对于有热心的小伙伴在微博上私信我，说我的uC/OS-II 一些函数简介篇幅有些过于长应该分开介绍。应小伙伴的要求，特此将文章分开进行讲解。上文主要介绍了OSInit()初始化函数，本文介绍任务相关的函数：OSTaskCreate()任务创建函数1，OSTaskCreateExt任务创建函数2，OSTaskSuspend()任务挂起，OSTaskResume()唤醒任务
1、主要作用：建立一个新任务。任务的建立可以在多任务环境启动之前，也可以在正在运行的任务中建立。中断处理程序中不能建立任务；注意，ISR中禁止建立任务，一个任务必须为无限循环结构。
2、函数原型：INT8U OSTaskCreate(void (*task)(void *pd), void *pdata, OS_STK *ptos, INT8U prio);
3、参数说明：
void (*task)(void *pd):指向任务代码首地址的指针。
void *pdata:指向一个数据结构，该结构用来在建立任务时向任务传递参数。
OS_STK *ptos: 指向堆栈任务栈顶的指针
INT8U prio：任务优先级
4、返回值介绍：
OS_NO_ERR：函数调用成功。
OS_PRIO_EXIST：具有该优先级的任务已经存在。
OS_PRIO_INVALID：参数指定的优先级大于OS_LOWEST_PRIO。
OS_NO_MORE_TCB：系统中没有OS_TCB可以分配给任务了。
5、函数主体在os_task.c中
1、主要作用：建立一个新任务。与OSTaskCreate()不同的是,OSTaskCreateExt()允许用户设置更多的细节内容。任务的建立可以在多任务环境启动之前,也可以在正在运行的任务中建立,但中断处理程序中不能建立新任务。,且不
2、函数原型：NT8U OSTaskCreateExt (void (*task)(void *pd),void *pdata, OS_STK *ptos,INT8U prio ，INT16U id, OS_STK *pbos,INT32U stk_size,void *pext,INT16U opt)
3、参数说明：
void (*task)(void *pd):指向任务代码首地址的指针。
void *pdata:指向一个数据结构，该结构用来在建立任务时向任务传递参数。
OS_STK *ptos: 指向堆栈任务栈顶的指针
INT8U prio：任务优先级
INT16U id： 任务ID，2.52版本，无实际作用，保留作为扩展用
OS_STK *pbos： 指向堆栈底部的指针，用于OSTaskStkChk()函数
INT32U stk_size：指定任务堆栈的大小，由OS_STK类型决定
void *pext：定义数据结构的指针，作为TCB的扩展
INT16U opt) ：存放于任务操作相关的信息，详见uCOS-II.H
4、返回值说明：
OS_NO_ERR：函数调用成功。
OS_PRIO_EXIST：具有该优先级的任务已经存在。
OS_PRIO_INVALID：参数指定的优先级大于OS_LOWEST_PRIO。
OS_NO_MORE_TCB：系统中没有OS_TCB可以分配给任务了。
5、函数主体在os_task.c中
1、主要作用： 无条件挂起一个任务。调用此函数的任务也可以传递参数 OS_PRIO_SELF，挂起调用任务本身。当前任务挂起后，只有其他任务才能唤醒被挂起的任务。任务挂起后，系统会重新进行任务调度，运行下一个优先级最高的就绪任务。唤醒挂起任务需要调用函数OSTaskResume()。任务的挂起是可以叠加到其他操作上的。例如，任务被挂起时正在进行延时操作，那么任务的唤醒就需要两个条件：延时的结束以及其他任务的唤醒操作。又如，任务被挂起时正在等待信号量，当任务从信号量的等待对列中清除后也不能立即运行，而必须等到被唤醒后。
2、函数原型：INT8U OSTaskSuspend(INT8U prio);
3、参数说明:prio为指定要获取挂起的任务优先级，也可以指定参数 OS_PRIO_SELF，挂起任务本身。此时，下一个优先级最高的就绪任务将运行。
4、返回值说明：
OS_NO_ERR：函数调用成功。
OS_TASK_SUSPEND_IDLE：试图挂起μC/OS-II中的空闲任务（Idle task）。此为非法操作。
OS_PRIO_INVALID：参数指定的优先级大于 OS_LOWEST_PRIO 或没有设定 OS_PRIO_SELF 的值。
OS_TASK_SUSPEND_PRIO：要挂起的任务不存在。
5、函数主体在os_task.c中
1、主要作用： 唤醒一个用 OSTaskSuspend() 函数挂起的任务。OSTaskResume() 也是唯一能“解挂”挂起任务的函数。
2、函数原型：INT8U OSTaskResume(INT8U prio);
3、参数说明：prio指定要唤醒任务的优先级。
4、返回值说明：
OS_NO_ERR：函数调用成功。
OS_TASK_RESUME_PRIO：要唤醒的任务不存在
OS_TASK_NOT_SUSPENDED：要唤醒的任务不在挂起状态。
OS_PRIO_INVALID：参数指定的优先级大于或等于OS_LOWEST_PRIO。
5、函数主体在os_task.c中、
/*
*********************************************************************************************************
* uC/OS-II
* The Real-Time Kernel
* TASK MANAGEMENT
*
* (c) Copyright 1992-2013, Micrium, Weston, FL
* All Rights Reserved
*
* File : OS_TASK.C
* By : Jean J. Labrosse
* Version : V2.92.08
*
* LICENSING TERMS:
* ---------------
* uC/OS-II is provided in source form for FREE evaluation, for educational use or for peaceful research.
* If you plan on using uC/OS-II in a commercial product you need to contact Micrium to properly license
* its use in your product. We provide ALL the source code for your convenience and to help you experience
* uC/OS-II. The fact that the source is provided does NOT mean that you can use it without paying a
* licensing fee.
*********************************************************************************************************
*/
#define MICRIUM_SOURCE
#ifndef OS_MASTER_FILE
#include <ucos_ii.h>
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* CHANGE PRIORITY OF A TASK
*
* Description: This function allows you to change the priority of a task dynamically. Note that the new
* priority MUST be available.
*
* Arguments : oldp is the old priority
*
* newp is the new priority
*
* Returns : OS_ERR_NONE is the call was successful
* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed
* (i.e. >= OS_LOWEST_PRIO)
* OS_ERR_PRIO_EXIST if the new priority already exist.
* OS_ERR_PRIO there is no task with the specified OLD priority (i.e. the OLD task does
* not exist.
* OS_ERR_TASK_NOT_EXIST if the task is assigned to a Mutex PIP.
