[mypyc] Add comment about incref/decref and free-threaded builds (#19155)

JukkaL · web-flow · commit 9b5b41053c85 · 2025-05-28T10:23:30.000+01:00
Follow-up to #19127.
diff --git a/mypyc/lib-rt/mypyc_util.h b/mypyc/lib-rt/mypyc_util.h
@@ -38,6 +38,9 @@
 //
 // Py_INCREF and other CPython operations check for immortality. This
 // can be expensive when we know that an object cannot be immortal.
+//
+// This optimization cannot be performed in free-threaded mode so we
+// fall back to just calling the normal incref/decref operations.
 
 static inline void CPy_INCREF_NO_IMM(PyObject *op)
 {

Original file line number	Diff line number	Diff line change
`@@ -38,6 +38,9 @@`
`38`	`38`	`//`
`39`	`39`	`// Py_INCREF and other CPython operations check for immortality. This`
`40`	`40`	`// can be expensive when we know that an object cannot be immortal.`
	`41`	`+//`
	`42`	`+// This optimization cannot be performed in free-threaded mode so we`
	`43`	`+// fall back to just calling the normal incref/decref operations.`
`41`	`44`
`42`	`45`	`static inline void CPy_INCREF_NO_IMM(PyObject *op)`
`43`	`46`	`{`