OS_TASK.C
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上传日期:2022-07-13
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- /*
- *********************************************************************************************************
- * uC/OS-II
- * The Real-Time Kernel
- * TASK MANAGEMENT
- *
- * (c) Copyright 1992-2001, Jean J. Labrosse, Weston, FL
- * All Rights Reserved
- *
- * File : OS_TASK.C
- * By : Jean J. Labrosse
- *********************************************************************************************************
- */
- #ifndef OS_MASTER_FILE
- #include "includes.h"
- #endif
- /*
- *********************************************************************************************************
- * 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_NO_ERR is the call was successful
- * OS_PRIO_INVALID if the priority you specify is higher that the maximum allowed
- * (i.e. >= OS_LOWEST_PRIO)
- * OS_PRIO_EXIST if the new priority already exist.
- * OS_PRIO_ERR there is no task with the specified OLD priority (i.e. the OLD task does
- * not exist.
- *********************************************************************************************************
- */
- #if OS_TASK_CHANGE_PRIO_EN > 0
- INT8U OSTaskChangePrio (INT8U oldprio, INT8U newprio)
- {
- #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
- OS_CPU_SR cpu_sr;
- #endif
- #if OS_EVENT_EN > 0
- OS_EVENT *pevent;
- #endif
- OS_TCB *ptcb;
- INT8U x;
- INT8U y;
- INT8U bitx;
- INT8U bity;
- #if OS_ARG_CHK_EN > 0
- if ((oldprio >= OS_LOWEST_PRIO && oldprio != OS_PRIO_SELF) ||
- newprio >= OS_LOWEST_PRIO) {
- return (OS_PRIO_INVALID);
- }
- #endif
- OS_ENTER_CRITICAL();
- if (OSTCBPrioTbl[newprio] != (OS_TCB *)0) { /* New priority must not already exist */
- OS_EXIT_CRITICAL();
- return (OS_PRIO_EXIST);
- } else {
- OSTCBPrioTbl[newprio] = (OS_TCB *)1; /* Reserve the entry to prevent others */
- OS_EXIT_CRITICAL();
- y = newprio >> 3; /* Precompute to reduce INT. latency */
- bity = OSMapTbl[y];
- x = newprio & 0x07;
- bitx = OSMapTbl[x];
- OS_ENTER_CRITICAL();
- if (oldprio == OS_PRIO_SELF) { /* See if changing self */
- oldprio = OSTCBCur->OSTCBPrio; /* Yes, get priority */
- }
- if ((ptcb = OSTCBPrioTbl[oldprio]) != (OS_TCB *)0) { /* Task to change must exist */
- OSTCBPrioTbl[oldprio] = (OS_TCB *)0; /* Remove TCB from old priority */
- if ((OSRdyTbl[ptcb->OSTCBY] & ptcb->OSTCBBitX) != 0x00) { /* If task is ready make it not */
- if ((OSRdyTbl[ptcb->OSTCBY] &= ~ptcb->OSTCBBitX) == 0x00) {
- OSRdyGrp &= ~ptcb->OSTCBBitY;
- }
- OSRdyGrp |= bity; /* Make new priority ready to run */
- OSRdyTbl[y] |= bitx;
- #if OS_EVENT_EN > 0
- } else {
- if ((pevent = ptcb->OSTCBEventPtr) != (OS_EVENT *)0) { /* Remove from event wait list */
- if ((pevent->OSEventTbl[ptcb->OSTCBY] &= ~ptcb->OSTCBBitX) == 0) {
- pevent->OSEventGrp &= ~ptcb->OSTCBBitY;
- }
- pevent->OSEventGrp |= bity; /* Add new priority to wait list */
- pevent->OSEventTbl[y] |= bitx;
- }
- #endif
- }
- OSTCBPrioTbl[newprio] = ptcb; /* Place pointer to TCB @ new priority */
- ptcb->OSTCBPrio = newprio; /* Set new task priority */
- ptcb->OSTCBY = y;
- ptcb->OSTCBX = x;
- ptcb->OSTCBBitY = bity;
- ptcb->OSTCBBitX = bitx;
- OS_EXIT_CRITICAL();
- OS_Sched(); /* Run highest priority task ready */
- return (OS_NO_ERR);
- } else {
- OSTCBPrioTbl[newprio] = (OS_TCB *)0; /* Release the reserved prio. */
- OS_EXIT_CRITICAL();
- return (OS_PRIO_ERR); /* Task to change didn't exist */
- }
- }
- }
- #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
- *
- * pdata 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 'pdata' as follows:
- *
- * void Task (void *pdata)
- * {
- * 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_NO_ERR if the function was successful.
