gh-104028: Reduce object creation while calling callback function from gc (gh-104030)

corona10 · web-flow · commit e1476942525a · 2023-05-01T14:03:24.000Z
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-05-01-14-10-38.gh-issue-104028.dxfh13.rst b/Misc/NEWS.d/next/Core and Builtins/2023-05-01-14-10-38.gh-issue-104028.dxfh13.rst
@@ -0,0 +1,2 @@
+Reduce object creation while calling callback function from gc.
+Patch by Dong-hee Na.
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
@@ -1388,10 +1388,19 @@ invoke_gc_callback(PyThreadState *tstate, const char *phase,
             return;
         }
     }
+
+    PyObject *phase_obj = PyUnicode_FromString(phase);
+    if (phase_obj == NULL) {
+        Py_XDECREF(info);
+        PyErr_WriteUnraisable(NULL);
+        return;
+    }
+
+    PyObject *stack[] = {phase_obj, info};
     for (Py_ssize_t i=0; i<PyList_GET_SIZE(gcstate->callbacks); i++) {
         PyObject *r, *cb = PyList_GET_ITEM(gcstate->callbacks, i);
         Py_INCREF(cb); /* make sure cb doesn't go away */
-        r = PyObject_CallFunction(cb, "sO", phase, info);
+        r = PyObject_Vectorcall(cb, stack, 2, NULL);
         if (r == NULL) {
             PyErr_WriteUnraisable(cb);
         }
@@ -1400,6 +1409,7 @@ invoke_gc_callback(PyThreadState *tstate, const char *phase,
         }
         Py_DECREF(cb);
     }
+    Py_DECREF(phase_obj);
     Py_XDECREF(info);
     assert(!_PyErr_Occurred(tstate));
 }

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+Reduce object creation while calling callback function from gc.`
	`2`	`+Patch by Dong-hee Na.`
Original file line number	Diff line number	Diff line change
`@@ -1388,10 +1388,19 @@ invoke_gc_callback(PyThreadState tstate, const char phase,`
`1388`	`1388`	`return;`
`1389`	`1389`	`}`
`1390`	`1390`	`}`
	`1391`	`+`
	`1392`	`+ PyObject *phase_obj = PyUnicode_FromString(phase);`
	`1393`	`+ if (phase_obj == NULL) {`
	`1394`	`+ Py_XDECREF(info);`
	`1395`	`+ PyErr_WriteUnraisable(NULL);`
	`1396`	`+ return;`
	`1397`	`+ }`
	`1398`	`+`
	`1399`	`+ PyObject *stack[] = {phase_obj, info};`
`1391`	`1400`	`for (Py_ssize_t i=0; i<PyList_GET_SIZE(gcstate->callbacks); i++) {`
`1392`	`1401`	`PyObject r, cb = PyList_GET_ITEM(gcstate->callbacks, i);`
`1393`	`1402`	`Py_INCREF(cb); /* make sure cb doesn't go away */`
`1394`		`- r = PyObject_CallFunction(cb, "sO", phase, info);`
	`1403`	`+ r = PyObject_Vectorcall(cb, stack, 2, NULL);`
`1395`	`1404`	`if (r == NULL) {`
`1396`	`1405`	`PyErr_WriteUnraisable(cb);`
`1397`	`1406`	`}`
`@@ -1400,6 +1409,7 @@ invoke_gc_callback(PyThreadState tstate, const char phase,`
`1400`	`1409`	`}`
`1401`	`1410`	`Py_DECREF(cb);`
`1402`	`1411`	`}`
	`1412`	`+ Py_DECREF(phase_obj);`
`1403`	`1413`	`Py_XDECREF(info);`
`1404`	`1414`	`assert(!_PyErr_Occurred(tstate));`
`1405`	`1415`	`}`