From fdeb6ec45ab898e2783e44495a756f56b42f4a80 Mon Sep 17 00:00:00 2001
From: Victor Stinner <victor.stinner@gmail.com>
Date: Fri, 13 Dec 2013 02:01:38 +0100
Subject: Issue #14432: Remove the thread state field from the frame structure.
 Fix a crash when a generator is created in a C thread that is destroyed while
 the generator is still used. The issue was that a generator contains a frame,
 and the frame kept a reference to the Python state of the destroyed C thread.
 The crash occurs when a trace function is setup.

---
 Lib/test/test_threading.py | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

(limited to 'Lib/test/test_threading.py')

diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index a84577cc0f0..73839e79369 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -662,6 +662,44 @@ class ThreadTests(BaseTestCase):
         self.assertRegex(err.rstrip(),
                          b"^sys:1: ResourceWarning: unclosed file ")
 
+    def test_frame_tstate_tracing(self):
+        # Issue #14432: Crash when a generator is created in a C thread that is
+        # destroyed while the generator is still used. The issue was that a
+        # generator contains a frame, and the frame kept a reference to the
+        # Python state of the destroyed C thread. The crash occurs when a trace
+        # function is setup.
+
+        def noop_trace(frame, event, arg):
+            # no operation
+            return noop_trace
+
+        def generator():
+            while 1:
+                yield "genereator"
+
+        def callback():
+            if callback.gen is None:
+                callback.gen = generator()
+            return next(callback.gen)
+        callback.gen = None
+
+        old_trace = sys.gettrace()
+        sys.settrace(noop_trace)
+        try:
+            # Install a trace function
+            threading.settrace(noop_trace)
+
+            # Create a generator in a C thread which exits after the call
+            _testcapi.call_in_temporary_c_thread(callback)
+
+            # Call the generator in a different Python thread, check that the
+            # generator didn't keep a reference to the destroyed thread state
+            for test in range(3):
+                # The trace function is still called here
+                callback()
+        finally:
+            sys.settrace(old_trace)
+
 
 class ThreadJoinOnShutdown(BaseTestCase):
 
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