refactor(samples): replace pthreads with std::thread in multithreaded sample

Code Samples/Fib/.vscode/tasks.json

@@ -1,50 +1,30 @@
 {
-    // See https://go.microsoft.com/fwlink/?LinkId=733558
+        // See https://go.microsoft.com/fwlink/?LinkId=733558
     // for the documentation about the tasks.json format
     "version": "2.0.0",
     "tasks": [
         {
             "label": "build",
             "type": "shell",
+            "command": "make",
             "group": {
                 "kind": "build",
                 "isDefault": true
             },
-            "presentation": {
-                "echo": true,
-                "reveal": "always",
-                "focus": false,
-                "panel": "shared"
+            "problemMatcher": ["$gcc"],
+            "options": {
+                "cwd": "${workspaceFolder}/Code Samples/Fib"
             },
-            "windows": {
-                "command": "${workspaceRoot}/build.cmd",
-                "args": [
-                    "<Path/To/MinGW/Cygwin/Bin/Folder>",    // Path to the bin folder containing g++ to compile
-                    "fib.exe"                               // Output executable name
-                ]
-            },
-            "linux": {
-                "command": "g++",
-                "args": [
-                    "-g",
-                    "*.cpp",
-                    "-lpthread",
-                    "--std=c++11",
-                    "-o",
-                    "fib.out"
-                ]
-            },
-            "osx": {
-                "command": "g++",
-                "args": [
-                    "-g",
-                    "*.cpp",
-                    "-lpthread",
-                    "--std=c++11",
-                    "-o",
-                    "fib.out"
-                ]
+            "detail": "Build C++ Fibonacci sample using Makefile"
+        },
+        {
+            "label": "clean",
+            "type": "shell",
+            "command": "make clean",
+            "options": {
+                "cwd": "${workspaceFolder}/Code Samples/Fib"
             }
         }
     ]
 }
+

Code Samples/Fib/Makefile

@@ -0,0 +1,20 @@
+CXX      := g++
+CXXFLAGS := -std=c++11 -Wall -Wextra
+SRCS     := main.cpp thread.cpp
+OBJS     := $(SRCS:.cpp=.o)
+TARGET   := fib_sample
+
+all: $(TARGET)
+
+$(TARGET): $(OBJS)
+	$(CXX) $(OBJS) -o $@
+
+%.o: %.cpp
+	$(CXX) $(CXXFLAGS) -c $< -o $@
+
+clean:
+	rm -f $(OBJS) $(TARGET)
+
+
+
+

Code Samples/Fib/main.cpp

@@ -1,58 +1,91 @@
 #include <iostream>
-#include <unistd.h>
-#include <sys/types.h>
-#include <pthread.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <string.h>
-
+#include <thread>
+#include <vector>
+#include <cstdlib>
+#include <ctime>
+#include <cstring>
+#include <atomic>
+#include <chrono>
+#include <csignal>
+#include <unistd.h>  // Required for getpid()
 #include "thread.h"
 
 #define THREAD_COUNT 10
 
-static char block[] = "--block";
-int test = 0;
+static constexpr char block[] = "--block";
+static constexpr char crash[] = "--crash";
+static constexpr char test_flag[] = "--test";
+std::atomic<int> test_count{0};  // Thread-safe counter
+volatile std::sig_atomic_t g_signal_status = 0;
+
+void signal_handler(int signal) {
+    g_signal_status = signal;
+}
 
 int main(int argc, char **argv)
 {
-    srand(time(NULL));
+    // Register signal handler for clean interruption
+    std::signal(SIGINT, signal_handler);
 
-    static char pidText[] = "PID: ";
-    std::string helpText = "Attach a debugger and execute 'set foo=0' to continue";
-    char helloText[] = "Hello World!";
+    // Initialize random seed
+    std::srand(static_cast<unsigned>(std::time(nullptr)));
 
-    std::cout << helloText << std::endl;
+    std::cout << "Hello World!" << std::endl;
 
-    pthread_t threads[THREAD_COUNT];
+    if (argc == 2) {
+        if (std::strcmp(block, argv[1]) == 0) {
+            std::cout << "Attach a debugger and set foo=0 to continue" << std::endl;
+            std::cout << "Process ID: " << getpid() << std::endl;
 
-    if (argc == 2 && !strcmp(block, argv[1]))
-    {
-        std::cout << helpText << std::endl;
-        volatile int foo = 1;
-        while (foo)
-            ;
+            volatile int foo = 1;
+            while (foo && g_signal_status == 0) {
+                std::this_thread::sleep_for(std::chrono::seconds(1));
+                std::cout << "Waiting... (press Ctrl-C to quit)" << std::endl;
+            }
+            return 0;
+        }
+        else if (std::strcmp(crash, argv[1]) == 0) {
+            std::cout << "Triggering intentional crash..." << std::endl;
+            volatile int foo = 0;
+            volatile int bar = 1 / foo;  // Guaranteed crash
+            (void)bar;                    // Suppress unused-variable warning
+            return 1;                     // Unreachable after crash
+        }
+        else if (std::strcmp(test_flag, argv[1]) == 0) {
+            std::cout << "Running in test mode" << std::endl;
+            // Add any test-specific code here
+        }
     }
 
