how to debug thread cpu 100%-优快云博客

本文介绍了一种简单的方法来调试导致CPU使用率达到100%的程序问题。通过一个示例程序，演示了如何使用top工具定位问题线程，使用pstack查看堆栈信息，以及如何生成和利用core dump文件进行更深入的问题定位。

when we write a program, cpu and memory usages are very important to indicate the stability of the program. Once the cpu usage reached 90%, there are some bugs in your program, and you must find the problem. Here is a simply guide to debug with cpu 100%. For example:

void *first_routine (void * args)
{
    while(1)
    {
        int a = 1;
        usleep(1);
    }

    return NULL;
}

int main()
{
    pthread_t thread_first, thread_second;
    pthread_create(&thread_first, NULL, &first_routine, NULL);

    while(1)
    {
        sleep(4);
    }
    return 0;
}

then complile it : gcc debug.c -o debug -lpthread , and run it .

iii) use top tool find the bug thread, top -p $pid -H

iv) use pstack : pstack $tid(bug thread), to look the stack of the bug thread. but pstack can't see the paraments. if you still can't determine the bug line, user gcore to get the program core. (gcore $pid)

v) gdb -c $core.file ./exe , and the use command bt(back trace), then use the paraments to determine the bug code.

转载于:https://www.cnblogs.com/memoryh/p/4104590.html