?? os_core.c
字號:
#if OS_TASK_PROFILE_EN > 0
OSTCBHighRdy->OSTCBCtxSwCtr++; /* Inc. # of context switches to this task */
#endif
OSCtxSwCtr++; /* Increment context switch counter */
OS_TASK_SW(); /* Perform a context switch */
}
}
}
OS_EXIT_CRITICAL();
}
/*$PAGE*/
/*
*********************************************************************************************************
* COPY AN ASCII STRING
*
* Description: This function is called by other uC/OS-II services to copy an ASCII string from a 'source'
* string to a 'destination' string.
*
* Arguments : pdest is a pointer to the string that will be receiving the copy. Note that there MUST
* be sufficient space in the destination storage area to receive this string.
*
* psrc is a pointer to the source string. The source string MUST NOT be greater than
* 254 characters.
*
* Returns : The size of the string (excluding the NUL terminating character)
*
* Notes : 1) This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/
#if (OS_EVENT_NAME_SIZE > 1) || (OS_FLAG_NAME_SIZE > 1) || (OS_MEM_NAME_SIZE > 1) || (OS_TASK_NAME_SIZE > 1)
INT8U OS_StrCopy (char *pdest, char *psrc)
{
INT8U len;
len = 0;
while (*psrc != OS_ASCII_NUL) {
*pdest++ = *psrc++;
len++;
}
*pdest = OS_ASCII_NUL;
return (len);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* DETERMINE THE LENGTH OF AN ASCII STRING
*
* Description: This function is called by other uC/OS-II services to determine the size of an ASCII string
* (excluding the NUL character).
*
* Arguments : psrc is a pointer to the string for which we need to know the size.
*
* Returns : The size of the string (excluding the NUL terminating character)
*
* Notes : 1) This function is INTERNAL to uC/OS-II and your application should not call it.
* 2) The string to check must be less than 255 characters long.
*********************************************************************************************************
*/
#if (OS_EVENT_NAME_SIZE > 1) || (OS_FLAG_NAME_SIZE > 1) || (OS_MEM_NAME_SIZE > 1) || (OS_TASK_NAME_SIZE > 1)
INT8U OS_StrLen (char *psrc)
{
INT8U len;
len = 0;
while (*psrc != OS_ASCII_NUL) {
psrc++;
len++;
}
return (len);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* IDLE TASK
*
* Description: This task is internal to uC/OS-II and executes whenever no other higher priority tasks
* executes because they are ALL waiting for event(s) to occur.
*
* Arguments : none
*
* Returns : none
*
* Note(s) : 1) OSTaskIdleHook() is called after the critical section to ensure that interrupts will be
* enabled for at least a few instructions. On some processors (ex. Philips XA), enabling
* and then disabling interrupts didn't allow the processor enough time to have interrupts
* enabled before they were disabled again. uC/OS-II would thus never recognize
* interrupts.
* 2) This hook has been added to allow you to do such things as STOP the CPU to conserve
* power.
*********************************************************************************************************
*/
void OS_TaskIdle (void *parg)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
cpu_sr = 0; /* Prevent compiler warning */
#endif
parg = parg; /* Prevent compiler warning for not using 'parg' */
for (;;) {
OS_ENTER_CRITICAL();
OSIdleCtr++;
OS_EXIT_CRITICAL();
OSTaskIdleHook(); /* Call user definable HOOK */
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* STATISTICS TASK
*
* Description: This task is internal to uC/OS-II and is used to compute some statistics about the
* multitasking environment. Specifically, OS_TaskStat() computes the CPU usage.
* CPU usage is determined by:
*
* OSIdleCtr
* OSCPUUsage = 100 * (1 - ------------) (units are in %)
* OSIdleCtrMax
*
* Arguments : parg this pointer is not used at this time.
*
* Returns : none
*
* Notes : 1) This task runs at a priority level higher than the idle task. In fact, it runs at the
* next higher priority, OS_IDLE_PRIO-1.
* 2) You can disable this task by setting the configuration #define OS_TASK_STAT_EN to 0.
* 3) You MUST have at least a delay of 2/10 seconds to allow for the system to establish the
* maximum value for the idle counter.
*********************************************************************************************************
*/
#if OS_TASK_STAT_EN > 0
void OS_TaskStat (void *parg)
{
INT32U run;
INT32U max;
INT8S usage;
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
cpu_sr = 0; /* Prevent compiler warning */
#endif
parg = parg; /* Prevent compiler warning for not using 'parg' */
while (OSStatRdy == FALSE) {
OSTimeDly(2 * OS_TICKS_PER_SEC / 10); /* Wait until statistic task is ready */
}
max = OSIdleCtrMax / 100L;
for (;;) {
OS_ENTER_CRITICAL();
OSIdleCtrRun = OSIdleCtr; /* Obtain the of the idle counter for the past second */
run = OSIdleCtr;
OSIdleCtr = 0L; /* Reset the idle counter for the next second */
OS_EXIT_CRITICAL();
if (max > 0L) {
usage = (INT8S)(100L - run / max);
if (usage >= 0) { /* Make sure we don't have a negative percentage */
OSCPUUsage = usage;
} else {
OSCPUUsage = 0;
}
} else {
OSCPUUsage = 0;
max = OSIdleCtrMax / 100L;
}
OSTaskStatHook(); /* Invoke user definable hook */
#if (OS_TASK_STAT_STK_CHK_EN > 0) && (OS_TASK_CREATE_EXT_EN > 0)
OS_TaskStatStkChk(); /* Check the stacks for each task */
#endif
OSTimeDly(OS_TICKS_PER_SEC / 10); /* Accumulate OSIdleCtr for the next 1/10 second */
}
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* CHECK ALL TASK STACKS
*
* Description: This function is called by OS_TaskStat() to check the stacks of each active task.
