title: No such file found with semaphore.h and ucontext.h
body: <p>I have my code here:</p>
  
  <pre><code>#define _GNU_SOURCE
  
  #include "lib-ult.h"
  
  #include &lt;stdio.h&gt;
  #include &lt;stdlib.h&gt;
  
  #include &lt;ucontext.h&gt;
  #include &lt;semaphore.h&gt;
  
  #define TRUE 1
  #define FALSE 0
  #define FAILURE -1
  
  typedef struct Node {
      ucontext_t* context;
      int priority;
  
      struct Node* next;
      struct Node* prev;
  } Node;
  
  int STACK_SIZE = 16384;
  
  sem_t queueLock;
  
  sem_t threadsLock;
  </code></pre>
  
  <p>And when I try to build the project I get <code>Error 1 error C1083: Cannot open include file: 'ucontext.h': No such file or directory</code> (and also for semaphore.h).</p>
  
  <p>Why is this?  How do I fix it?  Does it have to do with the fact that I have a Windows machine?</p>
  
  <p>Thank you!</p>