将 arguments 传递给 pthread_create() 时出错

Question

I am trying to create a Thread-Pool-like structure for pthread s to do identical jobs for network programming, which is very similar to this question . However, a problem occurred as I tried to pass the arguments of the init() method to pthread_create() .

Code

class ThreadPool{
    public:
        BlockingQueue socket_bq;
        pthread_mutex_t* threads[THREAD_NUM];   // store the pointer of threads

        ThreadPool();
        void init(pthread_attr_t* attr, void*start_routine(void*), void* arg);
};

void ThreadPool::init(pthread_attr_t* attr, void*start_routine(void*), void* arg){
    // create threads
    for(int i = 0; i < THREAD_NUM; i++){
        if(pthread_create(threads[i], attr, start_routine, arg)!=0){
            fprintf(stderr, "Thread Pool Init: falied when creatng threads");
            exit(1);
        }
    }
}

Error message

error: no matching function for call to 'pthread_create' if(pthread_create(threads[i], attr, start_routine, arg).=0){ ^~~~~~~~~~~~~~ /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/pthread:h:329:5: note: candidate function not viable, no known conversion from 'pthread_mutex_t *' (aka '_opaque_pthread_mutex_t *') to 'pthread_t _Nullable * _Nonnull' (aka '_opaque_pthread_t **') for 1st argument int pthread_create(pthread_t _Nullable * _Nonnull __restrict. ^ 1 error generated.

Answer 1

The definition of threads is likely incorrect. It should be:

pthread_t* threads[THREAD_NUM];