title: how to make an application thread safe?
body: <p>I thought thread safe, in particular, means it must satisfy the need for multiple threads to access the same shared data. But, it seems this definition is not enough.</p>
  
  <p>Can anyone please <strong>list out the things to be done or taken care of to make an application thread safe</strong>. If possible, give an answer with respect to C/C++ language.</p>