Revert "bpo-44645: Check for interrupts on any potentially backwards edge. (GH-27167)" (#27194)

This reverts commit 000e70a.

Author: pablogsal

Lib/test/test_threading.py

@@ -1604,31 +1604,6 @@ 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
-        iterations = 100_000_000
-
-        def worker():
-            nonlocal iterations
-            nonlocal started
-            started = True
-            while cont:
-                if iterations:
-                    iterations -= 1
-                else:
-                    return
-                pass
-
-        t = threading.Thread(target=worker)
-        t.start()
-        while not started:
-            pass
-        cont = False
-        t.join()
-        self.assertNotEqual(iterations, 0)
-
 
 class AtexitTests(unittest.TestCase):
 

Python/ceval.c

@@ -3638,17 +3638,14 @@ _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();
@@ -3665,14 +3662,12 @@ _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)
                 ;