mirror of
https://github.com/encounter/engine.git
synced 2026-03-30 11:09:55 -07:00
Michael Goderbauer
42 lines
1.1 KiB
C++
42 lines
1.1 KiB
C++
// Copyright 2013 The Flutter Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef FLUTTER_FML_MEMORY_WEAK_PTR_INTERNAL_H_
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#define FLUTTER_FML_MEMORY_WEAK_PTR_INTERNAL_H_
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#include "flutter/fml/macros.h"
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#include "flutter/fml/memory/ref_counted.h"
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namespace fml {
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namespace internal {
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// |WeakPtr<T>|s have a reference to a |WeakPtrFlag| to determine whether they
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// are valid (non-null) or not. We do not store a |T*| in this object since
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// there may also be |WeakPtr<U>|s to the same object, where |U| is a superclass
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// of |T|.
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//
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// This class in not thread-safe, though references may be released on any
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// thread (allowing weak pointers to be destroyed/reset/reassigned on any
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// thread).
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class WeakPtrFlag : public fml::RefCountedThreadSafe<WeakPtrFlag> {
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public:
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WeakPtrFlag();
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~WeakPtrFlag();
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bool is_valid() const { return is_valid_; }
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void Invalidate();
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private:
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bool is_valid_;
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FML_DISALLOW_COPY_AND_ASSIGN(WeakPtrFlag);
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};
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} // namespace internal
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} // namespace fml
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#endif // FLUTTER_FML_MEMORY_WEAK_PTR_INTERNAL_H_
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