多线程日志帮助 [英] Multithreaded Logging Help

问题描述

我的工作我的引擎多线程日志记录。但我是个有麻烦使它MT。问题是，即使我深深复制我的Logger对象到一个局部变量，我将不得不与文件的问题。由于两个线程会在同一时间，这将建立一个烂摊子写入同一个文件。这里是我的记录器类：

I am working on a multithreaded logging for my engine. But I ma having troubles making it MT. The problem is, even if I am deep copying my logger object into a local variable I am going to have problems with the files. Because two threads are going to write to the same file at the same time which will build a mess. Here is my logger class:

class Logger {
public:
    typedef std::vector<LogListener *> ListenerList;

private:
    ListenerList listeners;
            boost::mutex mutex;

public:
    Logger();
    ~Logger();

    Logger * write(const String &line);

};

Logger * Logger::write(const String &text) {

    if(listeners.empty()) return this;
    boost::unique_lock<boost::mutex> lock(mutex);
    for(ListenerList::iterator i = listeners.begin(); i != listeners.end(); ++i) {
        (*i)->write(text);
    }

    return this;

}

class FileLogListener : public LogListener {
    std::ofstream stream;
public:
    FileLogListener(const String &str) : stream(str.c_str(), std::ios::out | std::ios::app) { }
    void write(const String &text) {
        stream << text << std::endl;
    }

};

现在假设（避免互斥）：

Now suppose (avoiding mutexes):

//Thread 1

void func1() {
    Logger * log = new Logger;
    log->addListener("file.txt");
    log->write("Thread 1 Test");
}

//Thread 2

void func2() {
    Logger * log = new Logger;
    log->addListener("file.txt");
    log->write("Thread 2 test");
}

int main() {
  boost::thread t1(&func1);
  boost::thread t2(&func2);

  t1.join();
  t2.join();
  return 0;
}

file.txt的变得一团糟。

"file.txt" becomes a mess.

编辑：目前，我正在读和多线程观看讲座更好地理解它。

Currently, I am reading and watching lectures on Multithreading to understand it better.

编辑：以上记录仪的工作原理

The above logger works.

在前进，结果谢谢
卡西姆Gasimzada

Thanks in advance,
Gasim Gasimzada

推荐答案

要么不写同一个文件，或者将连载写入（例如，通过使用锁）。

Either don't write to the same file, or serialise the writes (e.g. by using a lock).

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