1 /* 2 * Copyright (C) 2021 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 #ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_PROTECT_CALLBACK_H 18 #define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_PROTECT_CALLBACK_H 19 20 #include <android-base/scopeguard.h> 21 #include <android-base/thread_annotations.h> 22 #include <android/binder_interface_utils.h> 23 #include <nnapi/Result.h> 24 #include <nnapi/Types.h> 25 #include <nnapi/hal/CommonUtils.h> 26 27 #include <functional> 28 #include <mutex> 29 #include <vector> 30 31 // See hardware/interfaces/neuralnetworks/utils/README.md for more information on AIDL interface 32 // lifetimes across processes and for protecting asynchronous calls across AIDL. 33 34 namespace aidl::android::hardware::neuralnetworks::utils { 35 36 class IProtectedCallback { 37 public: 38 /** 39 * Marks this object as a dead object. 40 */ 41 virtual void notifyAsDeadObject() = 0; 42 43 // Public virtual destructor to allow objects to be stored (and destroyed) as smart pointers. 44 // E.g., std::unique_ptr<IProtectedCallback>. 45 virtual ~IProtectedCallback() = default; 46 47 protected: 48 // Protect the non-destructor special member functions to prevent object slicing. 49 IProtectedCallback() = default; 50 IProtectedCallback(const IProtectedCallback&) = default; 51 IProtectedCallback(IProtectedCallback&&) noexcept = default; 52 IProtectedCallback& operator=(const IProtectedCallback&) = default; 53 IProtectedCallback& operator=(IProtectedCallback&&) noexcept = default; 54 }; 55 56 // Thread safe class 57 class DeathMonitor final { 58 public: 59 static void serviceDied(void* cookie); 60 void serviceDied(); 61 // Precondition: `killable` must be non-null. 62 void add(IProtectedCallback* killable) const; 63 // Precondition: `killable` must be non-null. 64 void remove(IProtectedCallback* killable) const; 65 66 private: 67 mutable std::mutex mMutex; 68 mutable std::vector<IProtectedCallback*> mObjects GUARDED_BY(mMutex); 69 }; 70 71 class DeathHandler final { 72 public: 73 static nn::GeneralResult<DeathHandler> create(std::shared_ptr<ndk::ICInterface> object); 74 75 DeathHandler(const DeathHandler&) = delete; 76 DeathHandler(DeathHandler&&) noexcept = default; 77 DeathHandler& operator=(const DeathHandler&) = delete; 78 DeathHandler& operator=(DeathHandler&&) noexcept = delete; 79 ~DeathHandler(); 80 81 using Cleanup = std::function<void()>; 82 // Precondition: `killable` must be non-null. 83 [[nodiscard]] ::android::base::ScopeGuard<Cleanup> protectCallback( 84 IProtectedCallback* killable) const; 85 getDeathMonitor()86 std::shared_ptr<DeathMonitor> getDeathMonitor() const { return kDeathMonitor; } 87 88 private: 89 DeathHandler(std::shared_ptr<ndk::ICInterface> object, 90 ndk::ScopedAIBinder_DeathRecipient deathRecipient, 91 std::shared_ptr<DeathMonitor> deathMonitor); 92 93 std::shared_ptr<ndk::ICInterface> kObject; 94 ndk::ScopedAIBinder_DeathRecipient kDeathRecipient; 95 std::shared_ptr<DeathMonitor> kDeathMonitor; 96 }; 97 98 } // namespace aidl::android::hardware::neuralnetworks::utils 99 100 #endif // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_PROTECT_CALLBACK_H 101