Linux线程调度实验

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <pthread.h>
#include <time.h>
#include <stdlib.h>
#include <errno.h>
#define _GNU_SOURCE
#define handle_error_en(en, msg) \
               do { errno = en; perror(msg); exit(EXIT_FAILURE); } while (0)
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          = %zu 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%zx bytes\n", prefix, v);  
}
void* computing(void* arg){
    int s;
    pthread_attr_t gattr;
    s = pthread_getattr_np(pthread_self(), &gattr);
    if (s != 0)
        handle_error_en(s, "pthread_getattr_np");
    printf("Thread attributes:\n");
    display_pthread_attr(&gattr, "\t");
    pause();
    pthread_exit(0);
}
int main(){
    pthread_t tid;
    pthread_attr_t attr;
    pthread_attr_init(&attr);
    // 线程创建函数
    pthread_create(&tid, &attr, computing, NULL);
    // 等待指定的线程结束
    pthread_join(tid,NULL);
    return 0;
}