[Python-checkins] Only check evalbreaker after calls and on backwards egdes. Makes sure that __exit__ or __aexit__ is called in with statments in case of interrupt. (GH-18334)
markshannon
webhook-mailer at python.org
Wed Mar 24 13:56:34 EDT 2021
https://github.com/python/cpython/commit/4958f5d69dd2bf86866c43491caf72f774ddec97
commit: 4958f5d69dd2bf86866c43491caf72f774ddec97
branch: master
author: Mark Shannon <mark at hotpy.org>
committer: markshannon <mark at hotpy.org>
date: 2021-03-24T17:56:12Z
summary:
Only check evalbreaker after calls and on backwards egdes. Makes sure that __exit__ or __aexit__ is called in with statments in case of interrupt. (GH-18334)
files:
A Misc/NEWS.d/next/Core and Builtins/2020-02-03-13-23-10.bpo-29988.8_UB5w.rst
M Python/ceval.c
diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-02-03-13-23-10.bpo-29988.8_UB5w.rst b/Misc/NEWS.d/next/Core and Builtins/2020-02-03-13-23-10.bpo-29988.8_UB5w.rst
new file mode 100644
index 0000000000000..9a19c615a88f6
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2020-02-03-13-23-10.bpo-29988.8_UB5w.rst
@@ -0,0 +1,3 @@
+Only handle asynchronous exceptions and requests to drop the GIL when
+returning from a call or on the back edges of loops. Makes sure that
+:meth:`__exit__` is always called in with statements, even for interrupts.
diff --git a/Python/ceval.c b/Python/ceval.c
index 3a37017c000d4..aef79e1a9db31 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1331,7 +1331,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
TARGET_##op
#ifdef LLTRACE
-#define FAST_DISPATCH() \
+#define DISPATCH() \
{ \
if (!lltrace && !_Py_TracingPossible(ceval2) && !PyDTrace_LINE_ENABLED()) { \
f->f_lasti = INSTR_OFFSET(); \
@@ -1341,7 +1341,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
goto fast_next_opcode; \
}
#else
-#define FAST_DISPATCH() \
+#define DISPATCH() \
{ \
if (!_Py_TracingPossible(ceval2) && !PyDTrace_LINE_ENABLED()) { \
f->f_lasti = INSTR_OFFSET(); \
@@ -1352,20 +1352,17 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
}
#endif
-#define DISPATCH() \
- { \
- if (!_Py_atomic_load_relaxed(eval_breaker)) { \
- FAST_DISPATCH(); \
- } \
- continue; \
- }
-
#else
#define TARGET(op) op
-#define FAST_DISPATCH() goto fast_next_opcode
-#define DISPATCH() continue
+#define DISPATCH() goto fast_next_opcode
+
#endif
+#define CHECK_EVAL_BREAKER() \
+ if (_Py_atomic_load_relaxed(eval_breaker)) { \
+ continue; \
+ }
+
/* Tuple access macros */
@@ -1857,7 +1854,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
and that all operation that succeed call [FAST_]DISPATCH() ! */
case TARGET(NOP): {
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(LOAD_FAST): {
@@ -1870,7 +1867,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
}
Py_INCREF(value);
PUSH(value);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(LOAD_CONST): {
@@ -1878,20 +1875,20 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
PyObject *value = GETITEM(consts, oparg);
Py_INCREF(value);
PUSH(value);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(STORE_FAST): {
PREDICTED(STORE_FAST);
PyObject *value = POP();
SETLOCAL(oparg, value);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(POP_TOP): {
PyObject *value = POP();
Py_DECREF(value);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(ROT_TWO): {
@@ -1899,7 +1896,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
PyObject *second = SECOND();
SET_TOP(second);
SET_SECOND(top);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(ROT_THREE): {
@@ -1909,7 +1906,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
SET_TOP(second);
SET_SECOND(third);
SET_THIRD(top);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(ROT_FOUR): {
@@ -1921,14 +1918,14 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
SET_SECOND(third);
SET_THIRD(fourth);
SET_FOURTH(top);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(DUP_TOP): {