*********************************************************************************************************
*/
#if OS_TASK_CHANGE_PRIO_EN > 0u
INT8U OSTaskChangePrio (INT8U oldprio,
INT8U newprio)
{
#if (OS_EVENT_EN)
OS_EVENT *pevent;
#if (OS_EVENT_MULTI_EN > 0u)
OS_EVENT **pevents;
#endif
#endif
OS_TCB *ptcb;
INT8U y_new;
INT8U x_new;
INT8U y_old;
OS_PRIO bity_new;
OS_PRIO bitx_new;
OS_PRIO bity_old;
OS_PRIO bitx_old;
#if OS_CRITICAL_METHOD == 3u
OS_CPU_SR cpu_sr = 0u; /* Storage for CPU status register */
#endif
/*$PAGE*/
#if OS_ARG_CHK_EN > 0u
if (oldprio >= OS_LOWEST_PRIO) {
if (oldprio != OS_PRIO_SELF) {
return (OS_ERR_PRIO_INVALID);
}
}
if (newprio >= OS_LOWEST_PRIO) {
return (OS_ERR_PRIO_INVALID);
}
#endif
OS_ENTER_CRITICAL();
if (OSTCBPrioTbl[newprio] != (OS_TCB *)0) { /* New priority must not already exist */
OS_EXIT_CRITICAL();
return (OS_ERR_PRIO_EXIST);
}
if (oldprio == OS_PRIO_SELF) { /* See if changing self */
oldprio = OSTCBCur->OSTCBPrio; /* Yes, get priority */
}
ptcb = OSTCBPrioTbl[oldprio];
if (ptcb == (OS_TCB *)0) { /* Does task to change exist? */
OS_EXIT_CRITICAL(); /* No, can‘t change its priority! */
return (OS_ERR_PRIO);
}
if (ptcb == OS_TCB_RESERVED) { /* Is task assigned to Mutex */
OS_EXIT_CRITICAL(); /* No, can‘t change its priority! */
return (OS_ERR_TASK_NOT_EXIST);
}
#if OS_LOWEST_PRIO <= 63u
y_new = (INT8U)(newprio >> 3u); /* Yes, compute new TCB fields */
x_new = (INT8U)(newprio & 0x07u);
#else
y_new = (INT8U)((INT8U)(newprio >> 4u) & 0x0Fu);
x_new = (INT8U)(newprio & 0x0Fu);
#endif
bity_new = (OS_PRIO)(1uL << y_new);
bitx_new = (OS_PRIO)(1uL << x_new);
OSTCBPrioTbl[oldprio] = (OS_TCB *)0; /* Remove TCB from old priority */
OSTCBPrioTbl[newprio] = ptcb; /* Place pointer to TCB @ new priority */
y_old = ptcb->OSTCBY;
bity_old = ptcb->OSTCBBitY;
bitx_old = ptcb->OSTCBBitX;
if ((OSRdyTbl[y_old] & bitx_old) != 0u) { /* If task is ready make it not */
OSRdyTbl[y_old] &= (OS_PRIO)~bitx_old;
if (OSRdyTbl[y_old] == 0u) {
OSRdyGrp &= (OS_PRIO)~bity_old;
}
OSRdyGrp |= bity_new; /* Make new priority ready to run */
OSRdyTbl[y_new] |= bitx_new;
}
#if (OS_EVENT_EN)
pevent = ptcb->OSTCBEventPtr;
if (pevent != (OS_EVENT *)0) {
pevent->OSEventTbl[y_old] &= (OS_PRIO)~bitx_old; /* Remove old task prio from wait list */
if (pevent->OSEventTbl[y_old] == 0u) {
pevent->OSEventGrp &= (OS_PRIO)~bity_old;
}
pevent->OSEventGrp |= bity_new; /* Add new task prio to wait list */
pevent->OSEventTbl[y_new] |= bitx_new;
}
#if (OS_EVENT_MULTI_EN > 0u)
if (ptcb->OSTCBEventMultiPtr != (OS_EVENT **)0) {
pevents = ptcb->OSTCBEventMultiPtr;
pevent = *pevents;
while (pevent != (OS_EVENT *)0) {
pevent->OSEventTbl[y_old] &= (OS_PRIO)~bitx_old; /* Remove old task prio from wait lists */
if (pevent->OSEventTbl[y_old] == 0u) {
pevent->OSEventGrp &= (OS_PRIO)~bity_old;
}
pevent->OSEventGrp |= bity_new; /* Add new task prio to wait lists */
pevent->OSEventTbl[y_new] |= bitx_new;
pevents++;
pevent = *pevents;
}
}
#endif
#endif
ptcb->OSTCBPrio = newprio; /* Set new task priority */
ptcb->OSTCBY = y_new;
ptcb->OSTCBX = x_new;
ptcb->OSTCBBitY = bity_new;
ptcb->OSTCBBitX = bitx_new;
OS_EXIT_CRITICAL();
if (OSRunning == OS_TRUE) {
OS_Sched(); /* Find new highest priority task */
}
return (OS_ERR_NONE);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* CREATE A TASK
*
* Description: This function is used to have uC/OS-II manage the execution of a task. Tasks can either
* be created prior to the start of multitasking or by a running task. A task cannot be
* created by an ISR.
*
* Arguments : task is a pointer to the task‘s code
*
* p_arg is a pointer to an optional data area which can be used to pass parameters to
* the task when the task first executes. Where the task is concerned it thinks
* it was invoked and passed the argument ‘p_arg‘ as follows:
*
* void Task (void *p_arg)
* {
* for (;;) {
* Task code;
* }
* }
*
* ptos is a pointer to the task‘s top of stack. If the configuration constant
* OS_STK_GROWTH is set to 1, the stack is assumed to grow downward (i.e. from high
* memory to low memory). ‘pstk‘ will thus point to the highest (valid) memory
* location of the stack. If OS_STK_GROWTH is set to 0, ‘pstk‘ will point to the
* lowest memory location of the stack and the stack will grow with increasing
* memory locations.
*
* prio is the task‘s priority. A unique priority MUST be assigned to each task and the
* lower the number, the higher the priority.
*
* Returns : OS_ERR_NONE if the function was successful.
* OS_ERR_PRIO_EXIST if the task priority already exist
* (each task MUST have a unique priority).
* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum
* allowed (i.e. >= OS_LOWEST_PRIO)
* OS_ERR_TASK_CREATE_ISR if you tried to create a task from an ISR.
* OS_ERR_ILLEGAL_CREATE_RUN_TIME if you tried to create a task after safety critical
* operation started.
