sweeper_video/src/main.cpp

// main.cpp
#include "app_config.hpp"
#include "rtsp_manager.hpp"
#include "logger.hpp"
#include "mqtt_client_wrapper.hpp"
#include <thread>
#include <atomic>
#include <csignal>
#include <unistd.h> // write, STDOUT_FILENO
#include <chrono>

std::atomic<bool> g_running(true);

static void minimal_signal_handler(int signum)
{
    // 只做非常有限且 async-signal-safe 的操作
    g_running.store(false, std::memory_order_relaxed);
    const char msg[] = "[MAIN] Signal received, initiating shutdown...\n";
    write(STDERR_FILENO, msg, sizeof(msg) - 1);
    // 不要调用 LOG_*、malloc、std::string、mutex、exit 等
}

int main()
{
    // 安装信号处理（SIGINT 和 SIGTERM）
    struct sigaction sigAct{};
    sigAct.sa_handler = minimal_signal_handler;
    sigemptyset(&sigAct.sa_mask);
    sigAct.sa_flags = 0;
    sigaction(SIGINT, &sigAct, nullptr);
    sigaction(SIGTERM, &sigAct, nullptr);
    signal(SIGPIPE, SIG_IGN);

    // 初始化日志文件
    Logger::set_log_to_file(get_executable_dir_file_path("app.log"));

    try
    {
        // 从可执行文件所在目录读取配置文件
        g_app_config = AppConfig::load_from_file(get_executable_dir_file_path("config.json"));
    }
    catch (const std::exception &e)
    {
        LOG_ERROR(std::string("Failed to load config: ") + e.what());
        return -1;
    }

    // 线程退出标志，用于超时等待
    std::atomic<bool> rtsp_thread_exited(false);
    std::atomic<bool> mqtt_thread_exited(false);

    // 先在主线程初始化 GStreamer
    RTSPManager::init();

    std::thread rtsp_thread([&]()
                            {
        RTSPManager::start(g_app_config.cameras);
        rtsp_thread_exited.store(true, std::memory_order_relaxed); });

    // std::thread mqtt_thread([&]()
    //                         {
    //     mqtt_client_thread_func();
    //     mqtt_thread_exited.store(true, std::memory_order_relaxed); });

    // 等待退出信号
    while (g_running.load(std::memory_order_relaxed))
        std::this_thread::sleep_for(std::chrono::milliseconds(200));

    LOG_INFO("[MAIN] Shutdown requested, stopping services...");

    // 等线程优雅退出：总等待时间 (可调整)
    const auto max_wait = std::chrono::seconds(5);
    const auto poll_interval = std::chrono::milliseconds(100);
    auto deadline = std::chrono::steady_clock::now() + max_wait;

    // 等 RTSP 线程退出
    while (!rtsp_thread_exited.load(std::memory_order_relaxed) &&
           std::chrono::steady_clock::now() < deadline)
    {
        std::this_thread::sleep_for(poll_interval);
    }
    if (rtsp_thread.joinable())
    {
        if (rtsp_thread_exited.load(std::memory_order_relaxed))
        {
            rtsp_thread.join();
            LOG_INFO("[MAIN] RTSP thread finished and joined.");
        }
        else
        {
            LOG_WARN("[MAIN] RTSP thread did not exit within timeout.");
        }
    }

    // 等 MQTT 线程退出
    deadline = std::chrono::steady_clock::now() + max_wait;
    while (!mqtt_thread_exited.load(std::memory_order_relaxed) &&
           std::chrono::steady_clock::now() < deadline)
    {
        std::this_thread::sleep_for(poll_interval);
    }
    if (mqtt_thread.joinable())
    {
        if (mqtt_thread_exited.load(std::memory_order_relaxed))
        {
            mqtt_thread.join();
            LOG_INFO("[MAIN] MQTT thread finished and joined.");
        }
        else
        {
            LOG_WARN("[MAIN] MQTT thread did not exit within timeout.");
        }
    }

    // 如果某些线程仍未退出，强制结束进程（不会跑全局析构）
    if ((rtsp_thread.joinable() && !rtsp_thread_exited.load(std::memory_order_relaxed)) ||
        (mqtt_thread.joinable() && !mqtt_thread_exited.load(std::memory_order_relaxed)))
    {
        LOG_ERROR("[MAIN] Threads did not exit in time. Forcing immediate termination.");
        _exit(1); // 强制退出（不会调用 atexit handlers）
    }

    LOG_INFO("[MAIN] Program exited cleanly.");

    return 0;
}