- * OS_PRIO_EXIT if the task priority already exist
- * (each task MUST have a unique priority).
- * OS_PRIO_INVALID if the priority you specify is higher that the maximum allowed
- * (i.e. >= OS_LOWEST_PRIO)
- *********************************************************************************************************
- */
- #if OS_TASK_CREATE_EN > 0
- INT8U OSTaskCreate (void (*task)(void *pd), void *pdata, OS_STK *ptos, INT8U prio)
- {
- #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
- OS_CPU_SR cpu_sr;
- #endif
- OS_STK *psp;
- INT8U err;
- #if OS_ARG_CHK_EN > 0
- if (prio > OS_LOWEST_PRIO) { /* Make sure priority is within allowable range */
- return (OS_PRIO_INVALID);
- }
- #endif
- OS_ENTER_CRITICAL();
- if (OSTCBPrioTbl[prio] == (OS_TCB *)0) { /* Make sure task doesn't already exist at this priority */
- OSTCBPrioTbl[prio] = (OS_TCB *)1; /* Reserve the priority to prevent others from doing ... */
- /* ... the same thing until task is created. */
- OS_EXIT_CRITICAL();
- psp = (OS_STK *)OSTaskStkInit(task, pdata, ptos, 0); /* Initialize the task's stack */
- err = OS_TCBInit(prio, psp, (OS_STK *)0, 0, 0, (void *)0, 0);
- if (err == OS_NO_ERR) {
- OS_ENTER_CRITICAL();
- OSTaskCtr++; /* Increment the #tasks counter */
- OS_EXIT_CRITICAL();
- if (OSRunning == 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_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
- *
- * pdata 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 'pdata' as follows:
- *
- * void Task (void *pdata)
- * {
- * 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. 'pstk' 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.
- *
- * Returns : OS_NO_ERR if the function was successful.
- * OS_PRIO_EXIT if the task priority already exist
- * (each task MUST have a unique priority).
- * OS_PRIO_INVALID if the priority you specify is higher that the maximum allowed
- * (i.e. > OS_LOWEST_PRIO)
- *********************************************************************************************************
- */
- /*$PAGE*/
- #if OS_TASK_CREATE_EXT_EN > 0
- INT8U OSTaskCreateExt (void (*task)(void *pd),
- void *pdata,
- OS_STK *ptos,
- INT8U prio,
- INT16U id,
- OS_STK *pbos,
- INT32U stk_size,
- void *pext,
- INT16U opt)
- {
- #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
- OS_CPU_SR cpu_sr;
- #endif
- OS_STK *psp;
- INT8U err;
- #if OS_ARG_CHK_EN > 0
- if (prio > OS_LOWEST_PRIO) { /* Make sure priority is within allowable range */
- return (OS_PRIO_INVALID);
- }
- #endif
- OS_ENTER_CRITICAL();
- if (OSTCBPrioTbl[prio] == (OS_TCB *)0) { /* Make sure task doesn't already exist at this priority */
- OSTCBPrioTbl[prio] = (OS_TCB *)1; /* Reserve the priority to prevent others from doing ... */
- /* ... the same thing until task is created. */
- OS_EXIT_CRITICAL();
- if (((opt & OS_TASK_OPT_STK_CHK) != 0x0000) || /* See if stack checking has been enabled */
- ((opt & OS_TASK_OPT_STK_CLR) != 0x0000)) { /* See if stack needs to be cleared */
- #if OS_STK_GROWTH == 1
- (void)memset(pbos, 0, stk_size * sizeof(OS_STK));
- #else
- (void)memset(ptos, 0, stk_size * sizeof(OS_STK));
- #endif
- }
- psp = (OS_STK *)OSTaskStkInit(task, pdata, ptos, opt); /* Initialize the task's stack */
- err = OS_TCBInit(prio, psp, pbos, id, stk_size, pext, opt);
- if (err == OS_NO_ERR) {
- OS_ENTER_CRITICAL();
- OSTaskCtr++; /* Increment the #tasks counter */
- OS_EXIT_CRITICAL();
- if (OSRunning == TRUE) { /* Find HPT if multitasking has started */
- OS_Sched();
- }
- } else {
- OS_ENTER_CRITICAL();
- OSTCBPrioTbl[prio] = (OS_TCB *)0; /* Make this priority avail. to others */
- OS_EXIT_CRITICAL();
- }
- return (err);
- }
- OS_EXIT_CRITICAL();
- return (OS_PRIO_EXIST);
- }
- #endif
- /*$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_NO_ERR if the call is successful
- * OS_TASK_DEL_IDLE if you attempted to delete uC/OS-II's idle task
- * OS_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_TASK_DEL_ERR if the task you want to delete does not exist
- * OS_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.
