[all-commits] [llvm/llvm-project] 14882d: [libc++][lit] Atomically update the persistent cac...

[Alexander Richardson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 14882d6b7440e797d8d60cb1f8207fe332cae033
      https://github.com/llvm/llvm-project/commit/14882d6b7440e797d8d60cb1f8207fe332cae033
  Author: Alexander Richardson <alexrichardson at google.com>
  Date:   2023-09-18 (Mon, 18 Sep 2023)

  Changed paths:
    M libcxx/utils/libcxx/test/dsl.py

  Log Message:
  -----------
  [libc++][lit] Atomically update the persistent cache (#66538)

When running multiple shards in parallel, one shard might write to the
cache while another one is reading this cache. Instead of updating the
file in place, write to a temporary file and swap the cache file using
os.replace(). This is an atomic operation and means shards will either
see the old state or the new one.