Add task

task3/CMakeLists.txt

@@ -7,3 +7,11 @@ target_sources(task3-chpt3ex12-rd PRIVATE
 
 target_link_libraries(task3-chpt3ex12-rd PRIVATE
         Qt6::Core)
+
+add_executable(task3-bonus-rd)
+
+target_sources(task3-bonus-rd PRIVATE
+        main-bonus-task-rd.cpp)
+
+target_link_libraries(task3-bonus-rd PRIVATE
+        Qt6::Core)

task3/main-bonus-task-rd.cpp

@@ -0,0 +1,119 @@
+/***************************************************************************
+ *
+ * main.cpp:    Code to solve Barlas Exersice 3-12.
+ *
+ * Version      0.5 by Hartmut Weber: Just a template. 3-11 not solved.
+ *              1.0 by .............
+ *
+ * Statemet of Version 1.0 Authorship:
+ *              .......<Your text>.........
+ *
+ **************************************************************************/
+#include <QCoreApplication>
+#include <QTimer>
+#include <QThread>
+#include <stdio.h>
+#include <QSemaphore>
+#include <QRandomGenerator>
+
+using namespace std;
+
+#define CHAR_COUNT_MAX 500
+#define TIME_FACTOR 2
+
+int charCount = 0;
+QSemaphore semCharCount(1);
+QRandomGenerator *randg = QRandomGenerator::global();
+
+QSemaphore lockBC_(0);
+QSemaphore lockC_(0);
+
+class AThread : public QThread {
+private:
+    int ID;
+public:
+    AThread(int i) : ID(i) {}
+
+    void run() {
+        while (charCount < CHAR_COUNT_MAX) {
+            lockBC_.release(1);
+            printf("A");
+            fflush(stdout);
+            semCharCount.acquire();
+            charCount++;
+            semCharCount.release();
+            msleep((randg->generate() % 3 + 1) * TIME_FACTOR);
+        }
+        return;
+    }
+};
+
+class BThread : public QThread {
+private:
+    int ID;
+public:
+    BThread(int i) : ID(i) {}
+
+    void run() {
+        while (charCount < CHAR_COUNT_MAX) {
+            if (lockBC_.tryAcquire(1)) {
+                if (lockC_.available() == 0) {
+                    lockC_.release(1);
+                }
+                printf("B");
+                fflush(stdout);
+                semCharCount.acquire();
+                charCount++;
+                semCharCount.release();
+            };
+            msleep((randg->generate() % 3 + 1) * TIME_FACTOR);
+        }
+        return;
+    }
+};
+
+class CThread : public QThread {
+private:
+    int ID;
+public:
+    CThread(int i) : ID(i) {}
+
+    void run() {
+        while (charCount < CHAR_COUNT_MAX) {
+            if (lockC_.tryAcquire(1) && lockBC_.tryAcquire(1)) {
+                printf("C");
+                fflush(stdout);
+                semCharCount.acquire();
+                charCount++;
+                semCharCount.release();
+            }
+            msleep((randg->generate() % 3 + 1) * TIME_FACTOR);
+        }
+        return;
+    }
+};
+
+int main(int argc, char *argv[]) {
+    QCoreApplication a(argc, argv);
+
+    printf("START\n\n");
+    fflush(stdout);
+    AThread *pTa = new AThread(1);
+    BThread *pTb = new BThread(2);
+    CThread *pTc = new CThread(3);
+
+    pTa->start();
+    pTb->start();
+    pTc->start();
+
+    pTa->wait();
+    pTb->wait();
+    pTc->wait();
+    printf("\n\n");
+    fflush(stdout);
+
+    // Let event loop do at least one turn. (https:/stackoverflow.com/questions/4180394)
+    QTimer::singleShot(0, &a, &QCoreApplication::quit); // Let event loop do at least one turn.
+
+    return a.exec();
+}