osq_wait

函数名称：Get a stable @node->next pointer, either for unlock() or unqueue() purposes.* Can return NULL in case we were the last queued and we updated @lock instead.

函数原型：static inline struct optimistic_spin_node *osq_wait_next(struct optimistic_spin_queue *lock, struct optimistic_spin_node *node, struct optimistic_spin_node *prev)

返回类型：struct optimistic_spin_node

参数：

类型	参数	名称
struct optimistic_spin_queue *	lock
struct optimistic_spin_node *	node
struct optimistic_spin_node *	prev

struct optimistic_spin_node * next = NULL

curr等于We use the value 0 to represent "no CPU", thus the encoded value* will be the CPU number incremented by 1.

old等于如果prev则coded CPU # + 1 value 否则OSQ_UNLOCKED_VAL

循环

如果atomic_read( & * Stores an encoded value of the CPU # of the tail node in the queue. * If the queue is empty, then it's set to OSQ_UNLOCKED_VAL.)恒等于curr且atomic_cmpxchg_acquire( & * Stores an encoded value of the CPU # of the tail node in the queue. * If the queue is empty, then it's set to OSQ_UNLOCKED_VAL., curr, old)恒等于curr则

退出

如果next则

next等于xchg( & next, NULL)

如果next则退出

cpu_relax()

返回:next

**调用者**
名称	描述
osq_lock
osq_unlock

源代码转换工具开放的插件接口	X
支持：c/c++/esqlc/java Oracle/Informix/Mysql 插件可实现：逻辑报告代码生成和批量转换代码

函数逻辑报告