98 lines
2.0 KiB
C++
98 lines
2.0 KiB
C++
#include <iostream>
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#include <QSemaphore>
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#include <QThread>
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#include <QCoreApplication>
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struct IPrintable {
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~IPrintable() = default;
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virtual auto print() const -> void = 0;
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};
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class PrintA : public IPrintable {
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private:
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QSemaphore &lockBC_;
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public:
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explicit PrintA(QSemaphore &lockBc) : lockBC_(lockBc) {}
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auto print() const -> void override {
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this->lockBC_.release(1);
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std::cout << "A";
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}
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};
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class PrintB : public IPrintable {
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private:
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QSemaphore &lockBC_;
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QSemaphore &lockC_;
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public:
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explicit PrintB(QSemaphore &lockBc, QSemaphore &lockC) : lockBC_(lockBc), lockC_(lockC) {}
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auto print() const -> void override {
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if (this->lockBC_.tryAcquire(1)) {
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if (this->lockC_.available() == 0) {
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this->lockC_.release(1);
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}
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std::cout << "B";
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}
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}
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};
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class PrintC : public IPrintable {
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private:
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QSemaphore &lockBC_;
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QSemaphore &lockC_;
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public:
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explicit PrintC(QSemaphore &lockBc, QSemaphore &lockC) : lockBC_(lockBc), lockC_(lockC) {}
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auto print() const -> void override {
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if (this->lockBC_.tryAcquire(1)) {
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if (this->lockC_.tryAcquire(1)) {
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std::cout << "C";
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} else {
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this->lockBC_.release(1);
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}
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}
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}
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};
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template<typename T>
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class Worker : public QThread {
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private:
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std::unique_ptr<IPrintable> printer_;
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public:
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template<typename ...Argts>
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Worker(QString tname, Argts &... args) : printer_(std::make_unique<T>(args...)) {};
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protected:
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void run() {
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while (true) {
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printer_->print();
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std::cout.flush();
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sleep(1);
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}
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}
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};
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int main(int argc, char *argv[]) {
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QSemaphore lockC(1);
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QSemaphore lockBC(0);
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Worker<PrintA> t1("Thread 1", lockBC);
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Worker<PrintB> t2("Thread 1", lockBC, lockC);
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Worker<PrintC> t3("Thread 1", lockBC, lockC);
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t1.start();
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t2.start();
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t3.start();
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t1.wait();
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t2.wait();
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t3.wait();
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return 0;
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}
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