Valentin Shergin b1814b37aa Fabric: Lock-free events 2/n: Reimagining of EventTarget
Summary:
EventTargetWrapper and EventTarget were merged into one class that controls an `instanceHandle` reference and extracting a strong reference to it.

This diff also decouples the operation of retaining a strong reference (with checking a `enabled` flag) from actual usage of this reference. This allows to wrap into a mutex only first part of this process and avoid possible deadlocks.

Reviewed By: sahrens

Differential Revision: D13616382

fbshipit-source-id: 9907bc12047386fcf027929ae2ae41c0b727cd06
2019-01-16 20:22:39 -08:00

54 lines
1.3 KiB
C++

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#pragma once
#include <folly/dynamic.h>
#include <jsi/jsi.h>
#include <react/events/EventTarget.h>
namespace facebook {
namespace react {
enum class EventPriority : int {
SynchronousUnbatched,
SynchronousBatched,
AsynchronousUnbatched,
AsynchronousBatched,
Sync = SynchronousUnbatched,
Work = SynchronousBatched,
Interactive = AsynchronousUnbatched,
Deferred = AsynchronousBatched
};
/*
* We need this types only to ensure type-safety when we deal with them.
* Conceptually, they are opaque pointers to some types that derived from those
* classes.
*
* `EventHandler` is managed as a `unique_ptr`, so it must have a *virtual*
* destructor to allow proper deallocation having only a pointer
* to the base (`EventHandler`) class.
*/
struct EventHandler {
virtual ~EventHandler() = default;
};
using UniqueEventHandler = std::unique_ptr<const EventHandler>;
using ValueFactory = std::function<jsi::Value(jsi::Runtime &runtime)>;
using EventPipe = std::function<void(
jsi::Runtime &runtime,
const EventTarget *eventTarget,
const std::string &type,
const ValueFactory &payloadFactory)>;
} // namespace react
} // namespace facebook