/* ********************************************************************************************************* * uC/OS-II * The Real-Time Kernel * TASK MANAGEMENT * * (c) Copyright 1992-2009, Micrium, Weston, FL * All Rights Reserved * * File : OS_TASK.C * By : Jean J. Labrosse * Version : V2.91 * * 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 Micriµm 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. ********************************************************************************************************* */ #ifndef OS_MASTER_FILE #include #endif /*$PAGE*/ /* ********************************************************************************************************* * CHANGE PRIORITY OF A TASK * * Description: This function allows you to change the priority of a task dynamically. Note that the new * priority MUST be available. * * Arguments : oldp is the old priority * * newp is the new priority * * Returns : OS_ERR_NONE is the call was successful * OS_ERR_PRIO_INVALID if the priority you specify is higher that the maximum allowed * (i.e. >= OS_LOWEST_PRIO) * OS_ERR_PRIO_EXIST if the new priority already exist. * OS_ERR_PRIO there is no task with the specified OLD priority (i.e. the OLD task does * not exist. * OS_ERR_TASK_NOT_EXIST if the task is assigned to a Mutex PIP. ********************************************************************************************************* */ #if OS_TASK_CHANGE_PRIO_EN > 0u INT8U OSTaskChangePrio (INT8U oldprio, INT8U newprio) { #if (OS_EVENT_EN) OS_EVENT *pevent; #if (OS_EVENT_MULTI_EN > 0u) OS_EVENT **pevents; #endif #endif OS_TCB *ptcb; INT8U y_new; INT8U x_new; INT8U y_old; OS_PRIO bity_new; OS_PRIO bitx_new; OS_PRIO bity_old; OS_PRIO bitx_old; #if OS_CRITICAL_METHOD == 3u OS_CPU_SR cpu_sr = 0u; /* Storage for CPU status register */ #endif /*$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_PRIO_EXIT 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. ********************************************************************************************************* */ #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(); } #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_PRIO_EXIT 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. ********************************************************************************************************* */ /*$PAGE*/ #if OS_TASK_CREATE_EXT_EN > 0u INT8U OSTaskCreateExt (void (*task)(void *p_arg), void *p_arg, OS_STK *ptos, INT8U prio, INT16U id, OS_STK *pbos, INT32U stk_size, void *pext, INT16U opt) { OS_STK *psp; INT8U err; #if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0u; #endif #ifdef OS_SAFETY_CRITICAL_IEC61508 if (OSSafetyCriticalStartFlag == OS_TRUE) { OS_SAFETY_CRITICAL_EXCEPTION(); } #endif #if OS_ARG_CHK_EN > 0u if (prio > OS_LOWEST_PRIO) { /* Make sure priority is within allowable range */ return (OS_ERR_PRIO_INVALID); } #endif OS_ENTER_CRITICAL(); if (OSIntNesting > 0u) { /* Make sure we don't create the task from within an ISR */ OS_EXIT_CRITICAL(); return (OS_ERR_TASK_CREATE_ISR); } if (OSTCBPrioTbl[prio] == (OS_TCB *)0) { /* Make sure task doesn't already exist at this priority */ OSTCBPrioTbl[prio] = OS_TCB_RESERVED;/* Reserve the priority to prevent others from doing ... */ /* ... the same thing until task is created. */ OS_EXIT_CRITICAL(); #if (OS_TASK_STAT_STK_CHK_EN > 0u) OS_TaskStkClr(pbos, stk_size, opt); /* Clear the task stack (if needed) */ #endif psp = OSTaskStkInit(task, p_arg, ptos, opt); /* Initialize the task's stack */ err = OS_TCBInit(prio, psp, pbos, id, stk_size, pext, opt); if (err == OS_ERR_NONE) { if (OSRunning == OS_TRUE) { /* Find HPT if multitasking has started */ OS_Sched(); } } else { OS_ENTER_CRITICAL(); OSTCBPrioTbl[prio] = (OS_TCB *)0; /* Make this priority avail. to others */ OS_EXIT_CRITICAL(); } return (err); } OS_EXIT_CRITICAL(); return (OS_ERR_PRIO_EXIST); } #endif /*$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 explicitely 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 */ 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(); } #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(); } #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 * sizeof(OS_STK); /* Compute number of free bytes on the stack */ p_stk_data->OSUsed = (size - nfree) * sizeof(OS_STK); /* Compute number of bytes used on the stack */ 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; #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 /*$PAGE*/ /* ********************************************************************************************************* * SET THE CURRENT VALUE OF A TASK VARIABLE * * Description: This function is called to change the current value of a task register. Task registers * are application specific and can be used to store task specific values such as 'error * numbers' (i.e. errno), statistics, etc. Each task register can hold a 32-bit value. * * Arguments : prio is the priority of the task you want to set the task register for. If you * specify OS_PRIO_SELF then the task register of the current task will be obtained. * * id is the 'id' of the desired task register. Note that the 'id' must be less * than OS_TASK_REG_TBL_SIZE * * value is the desired value for the task register. * * perr is a pointer to a variable that will hold an error code related to this call. * * OS_ERR_NONE if the call was successful * OS_ERR_PRIO_INVALID if you specified an invalid priority * OS_ERR_ID_INVALID if the 'id' is not between 0 and OS_TASK_REG_TBL_SIZE-1 * * Returns : The current value of the task's variable or 0 if an error is detected. * * Note(s) : The maximum number of task variables is 254 ********************************************************************************************************* */ #if OS_TASK_REG_TBL_SIZE > 0u void OSTaskRegSet (INT8U prio, INT8U id, INT32U value, INT8U *perr) { #if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */ OS_CPU_SR cpu_sr = 0u; #endif OS_TCB *ptcb; #if OS_ARG_CHK_EN > 0u if (prio >= OS_LOWEST_PRIO) { if (prio != OS_PRIO_SELF) { *perr = OS_ERR_PRIO_INVALID; return; } } if (id >= OS_TASK_REG_TBL_SIZE) { *perr = OS_ERR_ID_INVALID; return; } #endif OS_ENTER_CRITICAL(); if (prio == OS_PRIO_SELF) { /* See if need to get register from current task */ ptcb = OSTCBCur; } else { ptcb = OSTCBPrioTbl[prio]; } ptcb->OSTCBRegTbl[id] = value; OS_EXIT_CRITICAL(); *perr = OS_ERR_NONE; } #endif /*$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