title: Ada: Entry meaning
body: <p>I am an absolute beginner with Ada, and there's one thing I cannot find a concrete definition for - that's the statement <code>entry</code>.</p>
  
  <p>I understand an entry with a barrier - if the barrier is true, the statement can execute and if false, the task is queued until it's evaluated to be true.</p>
  
  <p>For example:</p>
  
  <pre><code>entry Get(Item : out Data_Item) when Number_In_Buffer /= 0 is
  begin
  ...
  end Get;
  </code></pre>
  
  <p>But what does it mean for the statement <code>entry</code> to appear <strong>without</strong> a following <code>when</code> statement?</p>