gh-151524: Make it clearer that _PyInstrumentation_DISABLE is immortal in the code (GH-151525)

lpyu001 · miss-islington · commit 4f11265a0d04 · 2026-08-07T15:35:00.000Z
(cherry picked from commit 52bed26) Co-authored-by: stevens <lipengyu@kylinos.cn>
diff --git a/Python/instrumentation.c b/Python/instrumentation.c
@@ -988,8 +988,12 @@ call_one_instrument(
     if (res == NULL) {
         return -1;
     }
+    if (res == &_PyInstrumentation_DISABLE) {
+        assert(_Py_IsImmortal(res));
+        return 1;
+    }
     Py_DECREF(res);
-    return (res == &_PyInstrumentation_DISABLE);
+    return 0;
 }
 
 static const int8_t MOST_SIGNIFICANT_BITS[16] = {

Original file line number	Diff line number	Diff line change
`@@ -988,8 +988,12 @@ call_one_instrument(`
`988`	`988`	`if (res == NULL) {`
`989`	`989`	`return -1;`
`990`	`990`	`}`
	`991`	`+ if (res == &_PyInstrumentation_DISABLE) {`
	`992`	`+ assert(_Py_IsImmortal(res));`
	`993`	`+ return 1;`
	`994`	`+ }`
`991`	`995`	`Py_DECREF(res);`
`992`		`- return (res == &_PyInstrumentation_DISABLE);`
	`996`	`+ return 0;`
`993`	`997`	`}`
`994`	`998`
`995`	`999`	`static const int8_t MOST_SIGNIFICANT_BITS[16] = {`