From 7c93cc91c70db325f3a32f74fad133615993a400 Mon Sep 17 00:00:00 2001 From: Patrick Hoefler <61934744+phofl@users.noreply.github.com> Date: Wed, 20 Sep 2023 17:54:23 +0200 Subject: [PATCH] Backport PR #55008 on branch 2.1.x (CoW: Clear dead references every time we add a new one) (#55220) CoW: Clear dead references every time we add a new one (#55008) (cherry picked from commit 7134f2c14e614980bcf366f979a0f85aafacbde6) --- pandas/_libs/internals.pyx | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/pandas/_libs/internals.pyx b/pandas/_libs/internals.pyx index adf4e8c926fa3..859ebce36eaa8 100644 --- a/pandas/_libs/internals.pyx +++ b/pandas/_libs/internals.pyx @@ -951,6 +951,11 @@ cdef class BlockValuesRefs: else: self.referenced_blocks = [] + def _clear_dead_references(self) -> None: + self.referenced_blocks = [ + ref for ref in self.referenced_blocks if ref() is not None + ] + def add_reference(self, blk: SharedBlock) -> None: """Adds a new reference to our reference collection. @@ -959,6 +964,7 @@ cdef class BlockValuesRefs: blk: SharedBlock The block that the new references should point to. """ + self._clear_dead_references() self.referenced_blocks.append(weakref.ref(blk)) def add_index_reference(self, index: object) -> None: @@ -969,6 +975,7 @@ cdef class BlockValuesRefs: index : Index The index that the new reference should point to. """ + self._clear_dead_references() self.referenced_blocks.append(weakref.ref(index)) def has_reference(self) -> bool: @@ -981,8 +988,6 @@ cdef class BlockValuesRefs: ------- bool """ - self.referenced_blocks = [ - ref for ref in self.referenced_blocks if ref() is not None - ] + self._clear_dead_references() # Checking for more references than block pointing to itself return len(self.referenced_blocks) > 1