- *********************************************************************************************************
- */
- /*$PAGE*/
- #if OS_TASK_DEL_EN > 0
- INT8U OSTaskDel (INT8U prio)
- {
- #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
- OS_CPU_SR cpu_sr;
- #endif
- #if OS_EVENT_EN > 0
- OS_EVENT *pevent;
- #endif
- #if (OS_VERSION >= 251) && (OS_FLAG_EN > 0) && (OS_MAX_FLAGS > 0)
- OS_FLAG_NODE *pnode;
- #endif
- OS_TCB *ptcb;
- if (OSIntNesting > 0) { /* See if trying to delete from ISR */
- return (OS_TASK_DEL_ISR);
- }
- #if OS_ARG_CHK_EN > 0
- if (prio == OS_IDLE_PRIO) { /* Not allowed to delete idle task */
- return (OS_TASK_DEL_IDLE);
- }
- if (prio >= OS_LOWEST_PRIO && prio != OS_PRIO_SELF) { /* Task priority valid ? */
- return (OS_PRIO_INVALID);
- }
- #endif
- OS_ENTER_CRITICAL();
- if (prio == OS_PRIO_SELF) { /* See if requesting to delete self */
- prio = OSTCBCur->OSTCBPrio; /* Set priority to delete to current */
- }
- if ((ptcb = OSTCBPrioTbl[prio]) != (OS_TCB *)0) { /* Task to delete must exist */
- if ((OSRdyTbl[ptcb->OSTCBY] &= ~ptcb->OSTCBBitX) == 0x00) { /* Make task not ready */
- OSRdyGrp &= ~ptcb->OSTCBBitY;
- }
- #if OS_EVENT_EN > 0
- pevent = ptcb->OSTCBEventPtr;
- if (pevent != (OS_EVENT *)0) { /* If task is waiting on event */
- if ((pevent->OSEventTbl[ptcb->OSTCBY] &= ~ptcb->OSTCBBitX) == 0) { /* ... remove task from */
- pevent->OSEventGrp &= ~ptcb->OSTCBBitY; /* ... event ctrl block */
- }
- }
- #endif
- #if (OS_VERSION >= 251) && (OS_FLAG_EN > 0) && (OS_MAX_FLAGS > 0)
- 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 = 0; /* Prevent OSTimeTick() from updating */
- ptcb->OSTCBStat = OS_STAT_RDY; /* Prevent task from being resumed */
- if (OSLockNesting < 255) {
- OSLockNesting++;
- }
- OS_EXIT_CRITICAL(); /* Enabling INT. ignores next instruc. */
- OS_Dummy(); /* ... Dummy ensures that INTs will be */
- OS_ENTER_CRITICAL(); /* ... disabled HERE! */
- if (OSLockNesting > 0) {
- 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;
- OS_EXIT_CRITICAL();
- OS_Sched(); /* Find new highest priority task */
- return (OS_NO_ERR);
- }
- OS_EXIT_CRITICAL();
- return (OS_TASK_DEL_ERR);
- }
- #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_TASK_DEL_REQ, another task requested a task delete. Task #10 would look like
- * this:
- *
- * void Task(void *data)
- * {
- * .
- * .
- * while (1) {
- * OSTimeDly(1);
- * if (OSTaskDelReq(OS_PRIO_SELF) == OS_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_NO_ERR if the task exist and the request has been registered
- * OS_TASK_NOT_EXIST if the task has been deleted. This allows the caller to know whether
- * the request has been executed.
