Add docs about batch() API to Performance FAQ (#3431)

* Add docs about batch API to Performance FAQ

* Update Performance.md

docs/faq/Performance.md

@@ -110,7 +110,25 @@ However, you _do_ need to create a copied and updated object for each level of n
 
 Redux notifies subscribers after each successfully dispatched action (i.e. an action reached the store and was handled by reducers). In some cases, it may be useful to cut down on the number of times subscribers are called, particularly if an action creator dispatches multiple distinct actions in a row.
 
-If you use React, note that you can improve performance of multiple synchronous dispatches by wrapping them in `ReactDOM.unstable_batchedUpdates()`, but this API is experimental and may be removed in any React release so don't rely on it too heavily. Take a look at [redux-batched-actions](https://github.com/tshelburne/redux-batched-actions) (a higher-order reducer that lets you dispatch several actions as if it was one and “unpack” them in the reducer), [redux-batched-subscribe](https://github.com/tappleby/redux-batched-subscribe) (a store enhancer that lets you debounce subscriber calls for multiple dispatches), or [redux-batch](https://github.com/manaflair/redux-batch) (a store enhancer that handles dispatching an array of actions with a single subscriber notification).
+There are several addons that add batching capabilities in various ways, like: [redux-batched-actions](https://github.com/tshelburne/redux-batched-actions) (a higher-order reducer that lets you dispatch several actions as if it was one and “unpack” them in the reducer), [redux-batched-subscribe](https://github.com/tappleby/redux-batched-subscribe) (a store enhancer that lets you debounce subscriber calls for multiple dispatches), or [redux-batch](https://github.com/manaflair/redux-batch) (a store enhancer that handles dispatching an array of actions with a single subscriber notification).
+
+For React-Redux specifically, starting in [React-Redux v7](https://github.com/reduxjs/react-redux/releases/tag/v7.0.1) a new `batch` public API is available to help minimize the number of React re-renders when dispatching actions outside of React event handlers.  It wraps React's `unstable_batchedUpdate()` API, allows any React updates in an event loop tick to be batched together into a single render pass. React already uses this internally for its own event handler callbacks. This API is actually part of the renderer packages like ReactDOM and React Native, not the React core itself.
+
+Since React-Redux needs to work in both ReactDOM and React Native environments, we've taken care of importing this API from the correct renderer at build time for our own use. We also now re-export this function publicly ourselves, renamed to `batch()`. You can use it to ensure that multiple actions dispatched outside of React only result in a single render update, like this:
+
+```
+import { batch } from "react-redux";
+
+function myThunk() {
+    return (dispatch, getState) => {
+        // should only result in one combined re-render, not two
+        batch(() => {
+            dispatch(increment());
+            dispatch(increment());
+        })
+    }
+}
+```
 
 #### Further information
 
@@ -121,6 +139,7 @@ If you use React, note that you can improve performance of multiple synchronous
 - [#911: Batching actions](https://github.com/reduxjs/redux/issues/911)
 - [#1813: Use a loop to support dispatching arrays](https://github.com/reduxjs/redux/pull/1813)
 - [React Redux #263: Huge performance issue when dispatching hundreds of actions](https://github.com/reduxjs/react-redux/issues/263)
+- [React-Redux #1177: Roadmap: v6, Context, Subscriptions, and Hooks](https://github.com/reduxjs/react-redux/issues/1177)
 
 **Libraries**