*
* Arguments : none
*
* Returns : none
*********************************************************************************************************
*/
#if (OS_TASK_STAT_STK_CHK_EN > 0) && (OS_TASK_CREATE_EXT_EN > 0)
void OS_TaskStatStkChk (void)
{
OS_TCB *ptcb;
OS_STK_DATA stk_data;
INT8U err;
INT8U prio;
for (prio = 0; prio <= OS_IDLE_PRIO; prio++) {
err = OSTaskStkChk(prio, &stk_data);
if (err == OS_NO_ERR) {
ptcb = OSTCBPrioTbl[prio];
if (ptcb != (OS_TCB *)0) { /* Make sure task 'ptcb' is ... */
if (ptcb != (OS_TCB *)1) { /* ... still valid. */
#if OS_TASK_PROFILE_EN > 0
#if OS_STK_GROWTH == 1
ptcb->OSTCBStkBase = ptcb->OSTCBStkBottom + ptcb->OSTCBStkSize;
#else
ptcb->OSTCBStkBase = ptcb->OSTCBStkBottom - ptcb->OSTCBStkSize;
#endif
ptcb->OSTCBStkUsed = (INT32U)stk_data.OSUsed; /* Store the number of bytes used */
#endif
}
}
}
}
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZE TCB
*
* Description: This function is internal to uC/OS-II and is used to initialize a Task Control Block when
* a task is created (see OSTaskCreate() and OSTaskCreateExt()).
*
* Arguments : prio is the priority of the task being created
*
* ptos is a pointer to the task's top-of-stack assuming that the CPU registers
* have been placed on the stack. Note that the top-of-stack corresponds to a
* 'high' memory location is OS_STK_GROWTH is set to 1 and a 'low' memory
* location if OS_STK_GROWTH is set to 0. Note that stack growth is CPU
* specific.
*
* pbos is a pointer to the bottom of stack. A NULL pointer is passed if called by
* 'OSTaskCreate()'.
*
* id is the task's ID (0..65535)
*
* stk_size is the size of the stack (in 'stack units'). If the stack units are INT8Us
* then, 'stk_size' contains the number of bytes for the stack. If the stack
* units are INT32Us then, the stack contains '4 * stk_size' bytes. The stack
* units are established by the #define constant OS_STK which is CPU
* specific. 'stk_size' is 0 if called by 'OSTaskCreate()'.
*
* pext is a pointer to a user supplied memory area that is used to extend the task
* control block. This allows you to store the contents of floating-point
* registers, MMU registers or anything else you could find useful during a
* context switch. You can even assign a name to each task and store this name
* in this TCB extension. A NULL pointer is passed if called by OSTaskCreate().
*
* opt options as passed to 'OSTaskCreateExt()' or,
* 0 if called from 'OSTaskCreate()'.
*
* Returns : OS_NO_ERR if the call was successful
* OS_NO_MORE_TCB if there are no more free TCBs to be allocated and thus, the task cannot
* be created.
*
* Note : This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/
INT8U OS_TCBInit (INT8U prio, OS_STK *ptos, OS_STK *pbos, INT16U id, INT32U stk_size, void *pext, INT16U opt)
{
OS_TCB *ptcb;
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
cpu_sr = 0; /* Prevent compiler warning */
#endif
OS_ENTER_CRITICAL();
ptcb = OSTCBFreeList; /* Get a free TCB from the free TCB list */
if (ptcb != (OS_TCB *)0) {
OSTCBFreeList = ptcb->OSTCBNext; /* Update pointer to free TCB list */
OS_EXIT_CRITICAL();
ptcb->OSTCBStkPtr = ptos; /* Load Stack pointer in TCB */
ptcb->OSTCBPrio = prio; /* Load task priority into TCB */
ptcb->OSTCBStat = OS_STAT_RDY; /* Task is ready to run */
ptcb->OSTCBPendTO = FALSE; /* Clear the Pend timeout flag */
ptcb->OSTCBDly = 0; /* Task is not delayed */
#if OS_TASK_CREATE_EXT_EN > 0
ptcb->OSTCBExtPtr = pext; /* Store pointer to TCB extension */
ptcb->OSTCBStkSize = stk_size; /* Store stack size */
ptcb->OSTCBStkBottom = pbos; /* Store pointer to bottom of stack */
ptcb->OSTCBOpt = opt; /?? 快捷鍵說明
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