[all-commits] [llvm/llvm-project] f23ee0: [clangd] Fix race in Global CDB shutdown

[Sam McCall via All-commits]

  Branch: refs/heads/release/12.x
  Home:   https://github.com/llvm/llvm-project
  Commit: f23ee06ec27e991f9f1fbb646f3a2288aeedee71
      https://github.com/llvm/llvm-project/commit/f23ee06ec27e991f9f1fbb646f3a2288aeedee71
  Author: Sam McCall <sam.mccall at gmail.com>
  Date:   2021-02-16 (Tue, 16 Feb 2021)

  Changed paths:
    M clang-tools-extra/clangd/GlobalCompilationDatabase.cpp

  Log Message:
  -----------
  [clangd] Fix race in Global CDB shutdown

I believe the atomic write can be reordered after the notify, and that
seems to be happening on mac m1: http://45.33.8.238/macm1/2654/step_8.txt
In practice maybe seq_cst is enough? But no reason not to lock here.

https://bugs.llvm.org/show_bug.cgi?id=48998
(cherry picked from commit 6ac3fd9706047304c52a678884122a3a6bc55432)