init.py

@@ -141,6 +141,11 @@ def test_spawn(self):
 
     @support.skip_if_sanitizer("TSAN doesn't support threads after fork", thread=True)
     def test_forkserver(self):
+        import multiprocessing
+        try:
+            multiprocessing.get_context("forkserver")
+        except ValueError as err:
+            self.skipTest(str(err))
         self._test(ProcessPoolForkserverFailingInitializerTest)
 
 

Lib/test/test_concurrent_futures/util.py

@@ -119,7 +119,10 @@ def get_context(self):
             self.skipTest("require unix system")
         if support.check_sanitizer(thread=True):
             self.skipTest("TSAN doesn't support threads after fork")
-        return super().get_context()
+        try:
+            return super().get_context()
+        except ValueError as err:
+            self.skipTest(str(err))
 
 
 def create_executor_tests(remote_globals, mixin, bases=(BaseTestCase,),