c++ - 尝试显示我的线程的优先级时出现分段错误

Question

我创建了两个线程，我想在创建它们后查看它们的优先级：- 为此，我编写了以下代码：-

   #include <iostream>
   #include <unistd.h>
   #include <pthread.h>
   #include <sched.h>
   #include <string.h>
   #include <errno.h>
   int main()
   { //something
     struct sched_param main_param, t1_param, t2_param;
     pthread_t t1, t2;
      int *sched1, *sched2;
     if (pthread_create(&t1, NULL, fn1, NULL) != 0) // inside fn1 thread sleeps in loop
      {
        std::cout << "couldn't create t1" << std::endl;
        return -1;
       }
     if (pthread_create(&t2, NULL, fn2, NULL) != 0)  //inside fn2 thread sleeps in loop
      {
        std::cout << "couldn't create t2" << std::endl;
        return -1;
      }

   if (pthread_getschedparam(t1, sched1, &t1_param) != 0) 
     {
       std::cout << "error setting priority for T1: (" << errno << "), " << 
        strerror(errno) << std::endl;
     }
  std::cout << "t1 thread will have a prio of " << t1_param.sched_priority << std::endl;
   if (pthread_getschedparam(t1, sched2, &t1_param) != 0) 
     {
       std::cout << "error setting priority for T1: (" << errno << "), " << 
       strerror(errno) << std::endl;
     }
   std::cout << "t2 thread will have a prio of " << t2_param.sched_priority <<std::endl;

 // something 
 } 

只有当我添加与pthread_getschedparam我得到分段错误相关的代码时，否则代码工作正常。我在这里做错了吗？我什至尝试替换arhumentsched1并sched2通过NULL

Answer 1

您声明了指针sched1和sched2类型int*，但从未初始化这些指针。您需要分配int变量，然后将指针传递给这些变量。

像这样：

int sched1, sched2;
.....
if (pthread_getschedparam(t1, &sched1, ....

Answer 2

整数 *sched1;
pthread_getschedparam(t1, sched1, &t1_param); // sched1 是未初始化的指针！

考虑这个变化：

int sched1;
pthread_getschedparam(t1, &sched1, &t1_param);