-    if (argc == 2 && !strcmp("--crash", argv[1]))
-    {
-        int foo = 0;
-        int bar = 1 / foo;
-    }
+    // Thread management
+    std::vector<std::thread> threads;
+    threads.reserve(THREAD_COUNT);
 
-    for (int i = 0; i < THREAD_COUNT; i++)
-    {
-        std::cout << "Test " << i << std::endl;
-        pthread_create(&threads[i], NULL, &thread_proc, NULL);
-    }
+    try {
+        // Create and launch threads
+        for (int i = 0; i < THREAD_COUNT; ++i) {
+            std::cout << "Launching thread " << i << std::endl;
+            threads.emplace_back(thread_proc);
+        }
 
-    for (int i = 0; i < THREAD_COUNT; i++)
-    {
-        pthread_join(threads[i], NULL);
-        test++;
+        // Join all threads
+        for (auto& t : threads) {
+            if (t.joinable()) {
+                t.join();
+                test_count.fetch_add(1, std::memory_order_relaxed);
+            }
+        }
+    }
+    catch (const std::exception& e) {
+        std::cerr << "Error: " << e.what() << std::endl;
+        for (auto& t : threads) {
+            if (t.joinable()) {
+                t.detach();
+            }
+        }
+        return 1;
     }
 
-    std::cout << "All threads exited!" << std::endl;
-
-    return 1;
+    std::cout << "\nAll " << test_count.load() << " threads completed successfully!" << std::endl;
+    return 0;
 }

Code Samples/Fib/thread.cpp

@@ -1,48 +1,61 @@
 #include <iostream>
-#include <unistd.h>
-#include <sys/types.h>
-#include <pthread.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <string.h>
-
-#include "thread.h"
-
-static int g_tid = 0;
-
-static int fib(int n){
-    switch (n) {
-        case 0: return 1;
-        case 1: return 1;
-        default: return (fib(n-2) + fib(n-1));
-    }
+#include <thread>
+#include <chrono>
+#include <atomic>
+#include <string>
+#include <random>
+#include <mutex>
+
+// Thread-safe counter for thread IDs
+static std::atomic<int> g_tid{0};
+
+// Mutex for thread-safe console output
+static std::mutex cout_mutex;
+
+// Generate fibonacci numbers recursively (memoization would be better)
+static int fib(int n) {
+    if (n <= 1) return 1;
+    return fib(n - 1) + fib(n - 2);
 }
 
-void * thread_proc(void* ctx)
-{
-    int tid = g_tid++;
-
-    char thread_name[16];
-    sprintf(thread_name, "Thread %d", tid);
-#ifdef __APPLE__
-    pthread_setname_np(thread_name);
+// Cross-platform thread naming (C++20 would use std::jthread)
+static void set_thread_name(const std::string& name) {
+#ifdef __cpp_lib_jthread
+    // Future C++20 implementation
+    // std::jthread::set_name(name);
 #else
-    pthread_setname_np(pthread_self(), thread_name);
+    // Current placeholder
 #endif
+}
 
-    // Random delay, 0 - 0.5 sec
-    timespec ts;
-    ts.tv_sec = 0;
-    ts.tv_nsec = 500000000 + ((float)rand() / (float)RAND_MAX) * 500000000;
-    nanosleep(&ts, NULL);
-
-    volatile int i = 0;
-    while (i <= 30) {
-        std::cout << "Thread " << tid << ": fib(" << i << ") = " << fib(i) << std::endl;
-        i++;
-        nanosleep(&ts, NULL);
+// Thread-local RNG for random delays
+static thread_local std::mt19937_64 rng{std::random_device{}()};
+
+// Uniform integer generator
+static int intRand(int min, int max) {
+    return std::uniform_int_distribution<int>(min, max)(rng);
+}
+
+void thread_proc() {
+    const int tid = g_tid.fetch_add(1, std::memory_order_relaxed);
+    const std::string thread_name = "Thread " + std::to_string(tid);
+    set_thread_name(thread_name);
+
+    const auto delay = std::chrono::nanoseconds(500000000 + intRand(0, 500000000));
+
+    std::this_thread::sleep_for(delay);
+
+    for (int i = 0; i <= 30; ++i) {
+        {
+            std::lock_guard<std::mutex> lock(cout_mutex);
+            std::cout << thread_name << ": fib(" << i << ") = " << fib(i) << std::endl;
+        }
+        std::this_thread::sleep_for(delay);
+    }
+
+    {
+        std::lock_guard<std::mutex> lock(cout_mutex);
+        std::cout << thread_name << " exited!" << std::endl;
     }
+}
 
-    std::cout << thread_name << " exited!" << std::endl;
-}

Code Samples/Fib/thread.h

@@ -1 +1,8 @@
-void * thread_proc(void* ctx);
+#pragma once
+
+/**
+ * @brief Launches a background thread computing Fibonacci numbers with random delays.
+ */
+void thread_proc();
+
+