mirror of
https://github.com/facebook/react-native.git
synced 2025-11-01 09:14:26 +00:00
Samuel Susla
5fa6c5a941
Summary: changelog: [internal] You can read more about this rule on https://clang.llvm.org/extra/clang-tidy/checks/modernize-pass-by-value.html # Isn't it wasteful to copy? Isn't reference more efficient? This rule of thumb is no longer true since C++11 with move semantics. Let's look at some examples. # Option one ``` class TextHolder { public: TextBox(std::string const &text) : text_(text) {} private: std::string text_; }; ``` By using reference here, we prevent the caller from using rvalue to and avoiding copy. Regardless of what the caller passes in, copy always happens. # Option two ``` class TextHolder { public: TextBox(std::string const &text) : text_(text) {} TextBox(std::string &&text) : text_(std::move(text)) {} private: std::string text_; }; ``` Here, we provide two constructors, one for const reference and one for rvalue reference. This gives the caller option to avoid copy. But now we have two constructors, which is not ideal. # Option three (what we do in this diff) ``` class TextHolder { public: TextBox(std::string text) : text_(std::move(text)) {} private: std::string text_; }; ``` Here, the caller has option to avoid copy and we only have single constructor. Reviewed By: fkgozali, JoshuaGross Differential Revision: D33276841 fbshipit-source-id: 619d5123d2e28937b22874650366629f24f20a63
63 lines
1.9 KiB
C++
63 lines
1.9 KiB
C++
/*
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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#include "LeakChecker.h"
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#include <glog/logging.h>
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#include <jsi/instrumentation.h>
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#include <utility>
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namespace facebook {
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namespace react {
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LeakChecker::LeakChecker(RuntimeExecutor runtimeExecutor)
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: runtimeExecutor_(std::move(runtimeExecutor)) {}
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void LeakChecker::uiManagerDidCreateShadowNodeFamily(
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ShadowNodeFamily::Shared const &shadowNodeFamily) const {
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registry_.add(shadowNodeFamily);
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}
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void LeakChecker::stopSurface(SurfaceId surfaceId) {
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if (previouslyStoppedSurface_ > 0) {
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// Dispatch the check onto JavaScript thread to make sure all other
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// cleanup code has had chance to run.
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runtimeExecutor_([previouslySoppedSurface = previouslyStoppedSurface_,
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this](jsi::Runtime &runtime) {
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runtime.instrumentation().collectGarbage("LeakChecker");
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// For now check the previous surface because React uses double
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// buffering which keeps the surface that was just stopped in
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// memory. This is a documented problem in the last point of
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// https://github.com/facebook/react/issues/16087
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checkSurfaceForLeaks(previouslySoppedSurface);
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});
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}
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previouslyStoppedSurface_ = surfaceId;
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}
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void LeakChecker::checkSurfaceForLeaks(SurfaceId surfaceId) const {
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auto weakFamilies = registry_.weakFamiliesForSurfaceId(surfaceId);
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unsigned int numberOfLeaks = 0;
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for (auto const &weakFamily : weakFamilies) {
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auto strong = weakFamily.lock();
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if (strong) {
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++numberOfLeaks;
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}
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}
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if (numberOfLeaks > 0) {
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LOG(ERROR) << "[LeakChecker] Surface with id: " << surfaceId
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<< " has leaked " << numberOfLeaks << " components out of "
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<< weakFamilies.size();
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}
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registry_.removeFamiliesWithSurfaceId(surfaceId);
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}
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} // namespace react
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} // namespace facebook
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