用多线程修改结构C编程

Question

I have been all over the internet with no one directly answering this question. So I have a struct in my main process and I need multiple threads to modify it. I know that I am going to need mutexs to protect the data, but is there any way to share pointers with out passing it as an arg in pthread_create. I understand that threads share the same memory address and there for if I allocate in one the other should have access to it. But with out passing a pointer how do the threads know that a certain pointer already exists.

Answer 1

The typical answer to your question is that rather than passing the pointer directly to the thread when you call pthread_create , you instead pass a pointer to some higher-level structure that serves as your communication with the thread.

For example, say you are writing a network server that receives requests from clients and then needs to process those requests. The threads that process requests from clients would typically be passed the address of some kind of waitable queue. When a thread receives a request from a client, it would put that request in the waitable queue. The threads that process client requests are already waiting for things to be put on that queue, and they get the information about the request they need to process from the queue.