*********************************************************************************************************
*/
#if OS_TASK_CREATE_EN > 0u
INT8U OSTaskCreate (void (*task)(void *p_arg),
void *p_arg,
OS_STK *ptos,
INT8U prio)
{
OS_STK *psp;
INT8U err;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#ifdef OS_SAFETY_CRITICAL_IEC61508
if (OSSafetyCriticalStartFlag == OS_TRUE) {
OS_SAFETY_CRITICAL_EXCEPTION();
return (OS_ERR_ILLEGAL_CREATE_RUN_TIME);
}
#endif
#if OS_ARG_CHK_EN > 0u
if (prio > OS_LOWEST_PRIO) { /* Make sure priority is within allowable range */
return (OS_ERR_PRIO_INVALID);
}
#endif
OS_ENTER_CRITICAL();
if (OSIntNesting > 0u) { /* 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) { /* Make sure task doesn‘t already exist at this priority */
OSTCBPrioTbl[prio] = OS_TCB_RESERVED;/* Reserve the priority to prevent others from doing ... */
/* ... the same thing until task is created. */
OS_EXIT_CRITICAL();
psp = OSTaskStkInit(task, p_arg, ptos, 0u); /* Initialize the task‘s stack */
err = OS_TCBInit(prio, psp, (OS_STK *)0, 0u, 0u, (void *)0, 0u);
if (err == OS_ERR_NONE) {
if (OSRunning == OS_TRUE) { /* Find highest priority task if multitasking has started */
OS_Sched();
}
} else {
OS_ENTER_CRITICAL();
OSTCBPrioTbl[prio] = (OS_TCB *)0;/* Make this priority available to others */
OS_EXIT_CRITICAL();
}
return (err);
}
OS_EXIT_CRITICAL();
return (OS_ERR_PRIO_EXIST);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* CREATE A TASK (Extended Version)
*
* Description: This function is used to have uC/OS-II manage the execution of a task. Tasks can either
* be created prior to the start of multitasking or by a running task. A task cannot be
* created by an ISR. This function is similar to OSTaskCreate() except that it allows
* additional information about a task to be specified.
*
* Arguments : task is a pointer to the task‘s code
*
* p_arg is a pointer to an optional data area which can be used to pass parameters to
* the task when the task first executes. Where the task is concerned it thinks
* it was invoked and passed the argument ‘p_arg‘ as follows:
*
* void Task (void *p_arg)
* {
* for (;;) {
* Task code;
* }
* }
*
* ptos is a pointer to the task‘s top of stack. If the configuration constant
* OS_STK_GROWTH is set to 1, the stack is assumed to grow downward (i.e. from high
* memory to low memory). ‘ptos‘ will thus point to the highest (valid) memory
* location of the stack. If OS_STK_GROWTH is set to 0, ‘ptos‘ will point to the
* lowest memory location of the stack and the stack will grow with increasing
* memory locations. ‘ptos‘ MUST point to a valid ‘free‘ data item.
*
* prio is the task‘s priority. A unique priority MUST be assigned to each task and the
* lower the number, the higher the priority.
*
* id is the task‘s ID (0..65535)
*
* pbos is a pointer to the task‘s bottom of stack. If the configuration constant
* OS_STK_GROWTH is set to 1, the stack is assumed to grow downward (i.e. from high
* memory to low memory). ‘pbos‘ will thus point to the LOWEST (valid) memory
* location of the stack. If OS_STK_GROWTH is set to 0, ‘pbos‘ will point to the
* HIGHEST memory location of the stack and the stack will grow with increasing
* memory locations. ‘pbos‘ MUST point to a valid ‘free‘ data item.
*
* stk_size is the size of the stack in number of elements. If OS_STK is set to INT8U,
* ‘stk_size‘ corresponds to the number of bytes available. If OS_STK is set to
* INT16U, ‘stk_size‘ contains the number of 16-bit entries available. Finally, if
* OS_STK is set to INT32U, ‘stk_size‘ contains the number of 32-bit entries
* available on the stack.
*
* pext is a pointer to a user supplied memory location which is used as a TCB extension.
* For example, this user memory can hold the contents of floating-point registers
* during a context switch, the time each task takes to execute, the number of times
* the task has been switched-in, etc.
*
* opt contains additional information (or options) about the behavior of the task. The
* LOWER 8-bits are reserved by uC/OS-II while the upper 8 bits can be application
* specific. See OS_TASK_OPT_??? in uCOS-II.H. Current choices are:
*
* OS_TASK_OPT_STK_CHK Stack checking to be allowed for the task
* OS_TASK_OPT_STK_CLR Clear the stack when the task is created
* OS_TASK_OPT_SAVE_FP If the CPU has floating-point registers, save them
* during a context switch.
*
* Returns : OS_ERR_NONE if the function was successful.
* OS_ERR_PRIO_EXIST if the task priority already exist
* (each task MUST have a unique priority).
* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum
* allowed (i.e. > OS_LOWEST_PRIO)
* OS_ERR_TASK_CREATE_ISR if you tried to create a task from an ISR.
* OS_ERR_ILLEGAL_CREATE_RUN_TIME if you tried to create a task after safety critical
* operation started.
*********************************************************************************************************
*/
/*$PAGE*/
#if OS_TASK_CREATE_EXT_EN > 0u
INT8U OSTaskCreateExt (void (*task)(void *p_arg),
void *p_arg,
OS_STK *ptos,
INT8U prio,
INT16U id,
OS_STK *pbos,
INT32U stk_size,
void *pext,
INT16U opt)
{
OS_STK *psp;
INT8U err;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#ifdef OS_SAFETY_CRITICAL_IEC61508
if (OSSafetyCriticalStartFlag == OS_TRUE) {
OS_SAFETY_CRITICAL_EXCEPTION();
return (OS_ERR_ILLEGAL_CREATE_RUN_TIME);
}
#endif
#if OS_ARG_CHK_EN > 0u
if (prio > OS_LOWEST_PRIO) { /* Make sure priority is within allowable range */
return (OS_ERR_PRIO_INVALID);
}
#endif
OS_ENTER_CRITICAL();
if (OSIntNesting > 0u) { /* Make sure we don‘t create the task from within an ISR */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_CREATE_ISR);
}
if (OSTCBPrioTbl[prio] == (OS_TCB *)0) { /* Make sure task doesn‘t already exist at this priority */
OSTCBPrioTbl[prio] = OS_TCB_RESERVED;/* Reserve the priority to prevent others from doing ... */
/* ... the same thing until task is created. */
OS_EXIT_CRITICAL();
#if (OS_TASK_STAT_STK_CHK_EN > 0u)
OS_TaskStkClr(pbos, stk_size, opt); /* Clear the task stack (if needed) */
#endif
psp = OSTaskStkInit(task, p_arg, ptos, opt); /* Initialize the task‘s stack */
err = OS_TCBInit(prio, psp, pbos, id, stk_size, pext, opt);
if (err == OS_ERR_NONE) {
if (OSRunning == OS_TRUE) { /* Find HPT if multitasking has started */
OS_Sched();
}
} else {
OS_ENTER_CRITICAL();
OSTCBPrioTbl[prio] = (OS_TCB *)0; /* Make this priority avail. to others */
OS_EXIT_CRITICAL();
}
return (err);
}
OS_EXIT_CRITICAL();
return (OS_ERR_PRIO_EXIST);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* DELETE A TASK
*
* Description: This function allows you to delete a task. The calling task can delete itself by
* its own priority number. The deleted task is returned to the dormant state and can be
* re-activated by creating the deleted task again.
