简单的java对象池（非阻塞）

    之前在练习对象池，大致看了下commons.pool的代码，并不是用阻塞方法去得到对象，而是用一个循环一直去请求，据说这样效率要比阻塞的好很多。不知道是否用的什么循环CAS（啊啊啊，我是算法渣，待求证）

public class MyObjectPool2<T> {      private int max = 5;      private int min = 2;      private long maxwait = 10000;  //超时时间      private Class<? extends T> objclass;      private ConcurrentLinkedQueue<T> pool = null;  //未使用对象队列      private ConcurrentLinkedQueue<T> usedpool = null;      private ReentrantLock lock = new ReentrantLock();        public MyObjectPool2(Class<? extends T> objclass){          this.objclass = objclass;      }        public void createPool(){          if(pool == null){              synchronized (this){                  if(pool == null){                      max = max >0 ? max : 5;                      min = min > 0 ? min : 0;                      pool = new ConcurrentLinkedQueue<T>();  //初始化                      usedpool = new ConcurrentLinkedQueue<T>();                      for(int i=0;i<min;i++){                          try{                              T obj = objclass.newInstance();                              pool.add(obj);                          }catch (Exception e){}                      }                  }              }          }      }        public T get(){          T obj = null;          long time = maxwait;          boolean create = false;          while(obj == null){              if(time <= 0) break;              long temptime = System.currentTimeMillis();              obj = pool.poll();              if(obj == null){                  obj = createObj();                  create = true;                  if(obj == null){                      temptime = System.currentTimeMillis() - temptime;                      time = maxwait - temptime;                  }              }              if(obj != null && !create){                  if(!usedpool.contains(obj)) usedpool.add(obj);              }          }          return obj;      }        public T createObj(){          T obj = null;          lock.lock();          try{              if(pool.size() + usedpool.size() < max){                  obj = objclass.newInstance();                  usedpool.add(obj);              }          }catch (Exception e){          }finally {              lock.unlock();          }          return obj;      }        public void giveback(T obj){          if(obj == null) return;          if(!pool.contains(obj)) pool.add(obj);          usedpool.remove(obj);      }        public void distroy(){        }  }

public static void main(String[] args) {          final MyObjectPool2<User> pool = new MyObjectPool2(User.class);          pool.createPool();          User u1 = pool.get();          User u2 = pool.get();          User u3 = pool.get();          User u4 = pool.get();          new Thread(new Runnable() {              @Override              public void run() {                  System.out.println("u5 start get");                  User u5 = pool.get();                  System.out.println("u5:" + u5);                  try{                      TimeUnit.SECONDS.sleep(3);//模拟操作该对象                  }catch(Exception e){}                  pool.giveback(u5);                  System.out.println("u5 giveback");              }          }).start();          new Thread(new Runnable() {              @Override              public void run() {                  try{                      TimeUnit.SECONDS.sleep(1);                      System.out.println("u6 start get");                      User u6 = pool.get();                      System.out.println("u6:" + u6);                  }catch(Exception e){}              }          }).start();      }

u5 start get  u5:kyle.objectPool.User@1cf536e8  u6 start get  u5 giveback  u6:kyle.objectPool.User@1cf536e8