PT_MAGIC
t->pt_magic = PT_MAGIC;
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
(t1 != NULL) && (t1->pt_magic == PT_MAGIC));
(t2 != NULL) && (t2->pt_magic == PT_MAGIC));
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);
thread->pt_magic == PT_MAGIC);