垃圾回收 永生代

https://docs.python.org/3/library/gc.html#module-gc

gc. freeze ()

Freeze all the objects tracked by gc - move them to a permanent generation and ignore all the future collections. This can be used before a POSIX fork() call to make the gc copy-on-write friendly or to speed up collection. Also collection before a POSIX fork() call may free pages for future allocation which can cause copy-on-write too so it’s advised to disable gc in master process and freeze before fork and enable gc in child process.

New in version 3.7.

gc. unfreeze ()

Unfreeze the objects in the permanent generation, put them back into the oldest generation.

New in version 3.7.

gc. get_freeze_count ()

Return the number of objects in the permanent generation.