1 /* 2 * Copyright (c) 2025 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 /** 17 * @addtogroup FFRT 18 * @{ 19 * 20 * @brief Provides FFRT C++ APIs. 21 * 22 * @since 18 23 */ 24 25 /** 26 * @file shared_mutex.h 27 * 28 * @brief Declares the shared_mutex interfaces in C++. 29 * 30 * @library libffrt.z.so 31 * @kit FunctionFlowRuntimeKit 32 * @syscap SystemCapability.Resourceschedule.Ffrt.Core 33 * @since 18 34 */ 35 36 #ifndef FFRT_API_CPP_SHARED_MUTEX_H 37 #define FFRT_API_CPP_SHARED_MUTEX_H 38 39 #include "c/shared_mutex.h" 40 41 namespace ffrt { 42 /** 43 * @class shared_mutex 44 * @brief A class for managing a shared mutex, providing synchronization mechanisms. 45 * 46 * This class offers methods to support: 47 * - Exclusive locking: Ensures only one thread can access critical sections. 48 * - Shared locking: Allows multiple threads to read simultaneously. 49 * 50 * @since 18 51 */ 52 class shared_mutex : public ffrt_rwlock_t { 53 public: 54 /** 55 * @brief Constructs a shared_mutex object and initializes the underlying lock. 56 * 57 * @since 18 58 */ shared_mutex()59 shared_mutex() 60 { 61 ffrt_rwlock_init(this, nullptr); 62 } 63 64 /** 65 * @brief Destroys the shared_mutex object and releases the underlying lock. 66 * 67 * @since 18 68 */ ~shared_mutex()69 ~shared_mutex() 70 { 71 ffrt_rwlock_destroy(this); 72 } 73 74 /** 75 * @brief Deleted copy constructor to prevent copying of the shared_mutex object. 76 */ 77 shared_mutex(const shared_mutex&) = delete; 78 79 /** 80 * @brief Deleted copy assignment operator to prevent assignment of the shared_mutex object. 81 */ 82 void operator=(const shared_mutex&) = delete; 83 84 /** 85 * @brief Acquires an exclusive lock, blocking other threads. 86 * 87 * @since 18 88 */ lock()89 inline void lock() 90 { 91 ffrt_rwlock_wrlock(this); 92 } 93 94 /** 95 * @brief Attempts to acquire an exclusive lock without blocking. 96 * 97 * @return true if the lock is successfully acquired; false otherwise. 98 * @since 18 99 */ try_lock()100 inline bool try_lock() 101 { 102 return ffrt_rwlock_trywrlock(this) == ffrt_success ? true : false; 103 } 104 105 /** 106 * @brief Releases the exclusive lock. 107 * 108 * @since 18 109 */ unlock()110 inline void unlock() 111 { 112 ffrt_rwlock_unlock(this); 113 } 114 115 /** 116 * @brief Acquires a shared lock, allowing concurrent access by multiple threads. 117 * 118 * @since 18 119 */ lock_shared()120 inline void lock_shared() 121 { 122 ffrt_rwlock_rdlock(this); 123 } 124 125 /** 126 * @brief Attempts to acquire a shared lock without blocking. 127 * 128 * @return true if the lock is successfully acquired; false otherwise. 129 * @since 18 130 */ try_lock_shared()131 inline bool try_lock_shared() 132 { 133 return ffrt_rwlock_tryrdlock(this) == ffrt_success ? true : false; 134 } 135 136 /** 137 * @brief Releases the shared lock. 138 * 139 * @since 18 140 */ unlock_shared()141 inline void unlock_shared() 142 { 143 ffrt_rwlock_unlock(this); 144 } 145 }; 146 } // namespace ffrt 147 148 #endif // FFRT_API_CPP_SHARED_MUTEX_H 149 /** @} */