1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #pragma once 18 19 #include <utility> // for std::move, std::forward 20 21 namespace android { 22 namespace base { 23 24 // ScopeGuard ensures that the specified functor is executed no matter how the 25 // current scope exits. 26 template <typename F> 27 class ScopeGuard { 28 public: ScopeGuard(F && f)29 ScopeGuard(F&& f) : f_(std::forward<F>(f)), active_(true) {} 30 ScopeGuard(ScopeGuard && that)31 ScopeGuard(ScopeGuard&& that) noexcept : f_(std::move(that.f_)), active_(that.active_) { 32 that.active_ = false; 33 } 34 35 template <typename Functor> ScopeGuard(ScopeGuard<Functor> && that)36 ScopeGuard(ScopeGuard<Functor>&& that) : f_(std::move(that.f_)), active_(that.active_) { 37 that.active_ = false; 38 } 39 ~ScopeGuard()40 ~ScopeGuard() { 41 if (active_) f_(); 42 } 43 44 ScopeGuard() = delete; 45 ScopeGuard(const ScopeGuard&) = delete; 46 void operator=(const ScopeGuard&) = delete; 47 void operator=(ScopeGuard&& that) = delete; 48 Disable()49 void Disable() { active_ = false; } 50 active()51 bool active() const { return active_; } 52 53 private: 54 template <typename Functor> 55 friend class ScopeGuard; 56 57 F f_; 58 bool active_; 59 }; 60 61 template <typename F> make_scope_guard(F && f)62ScopeGuard<F> make_scope_guard(F&& f) { 63 return ScopeGuard<F>(std::forward<F>(f)); 64 } 65 66 } // namespace base 67 } // namespace android 68