互斥体作为类的成员

我正在尝试制作一个简单的订阅者-生产者模式，其中多个订阅者和一个生产者在不同的线程中运行(原因是要了解有关线程的更多信息(。然而，我正在努力使互斥锁成为生产者类的一员。代码给出如下：

class Producer {
private:
vector<Subscriber* > subs;
thread th;
int counter;
mutex mux;
public:
Producer() : counter(counter), th(&Producer::run, this) {};
void addSubscriber(Subscriber* s);
void notify();
void incrementCounter();
void run();
void callJoin(){th.join(); } 
};
void Producer::run() {
for (int i = 0; i < 10; i++) {
incrementCounter();
this_thread::sleep_for(std::chrono::milliseconds(3000));
}
}
void Producer::addSubscriber(Subscriber* s) {
lock_guard<mutex> lock(mux);
subs.push_back(s); 
}
void Producer::notify() {
lock_guard<mutex> lock(mux);
for (auto it = subs.begin(); it != subs.end(); ++it) {
(*it)->setCounterCopy(counter);
}
}
void Producer::incrementCounter() {
counter++;
notify(); 
}

订阅者类：

class Subscriber {
private:
string name;
thread th;
atomic<int> counterCopy = 0;
public:
Subscriber(string name) : name(name),  th(&Subscriber::run, this) {};
void run() {
while (true) {
cout << name << ": " << counterCopy << endl; 
this_thread::sleep_for(std::chrono::milliseconds(1000));            
}
}
void callJoin() { th.join(); }
void setCounterCopy(int counterCopy) { this->counterCopy = counterCopy; };
};

主要：

int main() {
Producer p;
Subscriber s1("Sub1");
p.addSubscriber(&s1);
s1.callJoin();
p.callJoin();
return 0;
}

lock_guard的目的是防止生产者在将订阅者添加到矢量时同时通知矢量中的订阅者。但是，此例外被抛在通知Exception thrown at 0x59963734 (msvcp140d.dll) in Project1.exe: 0xC0000005: Access violation reading location 0x00000000.的lock_guard 有谁知道此例外的原因可能是什么？如果将互斥锁设置为全局参数，则工作正常。也请随意评论代码的其他问题。线程对我来说是全新的。