*
* Arguments : prio is the priority of the task to delete. Note that you can explicitly delete
* the current task without knowing its priority level by setting ‘prio‘ to
* OS_PRIO_SELF.
*
* Returns : OS_ERR_NONE if the call is successful
* OS_ERR_TASK_DEL_IDLE if you attempted to delete uC/OS-II‘s idle task
* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed
* (i.e. >= OS_LOWEST_PRIO) or, you have not specified OS_PRIO_SELF.
* OS_ERR_TASK_DEL if the task is assigned to a Mutex PIP.
* OS_ERR_TASK_NOT_EXIST if the task you want to delete does not exist.
* OS_ERR_TASK_DEL_ISR if you tried to delete a task from an ISR
*
* Notes : 1) To reduce interrupt latency, OSTaskDel() ‘disables‘ the task:
* a) by making it not ready
* b) by removing it from any wait lists
* c) by preventing OSTimeTick() from making the task ready to run.
* The task can then be ‘unlinked‘ from the miscellaneous structures in uC/OS-II.
* 2) The function OS_Dummy() is called after OS_EXIT_CRITICAL() because, on most processors,
* the next instruction following the enable interrupt instruction is ignored.
* 3) An ISR cannot delete a task.
* 4) The lock nesting counter is incremented because, for a brief instant, if the current
* task is being deleted, the current task would not be able to be rescheduled because it
* is removed from the ready list. Incrementing the nesting counter prevents another task
* from being schedule. This means that an ISR would return to the current task which is
* being deleted. The rest of the deletion would thus be able to be completed.
*********************************************************************************************************
*/
#if OS_TASK_DEL_EN > 0u
INT8U OSTaskDel (INT8U prio)
{
#if (OS_FLAG_EN > 0u) && (OS_MAX_FLAGS > 0u)
OS_FLAG_NODE *pnode;
#endif
OS_TCB *ptcb;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
if (OSIntNesting > 0u) { /* See if trying to delete from ISR */
return (OS_ERR_TASK_DEL_ISR);
}
if (prio == OS_TASK_IDLE_PRIO) { /* Not allowed to delete idle task */
return (OS_ERR_TASK_DEL_IDLE);
}
#if OS_ARG_CHK_EN > 0u
if (prio >= OS_LOWEST_PRIO) { /* Task priority valid ? */
if (prio != OS_PRIO_SELF) {
return (OS_ERR_PRIO_INVALID);
}
}
#endif
/*$PAGE*/
OS_ENTER_CRITICAL();
if (prio == OS_PRIO_SELF) { /* See if requesting to delete self */
prio = OSTCBCur->OSTCBPrio; /* Set priority to delete to current */
}
ptcb = OSTCBPrioTbl[prio];
if (ptcb == (OS_TCB *)0) { /* Task to delete must exist */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_NOT_EXIST);
}
if (ptcb == OS_TCB_RESERVED) { /* Must not be assigned to Mutex */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_DEL);
}
OSRdyTbl[ptcb->OSTCBY] &= (OS_PRIO)~ptcb->OSTCBBitX;
if (OSRdyTbl[ptcb->OSTCBY] == 0u) { /* Make task not ready */
OSRdyGrp &= (OS_PRIO)~ptcb->OSTCBBitY;
}
#if (OS_EVENT_EN)
if (ptcb->OSTCBEventPtr != (OS_EVENT *)0) {
OS_EventTaskRemove(ptcb, ptcb->OSTCBEventPtr); /* Remove this task from any event wait list */
}
#if (OS_EVENT_MULTI_EN > 0u)
if (ptcb->OSTCBEventMultiPtr != (OS_EVENT **)0) { /* Remove this task from any events‘ wait lists*/
OS_EventTaskRemoveMulti(ptcb, ptcb->OSTCBEventMultiPtr);
}
#endif
#endif
#if (OS_FLAG_EN > 0u) && (OS_MAX_FLAGS > 0u)
pnode = ptcb->OSTCBFlagNode;
if (pnode != (OS_FLAG_NODE *)0) { /* If task is waiting on event flag */
OS_FlagUnlink(pnode); /* Remove from wait list */
}
#endif
ptcb->OSTCBDly = 0u; /* Prevent OSTimeTick() from updating */
ptcb->OSTCBStat = OS_STAT_RDY; /* Prevent task from being resumed */
ptcb->OSTCBStatPend = OS_STAT_PEND_OK;
if (OSLockNesting < 255u) { /* Make sure we don‘t context switch */
OSLockNesting++;
}
OS_EXIT_CRITICAL(); /* Enabling INT. ignores next instruc. */
OS_Dummy(); /* ... Dummy ensures that INTs will be */
OS_ENTER_CRITICAL(); /* ... disabled HERE! */
if (OSLockNesting > 0u) { /* Remove context switch lock */
OSLockNesting--;
}
OSTaskDelHook(ptcb); /* Call user defined hook */
#if OS_TASK_CREATE_EXT_EN > 0u
#if defined(OS_TLS_TBL_SIZE) && (OS_TLS_TBL_SIZE > 0u)
OS_TLS_TaskDel(ptcb); /* Call TLS hook */
#endif
#endif
OSTaskCtr--; /* One less task being managed */
OSTCBPrioTbl[prio] = (OS_TCB *)0; /* Clear old priority entry */
if (ptcb->OSTCBPrev == (OS_TCB *)0) { /* Remove from TCB chain */
ptcb->OSTCBNext->OSTCBPrev = (OS_TCB *)0;
OSTCBList = ptcb->OSTCBNext;
} else {
ptcb->OSTCBPrev->OSTCBNext = ptcb->OSTCBNext;
ptcb->OSTCBNext->OSTCBPrev = ptcb->OSTCBPrev;
}
ptcb->OSTCBNext = OSTCBFreeList; /* Return TCB to free TCB list */
OSTCBFreeList = ptcb;
#if OS_TASK_NAME_EN > 0u
ptcb->OSTCBTaskName = (INT8U *)(void *)"?";
#endif
OS_EXIT_CRITICAL();
if (OSRunning == OS_TRUE) {
OS_Sched(); /* Find new highest priority task */
}
return (OS_ERR_NONE);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* REQUEST THAT A TASK DELETE ITSELF
*
* Description: This function is used to:
* a) notify a task to delete itself.
