任务控制块

📚 本节导读

用途: 描述和管理任务的核心数据结构

来源: kernel/include/os_dummy.h:36

一、概述

1.1 概念定义

任务控制块（Task Control Block, TCB）是 OneOS 中用于描述和管理任务的核心数据结构。

1.2 作用

• 保存任务的运行状态
• 管理任务栈
• 维护任务优先级
• 链接到调度队列

二、结构体定义

2.1 完整定义

struct dummy_task
{
    /* begin: The order, position and content cannot be changed */
    void *stack_top_dummy;   /* Point to SP */
    void *stack_begin_dummy; /* The begin address of task stack */
    void *stack_end_dummy;   /* The end address of task stack */

    uint16_t state; /* Task state, refer to OS_TASK_STATE_INIT, OS_TASK_STATE_READY ... */
    /* end:   The order, position and content cannot be changed */

    uint8_t current_priority_dummy; /* Current priority. */
    uint8_t backup_priority_dummy;  /* Backup priority. */

    os_err_t err_code_dummy;      /* Error code. */
    os_err_t switch_retval_dummy; /* Task switch return value, defined in os_errno.h*/

    uint8_t object_inited_dummy;     /* If task object is inited, value is OS_KOBJ_INITED */
    uint8_t object_alloc_type_dummy; /* Indicates whether memory is allocated dynamically or statically,
                                     value is OS_KOBJ_ALLOC_TYPE_STATIC or OS_KOBJ_ALLOC_TYPE_DYNAMIC */
    uint8_t pad[2];

    os_list_node_t resource_node_dummy; /* Node in resource list */
    os_list_node_t task_node_dummy;     /* Node in ready queue or blocking queue */

    os_list_node_t tick_node_dummy;     /* Node in tick queue */
    os_tick_t      tick_timeout_dummy;  /* Timeout */
    os_tick_t      tick_absolute_dummy; /* Absolute time of timeout */

    os_tick_t time_slice_dummy;           /* Task's slice time (unit: tick). */
    os_tick_t remaining_time_slice_dummy; /* Task's remaining slice time (unit: tick). */

    os_list_node_t *block_list_head_dummy; /* Where the task is blocked at */
    os_bool_t       is_wake_prio_dummy;    /* The wake type to task at block_list_head, according to priority or not */

#if defined(OS_USING_EVENT)
    uint32_t event_set_dummy;
    uint32_t event_option_dummy;
#endif

#if defined(OS_USING_MUTEX)
    os_list_node_t hold_mutex_list_head_dummy;
#endif

#if defined(OS_USING_SMP)
    int32_t cpu_index_dummy; /* The number of the cpu that the task is running on.
                             -1 means the task is not running. */
    int32_t cpu_affinity_dummy;

    os_list_node_t join_node_dummy; /* Node in join queue */
#endif

    os_ubase_t swap_data_dummy;

    void (*cleanup_dummy)(void *user_data); /* The cleanup function is provided by the user */
    void *user_data_dummy;                  /* Private user data beyond this task. */

    char name_dummy[OS_NAME_MAX + 1]; /* Task name */

#if defined(OS_USING_CPU_MONITOR)
    cpu_use_info_t usage_info_dummy;
#endif
};

typedef struct dummy_task dummy_task_t;
typedef dummy_task_t *os_task_id;

三、关键字段说明

3.1 不可变字段（顺序和位置不能改变）

字段	类型	说明
stack_top_dummy	void *	栈顶指针（SP）
stack_begin_dummy	void *	栈起始地址
stack_end_dummy	void *	栈结束地址
state	uint16_t	任务状态

3.2 优先级相关

字段	类型	说明
current_priority_dummy	uint8_t	当前优先级
backup_priority_dummy	uint8_t	备份优先级（用于优先级继承）

3.3 链表节点

字段	类型	说明
resource_node_dummy	os_list_node_t	资源列表节点
task_node_dummy	os_list_node_t	就绪队列或阻塞队列节点
tick_node_dummy	os_list_node_t	时间队列节点

3.4 时间相关

字段	类型	说明
tick_timeout_dummy	os_tick_t	超时时间
tick_absolute_dummy	os_tick_t	绝对超时时间
time_slice_dummy	os_tick_t	任务时间片
remaining_time_slice_dummy	os_tick_t	剩余时间片

3.5 用户相关

字段	类型	说明
cleanup_dummy	函数指针	清理回调函数
user_data_dummy	void *	用户私有数据
name_dummy	char[]	任务名称

四、相关类型

4.1 os_task_id

typedef dummy_task_t *os_task_id;

说明: 任务 ID 类型，实际上是任务控制块指针。