title: Where is the program counter stored during thread context switch?
body: <p>When I call <code>pthread_yield</code> or <code>pthread_block</code> and the CPU does a context switch</p>
  
  <p>Is the program counter stored in the <strong>thread stack</strong> (alongside its temporary registers) or in the <strong>thread control block</strong> (alongside the stack pointer)</p>