Files
react-native/ReactCommon/react/renderer/mounting/MountingCoordinator.h
T
Valentin Shergin 6729a3e0bf Fabric: Reviving of RN_SHADOW_TREE_INTROSPECTION in DEBUG mode
Summary:
Shadow tree introspection was disabled for a while, now we need it back working. This diff also restructures the logic of `MountingCoordinator::pullTransaction()` splitting it into two sections, first one for the base case and the second for the overriding case.

Changelog: [Internal] Fabric-specific internal change.

Reviewed By: mdvacca

Differential Revision: D23374948

fbshipit-source-id: 0b5f1c598975bceb3dcb6a0eaee67ff58ef9dda1
2020-08-28 10:22:41 -07:00

126 lines
4.1 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 <better/optional.h>
#include <chrono>
#include <react/renderer/mounting/Differentiator.h>
#include <react/renderer/mounting/MountingOverrideDelegate.h>
#include <react/renderer/mounting/MountingTransaction.h>
#include <react/renderer/mounting/ShadowTreeRevision.h>
#include <react/renderer/mounting/TelemetryController.h>
#include "ShadowTreeRevision.h"
#ifndef NDEBUG
#define RN_SHADOW_TREE_INTROSPECTION 1
#endif
#ifdef RN_SHADOW_TREE_INTROSPECTION
#include <react/renderer/mounting/stubs.h>
#endif
namespace facebook {
namespace react {
/*
* Stores inside all non-mounted yet revisions of a shadow tree and coordinates
* mounting. The object stores the most recent mounted revision and the most
* recent committed one. Then when a new mounting transaction is requested the
* object generates mutation instructions and returns it as a
* `MountingTransaction`.
*/
class MountingCoordinator final {
public:
using Shared = std::shared_ptr<MountingCoordinator const>;
/*
* The constructor is meant to be used only inside `ShadowTree`, and it's
* `public` only to enable using with `std::make_shared<>`.
*/
MountingCoordinator(
ShadowTreeRevision baseRevision,
std::weak_ptr<MountingOverrideDelegate const> delegate,
bool enableReparentingDetection = false);
/*
* Returns the id of the surface that the coordinator belongs to.
*/
SurfaceId getSurfaceId() const;
/*
* Computes a consequent mounting transaction and returns it.
* The returning transaction can accumulate multiple recent revisions of a
* shadow tree. Returns empty optional if there no new shadow tree revision to
* mount.
* The method is thread-safe and can be called from any thread.
* However, a consumer should always call it on the same thread (e.g. on the
* main thread) or ensure sequentiality of mount transactions separately.
*/
better::optional<MountingTransaction> pullTransaction() const;
/*
* Blocks the current thread until a new mounting transaction is available or
* after the specified `timeout` duration.
* Returns `false` if a timeout occurred before a new transaction available.
* Call `pullTransaction` right after the method to retrieve the transaction.
* Similarly to `pullTransaction` this method is thread-safe but the consumer
* should call it on the same thread (e.g. on the main thread) or ensure
* sequentiality of mount transactions separately.
*/
bool waitForTransaction(std::chrono::duration<double> timeout) const;
TelemetryController const &getTelemetryController() const;
/*
* Methods from this section are meant to be used by
* `MountingOverrideDelegate` only.
*/
public:
void updateBaseRevision(ShadowTreeRevision const &baseRevision) const;
void resetLatestRevision() const;
/*
* Methods from this section are meant to be used by `ShadowTree` only.
*/
private:
friend class ShadowTree;
void push(ShadowTreeRevision &&revision) const;
/*
* Revokes the last pushed `ShadowTreeRevision`.
* Generating a `MountingTransaction` requires some resources which the
* `MountingCoordinator` does not own (e.g. `ComponentDescriptor`s). Revoking
* committed revisions allows the owner (a Shadow Tree) to make sure that
* those resources will not be accessed (e.g. by the Mounting Layer).
*/
void revoke() const;
private:
SurfaceId const surfaceId_;
mutable std::mutex mutex_;
mutable ShadowTreeRevision baseRevision_;
mutable better::optional<ShadowTreeRevision> lastRevision_{};
mutable MountingTransaction::Number number_{0};
mutable std::condition_variable signal_;
std::weak_ptr<MountingOverrideDelegate const> mountingOverrideDelegate_;
TelemetryController telemetryController_;
bool enableReparentingDetection_{false}; // temporary
#ifdef RN_SHADOW_TREE_INTROSPECTION
mutable StubViewTree stubViewTree_; // Protected by `mutex_`.
#endif
};
} // namespace react
} // namespace facebook