- * OS_TASK_DEL_IDLE if you requested to delete uC/OS-II's idle task
- * OS_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_TASK_DEL_REQ if a task (possibly another task) requested that the running task be
- * deleted.
- *********************************************************************************************************
- */
- /*$PAGE*/
- #if OS_TASK_DEL_EN > 0
- INT8U OSTaskDelReq (INT8U prio)
- {
- #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
- OS_CPU_SR cpu_sr;
- #endif
- BOOLEAN stat;
- INT8U err;
- OS_TCB *ptcb;
- #if OS_ARG_CHK_EN > 0
- if (prio == OS_IDLE_PRIO) { /* Not allowed to delete idle task */
- return (OS_TASK_DEL_IDLE);
- }
- if (prio >= OS_LOWEST_PRIO && prio != OS_PRIO_SELF) { /* Task priority valid ? */
- return (OS_PRIO_INVALID);
- }
- #endif
- if (prio == OS_PRIO_SELF) { /* See if a task is requesting to ... */
- OS_ENTER_CRITICAL(); /* ... this task to delete itself */
- stat = OSTCBCur->OSTCBDelReq; /* Return request status to caller */
- OS_EXIT_CRITICAL();
- return (stat);
- }
- OS_ENTER_CRITICAL();
- if ((ptcb = OSTCBPrioTbl[prio]) != (OS_TCB *)0) { /* Task to delete must exist */
- ptcb->OSTCBDelReq = OS_TASK_DEL_REQ; /* Set flag indicating task to be DEL. */
- err = OS_NO_ERR;
- } else {
- err = OS_TASK_NOT_EXIST; /* Task must be deleted */
- }
- OS_EXIT_CRITICAL();
- return (err);
- }
- #endif
- /*$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_NO_ERR if the requested task is resumed
- * OS_PRIO_INVALID if the priority you specify is higher that the maximum allowed
- * (i.e. >= OS_LOWEST_PRIO)
- * OS_TASK_RESUME_PRIO if the task to resume does not exist
- * OS_TASK_NOT_SUSPENDED if the task to resume has not been suspended
- *********************************************************************************************************
- */
- #if OS_TASK_SUSPEND_EN > 0
- INT8U OSTaskResume (INT8U prio)
- {
- #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
- OS_CPU_SR cpu_sr;
- #endif
- OS_TCB *ptcb;
- #if OS_ARG_CHK_EN > 0
- if (prio >= OS_LOWEST_PRIO) { /* Make sure task priority is valid */
- return (OS_PRIO_INVALID);
- }
- #endif
- OS_ENTER_CRITICAL();
- if ((ptcb = OSTCBPrioTbl[prio]) == (OS_TCB *)0) { /* Task to suspend must exist */
- OS_EXIT_CRITICAL();
- return (OS_TASK_RESUME_PRIO);
- }
- if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) != 0x00) { /* Task must be suspended */
- if (((ptcb->OSTCBStat &= ~OS_STAT_SUSPEND) == OS_STAT_RDY) && /* Remove suspension */
- (ptcb->OSTCBDly == 0)) { /* Must not be delayed */
- OSRdyGrp |= ptcb->OSTCBBitY; /* Make task ready to run */
- OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
- OS_EXIT_CRITICAL();
- OS_Sched();
- } else {
- OS_EXIT_CRITICAL();
- }
- return (OS_NO_ERR);
- }
- OS_EXIT_CRITICAL();
- return (OS_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
- *
- * pdata is a pointer to a data structure of type OS_STK_DATA.
