[libcxx-commits] [PATCH] D114119: [libcxx] Fix potential lost wake-up in counting semaphore

[Jan Kokemüller via Phabricator via libcxx-commits]

jiixyj added a comment.

Wouldn't it also be possible to just unconditionally notify the atomic? Something like this:

  __a.fetch_add(__update, memory_order_release);
  if(__update > 1)
      __a.notify_all();
  else
      __a.notify_one();

One downside is that there might be some unneeded calls to the platform wake function (`futex`, etc.), but it would have the advantage of avoiding thundering herd problems if there are many consumers and a single producer repeatedly calling `notify_one()`.


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  https://reviews.llvm.org/D114119/new/

https://reviews.llvm.org/D114119