通过t r yLock避免死锁

public boolean transferMoney(Account fromAcct,Account toAcct,DollarAmount amount,long timeout,TimeUnit unit) throws InsufficientFundsException,InterruptedException{
    
    
  long fixedDelay = getFixedDelayComponentNanos(timeout,unit);
  long randMod = getRandomDelayModulusNanos(timeout,unit);
  long stopTime = System.nanoTime()+unit.toNanos(timeout);

  while(true){
    
    
     if(fromAcct.lock.tryLock()){
    
    
       try{
    
    
          if(toAcct.lock.tryLock()){
    
    
            try{
    
    
              if(fromAcct.getBalance().compareTo(amount) < 0)
              throw new InsufficientFundsException();
     else{
    
    
       fromAcct.debit(amount);
       toAcct.credit(amount);
       return true;
     }
  }finally{
    
    
    toAcct.lock.unlock();
  }
}
}finally{
    
    
  toAcct.lock.unlock();
}
if(System.nanoTime() < stopTime){
    
    
   return false;
 }
 NANOSECONDS.sleep(fixedDelay+rnd.nextLong()%randMod);
}