1 /* 2 * Copyright (c) 2017-2018 Arm Limited. 3 * 4 * SPDX-License-Identifier: MIT 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to 8 * deal in the Software without restriction, including without limitation the 9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 10 * sell copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in all 14 * copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 22 * SOFTWARE. 23 */ 24 #ifndef __ARM_COMPUTE_UTILS_SEMAMPHORE_H__ 25 #define __ARM_COMPUTE_UTILS_SEMAMPHORE_H__ 26 27 #include "Mutex.h" 28 #include "support/Mutex.h" 29 #include <condition_variable> 30 31 namespace arm_compute 32 { 33 #ifndef NO_MULTI_THREADING 34 /** Semamphore class */ 35 class Semaphore 36 { 37 public: 38 /** Default Constuctor 39 * 40 * @param[in] value Semaphore initial value 41 */ 42 Semaphore(int value = 0) _value(value)43 : _value(value), _m(), _cv() 44 { 45 } 46 /** Signals a semaphore */ signal()47 inline void signal() 48 { 49 { 50 std::lock_guard<std::mutex> lock(_m); 51 ++_value; 52 } 53 _cv.notify_one(); 54 } 55 /** Waits on a semaphore */ wait()56 inline void wait() 57 { 58 std::unique_lock<std::mutex> lock(_m); 59 _cv.wait(lock, [this]() 60 { 61 return _value > 0; 62 }); 63 --_value; 64 } 65 66 private: 67 int _value; 68 arm_compute::Mutex _m; 69 std::condition_variable _cv; 70 }; 71 #else /* NO_MULTI_THREADING */ 72 /** Empty semamphore class */ 73 class Semaphore 74 { 75 public: 76 Semaphore(int value = 0) 77 : _value(value) 78 { 79 (void)_value; 80 } 81 /** Signals a semaphore */ 82 inline void signal() 83 { 84 (void)_value; 85 } 86 /** Waits on a semaphore */ 87 inline void wait() 88 { 89 (void)_value; 90 } 91 92 private: 93 int _value; 94 }; 95 #endif /* NO_MULTI_THREADING */ 96 } // arm_compute 97 #endif /* __ARM_COMPUTE_UTILS_SEMAMPHORE_H__ */ 98