PyObject *top = TOP();
Py_INCREF(top);
PUSH(top);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(DUP_TOP_TWO): {
@@ -1939,7 +1936,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
STACK_GROW(2);
SET_TOP(top);
SET_SECOND(second);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(UNARY_POSITIVE): {
@@ -2704,7 +2701,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
UNWIND_EXCEPT_HANDLER(b);
Py_DECREF(POP());
JUMPBY(oparg);
- FAST_DISPATCH();
+ DISPATCH();
}
else {
PyObject *val = POP();
@@ -2718,7 +2715,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
PyObject *value = PyExc_AssertionError;
Py_INCREF(value);
PUSH(value);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(LOAD_BUILD_CLASS): {
@@ -3620,7 +3617,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
Py_DECREF(right);
PREDICT(POP_JUMP_IF_FALSE);
PREDICT(POP_JUMP_IF_TRUE);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(CONTAINS_OP): {
@@ -3637,7 +3634,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
PUSH(b);
PREDICT(POP_JUMP_IF_FALSE);
PREDICT(POP_JUMP_IF_TRUE);
- FAST_DISPATCH();
+ DISPATCH();
}
#define CANNOT_CATCH_MSG "catching classes that do not inherit from "\
@@ -3734,7 +3731,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
case TARGET(JUMP_FORWARD): {
JUMPBY(oparg);
- FAST_DISPATCH();
+ DISPATCH();
}
case TARGET(POP_JUMP_IF_FALSE): {
@@ -3743,12 +3740,12 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
int err;
if (cond == Py_True) {
Py_DECREF(cond);
- FAST_DISPATCH();
+ DISPATCH();
}
if (cond == Py_False) {
Py_DECREF(cond);
JUMPTO(oparg);
- FAST_DISPATCH();
+ DISPATCH();
}
err = PyObject_IsTrue(cond);
Py_DECREF(cond);
@@ -3767,12 +3764,12 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
int err;
if (cond == Py_False) {
Py_DECREF(cond);
- FAST_DISPATCH();
+ DISPATCH();
}
if (cond == Py_True) {
Py_DECREF(cond);
JUMPTO(oparg);
- FAST_DISPATCH();
+ DISPATCH();
}
err = PyObject_IsTrue(cond);
Py_DECREF(cond);
@@ -3792,11 +3789,11 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
if (cond == Py_True) {
STACK_SHRINK(1);
Py_DECREF(cond);
- FAST_DISPATCH();
+ DISPATCH();
}
if (cond == Py_False) {
JUMPTO(oparg);
- FAST_DISPATCH();
+ DISPATCH();
}
err = PyObject_IsTrue(cond);
if (err > 0) {
@@ -3816,11 +3813,11 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
if (cond == Py_False) {
STACK_SHRINK(1);
Py_DECREF(cond);
- FAST_DISPATCH();
+ DISPATCH();
}
if (cond == Py_True) {
JUMPTO(oparg);
- FAST_DISPATCH();
+ DISPATCH();
}
err = PyObject_IsTrue(cond);
if (err > 0) {
@@ -3838,18 +3835,8 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
case TARGET(JUMP_ABSOLUTE): {
PREDICTED(JUMP_ABSOLUTE);
JUMPTO(oparg);
-#if FAST_LOOPS
- /* Enabling this path speeds-up all while and for-loops by bypassing
- the per-loop checks for signals. By default, this should be turned-off
- because it prevents detection of a control-break in tight loops like
- "while 1: pass". Compile with this option turned-on when you need
- the speed-up and do not need break checking inside tight loops (ones
- that contain only instructions ending with FAST_DISPATCH).
- */
- FAST_DISPATCH();
-#else
+ CHECK_EVAL_BREAKER();
DISPATCH();
-#endif
}
case TARGET(GET_LEN): {
@@ -4260,6 +4247,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
PUSH(res);
if (res == NULL)
goto error;
+ CHECK_EVAL_BREAKER();
DISPATCH();
}
@@ -4273,6 +4261,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
if (res == NULL) {
goto error;
}
+ CHECK_EVAL_BREAKER();
DISPATCH();
}
@@ -4292,6 +4281,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
if (res == NULL) {
goto error;
}
+ CHECK_EVAL_BREAKER();
DISPATCH();
}
@@ -4338,6 +4328,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
if (result == NULL) {
goto error;
}
+ CHECK_EVAL_BREAKER();
DISPATCH();
}
More information about the Python-checkins
mailing list