/* start the threads; will not return */ thread_pool_start(tpp);
The thread_pool_start() function starts up the thread pool. Each newly created thread allocates a context structure of the type defined by THREAD_POOL_PARAM_T using the context_alloc function we gave above in the attribute structure. They'll then block on the block_func and when the block_func returns, they'll call the handler_func, both of which were also given through the attributes structure. Each thread essentially does the same thing that the single-threaded resource manager above does for its message loop.
From this point on, your resource manager is ready to handle messages. Since we gave the POOL_FLAG_EXIT_SELF flag to thread_pool_create(), once the threads have been started up, pthread_exit() will be called and this calling thread will exit.