linux内核分析--内核中的数据结构之红黑树（续）

#include<linux/rbtree.h>#include <linux/string.h>#include "kn_common.h"MODULE_LICENSE("Dual BSD/GPL");struct student{    int id;    char* name;    struct rb_node node;};static int insert_student(struct student*, struct rb_root*);static int remove_student(struct student*, struct rb_root*);static int display_student(struct rb_root*, int);static void display_student_from_small(struct rb_node*);static void display_student_from_big(struct rb_node*);static void print_student(struct student*);static int testrbtree_init(void){#define N 10    struct rb_root root = RB_ROOT;    struct student *stu[N];    char tmp_name[5] = {'w', 'y', 'b', '0', '\0'};    int i;    // init N struct student    for (i=0; i<N; i++)    {        stu[i] = kmalloc(sizeof(struct student), GFP_KERNEL);        stu[i]->id = i;        stu[i]->name = kmalloc(sizeof(char)*5, GFP_KERNEL);        tmp_name[3] = (char)(i+48);        strcpy(stu[i]->name, tmp_name);        // stu_name[3] = (char)(i+48);        stu[i]->node.rb_left = NULL;        stu[i]->node.rb_right = NULL;    }    for (i=0; i < N; ++i)    {        printk(KERN_ALERT "id=%d   name=%s\n", stu[i]->id, stu[i]->name);    }        // add N student to rbtree    print_current_time(0);    for (i=0; i < N; i++)        insert_student(stu[i], &root);    // display all students    printk(KERN_ALERT "print from small to big!\n");    display_student(&root, -1);    printk(KERN_ALERT "print from big to small!\n");    display_student(&root, 1);    // delete student 8    remove_student(stu[7], &root);    display_student(&root, -1);        // free all student    for (i=0; i<N; ++i)    {        kfree(stu[i]->name);        kfree(stu[i]);    }                        return 0;}static int insert_student(struct student* stu, struct rb_root* root){    struct rb_node* parent;    struct rb_node* tmp_rb;    struct student* tmp_stu;    /* first time to insert node */    if (!root->rb_node)    {        root->rb_node = &(stu->node);        rb_set_parent(&(stu->node), NULL);        rb_set_black(&(stu->node));        return 0;    }    /* find where to insert node */    tmp_rb = root->rb_node;    while(tmp_rb)    {        parent = tmp_rb;        tmp_stu = rb_entry(tmp_rb, struct student, node);        if (tmp_stu->id > stu->id)            tmp_rb = parent->rb_left;        else if (tmp_stu->id < stu->id)            tmp_rb = parent->rb_right;        else            break;    }    /* the student's id  is already in the rbtree */    if (tmp_rb)    {        printk(KERN_ALERT "this student has been inserted!\n");        return 1;    }        if (tmp_stu->id > stu->id)        parent->rb_left = &(stu->node);    else        parent->rb_right = &(stu->node);    rb_set_parent(&(stu->node), parent);    rb_insert_color(&(stu->node), root);        return 0;}static int remove_student(struct student* stu, struct rb_root* root){    rb_erase(&(stu->node), root);        return 0;}static int display_student(struct rb_root *root, int order){    if (!root->rb_node)        return 1;    if (order < 0)        display_student_from_small(root->rb_node);    else        display_student_from_big(root->rb_node);        return 0;}static void display_student_from_small(struct rb_node* node){    struct student *tmp_stu;        if (node)    {        display_student_from_small(node->rb_left);        tmp_stu = rb_entry(node, struct student, node);        print_student(tmp_stu);        display_student_from_small(node->rb_right);    }}static void display_student_from_big(struct rb_node* node){    struct student *tmp_stu;        if (node)    {        display_student_from_big(node->rb_right);        tmp_stu = rb_entry(node, struct student, node);        print_student(tmp_stu);        display_student_from_big(node->rb_left);    }}static void print_student(struct student* stu){    printk(KERN_ALERT "=========================\n");    print_current_time(0);    printk(KERN_ALERT "id=%d\tname=%s\n", stu->id, stu->name);    printk(KERN_ALERT "=========================\n");}static void testrbtree_exit(void){    printk(KERN_ALERT "*************************\n");    print_current_time(0);    printk(KERN_ALERT "testrbtree is exited!\n");    printk(KERN_ALERT "*************************\n");        }module_init(testrbtree_init);module_exit(testrbtree_exit);

注：其中用到的kn_common.h和kn_common.c文件与队列的示例中一样。

Makefile：

obj-m += rbtree.orbtree-objs := testrbtree.o kn_common.o#generate the pathCURRENT_PATH:=$(shell pwd)#the current kernel version numberLINUX_KERNEL:=$(shell uname -r)#the absolute pathLINUX_KERNEL_PATH:=/usr/src/kernels/$(LINUX_KERNEL)#complie objectall:    make -C $(LINUX_KERNEL_PATH) M=$(CURRENT_PATH) modules    rm -rf modules.order Module.symvers .*.cmd *.o *.mod.c .tmp_versions *.unsigned#cleanclean:    rm -rf modules.order Module.symvers .*.cmd *.o *.mod.c *.ko .tmp_versions *.unsigned

安装,卸载内核模块以及查看内核模块的运行结果：

insmod rbtree.kormmod rbtreedmesg | tail -135