Allocate a thread pool handle

/* allocate a thread pool handle */
if((tpp = thread_pool_create(&pool_attr, 
                             POOL_FLAG_EXIT_SELF)) == NULL) {
    fprintf(stderr, "%s: Unable to initialize thread pool.\n",
    return EXIT_FAILURE;

The thread pool handle is used to control the thread pool. Among other things, it contains the given attributes and flags. The thread_pool_create() function allocates and fills in this handle.