You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
{{ message }}
Repository navigation
Make the garbage collector thread-safe in --disable-gil builds #112529
Python's cyclic garbage collector relies on the global interpreter lock for thread-safety. There are a number of changes needed to make the GC thread-safe in --disable-gil builds.
My intention is to implement these as a series of smaller changes.
Garbage collection is guarded by gcstate->collecting. This need to be made thread-safe.
The --disable-gil builds should find GC-enabled objects by traversing the mimalloc heaps, because the _gc_next/_gc_prev lists are not thread-safe. (Note it's safe to use the lists during stop-the-world pauses; we just can't maintain them safely during normal Python execution).
The --disable-gil builds should probably use only a single generation to avoid frequent stop-the-world pauses
Eventually, we can get rid of the GC pre-header in --disable-gil builds to save memory. (This will require updating the trashcan mechanism.)
Remaining work:
Fix scheduling of free-threaded GC (currently scheduled as if there is a young generation)
Update Python docs
Refactor out common code from gc.c and gc_free_threaded.c
Feature or enhancement
Python's cyclic garbage collector relies on the global interpreter lock for thread-safety. There are a number of changes needed to make the GC thread-safe in
--disable-gilbuilds.My intention is to implement these as a series of smaller changes.
gcstate->collecting. This need to be made thread-safe.--disable-gilbuilds should stop-the-world when finding garbage, but not when calling finalizers or destructors. (depends on Implement stop-the-world functionality (for--disable-gilbuilds) #111964)--disable-gilbuilds should find GC-enabled objects by traversing the mimalloc heaps, because the_gc_next/_gc_prevlists are not thread-safe. (Note it's safe to use the lists during stop-the-world pauses; we just can't maintain them safely during normal Python execution).--disable-gilbuilds should probably use only a single generation to avoid frequent stop-the-world pauses--disable-gilbuilds to save memory. (This will require updating the trashcan mechanism.)Remaining work:
gc.candgc_free_threaded.cSee also #111964
Linked PRs
gcstate->collecting#112533