Interface RecursiveThreadGroupLock

Method Details

• isOriginalOwner

  boolean isOriginalOwner()

  Returns true if the current thread is the original lock owner, ie. successfully claimed this lock the first time, ie. RecursiveLock.getHoldCount() == 1.

• isOriginalOwner

  boolean isOriginalOwner(Thread thread)

  Returns true if the passed thread is the original lock owner, ie. successfully claimed this lock the first time, ie. RecursiveLock.getHoldCount() == 1.

• addOwner

  void addOwner(Thread t) throws RuntimeException, IllegalArgumentException

  Add a thread to the list of additional lock owners, which enables them to recursively claim this lock.

  The caller must hold this lock and be the original lock owner, see isOriginalOwner().

  If the original owner releases this lock via unlock() all additional lock owners are released as well. This ensures consistency of spawn off additional lock owner threads and it's release.

  Use case:

   Thread2 thread2 = new Thread2();
  
   Thread1 {
  
     // Claim this lock and become the original lock owner.
     lock.lock();
  
     try {
  
       // Allow Thread2 to claim the lock, ie. make thread2 an additional lock owner
       addOwner(thread2);
  
       // Start thread2
       thread2.start();
  
       // Wait until thread2 has finished requiring this lock, but keep thread2 running
       while(!thread2.waitForResult()) sleep();
  
       // Optional: Only if sure that this thread doesn't hold the lock anymore,
       // otherwise just release the lock via unlock().
       removeOwner(thread2);
  
     } finally {
  
       // Release this lock and remove all additional lock owners.
       // Implicit wait until thread2 gets off the lock.
       lock.unlock();
  
     }
  
   }.start();
   

  Parameters:

  t - the thread to be added to the list of additional owning threads

  Throws:

  RuntimeException - if the current thread does not hold the lock.

  IllegalArgumentException - if the passed thread is the lock owner or already added.

  See Also:

  • removeOwner(Thread)
  • unlock()
  • Lock.lock()

• removeOwner

  void removeOwner(Thread t) throws RuntimeException, IllegalArgumentException

  Remove a thread from the list of additional lock owner threads.

  The caller must hold this lock and be the original lock owner, see isOriginalOwner().

  Only use this method if sure that the thread doesn't hold the lock anymore.

  Parameters:

  t - the thread to be removed from the list of additional owning threads

  Throws:

  RuntimeException - if the current thread does not hold the lock.

  IllegalArgumentException - if the passed thread is not added by addOwner(Thread)

• unlock

  void unlock() throws RuntimeException

  Wait's until all additional owners released this lock before releasing it.

  Release the lock.

  Specified by:

  unlock in interface Lock

  Throws:

  RuntimeException - in case the lock is not acquired by this thread.

• unlock

  void unlock(Runnable taskAfterUnlockBeforeNotify)

  Wait's until all additional owners released this lock before releasing it.

  Execute the Runnable taskAfterUnlockBeforeNotify while holding the exclusive lock.

  Then release the lock.

  Specified by:

  unlock in interface ThreadLock