c、linux - 在内核中使用 pthread.h

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我正在尝试测试 9*9 数独问题的有效性，结果应通过 printk(KERN_INFO "blablabla") 打印。我尝试了两种方法来编译我的c文件，make和gcc myfile.c myfile -o -lpthread 。然而，它们都不起作用。

当我打电话make时它给我带来了一个 fatal error : pthread.h:没有这样的文件或目录，但它就在路径 /usr/include 中.

然后我从网上找到了一些推荐，所以我尝试了gcc这次。不幸的是，我在调用gcc myfile.c myfile -o -lpthread后遇到了一堆错误。比如

/usr/include/linux/list.h: In function 'INIT_LIST_HEAD': /usr/include/linux/list.h:27:17: error: dereferencing pointer to incomplete type 'struct list_head'

和

error: unknown type name 'bool' ,

仅举几例。关键是我在通过 sudo apt-get update -y 升级我的软件之后遇到了这些错误.

代码如下:

#include <pthread.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>

typedef struct
{
    int row;
    int col;
    int (* board)[9];
} parameters;

void * find_rows(void * params);

void * find_cols(void * params);

void * check_valid(void * params);

/***************
 * ENTRY POINT
 **************/
int thread_init(void)
{
    // ====== Create the board =======
    int board[9][9] = {
            {6, 2, 4, 5, 3, 9, 1, 8, 7},
            {5, 1, 9, 7, 2, 8, 6, 3, 4},
            {8, 3, 7, 6, 1, 4, 2, 9, 5},
            {1, 4, 3, 8, 6, 5, 7, 2, 9},
            {9, 5, 8, 2, 4, 7, 3, 6, 1},
            {7, 6, 2, 3, 9, 1, 4, 5, 8},
            {3, 7, 1, 9, 5, 6, 8, 4, 2},
            {4, 9, 6, 1, 8, 2, 5, 7, 3},
            {2, 8, 5, 4, 7, 3, 9, 1, 6}
        };

    /*int  i, j = 0;
    size_t count;
    int board[9][9];
    char *line = (char *) malloc(100);

    FILE *file;
    file = fopen("test.txt", "r");

    while(getline(&line, &count, file) != -1) {
        for (count > 0; count--; j++)
            sscanf(line, "%d", &board[i][j]);
        i++;
    }*/

    parameters * data = (parameters *) malloc(sizeof(parameters));
    data->row = 0;
    data->col = 0;
    data->board = board;

    // ====== Create the parameters for the 3x3 threads ======

    // First 3x3
    parameters * data1 = (parameters *) malloc(sizeof(parameters));
    data1->row = 0;
    data1->col = 0;
    data1->board = board;

    // Second 3x3
    parameters * data2 = (parameters *) malloc(sizeof(parameters));
    data2->row = 0;
    data2->col = 3;
    data2->board = board;

    // Third 3x3
    parameters * data3 = (parameters *) malloc(sizeof(parameters));
    data3->row = 0;
    data3->col = 6;
    data3->board = board;

    // Fourth 3x3
    parameters * data4 = (parameters *) malloc(sizeof(parameters));
    data4->row = 3;
    data4->col = 0;
    data4->board = board;

    // Fifth 3x3
    parameters * data5 = (parameters *) malloc(sizeof(parameters));
    data5->row = 3;
    data5->col = 3;
    data5->board = board;

    // Sixth 3x3
    parameters * data6 = (parameters *) malloc(sizeof(parameters));
    data6->row = 3;
    data6->col = 6;
    data6->board = board;

    // Seventh 3x3
    parameters * data7 = (parameters *) malloc(sizeof(parameters));
    data7->row = 6;
    data7->col = 0;
    data7->board = board;

    // Eighth 3x3
    parameters * data8 = (parameters *) malloc(sizeof(parameters));
    data8->row = 6;
    data8->col = 3;
    data8->board = board;

    // Ninth 3x3
    parameters * data9 = (parameters *) malloc(sizeof(parameters));
    data9->row = 6;
    data9->col = 6;
    data9->board = board;

    // ====== Create the threads ======
    pthread_t thread_rows, thread_cols, thread1, thread2, thread3, thread4, thread5, thread6, thread7, thread8, thread9;

    // ====== Create the return values for the threads ======
    void * all_rows;
    void * all_cols;
    void * square1;
    void * square2;
    void * square3;
    void * square4;
    void * square5;
    void * square6;
    void * square7;
    void * square8;
    void * square9;

    // ====== Initialize the threads ======
    pthread_create(&thread_rows, NULL, find_rows, (void *) data);
    pthread_create(&thread_cols, NULL, find_cols, (void *) data);
    pthread_create(&thread1, NULL, check_valid, (void *) data1);
    pthread_create(&thread2, NULL, check_valid, (void *) data2);
    pthread_create(&thread3, NULL, check_valid, (void *) data3);
    pthread_create(&thread4, NULL, check_valid, (void *) data4);
    pthread_create(&thread5, NULL, check_valid, (void *) data5);
    pthread_create(&thread6, NULL, check_valid, (void *) data6);
    pthread_create(&thread7, NULL, check_valid, (void *) data7);
    pthread_create(&thread8, NULL, check_valid, (void *) data8);
    pthread_create(&thread9, NULL, check_valid, (void *) data9);