* b) to see if a task requested that the current task delete itself.
* This function is a little tricky to understand. Basically, you have a task that needs
* to be deleted however, this task has resources that it has allocated (memory buffers,
* semaphores, mailboxes, queues etc.). The task cannot be deleted otherwise these
* resources would not be freed. The requesting task calls OSTaskDelReq() to indicate that
* the task needs to be deleted. Deleting of the task is however, deferred to the task to
* be deleted. For example, suppose that task #10 needs to be deleted. The requesting task
* example, task #5, would call OSTaskDelReq(10). When task #10 gets to execute, it calls
* this function by specifying OS_PRIO_SELF and monitors the returned value. If the return
* value is OS_ERR_TASK_DEL_REQ, another task requested a task delete. Task #10 would look like
* this:
*
* void Task(void *p_arg)
* {
* .
* .
* while (1) {
* OSTimeDly(1);
* if (OSTaskDelReq(OS_PRIO_SELF) == OS_ERR_TASK_DEL_REQ) {
* Release any owned resources;
* De-allocate any dynamic memory;
* OSTaskDel(OS_PRIO_SELF);
* }
* }
* }
*
* Arguments : prio is the priority of the task to request the delete from
*
* Returns : OS_ERR_NONE if the task exist and the request has been registered
* OS_ERR_TASK_NOT_EXIST if the task has been deleted. This allows the caller to know whether
* the request has been executed.
* OS_ERR_TASK_DEL if the task is assigned to a Mutex.
* OS_ERR_TASK_DEL_IDLE if you requested to delete uC/OS-II‘s idle task
* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed
* (i.e. >= OS_LOWEST_PRIO) or, you have not specified OS_PRIO_SELF.
* OS_ERR_TASK_DEL_REQ if a task (possibly another task) requested that the running task be
* deleted.
*********************************************************************************************************
*/
/*$PAGE*/
#if OS_TASK_DEL_EN > 0u
INT8U OSTaskDelReq (INT8U prio)
{
INT8U stat;
OS_TCB *ptcb;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
if (prio == OS_TASK_IDLE_PRIO) { /* Not allowed to delete idle task */
return (OS_ERR_TASK_DEL_IDLE);
}
#if OS_ARG_CHK_EN > 0u
if (prio >= OS_LOWEST_PRIO) { /* Task priority valid ? */
if (prio != OS_PRIO_SELF) {
return (OS_ERR_PRIO_INVALID);
}
}
#endif
if (prio == OS_PRIO_SELF) { /* See if a task is requesting to ... */
OS_ENTER_CRITICAL(); /* ... this task to delete itself */
stat = OSTCBCur->OSTCBDelReq; /* Return request status to caller */
OS_EXIT_CRITICAL();
return (stat);
}
OS_ENTER_CRITICAL();
ptcb = OSTCBPrioTbl[prio];
if (ptcb == (OS_TCB *)0) { /* Task to delete must exist */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_NOT_EXIST); /* Task must already be deleted */
}
if (ptcb == OS_TCB_RESERVED) { /* Must NOT be assigned to a Mutex */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_DEL);
}
ptcb->OSTCBDelReq = OS_ERR_TASK_DEL_REQ; /* Set flag indicating task to be DEL. */
OS_EXIT_CRITICAL();
return (OS_ERR_NONE);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* GET THE NAME OF A TASK
*
* Description: This function is called to obtain the name of a task.
*
* Arguments : prio is the priority of the task that you want to obtain the name from.
*
* pname is a pointer to a pointer to an ASCII string that will receive the name of the task.
*
* perr is a pointer to an error code that can contain one of the following values:
*
* OS_ERR_NONE if the requested task is resumed
* OS_ERR_TASK_NOT_EXIST if the task has not been created or is assigned to a Mutex
* OS_ERR_PRIO_INVALID if you specified an invalid priority:
* A higher value than the idle task or not OS_PRIO_SELF.
* OS_ERR_PNAME_NULL You passed a NULL pointer for ‘pname‘
* OS_ERR_NAME_GET_ISR You called this function from an ISR
*
*
* Returns : The length of the string or 0 if the task does not exist.
*********************************************************************************************************
*/
#if OS_TASK_NAME_EN > 0u
INT8U OSTaskNameGet (INT8U prio,
INT8U **pname,
INT8U *perr)
{
OS_TCB *ptcb;
INT8U len;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#ifdef OS_SAFETY_CRITICAL
if (perr == (INT8U *)0) {
OS_SAFETY_CRITICAL_EXCEPTION();
return (0u);
}
#endif
#if OS_ARG_CHK_EN > 0u
if (prio > OS_LOWEST_PRIO) { /* Task priority valid ? */
if (prio != OS_PRIO_SELF) {
*perr = OS_ERR_PRIO_INVALID; /* No */
return (0u);
}
}
if (pname == (INT8U **)0) { /* Is ‘pname‘ a NULL pointer? */
*perr = OS_ERR_PNAME_NULL; /* Yes */
return (0u);
}
#endif
if (OSIntNesting > 0u) { /* See if trying to call from an ISR */
*perr = OS_ERR_NAME_GET_ISR;
return (0u);
}
OS_ENTER_CRITICAL();
if (prio == OS_PRIO_SELF) { /* See if caller desires it‘s own name */
prio = OSTCBCur->OSTCBPrio;
}
ptcb = OSTCBPrioTbl[prio];
if (ptcb == (OS_TCB *)0) { /* Does task exist? */
OS_EXIT_CRITICAL(); /* No */
*perr = OS_ERR_TASK_NOT_EXIST;
return (0u);
}
if (ptcb == OS_TCB_RESERVED) { /* Task assigned to a Mutex? */
OS_EXIT_CRITICAL(); /* Yes */
*perr = OS_ERR_TASK_NOT_EXIST;
return (0u);
}
*pname = ptcb->OSTCBTaskName;
len = OS_StrLen(*pname);
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
return (len);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* ASSIGN A NAME TO A TASK
*
* Description: This function is used to set the name of a task.
*
* Arguments : prio is the priority of the task that you want the assign a name to.
*
* pname is a pointer to an ASCII string that contains the name of the task.
*
* perr is a pointer to an error code that can contain one of the following values:
*
* OS_ERR_NONE if the requested task is resumed
* OS_ERR_TASK_NOT_EXIST if the task has not been created or is assigned to a Mutex
* OS_ERR_PNAME_NULL You passed a NULL pointer for ‘pname‘
* OS_ERR_PRIO_INVALID if you specified an invalid priority:
* A higher value than the idle task or not OS_PRIO_SELF.
