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对于有热心的小伙伴在上私信我，说我的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
OSTaskCreate()任务创建函数
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
OSTaskCreateExt任务创建函数2
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OSTaskSuspend()任务挂起：
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OSTaskResume()唤醒任务
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、附os_task.c代码：
/*********************************************************************************************************** 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#endif/*$PAGE*//*********************************************************************************************************** CHANGE PRIORITY OF A TASK** Description: This function allows you to change the priority of a task dynamically. Note that the new* priority MUST be available.** Arguments : oldp is the old priority** newp is the new priority** Returns : OS_ERR_NONE is the call was successful* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed* (i.e. >= OS_LOWEST_PRIO)* OS_ERR_PRIO_EXIST if the new priority already exist.* OS_ERR_PRIO there is no task with the specified OLD priority (i.e. the OLD task does* not exist.* OS_ERR_TASK_NOT_EXIST if the task is assigned to a Mutex PIP.**********************************************************************************************************/#if OS_TASK_CHANGE_PRIO_EN > 0uINT8U OSTaskChangePrio (INT8U oldprio, INT8U newprio){#if (OS_EVENT_EN) OS_EVENT *pevent;#if (OS_EVENT_MULTI_EN > 0u) OS_EVENT **pevents;#endif#endif OS_TCB *ptcb; INT8U y_new; INT8U x_new; INT8U y_old; OS_PRIO bity_new; OS_PRIO bitx_new; OS_PRIO bity_old; OS_PRIO bitx_old;#if OS_CRITICAL_METHOD == 3u OS_CPU_SR cpu_sr = 0u; /* Storage for CPU status register */#endif/*$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 > 0uINT8U 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.**********************************************************************************************************//*$PAGE*/#if OS_TASK_CREATE_EXT_EN > 0uINT8U OSTaskCreateExt (void (*task)(void *p_arg), void *p_arg, OS_STK *ptos, INT8U prio, INT16U id, OS_STK *pbos, INT32U stk_size, void *pext, INT16U opt){ OS_STK *psp; INT8U err;#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0u;#endif#ifdef OS_SAFETY_CRITICAL_IEC61508 if (OSSafetyCriticalStartFlag == OS_TRUE) { OS_SAFETY_CRITICAL_EXCEPTION(); return (OS_ERR_ILLEGAL_CREATE_RUN_TIME); }#endif#if OS_ARG_CHK_EN > 0u if (prio > OS_LOWEST_PRIO) { /* Make sure priority is within allowable range */ return (OS_ERR_PRIO_INVALID); }#endif OS_ENTER_CRITICAL(); if (OSIntNesting > 0u) { /* Make sure we don't create the task from within an ISR */ OS_EXIT_CRITICAL(); return (OS_ERR_TASK_CREATE_ISR); } if (OSTCBPrioTbl[prio] == (OS_TCB *)0) { /* Make sure task doesn't already exist at this priority */ OSTCBPrioTbl[prio] = OS_TCB_RESERVED;/* Reserve the priority to prevent others from doing ... */ /* ... the same thing until task is created. */ OS_EXIT_CRITICAL();#if (OS_TASK_STAT_STK_CHK_EN > 0u) OS_TaskStkClr(pbos, stk_size, opt); /* Clear the task stack (if needed) */#endif psp = OSTaskStkInit(task, p_arg, ptos, opt); /* Initialize the task's stack */ err = OS_TCBInit(prio, psp, pbos, id, stk_size, pext, opt); if (err == OS_ERR_NONE) { if (OSRunning == OS_TRUE) { /* Find HPT if multitasking has started */ OS_Sched(); } } else { OS_ENTER_CRITICAL(); OSTCBPrioTbl[prio] = (OS_TCB *)0; /* Make this priority avail. to others */ OS_EXIT_CRITICAL(); } return (err); } OS_EXIT_CRITICAL(); return (OS_ERR_PRIO_EXIST);}#endif/*$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 > 0uINT8U 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.**********************************************************************************************************//*$PAGE*/#if OS_TASK_DEL_EN > 0uINT8U OSTaskDelReq (INT8U prio){ INT8U stat; OS_TCB *ptcb;#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0u;#endif if (prio == OS_TASK_IDLE_PRIO) { /* Not allowed to delete idle task */ return (OS_ERR_TASK_DEL_IDLE); }#if OS_ARG_CHK_EN > 0u if (prio >= OS_LOWEST_PRIO) { /* Task priority valid ? */ if (prio != OS_PRIO_SELF) { return (OS_ERR_PRIO_INVALID); } }#endif if (prio == OS_PRIO_SELF) { /* See if a task is requesting to ... */ OS_ENTER_CRITICAL(); /* ... this task to delete itself */ stat = OSTCBCur->OSTCBDelReq; /* Return