    // ======= Wait for all threads to finish their tasks =======
    pthread_join(thread_rows, &all_rows);
    pthread_join(thread_cols, &all_cols);
    pthread_join(thread1, &square1);
    pthread_join(thread2, &square2);
    pthread_join(thread3, &square3);
    pthread_join(thread4, &square4);
    pthread_join(thread5, &square5);
    pthread_join(thread6, &square6);
    pthread_join(thread7, &square7);
    pthread_join(thread8, &square8);
    pthread_join(thread9, &square9);

    // ====== Check whether the Sudoku Puzzle was solved ======
    if (    (int)(uintptr_t) all_rows == 1 &&
            (int)(uintptr_t) all_cols == 1 &&
            (int)(uintptr_t) square1 == 1 &&
            (int)(uintptr_t) square2 == 1 &&
            (int)(uintptr_t) square3 == 1 &&
            (int)(uintptr_t) square4 == 1 &&
            (int)(uintptr_t) square5 == 1 &&
            (int)(uintptr_t) square6 == 1 &&
            (int)(uintptr_t) square7 == 1 &&
            (int)(uintptr_t) square8 == 1 &&
            (int)(uintptr_t) square9 == 1 )
    {
        printf("The Sudoku Puzzle is solved!\n");
    }
    else
    {
        printf("The Sudoku Puzzle is NOT solved.\n");
    }

    return 0;
}

void * find_rows(void * params) {
    parameters * data = (parameters *) params;
    int startRow = data->row;
    int startCol = data->col;
    for (int i = startRow; i < 9; ++i) {
        int row[10] = {0};
        for (int j = startCol; j < 9; ++j) {
            int val = data->board[i][j];
            if (row[val] != 0) {
                return (void *) 0;
            }
            else{
                row[val] = 1;
            }
        }
    }
    return (void *) 1;
}

void * find_cols(void * params) {
    parameters * data = (parameters *) params;
    int startRow = data->row;
    int startCol = data->col;
    for (int i = startCol; i < 9; ++i) {
        int col[10] = {0};
        for (int j = startRow; j < 9; ++j) {
            int val = data->board[j][i];
            if (col[val] != 0) {
                return (void *) 0;
            }
            else{
                col[val] = 1;
            }
        }
    }
    return (void *) 1;
}

void * check_valid(void * params) {
    parameters * data = (parameters *) params;
    int startRow = data->row;
    int startCol = data->col;
    int saved[10] = {0};
    for (int i = startRow; i < startRow + 3; ++i) {
        for (int j = startCol; j < startCol + 3; ++j) {
            int val = data->board[i][j];
            if (saved[val] != 0) {
                return (void *) 0;
            }
            else{
                saved[val] = 1;
            }
        }
    }
    return (void *) 1;
}

void thread_exit(void)
{
    printk(KERN_INFO "Removing Module\n");
}

module_init( thread_init );
module_exit( thread_exit );

我只是不知道出了什么问题......也不知道如何调试。

提前致谢。

Answer 1

不要使用<pthread.h>在内核代码中

您对 kernel 之间的差异感到非常困惑代码和应用程​​序 ( user-space ) 代码。您应该避免编写内核代码。了解 CPU modes .

^{(在敢于编写一行内核代码，甚至是微不足道的 kernel module 之前，您需要成为 C 语言和 Linux 应用程序编程的大师)}

内核代码适用于类似 device drivers 的内容，不适用于数独。当然，您不能在内核代码中使用 pthread :内核通过提供 clone(2) 来实现线程。应用程序的系统调用。 POSIX C 库 - 您的 libc.so ，通常是 GNU glibc - 正在实现pthreads(7)在许多人的帮助下system calls -列于syscalls(2) -，包括clone和 futex(7) .

阅读 Operating Systems: Three easy pieces 更多地了解操作系统的作用。

I just can't figure out what went wrong

你的整个方法都是错误的。 扔掉你的代码。

<小时/>

学习多线程 POSIX 应用程序编程

阅读ALP (和 intro(2) 然后 intro(3) ...)学习如何编写 Linux 应用程序代码。

花几天时间阅读一些内容 pthread tutorial .

然后，使用 Posix 线程编写一些应用程序(因此具有 main 并调用 pthread_create(3) 和 pthread_join(3) )来解决您的数独问题。您可能需要mutexes和 conditional variables用于同步。

如果您想学习内核编程，请从一些更简单的任务开始。在此之前，请非常熟练地掌握 Linux 应用程序编程。

^{(添加 kernel threads 确实很困难；它们根本不是 POSIX 线程。将其留给高级内核开发人员；先学习用户空间线程编程，这已经够困难的了。)}

所以放弃你的内核编程想法吧。重点学习 C 编程和 POSIX 应用程序编程(需要 many 年)。

编译您的 ( user-space ) 代码，其中包含所有警告和调试信息: gcc -Wall -Wextra -g与 GCC 。改进它以获得没有警告。学习使用 gcc compiler , build automation类似 GNU make 的工具或 ninja ， gdb debugger , valgrind , address sanitizers及其他instrumentation options .