* OS_ERR_NAME_SET_ISR if you called this function from an ISR
*
* Returns : None
*********************************************************************************************************
*/
#if OS_TASK_NAME_EN > 0u
void OSTaskNameSet (INT8U prio,
INT8U *pname,
INT8U *perr)
{
OS_TCB *ptcb;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#ifdef OS_SAFETY_CRITICAL
if (perr == (INT8U *)0) {
OS_SAFETY_CRITICAL_EXCEPTION();
return;
}
#endif
#if OS_ARG_CHK_EN > 0u
if (prio > OS_LOWEST_PRIO) { /* Task priority valid ? */
if (prio != OS_PRIO_SELF) {
*perr = OS_ERR_PRIO_INVALID; /* No */
return;
}
}
if (pname == (INT8U *)0) { /* Is ‘pname‘ a NULL pointer? */
*perr = OS_ERR_PNAME_NULL; /* Yes */
return;
}
#endif
if (OSIntNesting > 0u) { /* See if trying to call from an ISR */
*perr = OS_ERR_NAME_SET_ISR;
return;
}
OS_ENTER_CRITICAL();
if (prio == OS_PRIO_SELF) { /* See if caller desires to set it‘s own name */
prio = OSTCBCur->OSTCBPrio;
}
ptcb = OSTCBPrioTbl[prio];
if (ptcb == (OS_TCB *)0) { /* Does task exist? */
OS_EXIT_CRITICAL(); /* No */
*perr = OS_ERR_TASK_NOT_EXIST;
return;
}
if (ptcb == OS_TCB_RESERVED) { /* Task assigned to a Mutex? */
OS_EXIT_CRITICAL(); /* Yes */
*perr = OS_ERR_TASK_NOT_EXIST;
return;
}
ptcb->OSTCBTaskName = pname;
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* RESUME A SUSPENDED TASK
*
* Description: This function is called to resume a previously suspended task. This is the only call that
* will remove an explicit task suspension.
*
* Arguments : prio is the priority of the task to resume.
*
* Returns : OS_ERR_NONE if the requested task is resumed
* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed
* (i.e. >= OS_LOWEST_PRIO)
* OS_ERR_TASK_RESUME_PRIO if the task to resume does not exist
* OS_ERR_TASK_NOT_EXIST if the task is assigned to a Mutex PIP
* OS_ERR_TASK_NOT_SUSPENDED if the task to resume has not been suspended
*********************************************************************************************************
*/
#if OS_TASK_SUSPEND_EN > 0u
INT8U OSTaskResume (INT8U prio)
{
OS_TCB *ptcb;
#if OS_CRITICAL_METHOD == 3u /* Storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#if OS_ARG_CHK_EN > 0u
if (prio >= OS_LOWEST_PRIO) { /* Make sure task priority is valid */
return (OS_ERR_PRIO_INVALID);
}
#endif
OS_ENTER_CRITICAL();
ptcb = OSTCBPrioTbl[prio];
if (ptcb == (OS_TCB *)0) { /* Task to suspend must exist */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_RESUME_PRIO);
}
if (ptcb == OS_TCB_RESERVED) { /* See if assigned to Mutex */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_NOT_EXIST);
}
if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) != OS_STAT_RDY) { /* Task must be suspended */
ptcb->OSTCBStat &= (INT8U)~(INT8U)OS_STAT_SUSPEND; /* Remove suspension */
if (ptcb->OSTCBStat == OS_STAT_RDY) { /* See if task is now ready */
if (ptcb->OSTCBDly == 0u) {
OSRdyGrp |= ptcb->OSTCBBitY; /* Yes, Make task ready to run */
OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
OS_EXIT_CRITICAL();
if (OSRunning == OS_TRUE) {
OS_Sched(); /* Find new highest priority task */
}
} else {
OS_EXIT_CRITICAL();
}
} else { /* Must be pending on event */
OS_EXIT_CRITICAL();
}
return (OS_ERR_NONE);
}
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_NOT_SUSPENDED);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* STACK CHECKING
*
* Description: This function is called to check the amount of free memory left on the specified task‘s
* stack.
*
* Arguments : prio is the task priority
*
* p_stk_data is a pointer to a data structure of type OS_STK_DATA.
*
* Returns : OS_ERR_NONE upon success
* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed
* (i.e. > OS_LOWEST_PRIO) or, you have not specified OS_PRIO_SELF.
* OS_ERR_TASK_NOT_EXIST if the desired task has not been created or is assigned to a Mutex PIP
* OS_ERR_TASK_OPT if you did NOT specified OS_TASK_OPT_STK_CHK when the task was created
* OS_ERR_PDATA_NULL if ‘p_stk_data‘ is a NULL pointer
*********************************************************************************************************
*/
#if (OS_TASK_STAT_STK_CHK_EN > 0u) && (OS_TASK_CREATE_EXT_EN > 0u)
INT8U OSTaskStkChk (INT8U prio,
OS_STK_DATA *p_stk_data)
{
OS_TCB *ptcb;
OS_STK *pchk;
INT32U nfree;
INT32U size;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#if OS_ARG_CHK_EN > 0u
if (prio > OS_LOWEST_PRIO) { /* Make sure task priority is valid */
if (prio != OS_PRIO_SELF) {
return (OS_ERR_PRIO_INVALID);
}
}
if (p_stk_data == (OS_STK_DATA *)0) { /* Validate ‘p_stk_data‘ */
return (OS_ERR_PDATA_NULL);
}
#endif
p_stk_data->OSFree = 0u; /* Assume failure, set to 0 size */
p_stk_data->OSUsed = 0u;
OS_ENTER_CRITICAL();
if (prio == OS_PRIO_SELF) { /* See if check for SELF */
prio = OSTCBCur->OSTCBPrio;
}
ptcb = OSTCBPrioTbl[prio];
if (ptcb == (OS_TCB *)0) { /* Make sure task exist */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_NOT_EXIST);
}
if (ptcb == OS_TCB_RESERVED) {
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_NOT_EXIST);
}
if ((ptcb->OSTCBOpt & OS_TASK_OPT_STK_CHK) == 0u) { /* Make sure stack checking option is set */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_OPT);
}
nfree = 0u;
size = ptcb->OSTCBStkSize;
pchk = ptcb->OSTCBStkBottom;
OS_EXIT_CRITICAL();
#if OS_STK_GROWTH == 1u
while (*pchk++ == (OS_STK)0) { /* Compute the number of zero entries on the stk */
nfree++;
}
#else
while (*pchk-- == (OS_STK)0) {
nfree++;
}
#endif
p_stk_data->OSFree = nfree; /* Store number of free entries on the stk */
p_stk_data->OSUsed = size - nfree; /* Compute number of entries used on the stk */
return (OS_ERR_NONE);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* SUSPEND A TASK
*
* Description: This function is called to suspend a task. The task can be the calling task if the
* priority passed to OSTaskSuspend() is the priority of the calling task or OS_PRIO_SELF.
