From b43b156c5e8909315ece92fc434123d3f93b5a61 Mon Sep 17 00:00:00 2001
From: Stefan Behnel <stefan_ml@behnel.de>
Date: Fri, 25 Aug 2017 18:22:41 +0200
Subject: [PATCH] Only reset the frame backlink of *internally* created
exception tracebacks in generators/coroutines, not the ones stored away from
the caller state.
---
Cython/Utility/Coroutine.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/Cython/Utility/Coroutine.c b/Cython/Utility/Coroutine.c
index a179e5793..6f9c6af36 100644
--- a/Cython/Utility/Coroutine.c
+++ b/Cython/Utility/Coroutine.c
@@ -397,23 +397,18 @@ static PyObject *__Pyx_Coroutine_Throw(PyObject *gen, PyObject *args); /*proto*/
}
#define __Pyx_Coroutine_ResetAndClearException(self) { \
__Pyx_ExceptionReset((self)->exc_type, (self)->exc_value, (self)->exc_traceback); \
- __Pyx_Coroutine_ResetFrameBackpointer(self); \
(self)->exc_type = (self)->exc_value = (self)->exc_traceback = NULL; \
}
#if CYTHON_FAST_THREAD_STATE
#define __Pyx_PyGen_FetchStopIterationValue(pvalue) \
__Pyx_PyGen__FetchStopIterationValue($local_tstate_cname, pvalue)
-#define __Pyx_Coroutine_ResetFrameBackpointer(self) \
- __Pyx__Coroutine_ResetFrameBackpointer($local_tstate_cname, self)
#else
#define __Pyx_PyGen_FetchStopIterationValue(pvalue) \
__Pyx_PyGen__FetchStopIterationValue(__Pyx_PyThreadState_Current, pvalue)
-#define __Pyx_Coroutine_ResetFrameBackpointer(self) \
- __Pyx__Coroutine_ResetFrameBackpointer(__Pyx_PyThreadState_Current, self)
#endif
static int __Pyx_PyGen__FetchStopIterationValue(PyThreadState *tstate, PyObject **pvalue); /*proto*/
-static CYTHON_INLINE void __Pyx__Coroutine_ResetFrameBackpointer(PyThreadState *tstate, __pyx_CoroutineObject *self);
+static CYTHON_INLINE void __Pyx_Coroutine_ResetFrameBackpointer(__pyx_CoroutineObject *self); /*proto*/
//////////////////// Coroutine.proto ////////////////////
@@ -667,7 +662,14 @@ PyObject *__Pyx_Coroutine_SendEx(__pyx_CoroutineObject *self, PyObject *value, i
tstate = __Pyx_PyThreadState_Current;
#endif
- if (self->exc_type && self->exc_type != Py_None) {
+ // Traceback/Frame rules:
+ // - on entry, save external exception state in self->exc_*, restore it on exit
+ // - on exit, keep internally generated exceptions in self->exc_*, clear everything else
+ // - on entry, set "f_back" pointer of internal exception traceback to (current) outer call frame
+ // - on exit, clear "f_back" of internal exception traceback
+ // - do not touch external frames and tracebacks
+
+ if (self->exc_type) {
#if CYTHON_COMPILING_IN_PYPY || CYTHON_COMPILING_IN_PYSTON
// FIXME: what to do in PyPy?
#else
@@ -700,20 +702,17 @@ PyObject *__Pyx_Coroutine_SendEx(__pyx_CoroutineObject *self, PyObject *value, i
return retval;
}
-static CYTHON_INLINE void __Pyx__Coroutine_ResetFrameBackpointer(PyThreadState *tstate, __pyx_CoroutineObject *self) {
+static CYTHON_INLINE void __Pyx_Coroutine_ResetFrameBackpointer(__pyx_CoroutineObject *self) {
// Don't keep the reference to f_back any longer than necessary. It
// may keep a chain of frames alive or it could create a reference
// cycle.
- if (self->exc_traceback) {
+ if (likely(self->exc_traceback)) {
#if CYTHON_COMPILING_IN_PYPY || CYTHON_COMPILING_IN_PYSTON
// FIXME: what to do in PyPy?
#else
PyTracebackObject *tb = (PyTracebackObject *) self->exc_traceback;
PyFrameObject *f = tb->tb_frame;
- // do not accidentally break any other frame links
- // FIXME: any other cases? e.g. do we need to follow up the back link chain?
- if (f->f_back == tstate->frame)
- Py_CLEAR(f->f_back);
+ Py_CLEAR(f->f_back);
#endif
}
}
--
2.30.9