μC/OS-II---内核：任务调度

内核：调度（oc_core.c文件的函数）

OS_TCB（任务控制块）初始化

INT8U   OS_TCBInit    (INT8U            prio,OS_STK          *ptos,OS_STK          *pbos,INT16U           id,INT32U           stk_size,void            *pext,INT16U           opt);

任务控制块列表(ucos_ii.h文件的函数)

OS_EXT  OS_TCB            OSTCBTbl[OS_MAX_TASKS + OS_N_SYS_TASKS];

系统调用，主动让渡CPU

void  OS_Sched (void)
{#if OS_CRITICAL_METHOD == 3u                           /* Allocate storage for CPU status register     */OS_CPU_SR  cpu_sr = 0u;#endifOS_ENTER_CRITICAL();if (OSIntNesting == 0u)                            /* Schedule only if all ISRs done and ...       */{if (OSLockNesting == 0u)                       /* ... scheduler is not locked                  */{OS_SchedNew();OSTCBHighRdy = OSTCBPrioTbl[OSPrioHighRdy];if (OSPrioHighRdy != OSPrioCur)            /* No Ctx Sw if current task is highest rdy     */{#if OS_TASK_PROFILE_EN > 0uOSTCBHighRdy->OSTCBCtxSwCtr++;         /* Inc. # of context switches to this task      */#endifOSCtxSwCtr++;                          /* Increment context switch counter             */OS_TASK_SW();                          /* Perform a context switch                     */}}}OS_EXIT_CRITICAL();
}

发生中断，强制当前任务让渡CPU

void  OSIntExit (void)
{#if OS_CRITICAL_METHOD == 3u                               /* Allocate storage for CPU status register */OS_CPU_SR  cpu_sr = 0u;#endifif (OSRunning == OS_TRUE){OS_ENTER_CRITICAL();if (OSIntNesting > 0u)                             /* Prevent OSIntNesting from wrapping       */{OSIntNesting--;}if (OSIntNesting == 0u)                            /* Reschedule only if all ISRs complete ... */{if (OSLockNesting == 0u)                       /* ... and not locked.                      */{OS_SchedNew();OSTCBHighRdy = OSTCBPrioTbl[OSPrioHighRdy];if (OSPrioHighRdy != OSPrioCur)            /* No Ctx Sw if current task is highest rdy */{#if OS_TASK_PROFILE_EN > 0uOSTCBHighRdy->OSTCBCtxSwCtr++;         /* Inc. # of context switches to this task  */#endifOSCtxSwCtr++;                          /* Keep track of the number of ctx switches */OSIntCtxSw();                          /* Perform interrupt level ctx switch       */}}}OS_EXIT_CRITICAL();}
}

就绪表(ucos_ii.h文件的函数)

OS_EXT  OS_PRIO           OSRdyTbl[OS_RDY_TBL_SIZE];       /* Table of tasks which are ready to run    */

设置任务进入就绪态

设置任务脱离就绪态

在就绪表中找到优先级最高(数最小)的任务