通过全局变量反应互斥量

Question

我们正在使用 React 和 Redux
我们如何借助互斥锁来保护资源不被访问？

是否可以通过全局变量来执行此操作以及将它们存储在何处？
PS 由于状态更新延迟，我们不想通过 Redux 执行此操作

提供更多上下文的小示例

export default function configureStore() {
  const store = createStore(rootReducer, persistedState, composedEnhancers);
  store.subscribe(
    // saveState saves state to localStorage
    // here we need mutex which will prevent state from saving to localStorage
    // and some way to toggle this mutex
    throttle(() => {
      saveState(store.getState());
    }, 2000),
  );
  return store;
}

Answer 1

我可能没有完全理解你。您是否试图让程序等待一行代码执行完后再继续下一行？这样，多个 "things" 就不会同时访问同一个资源。您可以使用 async/await 函数来执行此操作。例如：

async function f() {

  let promise = new Promise((resolve, reject) => {
    setTimeout(() => resolve("done!"), 1000)
  });

  let result = await promise; // wait till the promise resolves (*)

  alert(result); // "done!"
}

f();

Answer 2

我不确定这是否是正确的解决方案
请记住，这是有效的，因为 store.subscribe 监听 redux 状态变化

export default function configureStore() {
  const store = createStore(rootReducer, persistedState, composedEnhancers);
    store.subscribe(
      throttle(() => {
        const currentState = store.getState();
        // if we allowing state to sync with localStorage
        if (currentState.isMutexVariable) {
          saveState(currentState);
        }
      }, 2000),
    );
  return store;
}

通过全局变量反应互斥量

React mutex via global variable

javascript

concurrency

mutex

reactjs