C中等待父线程输入时如何创建子线程和阻塞

Question

I am new to the community but I just got quick question about Threading. So I am trying to create a Parent Thread that creates Six Child Threads. So what I have done so far is that, I've created a normal pthread_create which creates an thread but I am not quite sure how to create a child threads.

Creating a Parent Thread that creates Six Child Threads?

//Create a parent thread 
int main()
{ 
//I have created an array of thread to keep track of the threads in a data structure

   pthread_t parentThread[6];

   pthread_create(&parentThread[0], NULL, A, NULL);
    pthread_create(&parentThread[1], NULL, B, NULL);
    pthread_create(&parentThread[2], NULL, C, NULL);
    pthread_create(&parentThread[3], NULL, D, NULL);
    pthread_create(&parentThread[4], NULL, E, NULL);
    pthread_create(&parentThread[5], NULL, F, NULL);
 

}

Block while waiting for input from the Parent Thread

   //Do I just use pthread_join to block while for input from the parent thread? 
   pthread_create(&parentThread[0], NULL, A, NULL);
   pthread_join(parentThread[0], NULL); 
   pthread_create(&parentThread[1], NULL, B, NULL); 
   pthread_join(parentThread[1], NULL); 
   ...... 
   ......

Answer 1

For threading, when trying to block, you use pthread condition variables and mutexes. You must lock a mutex so that threads can't access whatever you lock, then you need a condition variable so that threads will wait until the condition variables are altered. You can think of condition variables as "wait channels". If you are trying to retain the data from a thread you can use join, but if not then I suggest using pthread_exit. It's very hard to tell from your code, but you aren't creating a single parent thread. From the looks of it, you're creating a bunch of threads in main, which I assume are your "child threads". If you're trying to implement what I think, then you need a separate function that you will give to a single thread(parent thread) to execute (which I assume will create other threads). This function will have to return a void pointer to fit the parameters of the pthread_create function. I suggest reading the man page for pthread functions, because this code doesn't really give me the idea that you know what you're trying to implement. If you're trying to communicate between threads, I suggest using pipes.