Reports calls to wait() methods that may occur while the current thread is holding two locks.

Since calling wait() only releases one lock on its target, waiting with two locks held can easily lead to a deadlock.

Example:


  synchronized (lockA) {
    synchronized (lockB) {
      lockB.wait(); //warning
      //thread A is stuck here holding lockA
    }
  }

  synchronized (lockA) { //thread B can't enter the block and release thread A
    lockB.notify();
  }