Index: runtime/lib/async_patch.dart |
diff --git a/runtime/lib/async_patch.dart b/runtime/lib/async_patch.dart |
index d78534719656c37ca06fc3cdc7354a930bbeadad..682ee8b10a4ec2d6b8496a5f06496f428819a00e 100644 |
--- a/runtime/lib/async_patch.dart |
+++ b/runtime/lib/async_patch.dart |
@@ -4,181 +4,3 @@ |
import "dart:_internal"; |
-// We need to pass the value as first argument and leave the second and third |
-// arguments empty (used for error handling). |
-// See vm/ast_transformer.cc for usage. |
-Function _asyncThenWrapperHelper(continuation) { |
- // Any function that is used as an asynchronous callback must be registered |
- // in the current Zone. Normally, this is done by the future when a |
- // callback is registered (for example with `.then` or `.catchError`). In our |
- // case we want to reuse the same callback multiple times and therefore avoid |
- // the multiple registrations. For our internal futures (`_Future`) we can |
- // use the shortcut-version of `.then`, and skip the registration. However, |
- // that means that the continuation must be registered by us. |
- // |
- // Furthermore, we know that the root-zone doesn't actually do anything and |
- // we can therefore skip the registration call for it. |
- // |
- // Note, that the continuation accepts up to three arguments. If the current |
- // zone is the root zone, we don't wrap the continuation, and a bad |
- // `Future` implementation could potentially invoke the callback with the |
- // wrong number of arguments. |
- if (Zone.current == Zone.ROOT) return continuation; |
- return Zone.current.registerUnaryCallback((x) => continuation(x, null, null)); |
-} |
- |
-// We need to pass the exception and stack trace objects as second and third |
-// parameter to the continuation. See vm/ast_transformer.cc for usage. |
-Function _asyncErrorWrapperHelper(continuation) { |
- // See comments of `_asyncThenWrapperHelper`. |
- var errorCallback = (e, s) => continuation(null, e, s); |
- if (Zone.current == Zone.ROOT) return errorCallback; |
- return Zone.current.registerBinaryCallback(errorCallback); |
-} |
- |
-/// Registers the [thenCallback] and [errorCallback] on the given [object]. |
-/// |
-/// If [object] is not a future, then it is wrapped into one. |
-/// |
-/// Returns the result of registering with `.then`. |
-Future _awaitHelper( |
- var object, Function thenCallback, Function errorCallback) { |
- if (object is! Future) { |
- object = new _Future().._setValue(object); |
- } else if (object is! _Future) { |
- return object.then(thenCallback, onError: errorCallback); |
- } |
- // `object` is a `_Future`. |
- // |
- // Since the callbacks have been registered in the current zone (see |
- // [_asyncThenWrapperHelper] and [_asyncErrorWrapperHelper]), we can avoid |
- // another registration and directly invoke the no-zone-registration `.then`. |
- // |
- // We can only do this for our internal futures (the default implementation of |
- // all futures that are constructed by the `dart:async` library). |
- return object._thenNoZoneRegistration(thenCallback, errorCallback); |
-} |
- |
-// _AsyncStarStreamController is used by the compiler to implement |
-// async* generator functions. |
-class _AsyncStarStreamController { |
- StreamController controller; |
- Function asyncStarBody; |
- bool isAdding = false; |
- bool onListenReceived = false; |
- bool isScheduled = false; |
- bool isSuspendedAtYield = false; |
- Completer cancellationCompleter = null; |
- |
- Stream get stream => controller.stream; |
- |
- void runBody() { |
- isScheduled = false; |
- isSuspendedAtYield = false; |
- asyncStarBody(); |
- } |
- |
- void scheduleGenerator() { |
- if (isScheduled || controller.isPaused || isAdding) { |
- return; |
- } |
- isScheduled = true; |
- scheduleMicrotask(runBody); |
- } |
- |
- // Adds element to steam, returns true if the caller should terminate |
- // execution of the generator. |
- // |
- // TODO(hausner): Per spec, the generator should be suspended before |
- // exiting when the stream is closed. We could add a getter like this: |
- // get isCancelled => controller.hasListener; |
- // The generator would translate a 'yield e' statement to |
- // controller.add(e); |
- // suspend; |
- // if (controller.isCancelled) return; |
- bool add(event) { |
- if (!onListenReceived) _fatal("yield before stream is listened to!"); |
- if (isSuspendedAtYield) _fatal("unexpected yield"); |
- // If stream is cancelled, tell caller to exit the async generator. |
- if (!controller.hasListener) { |
- return true; |
- } |
- controller.add(event); |
- scheduleGenerator(); |
- isSuspendedAtYield = true; |
- return false; |
- } |
- |
- // Adds the elements of stream into this controller's stream. |
- // The generator will be scheduled again when all of the |
- // elements of the added stream have been consumed. |
- // Returns true if the caller should terminate |
- // execution of the generator. |
- bool addStream(Stream stream) { |
- if (!onListenReceived) _fatal("yield before stream is listened to!"); |
- // If stream is cancelled, tell caller to exit the async generator. |
- if (!controller.hasListener) return true; |
- isAdding = true; |
- var whenDoneAdding = |
- controller.addStream(stream as Stream, cancelOnError: false); |
- whenDoneAdding.then((_) { |
- isAdding = false; |
- scheduleGenerator(); |
- }); |
- return false; |
- } |
- |
- void addError(error, stackTrace) { |
- if ((cancellationCompleter != null) && !cancellationCompleter.isCompleted) { |
- // If the stream has been cancelled, complete the cancellation future |
- // with the error. |
- cancellationCompleter.completeError(error, stackTrace); |
- return; |
- } |
- // If stream is cancelled, tell caller to exit the async generator. |
- if (!controller.hasListener) return; |
- controller.addError(error, stackTrace); |
- // No need to schedule the generator body here. This code is only |
- // called from the catch clause of the implicit try-catch-finally |
- // around the generator body. That is, we are on the error path out |
- // of the generator and do not need to run the generator again. |
- } |
- |
- close() { |
- if ((cancellationCompleter != null) && !cancellationCompleter.isCompleted) { |
- // If the stream has been cancelled, complete the cancellation future |
- // with the error. |
- cancellationCompleter.complete(); |
- } |
- controller.close(); |
- } |
- |
- _AsyncStarStreamController(this.asyncStarBody) { |
- controller = new StreamController(onListen: this.onListen, |
- onResume: this.onResume, |
- onCancel: this.onCancel); |
- } |
- |
- onListen() { |
- assert(!onListenReceived); |
- onListenReceived = true; |
- scheduleGenerator(); |
- } |
- |
- onResume() { |
- if (isSuspendedAtYield) { |
- scheduleGenerator(); |
- } |
- } |
- |
- onCancel() { |
- if (controller.isClosed) { |
- return null; |
- } |
- if (cancellationCompleter == null) { |
- cancellationCompleter = new Completer(); |
- scheduleGenerator(); |
- } |
- return cancellationCompleter.future; |
- } |
-} |