Chromium定制版中同一进程线程内getBrowserStoreParams111为何重复初始化？

在基于Chromium的定制版本中，Release模式下出现同一进程（PID:21636）、同一线程（线程ID:27808）内getBrowserStoreParams111函数的静态变量store_param被初始化两次的异常，Debug模式运行完全正常。

相关代码 #

common.h #

static int getBrowserStoreParams111(int type);

common.cc #

int Common::getBrowserStoreParams111(int type) {
  static int store_param = [type] {
      int result = type;
      std::cout << result << std::endl;
      {
        std::ofstream outfile("D:\\timestamp.log", std::ios::app); // 追加模式
        if (outfile.is_open()) {   
          auto now = std::chrono::system_clock::now();
          auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch()).count();
  
          // 写入日志文件
          outfile << "getBrowserStoreParams111getBrowserStoreParams111getBrowserStoreParams111.cc  timestamp(ms): " << ms << "    common" << "type:" << type << 
          "  current thread ID: " << std::this_thread::get_id() << std::endl;
          outfile.flush();
          outfile.close();
        }
      }
      return result;
  }();
  return store_param;
}

base\command_line.cc #

std::ofstream outfile1("D:\\timestamp.log", std::ios::app);
if (outfile1.is_open()) {   
  auto now = std::chrono::system_clock::now();
  DWORD pid = GetCurrentProcessId(); 
  auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch()).count();
  
  outfile1 << "begin command_line.cc timestamp(ms) init: " << ms << "  pid:"  << pid 
  << "  current thread ID: " << std::this_thread::get_id()
  << "initinit init:" << base::WideToUTF8(cmd_line) << std::endl;
  outfile1.flush();
  outfile1.close();
}

std::string strHtml = getBrowserStoreParams();
getBrowserStoreParams111(111);
std::ofstream outfile("D:\\timestamp.log", std::ios::app); 
if (outfile.is_open()) {   
  auto now = std::chrono::system_clock::now();
  DWORD pid = GetCurrentProcessId(); 
  auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch()).count();
  
  outfile << "end command_line.cc timestamp(ms): " << ms << "  pid:" << pid << std::endl;
  outfile.flush();
  outfile.close();
}

日志输出 #

begin command_line.cc timestamp(ms) init: 1741772439295 pid:21636 current thread ID: 27808 initinit init:out\Release\chrome.exe --token=abcd
getBrowserStoreParams111getBrowserStoreParams111getBrowserStoreParams111.cc timestamp(ms): 1741772439355 common type: 111 current thread ID: 27808
end command_line.cc timestamp(ms): 1741772439355 pid:21636

begin command_line.cc timestamp(ms) init: 1741772439718 pid:21636 current thread ID: 27808 initinit init:out\Release\chrome.exe --token=abcd
getBrowserStoreParams111getBrowserStoreParams111getBrowserStoreParams111.cc timestamp(ms): 1741772439731 common type: 111 current thread ID: 27808
end command_line.cc timestamp(ms): 1741772439731 pid:21636

日志显示getBrowserStoreParams111函数的静态变量初始化逻辑被执行了两次，且两次都在同一个进程和线程中。

原因分析与解决方案 #

核心原因 #

1. 文件级静态函数的多实例问题：common.h中声明的static函数是文件级静态，每个包含该头文件的编译单元都会生成独立的函数实例，每个实例拥有自己的store_param静态变量。如果base\command_line.cc所在模块被多次初始化，或其他编译单元也调用该函数，就会触发多次初始化。
2. Release模式编译器优化：Chromium使用的Clang/GCC在Release模式下的激进优化，可能破坏静态变量的初始化原子性，导致同一函数实例的静态变量被重复初始化。

解决方案 #

1. 修正函数声明范围：移除common.h中函数的static修饰符，改为类的静态成员函数，确保全局只有一个函数实例：

// common.h
class Common {
public:
    static int getBrowserStoreParams111(int type);
};

2. 强制单次初始化：使用std::call_once确保静态变量只初始化一次，规避编译器优化问题：

int Common::getBrowserStoreParams111(int type) {
    static std::once_flag init_flag;
    static int store_param;
    std::call_once(init_flag, [&](){
        store_param = type;
        std::cout << store_param << std::endl;
        {
            std::ofstream outfile("D:\\timestamp.log", std::ios::app);
            if (outfile.is_open()) {   
                auto now = std::chrono::system_clock::now();
                auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch()).count();
                outfile << "getBrowserStoreParams111.cc  timestamp(ms): " << ms << "    common type:" << type << 
                "  current thread ID: " << std::this_thread::get_id() << std::endl;
                outfile.flush();
                outfile.close();
            }
        }
    });
    return store_param;
}

3. 检查模块加载逻辑：确认base\command_line.cc所在模块是否被Chromium的加载机制重复初始化，排查进程内模块重复加载的可能性。

内容的提问来源于stack exchange，提问作者chuya wang