passing thread data structure

[Immortal-guard]

hi and thanks for this great job
I have a structure that im allocating memory for each thread and finally each thread has their own data structure for executing function
but I don't know how to pass their own thread_data while the task is in queue and I don't know which thread will execute it

struct thread_data
{
    /* some stuff */
};

void func(thread_data* data, int x)
{
	/* some stuff */
}

int main(int argc, char** argv)
{
	int num_thread = 4;

	thread_data* data = (thread_data*)malloc(num_thread * sizeof(thread_data)); // struct array for each thread
	if (data == NULL) return 1;

	thread_pool pool(num_thread);

	for (auto i = 1; i <= 100; i++)
		pool.push_task(func, &data[0], i); // !HERE! &data[0], &data[1], ... ?

	return 0;
}

if two or more threads are using the same structure, program crashes, they should have their own unique structure. How to solve this problem?

[bshoshany]

Sounds like you're having issues with data races. See a discussion here under "Threads and data races". There are several standard ways to handle this, such as using std::atomic or std::mutex. Both are used in the thread pool's code, so you are welcome to check it out as an example.