linux核心分析--核心中的資料結構之紅黑樹(續)
阿新 • • 發佈:2019-01-08
#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檔案與佇列的示例中一樣。
Makefile:
obj-m += rbtree.o rbtree-objs := testrbtree.o kn_common.o #generate the path CURRENT_PATH:=$(shell pwd) #the current kernel version number LINUX_KERNEL:=$(shell uname -r) #the absolute path LINUX_KERNEL_PATH:=/usr/src/kernels/$(LINUX_KERNEL) #complie object all: make -C $(LINUX_KERNEL_PATH) M=$(CURRENT_PATH) modules rm -rf modules.order Module.symvers .*.cmd *.o *.mod.c .tmp_versions *.unsigned #clean clean: rm -rf modules.order Module.symvers .*.cmd *.o *.mod.c *.ko .tmp_versions *.unsigned
安裝,解除安裝核心模組以及檢視核心模組的執行結果:
insmod rbtree.ko
rmmod rbtree
dmesg | tail -135