From ac9e4efc41231e0a3316e469c77c7f575db5805a Mon Sep 17 00:00:00 2001
From: Sam Gross <colesbury@gmail.com>
Date: Wed, 31 Jan 2024 21:44:04 +0000
Subject: [PATCH 1/3] gh-112529: Stop the world around gc.get_referents
We do not want to add locking in tp_traverse slot implementations.
Instead, stop-the-world when calling gc.get_referents. Note that the the
stop-the-world call is a no-op in the default build.
---
Modules/gcmodule.c | 40 +++++++++++++++++++++++++++-------------
1 file changed, 27 insertions(+), 13 deletions(-)
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index ffddef34ecce7a..e82d606038e410 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -235,6 +235,25 @@ referentsvisit(PyObject *obj, void *arg)
return PyList_Append(list, obj) < 0;
}
+static int
+append_referrents(PyObject *result, PyObject *args)
+{
+ for (Py_ssize_t i = 0; i < PyTuple_GET_SIZE(args); i++) {
+ traverseproc traverse;
+ PyObject *obj = PyTuple_GET_ITEM(args, i);
+
+ if (!_PyObject_IS_GC(obj))
+ continue;
+ traverse = Py_TYPE(obj)->tp_traverse;
+ if (! traverse)
+ continue;
+ if (traverse(obj, referentsvisit, result)) {
+ return -1;
+ }
+ }
+ return 0;
+}
+
/*[clinic input]
gc.get_referents
@@ -247,29 +266,24 @@ static PyObject *
gc_get_referents_impl(PyObject *module, PyObject *args)
/*[clinic end generated code: output=d47dc02cefd06fe8 input=b3ceab0c34038cbf]*/
{
- Py_ssize_t i;
if (PySys_Audit("gc.get_referents", "(O)", args) < 0) {
return NULL;
}
+ PyInterpreterState *interp = _PyInterpreterState_GET();
PyObject *result = PyList_New(0);
if (result == NULL)
return NULL;
- for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
- traverseproc traverse;
- PyObject *obj = PyTuple_GET_ITEM(args, i);
+ // NOTE: stop the world is a no-op in default build
+ _PyEval_StopTheWorld(interp);
+ int err = append_referrents(result, args);
+ _PyEval_StartTheWorld(interp);
- if (!_PyObject_IS_GC(obj))
- continue;
- traverse = Py_TYPE(obj)->tp_traverse;
- if (! traverse)
- continue;
- if (traverse(obj, referentsvisit, result)) {
- Py_DECREF(result);
- return NULL;
- }
+ if (err < 0) {
+ Py_CLEAR(result);
}
+
return result;
}
From b76f33b9ceaa86147f518136c7631413e61bbbf9 Mon Sep 17 00:00:00 2001
From: Sam Gross <colesbury@gmail.com>
Date: Thu, 1 Feb 2024 11:33:29 -0500
Subject: [PATCH 2/3] Update Modules/gcmodule.c
Co-authored-by: Pablo Galindo Salgado <Pablogsal@gmail.com>
---
Modules/gcmodule.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index e82d606038e410..94768e56202d61 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -245,7 +245,7 @@ append_referrents(PyObject *result, PyObject *args)
if (!_PyObject_IS_GC(obj))
continue;
traverse = Py_TYPE(obj)->tp_traverse;
- if (! traverse)
+ if (!traverse)
continue;
if (traverse(obj, referentsvisit, result)) {
return -1;
From e689f8b772c02b020f41687ab949d3997e5d3cbb Mon Sep 17 00:00:00 2001
From: Sam Gross <colesbury@gmail.com>
Date: Thu, 1 Feb 2024 16:35:38 +0000
Subject: [PATCH 3/3] Add braces to if-statements
---
Modules/gcmodule.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index 94768e56202d61..a2b66b9b78c169 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -239,14 +239,15 @@ static int
append_referrents(PyObject *result, PyObject *args)
{
for (Py_ssize_t i = 0; i < PyTuple_GET_SIZE(args); i++) {
- traverseproc traverse;
PyObject *obj = PyTuple_GET_ITEM(args, i);
-
- if (!_PyObject_IS_GC(obj))
+ if (!_PyObject_IS_GC(obj)) {
continue;
- traverse = Py_TYPE(obj)->tp_traverse;
- if (!traverse)
+ }
+
+ traverseproc traverse = Py_TYPE(obj)->tp_traverse;
+ if (!traverse) {
continue;
+ }
if (traverse(obj, referentsvisit, result)) {
return -1;
}