Zephyr 内核数据结构

struct _dnode {
	union {
		struct _dnode *head; /* ptr to head of list (sys_dlist_t) */
		struct _dnode *next; /* ptr to next node    (sys_dnode_t) */
	};
	union {
		struct _dnode *tail; /* ptr to tail of list (sys_dlist_t) */
		struct _dnode *prev; /* ptr to previous node (sys_dnode_t) */
	};
}

typedef struct _dnode sys_dlist_t;
typedef struct _dnode sys_dnode_t;

struct rbnode {
 struct rbnode *children[2];
};）

struct rbtree {
 struct rbnode *root;              //根节点
 rb_lessthan_t lessthan_fn;        //比较函数
 int max_depth;
#ifdef CONFIG_MISRA_SANE
 struct rbnode *iter_stack[Z_MAX_RBTREE_DEPTH];
 unsigned char iter_left[Z_MAX_RBTREE_DEPTH];
#endif
};

/* can be used for creating 'dummy' threads, e.g. for pending on objects */
struct _thread_base {

	/* this thread's entry in a ready/wait queue */
	union {
		sys_dnode_t qnode_dlist;
		struct rbnode qnode_rb;
	};

	/* wait queue on which the thread is pended (needed only for
	 * trees, not dumb lists)
	 */
	_wait_q_t *pended_on;                             //挂起的任务队列

	/* user facing 'thread options'; values defined in include/kernel.h */
	u8_t user_options;

	/* thread state */
	u8_t thread_state;                               //线程状态

	/*
	 * scheduler lock count and thread priority
	 *
	 * These two fields control the preemptibility of a thread.
	 *
	 * When the scheduler is locked, sched_locked is decremented, which
	 * means that the scheduler is locked for values from 0xff to 0x01. A
	 * thread is coop if its prio is negative, thus 0x80 to 0xff when
	 * looked at the value as unsigned.
	 *
	 * By putting them end-to-end, this means that a thread is
	 * non-preemptible if the bundled value is greater than or equal to
	 * 0x0080.
	 */
	union {
		struct {
#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__            //对preempt字段大小端处理
			u8_t sched_locked;
			s8_t prio;
#else /* LITTLE and PDP */
			s8_t prio;
			u8_t sched_locked;
#endif
		};
		u16_t preempt;                  //preempt 包含prio和sched_locked两个字段，用于控制线程的抢占性
	};

#ifdef CONFIG_SCHED_DEADLINE
	int prio_deadline;
#endif

	u32_t order_key;

#ifdef CONFIG_SMP                                   //注：多核CPU支持才需要
	/* True for the per-CPU idle threads */
	u8_t is_idle;

	/* CPU index on which thread was last run */
	u8_t cpu;

	/* Recursive count of irq_lock() calls */
	u8_t global_lock_count;

#endif

#ifdef CONFIG_SCHED_CPU_MASK
	/* "May run on" bits for each CPU */
	u8_t cpu_mask;
#endif

	/* data returned by APIs */
	void *swap_data;

#ifdef CONFIG_SYS_CLOCK_EXISTS
	/* this thread's entry in a timeout queue */
	struct _timeout timeout;
#endif
};

/**
 * @ingroup thread_apis
 * Thread Structure
 */
struct k_thread {

	struct _thread_base base;

	/** defined by the architecture, but all archs need these */
	struct _callee_saved callee_saved;

	/** static thread init data */
	void *init_data;

	/**
	 * abort function
	 * @req K-THREAD-002
	 * */
	void (*fn_abort)(void);

#if defined(CONFIG_THREAD_MONITOR)
	/** thread entry and parameters description */
	struct __thread_entry entry;

	/** next item in list of all threads */
	struct k_thread *next_thread;
#endif

#if defined(CONFIG_THREAD_NAME)
	/** Thread name */
	char name[CONFIG_THREAD_MAX_NAME_LEN];
#endif

#ifdef CONFIG_THREAD_CUSTOM_DATA
	/** crude thread-local storage */
	void *custom_data;
#endif

#ifdef CONFIG_THREAD_USERSPACE_LOCAL_DATA
	struct _thread_userspace_local_data *userspace_local_data;
#endif

#ifdef CONFIG_ERRNO
#ifndef CONFIG_USERSPACE
	/** per-thread errno variable */
	int errno_var;
#endif
#endif

#if defined(CONFIG_THREAD_STACK_INFO)
	/** Stack Info */
	struct _thread_stack_info stack_info;
#endif /* CONFIG_THREAD_STACK_INFO */

#if defined(CONFIG_USERSPACE)
	/** memory domain info of the thread */
	struct _mem_domain_info mem_domain_info;
	/** Base address of thread stack */
	k_thread_stack_t *stack_obj;
	/** current syscall frame pointer */
	void *syscall_frame;
#endif /* CONFIG_USERSPACE */


#if defined(CONFIG_USE_SWITCH)
	/* When using __switch() a few previously arch-specific items
	 * become part of the core OS
	 */

	/** z_swap() return value */
	int swap_retval;

	/** Context handle returned via arch_switch() */
	void *switch_handle;
#endif
	/** resource pool */
	struct k_mem_pool *resource_pool;

	/** arch-specifics: must always be at the end */
	struct _thread_arch arch;
};