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1、创建任务：
INT8U OSTaskCreate (void (*task)(void *p_arg), void *p_arg, OS_STK *ptos, INT8U prio) {
OS_STK *psp; INT8U err;
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0; #endif
#if OS_ARG_CHK_EN > 0
if (prio> OS_LOWEST_PRIO) /* Make sure priority is within allowable range */ {
return (OS_PRIO_INVALID); } #endif
OS_ENTER_CRITICAL();
if (OSIntNesting> 0) /* Make sure we don't create the task from within an ISR */ { OS_EXIT_CRITICAL();
return (OS_ERR_TASK_CREATE_ISR); }
if (OSTCBPrioTbl[prio] == (OS_TCB *)0)
/*task doesn't already exist at this
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priority */ {
OSTCBPrioTbl[prio] = (OS_TCB *)1; /* Reserve the priority others from doing*/ OS_EXIT_CRITICAL();
psp = OSTaskStkInit(task, p_arg, ptos, 0); /* Initialize the task's stack */ // 初始化TCB
err = OS_TCBInit(prio, psp, (OS_STK *)0, 0, 0, (void *)0, 0); if (err == OS_NO_ERR) {
if (OSRunning == OS_TRUE) /* priority task if multitasking has started */ { OS_Sched(); } } else {
OS_ENTER_CRITICAL();
OSTCBPrioTbl[prio] = (OS_TCB *)0;/* this priority available to others OS_EXIT_CRITICAL(); }
return (err); }
OS_EXIT_CRITICAL(); return (OS_PRIO_EXIST);
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} #endif
INT8U OSTaskDel (INT8U prio) {
#if OS_EVENT_EN
OS_EVENT *pevent; #endif
#if (OS_VERSION >= 251) && (OS_FLAG_EN > 0) && (OS_MAX_FLAGS > 0) OS_FLAG_NODE *pnode; #endif
OS_TCB *ptcb; INT8U y;
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0; #endif
if (OSIntNesting> 0) {
/* See if trying to delete from ISR
return (OS_TASK_DEL_ISR); }
if (prio == OS_TASK_IDLE_PRIO) {
/* Not allowed to delete idle task
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return (OS_TASK_DEL_IDLE); }
#if OS_ARG_CHK_EN > 0
if (prio>= OS_LOWEST_PRIO)
{ if (prio != OS_PRIO_SELF) {
return (OS_PRIO_INVALID); } } #endif
OS_ENTER_CRITICAL(); if (prio == OS_PRIO_SELF)
*/
{
prio = OSTCBCur->OSTCBPrio; }
ptcb = OSTCBPrioTbl[prio]; if (ptcb == (OS_TCB *)0)
{ OS_EXIT_CRITICAL();
/* Task priority valid ?
/* See if requesting to delete self /* Set priority to delete to current */ /* Task to delete must exist
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return (OS_TASK_NOT_EXIST); }
if (ptcb == (OS_TCB *)1)
/* Must not be assigned to Mutex
{ OS_EXIT_CRITICAL(); return (OS_TASK_DEL_ERR); }
y = ptcb->OSTCBY; OSRdyTbl[y] &= ~ptcb->OSTCBBitX; if (OSRdyTbl[y] == 0)
/* Make task not ready
{ OSRdyGrp&= ~ptcb->OSTCBBitY; } // 移除 #if OS_EVENT_EN
pevent = ptcb->OSTCBEventPtr;
/* If task is waiting on event
if (pevent != (OS_EVENT *)0) {
pevent->OSEventTbl[y] &= ~ptcb->OSTCBBitX; if (pevent->OSEventTbl[y] == 0) {
pevent->OSEventGrp&= ~ptcb->OSTCBBitY; /* ... event ctrl block
/* ... remove task from ...
实验一 ucos-ii源码结构分析