- *
- * Returns : OS_NO_ERR upon success
- * OS_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_TASK_NOT_EXIST if the desired task has not been created
- * OS_TASK_OPT_ERR if you did NOT specified OS_TASK_OPT_STK_CHK when the task was created
- *********************************************************************************************************
- */
- #if OS_TASK_CREATE_EXT_EN > 0
- INT8U OSTaskStkChk (INT8U prio, OS_STK_DATA *pdata)
- {
- #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
- OS_CPU_SR cpu_sr;
- #endif
- OS_TCB *ptcb;
- OS_STK *pchk;
- INT32U free;
- INT32U size;
- #if OS_ARG_CHK_EN > 0
- if (prio > OS_LOWEST_PRIO && prio != OS_PRIO_SELF) { /* Make sure task priority is valid */
- return (OS_PRIO_INVALID);
- }
- #endif
- pdata->OSFree = 0; /* Assume failure, set to 0 size */
- pdata->OSUsed = 0;
- 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_TASK_NOT_EXIST);
- }
- if ((ptcb->OSTCBOpt & OS_TASK_OPT_STK_CHK) == 0) { /* Make sure stack checking option is set */
- OS_EXIT_CRITICAL();
- return (OS_TASK_OPT_ERR);
- }
- free = 0;
- size = ptcb->OSTCBStkSize;
- pchk = ptcb->OSTCBStkBottom;
- OS_EXIT_CRITICAL();
- #if OS_STK_GROWTH == 1
- while (*pchk++ == (OS_STK)0) { /* Compute the number of zero entries on the stk */
- free++;
- }
- #else
- while (*pchk-- == (OS_STK)0) {
- free++;
- }
- #endif
- pdata->OSFree = free * sizeof(OS_STK); /* Compute number of free bytes on the stack */
- pdata->OSUsed = (size - free) * sizeof(OS_STK); /* Compute number of bytes used on the stack */
- return (OS_NO_ERR);
- }
- #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_NO_ERR if the requested task is suspended
- * OS_TASK_SUSPEND_IDLE if you attempted to suspend the idle task which is not allowed.
- * OS_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_TASK_SUSPEND_PRIO if the task to suspend does not exist
- *
- * 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 > 0
- INT8U OSTaskSuspend (INT8U prio)
- {
- #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
- OS_CPU_SR cpu_sr;
- #endif
- BOOLEAN self;
- OS_TCB *ptcb;
- #if OS_ARG_CHK_EN > 0
- if (prio == OS_IDLE_PRIO) { /* Not allowed to suspend idle task */
- return (OS_TASK_SUSPEND_IDLE);
- }
- if (prio >= OS_LOWEST_PRIO && prio != OS_PRIO_SELF) { /* Task priority valid ? */
- return (OS_PRIO_INVALID);
- }
- #endif
- OS_ENTER_CRITICAL();
- if (prio == OS_PRIO_SELF) { /* See if suspend SELF */
- prio = OSTCBCur->OSTCBPrio;
- self = TRUE;
- } else if (prio == OSTCBCur->OSTCBPrio) { /* See if suspending self */
- self = TRUE;
- } else {
- self = FALSE; /* No suspending another task */
- }
- if ((ptcb = OSTCBPrioTbl[prio]) == (OS_TCB *)0) { /* Task to suspend must exist */
- OS_EXIT_CRITICAL();
- return (OS_TASK_SUSPEND_PRIO);
- }
- if ((OSRdyTbl[ptcb->OSTCBY] &= ~ptcb->OSTCBBitX) == 0x00) { /* Make task not ready */
- OSRdyGrp &= ~ptcb->OSTCBBitY;
- }
- ptcb->OSTCBStat |= OS_STAT_SUSPEND; /* Status of task is 'SUSPENDED' */
- OS_EXIT_CRITICAL();
- if (self == TRUE) { /* Context switch only if SELF */
- OS_Sched();
- }
- return (OS_NO_ERR);
- }
- #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.
- *
- * Returns : OS_NO_ERR if the requested task is suspended
- * OS_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_PRIO_ERR if the desired task has not been created
- *********************************************************************************************************
- */
- #if OS_TASK_QUERY_EN > 0
- INT8U OSTaskQuery (INT8U prio, OS_TCB *pdata)
- {
- #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
- OS_CPU_SR cpu_sr;
- #endif
- OS_TCB *ptcb;
- #if OS_ARG_CHK_EN > 0
- if (prio > OS_LOWEST_PRIO && prio != OS_PRIO_SELF) { /* Task priority valid ? */
- return (OS_PRIO_INVALID);
- }
- #endif
- OS_ENTER_CRITICAL();
- if (prio == OS_PRIO_SELF) { /* See if suspend SELF */
- prio = OSTCBCur->OSTCBPrio;
- }
- if ((ptcb = OSTCBPrioTbl[prio]) == (OS_TCB *)0) { /* Task to query must exist */
- OS_EXIT_CRITICAL();
- return (OS_PRIO_ERR);
- }
- memcpy(pdata, ptcb, sizeof(OS_TCB)); /* Copy TCB into user storage area */
- OS_EXIT_CRITICAL();
- return (OS_NO_ERR);
- }
- #endif