*
* Arguments : prio is the priority of the task to suspend. If you specify OS_PRIO_SELF, the
* calling task will suspend itself and rescheduling will occur.
*
* Returns : OS_ERR_NONE if the requested task is suspended
* OS_ERR_TASK_SUSPEND_IDLE if you attempted to suspend the idle task which is not allowed.
* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed
* (i.e. >= OS_LOWEST_PRIO) or, you have not specified OS_PRIO_SELF.
* OS_ERR_TASK_SUSPEND_PRIO if the task to suspend does not exist
* OS_ERR_TASK_NOT_EXITS if the task is assigned to a Mutex PIP
*
* Note : You should use this function with great care. If you suspend a task that is waiting for
* an event (i.e. a message, a semaphore, a queue ...) you will prevent this task from
* running when the event arrives.
*********************************************************************************************************
*/
#if OS_TASK_SUSPEND_EN > 0u
INT8U OSTaskSuspend (INT8U prio)
{
BOOLEAN self;
OS_TCB *ptcb;
INT8U y;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#if OS_ARG_CHK_EN > 0u
if (prio == OS_TASK_IDLE_PRIO) { /* Not allowed to suspend idle task */
return (OS_ERR_TASK_SUSPEND_IDLE);
}
if (prio >= OS_LOWEST_PRIO) { /* Task priority valid ? */
if (prio != OS_PRIO_SELF) {
return (OS_ERR_PRIO_INVALID);
}
}
#endif
OS_ENTER_CRITICAL();
if (prio == OS_PRIO_SELF) { /* See if suspend SELF */
prio = OSTCBCur->OSTCBPrio;
self = OS_TRUE;
} else if (prio == OSTCBCur->OSTCBPrio) { /* See if suspending self */
self = OS_TRUE;
} else {
self = OS_FALSE; /* No suspending another task */
}
ptcb = OSTCBPrioTbl[prio];
if (ptcb == (OS_TCB *)0) { /* Task to suspend must exist */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_SUSPEND_PRIO);
}
if (ptcb == OS_TCB_RESERVED) { /* See if assigned to Mutex */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_NOT_EXIST);
}
y = ptcb->OSTCBY;
OSRdyTbl[y] &= (OS_PRIO)~ptcb->OSTCBBitX; /* Make task not ready */
if (OSRdyTbl[y] == 0u) {
OSRdyGrp &= (OS_PRIO)~ptcb->OSTCBBitY;
}
ptcb->OSTCBStat |= OS_STAT_SUSPEND; /* Status of task is ‘SUSPENDED‘ */
OS_EXIT_CRITICAL();
if (self == OS_TRUE) { /* Context switch only if SELF */
OS_Sched(); /* Find new highest priority task */
}
return (OS_ERR_NONE);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* QUERY A TASK
*
* Description: This function is called to obtain a copy of the desired task‘s TCB.
*
* Arguments : prio is the priority of the task to obtain information from.
*
* p_task_data is a pointer to where the desired task‘s OS_TCB will be stored.
*
* Returns : OS_ERR_NONE if the requested task is suspended
* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed
* (i.e. > OS_LOWEST_PRIO) or, you have not specified OS_PRIO_SELF.
* OS_ERR_PRIO if the desired task has not been created
* OS_ERR_TASK_NOT_EXIST if the task is assigned to a Mutex PIP
* OS_ERR_PDATA_NULL if ‘p_task_data‘ is a NULL pointer
*********************************************************************************************************
*/
#if OS_TASK_QUERY_EN > 0u
INT8U OSTaskQuery (INT8U prio,
OS_TCB *p_task_data)
{
OS_TCB *ptcb;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#if OS_ARG_CHK_EN > 0u
if (prio > OS_LOWEST_PRIO) { /* Task priority valid ? */
if (prio != OS_PRIO_SELF) {
return (OS_ERR_PRIO_INVALID);
}
}
if (p_task_data == (OS_TCB *)0) { /* Validate ‘p_task_data‘ */
return (OS_ERR_PDATA_NULL);
}
#endif
OS_ENTER_CRITICAL();
if (prio == OS_PRIO_SELF) { /* See if suspend SELF */
prio = OSTCBCur->OSTCBPrio;
}
ptcb = OSTCBPrioTbl[prio];
if (ptcb == (OS_TCB *)0) { /* Task to query must exist */
OS_EXIT_CRITICAL();
return (OS_ERR_PRIO);
}
if (ptcb == OS_TCB_RESERVED) { /* Task to query must not be assigned to a Mutex */
OS_EXIT_CRITICAL();
return (OS_ERR_TASK_NOT_EXIST);
}
/* Copy TCB into user storage area */
OS_MemCopy((INT8U *)p_task_data, (INT8U *)ptcb, sizeof(OS_TCB));
OS_EXIT_CRITICAL();
return (OS_ERR_NONE);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* GET THE CURRENT VALUE OF A TASK REGISTER
*
* Description: This function is called to obtain the current value of a task register. Task registers
* are application specific and can be used to store task specific values such as ‘error
* numbers‘ (i.e. errno), statistics, etc. Each task register can hold a 32-bit value.
*
* Arguments : prio is the priority of the task you want to get the task register from. If you
* specify OS_PRIO_SELF then the task register of the current task will be obtained.
*
* id is the ‘id‘ of the desired task register. Note that the ‘id‘ must be less
* than OS_TASK_REG_TBL_SIZE
*
* perr is a pointer to a variable that will hold an error code related to this call.
*
* OS_ERR_NONE if the call was successful
* OS_ERR_PRIO_INVALID if you specified an invalid priority
* OS_ERR_ID_INVALID if the ‘id‘ is not between 0 and OS_TASK_REG_TBL_SIZE-1
*
* Returns : The current value of the task‘s register or 0 if an error is detected.
*
* Note(s) : The maximum number of task variables is 254
*********************************************************************************************************
*/
#if OS_TASK_REG_TBL_SIZE > 0u
INT32U OSTaskRegGet (INT8U prio,
INT8U id,
INT8U *perr)
{
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
INT32U value;
OS_TCB *ptcb;
#ifdef OS_SAFETY_CRITICAL
if (perr == (INT8U *)0) {
OS_SAFETY_CRITICAL_EXCEPTION();
return (0u);
}
#endif
#if OS_ARG_CHK_EN > 0u
if (prio >= OS_LOWEST_PRIO) {
if (prio != OS_PRIO_SELF) {
*perr = OS_ERR_PRIO_INVALID;
return (0u);
}
}
if (id >= OS_TASK_REG_TBL_SIZE) {
*perr = OS_ERR_ID_INVALID;
return (0u);
}
#endif
OS_ENTER_CRITICAL();
if (prio == OS_PRIO_SELF) { /* See if need to get register from current task */
ptcb = OSTCBCur;
} else {
ptcb = OSTCBPrioTbl[prio];
}
value = ptcb->OSTCBRegTbl[id];
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
return (value);
}
#endif
/*$PAGE*/
/*
************************************************************************************************************************
* ALLOCATE THE NEXT AVAILABLE TASK REGISTER ID
*
* Description: This function is called to obtain a task register ID. This function thus allows task registers IDs to be
* allocated dynamically instead of statically.
