如何创建和显示线程的属性

Question

该程序创建五个线程,每个线程执行TaskCode函数,该函数将此线程的唯一编号打印到标准输出.

我的问题是如何创建和显示线程的属性？

Answer 1

该pthread_attr_init(3)联机帮助页包含一个示例程序,显示如何检索线程可用的属性.请注意,API不允许指定pthread_t线程标识符,因此只能返回当前线程的属性:

   static void
   display_pthread_attr(pthread_attr_t *attr, char *prefix)
   {
       int s, i;
       size_t v;
       void *stkaddr;
       struct sched_param sp;

       s = pthread_attr_getdetachstate(attr, &i);
       if (s != 0)
           handle_error_en(s, "pthread_attr_getdetachstate");
       printf("%sDetach state        = %s\n", prefix,
               (i == PTHREAD_CREATE_DETACHED) ? "PTHREAD_CREATE_DETACHED" :
               (i == PTHREAD_CREATE_JOINABLE) ? "PTHREAD_CREATE_JOINABLE" :
               "???");

       s = pthread_attr_getscope(attr, &i);
       if (s != 0)
           handle_error_en(s, "pthread_attr_getscope");
       printf("%sScope               = %s\n", prefix,
               (i == PTHREAD_SCOPE_SYSTEM)  ? "PTHREAD_SCOPE_SYSTEM" :
               (i == PTHREAD_SCOPE_PROCESS) ? "PTHREAD_SCOPE_PROCESS" :
               "???");

       s = pthread_attr_getinheritsched(attr, &i);
       if (s != 0)
           handle_error_en(s, "pthread_attr_getinheritsched");
       printf("%sInherit scheduler   = %s\n", prefix,
               (i == PTHREAD_INHERIT_SCHED)  ? "PTHREAD_INHERIT_SCHED" :
               (i == PTHREAD_EXPLICIT_SCHED) ? "PTHREAD_EXPLICIT_SCHED" :
               "???");

       s = pthread_attr_getschedpolicy(attr, &i);
       if (s != 0)
           handle_error_en(s, "pthread_attr_getschedpolicy");
       printf("%sScheduling policy   = %s\n", prefix,
               (i == SCHED_OTHER) ? "SCHED_OTHER" :
               (i == SCHED_FIFO)  ? "SCHED_FIFO" :
               (i == SCHED_RR)    ? "SCHED_RR" :
               "???");

       s = pthread_attr_getschedparam(attr, &sp);
       if (s != 0)
           handle_error_en(s, "pthread_attr_getschedparam");
       printf("%sScheduling priority = %d\n", prefix, sp.sched_priority);

       s = pthread_attr_getguardsize(attr, &v);
       if (s != 0)
           handle_error_en(s, "pthread_attr_getguardsize");
       printf("%sGuard size          = %d bytes\n", prefix, v);

       s = pthread_attr_getstack(attr, &stkaddr, &v);
       if (s != 0)
           handle_error_en(s, "pthread_attr_getstack");
       printf("%sStack address       = %p\n", prefix, stkaddr);
       printf("%sStack size          = 0x%x bytes\n", prefix, v);
   }