lab5, reader/writer problem

src/reader_writer.cpp

@@ -3,3 +3,100 @@
 //
 
 #include "reader_writer.h"
+
+#include <iostream>
+#include <sstream>
+#include <utility>
+#include <unistd.h>
+#include <vector>
+
+ReaderWriter::ReaderWriter(const int numReaders, const int numWriters, std::string filename)
+    : numReaders(numReaders), numWriters(numWriters), filename(std::move(filename)), readCount(0), writeCount(0) {
+    sem_init(&resourceAccess, 0, 1);
+    sem_init(&readCountAccess, 0, 1);
+}
+
+ReaderWriter::~ReaderWriter() {
+    sem_destroy(&resourceAccess);
+    sem_destroy(&readCountAccess);
+}
+
+void* ReaderWriter::reader(void* arg) {
+    auto* rw = static_cast<ReaderWriter*>(arg);
+
+    for (int i = 0; i < 5; ++i) {
+        sem_wait(&rw->readCountAccess);
+        rw->readCount++;
+        if (rw->readCount == 1) {
+            sem_wait(&rw->resourceAccess);
+        }
+        sem_post(&rw->readCountAccess);
+
+        if (std::ifstream file(rw->filename); file.is_open()) {
+            std::ostringstream output;
+            output << "Reader reading: ";
+            std::string line;
+            while (std::getline(file, line)) {
+                output << line << " ";
+            }
+            output << std::endl;
+            std::cout << output.str();
+        } else {
+            std::cerr << "Reader could not open file\n";
+        }
+
+        sem_wait(&rw->readCountAccess);
+        rw->readCount--;
+        if (rw->readCount == 0) {
+            sem_post(&rw->resourceAccess);
+        }
+        sem_post(&rw->readCountAccess);
+
+        sleep(1);
+    }
+    return nullptr;
+}
+
+
+
+void* ReaderWriter::writer(void* arg) {
+    auto* rw = static_cast<ReaderWriter*>(arg);
+
+    for (int i = 0; i < 5; ++i) {
+        sem_wait(&rw->resourceAccess);
+
+        std::ofstream file(rw->filename, std::ios::app);
+        if (file.is_open()) {
+            file << rw->writeCount << "\n";
+            std::cout << "Writer writing: " << rw->writeCount << std::endl;
+            rw->writeCount++;
+        } else {
+            std::cerr << "Writer could not open file\n";
+        }
+        file.close();
+
+        sem_post(&rw->resourceAccess);
+
+        sleep(1);
+    }
+    return nullptr;
+}
+
+void ReaderWriter::run() {
+    std::vector<pthread_t> readerThreads(numReaders);
+    std::vector<pthread_t> writerThreads(numWriters);
+
+    for (int i = 0; i < numReaders; ++i) {
+        pthread_create(&readerThreads[i], nullptr, reader, this);
+    }
+    for (int i = 0; i < numWriters; ++i) {
+        pthread_create(&writerThreads[i], nullptr, writer, this);
+    }
+
+    for (const auto& t : readerThreads) {
+        pthread_join(t, nullptr);
+    }
+    for (const auto& t : writerThreads) {
+        pthread_join(t, nullptr);
+    }
+}