Common Kernel Datatypes

Linked Lists : /include/linux/list.h

struct list_head {

  struct list_head *next, *prev;

  };

 

#define list_for_each_safe(pos, n, head) /

  for (pos = (head)->next, n = pos->next; pos != (head); /

  pos = n, n = pos->next)

 #define list_for_each_entry(pos, head, member) /

  for (pos = list_entry((head)->next, typeof(*pos), member); /

  prefetch(pos->member.next), &pos->member != (head); /

  pos = list_entry(pos->member.next, typeof(*pos), member))

  struct hlist_head {

  struct hlist_node *first;

  };

  struct hlist_node {

  struct hlist_node *next, **pprev;

  };

注意：pprev可以理解成向list的prev一样，是一个指向hlist_node的指针，又由于hlist_node的第一个元素next是一个指向 hlist_node的指针，pprev也是一个指向next的指针，即pprev是一个指向hlist_node的指针的指针。

 #define HLIST_HEAD_INIT { .first = NULL }

 #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL }

  

  These list constructs are used throughout the Linux kernel code in work queues, as we've seen in the scheduler, the timer, and the module-handling routines.

Trees

The red black tree used in Linux memory management is similar to an AVL tree. A red black tree is a balanced binary tree in which each node has a red or black color attribute.

Here are the rules for a red black tree:

• All nodes are either red or black.

• If a node is red, both its children are black.

• All leaf nodes are black.

• When traversing from the root node to a leaf, each path contains the same number of black nodes.

Both AVL and red black trees have a big-O of O log(n)