[問題] 看不懂的程式

看板LinuxDev作者kevin1130 (阿樂)時間18年前 (2007/05/18 22:35)推噓1(1推 0噓 0→)

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#include <linux/plist.h> #include <linux/spinlock.h> #ifdef CONFIG_DEBUG_PI_LIST static void plist_check_prev_next(struct list_head *t, struct list_head *p, struct list_head *n) { if (n->prev != p || p->next != n) { printk("top: %p, n: %p, p: %p\n", t, t->next, t->prev); printk("prev: %p, n: %p, p: %p\n", p, p->next, p->prev); printk("next: %p, n: %p, p: %p\n", n, n->next, n->prev); WARN_ON(1); } } static void plist_check_list(struct list_head *top) { struct list_head *prev = top, *next = top->next; plist_check_prev_next(top, prev, next); while (next != top) { prev = next; next = prev->next; plist_check_prev_next(top, prev, next); } } static void plist_check_head(struct plist_head *head) { WARN_ON(!head->lock); if (head->lock) WARN_ON_SMP(!spin_is_locked(head->lock)); plist_check_list(&head->prio_list); plist_check_list(&head->node_list); } #else # define plist_check_head(h) do { } while (0) #endif /** * plist_add - add @node to @head * * @node: &struct plist_node pointer * @head: &struct plist_head pointer */ void plist_add(struct plist_node *node, struct plist_head *head) { struct plist_node *iter; plist_check_head(head); WARN_ON(!plist_node_empty(node)); list_for_each_entry(iter, &head->prio_list, plist.prio_list) { if (node->prio < iter->prio) goto lt_prio; else if (node->prio == iter->prio) { iter = list_entry(iter->plist.prio_list.next, struct plist_node, plist.prio_list); goto eq_prio; } } lt_prio: list_add_tail(&node->plist.prio_list, &iter->plist.prio_list); eq_prio: list_add_tail(&node->plist.node_list, &iter->plist.node_list); plist_check_head(head); } /** * plist_del - Remove a @node from plist. * * @node: &struct plist_node pointer - entry to be removed * @head: &struct plist_head pointer - list head */ void plist_del(struct plist_node *node, struct plist_head *head) { plist_check_head(head); if (!list_empty(&node->plist.prio_list)) { struct plist_node *next = plist_first(&node->plist); list_move_tail(&next->plist.prio_list, &node->plist.prio_list); list_del_init(&node->plist.prio_list); } list_del_init(&node->plist.node_list); plist_check_head(head); } 以上不知道有沒有哪位大大看的懂小弟第一次接觸linux 所以很多地方都不懂不知道有沒有哪位大大可以幫幫忙如果可以的話希望可以寫一點註解實在看不懂謝謝!! -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 220.129.176.151