Function thread_alloc

freebsd/kern/kern_thread.c:713–736

* Allocate a thread. */

 * Allocate a thread.
 */
struct thread *
thread_alloc(int pages)
{
	struct thread *td;
	lwpid_t tid;

	if (!thread_count_inc()) {
		return (NULL);
	}

	tid = tid_alloc();
	td = uma_zalloc(thread_zone, M_WAITOK);
	KASSERT(td->td_kstack == 0, ("thread_alloc got thread with kstack"));
	if (!vm_thread_new(td, pages)) {
		uma_zfree(thread_zone, td);
		tid_free(tid);
		thread_count_dec();
		return (NULL);
	}
	td->td_tid = tid;
	cpu_thread_alloc(td);
	EVENTHANDLER_DIRECT_INVOKE(thread_ctor, td);
	return (td);
}

int
thread_alloc_stack(struct thread *td, int pages)