closes bpo-34004: Skip lock interruption tests on musl. (GH-9224)

miss-islington · benjaminp · web-flow · commit 5a435eac1b83 · 2018-09-12T14:11:45.000-07:00
Returning EINTR from pthread semaphore or lock acquisition is an optional POSIX feature. musl does not provide this feature, so some threadsignal tests fail when Python is built against it. There's no good way to test for musl, so we skip if we're on Linux and not using glibc pthreads. Also, hedge in the threading documentation about when we can provide interrupts from lock acquisition. (cherry picked from commit 5b10d51) Co-authored-by: Benjamin Peterson <benjamin@python.org>
diff --git a/Doc/library/threading.rst b/Doc/library/threading.rst
@@ -400,7 +400,8 @@ All methods are executed atomically.
          The *timeout* parameter is new.
 
       .. versionchanged:: 3.2
-         Lock acquires can now be interrupted by signals on POSIX.
+         Lock acquisition can now be interrupted by signals on POSIX if the
+         underlying threading implementation supports it.
 
 
    .. method:: release()
diff --git a/Lib/test/test_threadsignals.py b/Lib/test/test_threadsignals.py
@@ -78,6 +78,10 @@ def alarm_interrupt(self, sig, frame):
 
     @unittest.skipIf(USING_PTHREAD_COND,
                      'POSIX condition variables cannot be interrupted')
+    @unittest.skipIf(sys.platform.startswith('linux') and
+                     not sys.thread_info.version,
+                     'Issue 34004: musl does not allow interruption of locks '
+                     'by signals.')
     # Issue #20564: sem_timedwait() cannot be interrupted on OpenBSD
     @unittest.skipIf(sys.platform.startswith('openbsd'),
                      'lock cannot be interrupted on OpenBSD')
@@ -105,6 +109,10 @@ def test_lock_acquire_interruption(self):
 
     @unittest.skipIf(USING_PTHREAD_COND,
                      'POSIX condition variables cannot be interrupted')
+    @unittest.skipIf(sys.platform.startswith('linux') and
+                     not sys.thread_info.version,
+                     'Issue 34004: musl does not allow interruption of locks '
+                     'by signals.')
     # Issue #20564: sem_timedwait() cannot be interrupted on OpenBSD
     @unittest.skipIf(sys.platform.startswith('openbsd'),
                      'lock cannot be interrupted on OpenBSD')
