双向链表完结

Chapter11/ds/line/list/linklist/double/kernel/list.h

@@ -0,0 +1,56 @@
+#ifndef LINUX_LIST_H__
+#define LINUX_LIST_H__
+
+struct list_head
+{
+    struct list_head *prev;
+    struct list_head *next;
+};
+
+#define LIST_HEAD_INIT(name) \
+    {                        \
+        &(name), &(name)     \
+    }
+
+#define LIST_HEAD(name) struct list_head name = LIST_HEAD_INIT(name)
+
+static inline void __list_add(struct list_head *new,
+                              struct list_head *prev,
+                              struct list_head *next)
+{
+    next->prev = new;
+    new->next  = next;
+    new->prev  = prev;
+    prev->next = new;
+}
+
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+    __list_add(new, head, head->next);
+}
+
+#define __list_for_each(pos, head) \
+    for (pos = (head)->next; pos != (head); pos = pos->next)
+
+
+// 这个内核的链表仅包含两个指针，用来被数据包含
+// 希望由嵌入的指针找回到完整的结构体
+
+/**
+ * ptr->cur
+ * type->struct score_st
+ * member->node
+ *
+ */
+
+#define offsetof(TYPE, MEMBER) ((size_t) & ((TYPE *)0)->MEMBER)
+
+#define container_of(ptr, type, member)                    \
+    ({                                                     \
+        const typeof(((type *)0)->member) *__mptr = (ptr); \
+        (type *)((char *)__mptr - offsetof(type, member)); \
+    })
+
+#define list_entry(ptr, type, member) container_of(ptr, type, member)
+
+#endif

Chapter11/ds/line/list/linklist/double/kernel/main.c

@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "list.h"
+
+#define NAMESIZE 32
+
+struct score_st
+{
+    int              id;
+    char             name[NAMESIZE];
+    struct list_head node;
+    int              math;
+    int              chinese;
+};
+
+static void print_s(struct score_st *d)
+{
+    printf("%d %s %d %d \n", d->id, d->name, d->math, d->chinese);
+}
+
+int main()
+{
+    int               i;
+    struct score_st  *datap;
+    struct list_head *cur;
+
+    LIST_HEAD(head);
+
+    for (i = 0; i < 7; i++)
+    {
+        datap = malloc(sizeof(*datap));
+        if (NULL == datap)
+            exit(1);
+
+        datap->id = i;
+        snprintf(datap->name, NAMESIZE, "stu%d", i);
+        datap->math    = rand() % 100;
+        datap->chinese = rand() % 100;
+
+        list_add(&datap->node, &head);
+    }
+
+    __list_for_each(cur, &head)
+    {
+        datap = list_entry(cur, struct score_st, node);
+        print_s(datap);
+    }
+
+
+    __list_for_each(cur, &head)
+    {
+        datap = list_entry(cur, struct score_st, node);
+        if (5 == datap->id)
+            break;
+    }
+    if (cur == &head)
+        printf("Can not find!\n");
+    else
+        print_s(datap);
+
+    exit(0);
+}

Chapter11/ds/line/list/linklist/double/kernel/makefile

@@ -0,0 +1,31 @@
+# 方便起见一般都会先定义编译器链接器
+CC = gcc 
+LD = gcc
+
+# 正则表达式表示目录下所有.c文件，相当于：SRCS = main.c a.c b.c
+SRCS = $(wildcard *.c)
+
+# OBJS表示SRCS中把列表中的.c全部替换为.o，相当于：OBJS = main.o a.o b.o
+OBJS = $(patsubst %c, %o, $(SRCS))
+
+# 可执行文件的名字
+TARGET = main
+
+# .PHONE伪目标，具体含义百度一下一大堆介绍
+.PHONY:all clean
+
+# 要生成的目标文件
+all: $(TARGET)
+
+# 第一行依赖关系：冒号后面为依赖的文件，相当于Hello: main.o a.o b.o
+# 第二行规则：$@表示目标文件，$^表示所有依赖文件，$<表示第一个依赖文件
+$(TARGET): $(OBJS)
+	$(LD) -o $@ $^
+
+# 上一句目标文件依赖一大堆.o文件，这句表示所有.o都由相应名字的.c文件自动生成
+%.o:%.c
+	$(CC) -c $^
+
+# make clean删除所有.o和目标文件
+clean:
+	rm -f $(OBJS) $(TARGET)