Hi, Could you please review the following change for JDK-8156693?
http://cr.openjdk.java.net/~prappo/8156693/webrev.01/ This change addresses some WebSocket API refinements and enhancements from [1]. WebSocket returns `CompletableFuture` from some of its methods. CFs are used by an implementation to signal when the operation has completed. Currently, there is a number of known issues with how it's done. These issues reduce usability of the feature. 1. Change methods that return `CompletableFuture<Void>` to return `CompletableFuture<WebSocket>`. The design was based on a false assumption that `WebSocket` (possibly needed to continue asynchronous operation) is always accessible in the same scope where the returned CF is used. Before: CompletableFuture<WebSocket> wsf = webSocketBuilder.buildAsync(); wsf.thenCompose(ws -> ws.sendText("Hi ", false)) .thenCompose((v) -> wsf.join().sendText("there", false)).join(); After: CompletableFuture<WebSocket> wsf = webSocketBuilder.buildAsync(); wsf.thenCompose(ws -> ws.sendText("Hi ", false)) .thenCompose(ws -> ws.sendText("there", false)).join(); 2. Remove stipulation that `CompletableFuture` is returned immediately. This is needlessly restrictive for an implementation. It might also give a false impression that the method *always* dispatches to another thread and returns immediately. 3. Make methods that return `CompletableFuture` to relay (as mush as possible) recoverable or non-programming exceptions through returned CF. There's some evidence [2], [3] that this aspect actually makes it harder to use such methods in completely async computations. Thanks, -Pavel -------------------------------------------------------------------------------- [1] https://bugs.openjdk.java.net/browse/JDK-8155621 [2] http://mail.openjdk.java.net/pipermail/net-dev/2016-April/009638.html [3] http://cs.oswego.edu/pipermail/concurrency-interest/2016-May/015125.html