request status to caller */ OS_EXIT_CRITICAL(); return (stat); } OS_ENTER_CRITICAL(); ptcb = OSTCBPrioTbl[prio]; if (ptcb == (OS_TCB *)0) { /* Task to delete must exist */ OS_EXIT_CRITICAL(); return (OS_ERR_TASK_NOT_EXIST); /* Task must already be deleted */ } if (ptcb == OS_TCB_RESERVED) { /* Must NOT be assigned to a Mutex */ OS_EXIT_CRITICAL(); return (OS_ERR_TASK_DEL); } ptcb->OSTCBDelReq = OS_ERR_TASK_DEL_REQ; /* Set flag indicating task to be DEL. */ OS_EXIT_CRITICAL(); return (OS_ERR_NONE);}#endif/*$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 > 0uINT8U 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 > 0uvoid 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 > 0uINT8U 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 > 0uINT8U 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/*$PAGE*//*********************************************************************************************************** QUERY A TASK** Description: This function is called to obtain a copy of the desired task's TCB.** Arguments : prio is the priority of the task to obtain information from.** p_task_data is a pointer to where the desired task's OS_TCB will be stored.** Returns : OS_ERR_NONE if the requested task is suspended* OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed* (i.e. > OS_LOWEST_PRIO) or, you have not specified OS_PRIO_SELF.* OS_ERR_PRIO if the desired task has not been created* OS_ERR_TASK_NOT_EXIST if the task is assigned to a Mutex PIP* OS_ERR_PDATA_NULL if 'p_task_data' is a NULL pointer**********************************************************************************************************/#if OS_TASK_QUERY_EN > 0uINT8U OSTaskQuery (INT8U prio, OS_TCB *p_task_data){ OS_TCB *ptcb;#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0u;#endif#if OS_ARG_CHK_EN > 0u if (prio > OS_LOWEST_PRIO) { /* Task priority valid ? */ if (prio != OS_PRIO_SELF) { return (OS_ERR_PRIO_INVALID); } } if (p_task_data == (OS_TCB *)0) { /* Validate 'p_task_data' */ return (OS_ERR_PDATA_NULL); }#endif OS_ENTER_CRITICAL(); if (prio == OS_PRIO_SELF) { /* See if suspend SELF */ prio = OSTCBCur->OSTCBPrio; } ptcb = OSTCBPrioTbl[prio]; if (ptcb == (OS_TCB *)0) { /* Task to query must exist */ OS_EXIT_CRITICAL(); return (OS_ERR_PRIO); } if (ptcb == OS_TCB_RESERVED) { /* Task to query must not be assigned to a Mutex */ OS_EXIT_CRITICAL(); return (OS_ERR_TASK_NOT_EXIST); } /* Copy TCB into user storage area */ OS_MemCopy((INT8U *)p_task_data, (INT8U *)ptcb, sizeof(OS_TCB)); OS_EXIT_CRITICAL(); return (OS_ERR_NONE);}#endif/*$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 > 0uINT32U 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/*$PAGE*//************************************************************************************************************************** ALLOCATE THE NEXT AVAILABLE TASK REGISTER ID** Description: This function is called to obtain a task register ID. This function thus allows task registers IDs to be* allocated dynamically instead of statically.** Arguments : p_err is a pointer to a variable that will hold an error code related to this call.** OS_ERR_NONE if the call was successful* OS_ERR_NO_MORE_ID_AVAIL if you are attempting to assign more task register IDs than you * have available through OS_TASK_REG_TBL_SIZE.** Returns : The next available task register 'id' or OS_TASK_REG_TBL_SIZE if an error is detected.*************************************************************************************************************************/#if OS_TASK_REG_TBL_SIZE > 0uINT8U OSTaskRegGetID (INT8U *perr){#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0u;#endif INT8U id;#ifdef OS_SAFETY_CRITICAL if (perr == (INT8U *)0) { OS_SAFETY_CRITICAL_EXCEPTION(); return ((INT8U)OS_TASK_REG_TBL_SIZE); }#endif OS_ENTER_CRITICAL(); if (OSTaskRegNextAvailID >= OS_TASK_REG_TBL_SIZE) { /* See if we exceeded the number of IDs available */ *perr = OS_ERR_NO_MORE_ID_AVAIL; /* Yes, cannot allocate more task register IDs */ OS_EXIT_CRITICAL(); return ((INT8U)OS_TASK_REG_TBL_SIZE); } id = OSTaskRegNextAvailID; /* Assign the next available ID */ OSTaskRegNextAvailID++; /* Increment available ID for next request */ OS_EXIT_CRITICAL(); *perr = OS_ERR_NONE; return (id);}#endif/*$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 > 0uvoid 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