在调用wait（）之前调用锁对象的notify（）是否可以？(Is it okay to call notify() on a lock object before calling wait() on it?)

 我在我的代码中使用wait（）和notify（），并且有一种情况，在另一个线程的锁对象上实际调用等待之前，执行可以先到达notify（）。 我在锁对象中创建了一个“isWaitCalled”标志，并且如果wait（）没有被调用，就使用它跳过notify（）调用。 这个标志“isWaitCalled”是多余的吗？ 在等待其中一个场景之前调用notify（）是否可以？ 主题A： 
 
synchronized (syncObject) {
          try {
                if (!syncObject.isLoadComplete) {
                    syncObject.isWaitCalled = true;
                    syncObject.wait();
                }
          } catch (Exception ex) {
          }                                              
    }
 
 ThreadB： 
 
synchronized (syncObject) {
          try {
                if (!syncObject.isLoadComplete) {
                  syncObject.isLoadComplete =true;
                   if (syncObject.isWaitCalled) {
                       syncObject.notify();         
                   }                  
               }
          } catch (Exception ex) {
          }                                              
    }

I am using wait() and notify() in my code and there is a scenario where the execution can reach notify() first before a wait is actually called on the lock object on another thread. I created a flag "isWaitCalled" in the lock object and using it to skip notify() call if wait() is not called already. Is this flag "isWaitCalled" redundant? Is it okay if notify() is called before wait in one of the scenarios? Thread A:
 
synchronized (syncObject) {
          try {
                if (!syncObject.isLoadComplete) {
                    syncObject.isWaitCalled = true;
                    syncObject.wait();
                }
          } catch (Exception ex) {
          }                                              
    }
 
ThreadB:
 
synchronized (syncObject) {
          try {
                if (!syncObject.isLoadComplete) {
                  syncObject.isLoadComplete =true;
                   if (syncObject.isWaitCalled) {
                       syncObject.notify();         
                   }                  
               }
          } catch (Exception ex) {
          }                                              
    }

原文：https://stackoverflow.com/questions/40432886