71 lines
3.1 KiB
C++
71 lines
3.1 KiB
C++
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// Fig. 17.13: atomic.cpp
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// Incrementing integers from concurrent threads
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// with and without atomics.
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#include <atomic>
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#include <fmt/format.h>
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#include <iostream>
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#include <thread>
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int main() {
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int count1{0};
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std::atomic<int> atomicCount{0};
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int count2{0};
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std::atomic_ref<int> atomicRefCount{count2};
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{
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std::cout << "Two concurrent threads incrementing int count1, "
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<< "atomicCount and atomicRefCount\n\n";
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// lambda to increment counters
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auto incrementer{
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[&]() {
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for (int i{0}; i < 1000; ++i) {
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++count1; // no synchronization
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++atomicCount; // ++ is an atomic operation
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++atomicRefCount; // ++ is an atomic operation
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std::this_thread::yield(); // force thread to give up CPU
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}
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}
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};
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std::jthread t1{incrementer};
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std::jthread t2{incrementer};
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}
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std::cout << fmt::format("Final count1: {}\n", count1);
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std::cout << fmt::format("Final atomicCount: {}\n", atomicCount);
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std::cout << fmt::format("Final count2: {}\n", count2);
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}
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/************************************************************************
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* (C) Copyright 1992-2022 by Deitel & Associates, Inc. and *
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* Pearson Education, Inc. All Rights Reserved. *
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* *
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* DISCLAIMER: The authors and publisher of this book have used their *
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* best efforts in preparing the book. These efforts include the *
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* development, research, and testing of the theories and programs *
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* to determine their effectiveness. The authors and publisher make *
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* no warranty of any kind, expressed or implied, with regard to these *
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* programs or to the documentation contained in these books. The *
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* authors and publisher shall not be liable in any event for *
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* incidental or consequential damages in connection with, or arising *
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* out of, the furnishing, performance, or use of these programs. *
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***********************************************************************/
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/************************************************************************
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* (C) Copyright 1992-2022 by Deitel & Associates, Inc. and *
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* Pearson Education, Inc. All Rights Reserved. *
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* *
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* DISCLAIMER: The authors and publisher of this book have used their *
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* best efforts in preparing the book. These efforts include the *
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* development, research, and testing of the theories and programs *
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* to determine their effectiveness. The authors and publisher make *
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* no warranty of any kind, expressed or implied, with regard to these *
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* programs or to the documentation contained in these books. The *
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* authors and publisher shall not be liable in any event for *
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* incidental or consequential damages in connection with, or arising *
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* out of, the furnishing, performance, or use of these programs. *
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***********************************************************************/
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