3 Commits

Author	SHA1	Message	Date
Ben Niu	281f8f407e	Combine strong and weak refcounts in intrusive_ptr in a single refcount (#163394) ... Summary: Currently, we assume that refcount_ and weakcount_ are always stored in an 8-byte aligned address right next to each other. Based on this assumption, we load 8 bytes in intrusive_ptr::reset_ to check the values of both counts. However, that assumption is not part of C++ language standard so it's essentially undefined behavior. This change eliminates that assumption by combining refcount_ and weakcount_ in a single 64-bit count and we use the lower 32 bits for refcount_ and upper 32 bits for the weakcount_. In addition to eliminating the undefined behavior, the change also eliminates the read of weakcount_ after decrementing refcount_ in intrusive_ptr::reset_. This claws back lost performance introduced in https://github.com/pytorch/pytorch/pull/162784 for non-final refcount_ decrementing. Reviewed By: yfeldblum Differential Revision: D82869192 Pull Request resolved: https://github.com/pytorch/pytorch/pull/163394 Approved by: https://github.com/Skylion007	2025-09-22 17:53:28 +00:00
cyy	7663ffb673	[10/N] Fixes clang-tidy warnings in c10/util/*.h (#116326) ... Still a continued work for clean up c10/util/*.h Pull Request resolved: https://github.com/pytorch/pytorch/pull/116326 Approved by: https://github.com/Skylion007	2023-12-23 04:59:55 +00:00
Scott Wolchok	82712b7985	[PyTorch] Support ExclusivelyOwned<caffe2::Tensor> (#81964) ... Since `caffe2::Tensor` also shares `TensorImpl`, we can apply `ExclusivelyOwned` to it as needed. Differential Revision: [D38066340](https://our.internmc.facebook.com/intern/diff/D38066340/) Pull Request resolved: https://github.com/pytorch/pytorch/pull/81964 Approved by: https://github.com/ezyang	2022-07-27 22:14:40 +00:00