python · markshannon · Jul 19, 2021 · Jul 19, 2021
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
@@ -1604,6 +1604,31 @@ def test_interrupt_main_invalid_signal(self):
        self.assertRaises(ValueError, _thread.interrupt_main, signal.NSIG)
        self.assertRaises(ValueError, _thread.interrupt_main, 1000000)

+    @threading_helper.reap_threads
+    def test_can_interrupt_tight_loops(self):
+        cont = [True]
+        started = [False]
+        interrupted = [False]
+
+        def worker(started, cont, interrupted):
+            iterations = 100_000_000
+            started[0] = True
+            while cont[0]:
+                if iterations:
+                    iterations -= 1
+                else:
+                    return
+                pass
+            interrupted[0] = True
+
+        t = threading.Thread(target=worker,args=(started, cont, interrupted))
+        t.start()
+        while not started[0]:
+            pass
+        cont[0] = False
+        t.join()
+        self.assertTrue(interrupted[0])
+

 class AtexitTests(unittest.TestCase):


@@ -3759,14 +3759,17 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
            if (Py_IsFalse(cond)) {
                Py_DECREF(cond);
                JUMPTO(oparg);
+                CHECK_EVAL_BREAKER();
                DISPATCH();
            }
            err = PyObject_IsTrue(cond);
            Py_DECREF(cond);
            if (err > 0)
                ;
-            else if (err == 0)
+            else if (err == 0) {
                JUMPTO(oparg);
+                CHECK_EVAL_BREAKER();
+            }
            else
                goto error;
            DISPATCH();
@@ -3783,12 +3786,14 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
            if (Py_IsTrue(cond)) {
                Py_DECREF(cond);
                JUMPTO(oparg);
+                CHECK_EVAL_BREAKER();
                DISPATCH();
            }
            err = PyObject_IsTrue(cond);
            Py_DECREF(cond);
            if (err > 0) {
                JUMPTO(oparg);
+                CHECK_EVAL_BREAKER();
            }
            else if (err == 0)
                ;