Hi, there is an important regression of Boost Thread on Windows     https://github.com/boostorg/thread/issues/130 windows: Bug in boost::condition_variable on Windows Please, merge these two patches 1 https://github.com/boostorg/thread/commit/fdc0cbcd8ce8f34a19c7cdaf6f1fa679f0... 2 https://github.com/boostorg/thread/commit/395e3d786bc1dce9c60eb84da85f5845a2... I've sent a PR for the boost-1.65 release notes https://github.com/boostorg/website/pull/267 If there is a 1.65.1 point release, this issue should be a good candidate. Sorry for the disturbance Vicente