响应式网站导航栏,微信引流推广,wordpress自定义登录界面,自建企业邮箱链表和任务管理是freertos 的核心#xff0c;先分析链表源码#xff0c;freertos的链表是双向环形链表#xff0c;定义与数据结构在list.h中#xff0c;表项的初始化#xff0c;插入与删除在list.c中。 数据结构
一、表项数据结构
struct xLIST_ITEM
{listFIRST_LIST_IT…链表和任务管理是freertos 的核心先分析链表源码freertos的链表是双向环形链表定义与数据结构在list.h中表项的初始化插入与删除在list.c中。 数据结构
一、表项数据结构
struct xLIST_ITEM
{listFIRST_LIST_ITEM_INTEGRITY_CHECK_VALUEconfigLIST_VOLATILE TickType_t xItemValue;struct xLIST_ITEM * configLIST_VOLATILE pxNext;struct xLIST_ITEM * configLIST_VOLATILE pxPrevious; void * pvOwner;struct xLIST * configLIST_VOLATILE pxContainer;listSECOND_LIST_ITEM_INTEGRITY_CHECK_VALUE
};
typedef struct xLIST_ITEM ListItem_t;listFIRST_LIST_ITEM_INTEGRITY_CHECK_VALUElistSECOND_LIST_ITEM_INTEGRITY_CHECK_VALUE这两个是校验数据 #if ( configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES 0 )#define listFIRST_LIST_ITEM_INTEGRITY_CHECK_VALUE#define listSECOND_LIST_ITEM_INTEGRITY_CHECK_VALUE #else#define listFIRST_LIST_ITEM_INTEGRITY_CHECK_VALUE TickType_t xListItemIntegrityValue1;#define listSECOND_LIST_ITEM_INTEGRITY_CHECK_VALUE TickType_t xListItemIntegrityValue2;#endif不需要的情况下宏展开为空需下的的情况下是据TickType_t长度变化16-32位的5a5a #if ( configTICK_TYPE_WIDTH_IN_BITS TICK_TYPE_WIDTH_16_BITS )typedef uint16_t TickType_t;#define portMAX_DELAY ( TickType_t ) 0xffff
#elif ( configTICK_TYPE_WIDTH_IN_BITS TICK_TYPE_WIDTH_32_BITS )typedef uint32_t TickType_t;#define portMAX_DELAY ( TickType_t ) 0xffffffffUL
#else#error configTICK_TYPE_WIDTH_IN_BITS set to unsupported tick type width.
#endifconfigLIST_VOLATILE TickType_t xItemValue;
#define configLIST_VOLATILE volatile
#ifndef configLIST_VOLATILE#define configLIST_VOLATILE
#endif在调度任务时插入表项的依据值可以为优先级什么的 struct xLIST_ITEM * configLIST_VOLATILE pxNext;指向下一表项
struct xLIST_ITEM * configLIST_VOLATILE pxPrevious; 指向前一表项
void * pvOwner;指向该表项的指针
struct xLIST * configLIST_VOLATILE pxContainer;指向拥有该表项的链表。
二、链表数据结构
typedef struct xLIST
{listFIRST_LIST_INTEGRITY_CHECK_VALUEvolatile UBaseType_t uxNumberOfItems;ListItem_t * configLIST_VOLATILE pxIndex;MiniListItem_t xListEnd;listSECOND_LIST_INTEGRITY_CHECK_VALUE
} List_t; 分解
volatile UBaseType_t uxNumberOfItems;
typedef unsigned long UBaseType_t;表项数目
ListItem_t * configLIST_VOLATILE pxIndex;表项索引
MiniListItem_t xListEnd;表尾若定义configUSE_MINI_LIST_ITEM 使用缩减表项数据结构否则还是表项的数据结构参考以下
#if ( configUSE_MINI_LIST_ITEM 1 ) struct xMINI_LIST_ITEM{ listFIRST_LIST_ITEM_INTEGRITY_CHECK_VALUEconfigLIST_VOLATILE TickType_t xItemValue;struct xLIST_ITEM * configLIST_VOLATILE pxNext;struct xLIST_ITEM * configLIST_VOLATILE pxPrevious;}; typedef struct xMINI_LIST_ITEM MiniListItem_t;
#elsetypedef struct xLIST_ITEM MiniListItem_t;
#endif