*
* Arguments : p_err is a pointer to a variable that will hold an error code related to this call.
*
* OS_ERR_NONE if the call was successful
* OS_ERR_NO_MORE_ID_AVAIL if you are attempting to assign more task register IDs than you
* have available through OS_TASK_REG_TBL_SIZE.
*
* Returns : The next available task register ‘id‘ or OS_TASK_REG_TBL_SIZE if an error is detected.
************************************************************************************************************************
*/
#if OS_TASK_REG_TBL_SIZE > 0u
INT8U OSTaskRegGetID (INT8U *perr)
{
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
INT8U id;
#ifdef OS_SAFETY_CRITICAL
if (perr == (INT8U *)0) {
OS_SAFETY_CRITICAL_EXCEPTION();
return ((INT8U)OS_TASK_REG_TBL_SIZE);
}
#endif
OS_ENTER_CRITICAL();
if (OSTaskRegNextAvailID >= OS_TASK_REG_TBL_SIZE) { /* See if we exceeded the number of IDs available */
*perr = OS_ERR_NO_MORE_ID_AVAIL; /* Yes, cannot allocate more task register IDs */
OS_EXIT_CRITICAL();
return ((INT8U)OS_TASK_REG_TBL_SIZE);
}
id = OSTaskRegNextAvailID; /* Assign the next available ID */
OSTaskRegNextAvailID++; /* Increment available ID for next request */
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
return (id);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* SET THE CURRENT VALUE OF A TASK VARIABLE
*
* Description: This function is called to change the current value of a task register. Task registers
* are application specific and can be used to store task specific values such as ‘error
* numbers‘ (i.e. errno), statistics, etc. Each task register can hold a 32-bit value.
*
* Arguments : prio is the priority of the task you want to set the task register for. If you
* specify OS_PRIO_SELF then the task register of the current task will be obtained.
*
* id is the ‘id‘ of the desired task register. Note that the ‘id‘ must be less
* than OS_TASK_REG_TBL_SIZE
*
* value is the desired value for the task register.
*
* perr is a pointer to a variable that will hold an error code related to this call.
*
* OS_ERR_NONE if the call was successful
* OS_ERR_PRIO_INVALID if you specified an invalid priority
* OS_ERR_ID_INVALID if the ‘id‘ is not between 0 and OS_TASK_REG_TBL_SIZE-1
*
* Returns : The current value of the task‘s variable or 0 if an error is detected.
*
* Note(s) : The maximum number of task variables is 254
*********************************************************************************************************
*/
#if OS_TASK_REG_TBL_SIZE > 0u
void OSTaskRegSet (INT8U prio,
INT8U id,
INT32U value,
INT8U *perr)
{
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
OS_TCB *ptcb;
#ifdef OS_SAFETY_CRITICAL
if (perr == (INT8U *)0) {
OS_SAFETY_CRITICAL_EXCEPTION();
return;
}
#endif
#if OS_ARG_CHK_EN > 0u
if (prio >= OS_LOWEST_PRIO) {
if (prio != OS_PRIO_SELF) {
*perr = OS_ERR_PRIO_INVALID;
return;
}
}
if (id >= OS_TASK_REG_TBL_SIZE) {
*perr = OS_ERR_ID_INVALID;
return;
}
#endif
OS_ENTER_CRITICAL();
if (prio == OS_PRIO_SELF) { /* See if need to get register from current task */
ptcb = OSTCBCur;
} else {
ptcb = OSTCBPrioTbl[prio];
}
ptcb->OSTCBRegTbl[id] = value;
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* CATCH ACCIDENTAL TASK RETURN
*
* Description: This function is called if a task accidentally returns without deleting itself. In other
* words, a task should either be an infinite loop or delete itself if it‘s done.
*
* Arguments : none
*
* Returns : none
*
* Note(s) : This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/
void OS_TaskReturn (void)
{
OSTaskReturnHook(OSTCBCur); /* Call hook to let user decide on what to do */
#if OS_TASK_DEL_EN > 0u
(void)OSTaskDel(OS_PRIO_SELF); /* Delete task if it accidentally returns! */
#else
for (;;) {
OSTimeDly(OS_TICKS_PER_SEC);
}
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* CLEAR TASK STACK
*
* Description: This function is used to clear the stack of a task (i.e. write all zeros)
*
* Arguments : pbos is a pointer to the task‘s bottom of stack. If the configuration constant
* OS_STK_GROWTH is set to 1, the stack is assumed to grow downward (i.e. from high
* memory to low memory). ‘pbos‘ will thus point to the lowest (valid) memory
* location of the stack. If OS_STK_GROWTH is set to 0, ‘pbos‘ will point to the
* highest memory location of the stack and the stack will grow with increasing
* memory locations. ‘pbos‘ MUST point to a valid ‘free‘ data item.
*
* size is the number of ‘stack elements‘ to clear.
*
* opt contains additional information (or options) about the behavior of the task. The
* LOWER 8-bits are reserved by uC/OS-II while the upper 8 bits can be application
* specific. See OS_TASK_OPT_??? in uCOS-II.H.
*
* Returns : none
*********************************************************************************************************
*/
#if (OS_TASK_STAT_STK_CHK_EN > 0u) && (OS_TASK_CREATE_EXT_EN > 0u)
void OS_TaskStkClr (OS_STK *pbos,
INT32U size,
INT16U opt)
{
if ((opt & OS_TASK_OPT_STK_CHK) != 0x0000u) { /* See if stack checking has been enabled */
if ((opt & OS_TASK_OPT_STK_CLR) != 0x0000u) { /* See if stack needs to be cleared */
#if OS_STK_GROWTH == 1u
while (size > 0u) { /* Stack grows from HIGH to LOW memory */
size--;
*pbos++ = (OS_STK)0; /* Clear from bottom of stack and up! */
}
#else
while (size > 0u) { /* Stack grows from LOW to HIGH memory */
size--;
*pbos-- = (OS_STK)0; /* Clear from bottom of stack and down */
}
#endif
}
}
}
#endif版权声明：本文为博主原创文章，未经博主允许不得转载。
原文地址：http://blog.csdn.net/peace1213/article/details/47212433
