Revert "thread safe helpers"
Revert "thread safe helpers"

This reverts commit 81ad1f6f651ba5bc8b4323348a0036faafa686fc.

chenmusun/easyloggingpp,chenmusun/easyloggingpp,arvidsson/easyloggingpp,utiasASRL/easyloggingpp,utiasASRL/easyloggingpp,blankme/easyloggingpp,hellowshinobu/easyloggingpp,dreal-deps/easyloggingpp,lisong521/easyloggingpp,hellowshinobu/easyloggingpp,hellowshinobu/easyloggingpp,blankme/easyloggingpp,simonhang/easyloggingpp,dreal-deps/easyloggingpp,simonhang/easyloggingpp,spqr33/easyloggingpp,arvidsson/easyloggingpp,lisong521/easyloggingpp,blankme/easyloggingpp,spthaolt/easyloggingpp,spqr33/easyloggingpp,chenmusun/easyloggingpp,lisong521/easyloggingpp,dreal-deps/easyloggingpp,spqr33/easyloggingpp,arvidsson/easyloggingpp,utiasASRL/easyloggingpp,spthaolt/easyloggingpp,spthaolt/easyloggingpp,simonhang/easyloggingpp