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import java.lang.annotation.*;


/** Warns that access to a field, constructor or method
  * is restricted to a particular thread,
  * or to a thread that holds a particular lock.
  * <p>
  *     The restriction applies to a field, constructor or method.
  *     It does not necessarily apply to any object read from the field,
  *     or created by the constructor, or returned by the method.
  *     That object's own thread safety is formally indicated by its own API.
  *     However, if the object is not thread safe, and its API does not specify
  *     the particular restriction, then the field, constructor or method
  *     from which it came either confers its own restriction;
  *     or documents something else.
  *     </p>
  * <p>
  *     The opposite of ThreadRestricted is {@linkplain ThreadSafe ThreadSafe}.
  *     See its rules for <a href='ThreadSafe.html#Methods'>type-level annotation</a>,
  *     which also apply here.
  *     </p>
  *
  * <h3>A Particular Thread</h3>
  * <p>
  *     The restriction may be a particular thread.
  *     For instance, most Swing code is restricted
  *     to the AWT event dispatch thread. An appropriate annotation would be:
  *     </p>
  * <pre>
  *     &#064;ThreadRestricted( "AWT event dispatch" )</pre>
  * <p>
  *     As well, in the case of a constructor or method,
  *     it might implement an internal, runtime test of compliance:
  *     </p>
  * <pre>
  *     assert java.awt.EventQueue.isDispatchThread();</pre>
  *
  * <h3>Threads Holding a Particular Lock</h3>
  * <p>
  *     The restriction may specify a particular synchronization lock.
  *     For example:
  *     </p>
  * <pre>
  *     &#064;ThreadRestricted( "holds this" ) // or <em>class-name</em>.this
  *     &#064;ThreadRestricted( "holds obj" )
  *     &#064;ThreadRestricted( "holds lock" )</pre>
  * <p>
  *     These specify that threads must hold the object's
  *     general-purpose monitor (this); some other object's monitor (obj);
  *     or a special-purpose concurrent {@linkplain java.util.concurrent.locks.Lock Lock}:
  *     </p>
  * <p>
  *     As well, a test of compliance may be implemented.
  *     For an Object monitor, the test might be:
  *     </p>
  * <pre>
  *     assert Thread.holdsLock( this ); // or <em>class-name</em>.this
  *     assert Thread.holdsLock( obj );</pre>
  * <p>
  *     Or, for a Lock:
  *     </p>
  * <pre>
  *     assert lock.isHeldByCurrentThread();</pre>
  *
  * <h3>Unspecified</h3>
  * <p>
  *     The restriction may be left unspecified.
  *     This is the default value, so these are equivalent:
  *     </p>
  * <pre>
  *     &#064;ThreadRestricted
  *     &#064;ThreadRestricted("unspecified")</pre>
  * <p>
  *     Generally it appears at the type level.
  *     It defers the choice of restriction to the runtime code
  *     that constructs instances of that type.
  *     Runtime code will choose either a single threaded or locking restriction,
  *     and its choices may vary from instance to instance.
  *     In other words, an unpecified thread restriction
  *     simply means "not thread safe", and is handled in the usual way.
  *     </p>
  */
    @Documented @Retention( RetentionPolicy.SOURCE ) // till further retention needed
    @Target({ ElementType.CONSTRUCTOR, ElementType.FIELD, ElementType.METHOD, ElementType.TYPE })

public @interface ThreadRestricted
{


    /** Details of the thread restriction.
      */
    public String value() default "unspecified";



}