📄 os_core.c
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* Notes : 1) You MUST invoke OSIntEnter() and OSIntExit() in pair. In other words, for every call
* to OSIntEnter() at the beginning of the ISR you MUST have a call to OSIntExit() at the
* end of the ISR.
* 2) Rescheduling is prevented when the scheduler is locked (see OS_SchedLock())
*********************************************************************************************************
*/
void OSIntExit (void)
{
// printf("into OSIntExit\n");
if (OSRunning == TRUE)
{
OS_ENTER_CRITICAL();
if (OSIntNesting > 0)
{ /* Prevent OSIntNesting from wrapping */
OSIntNesting--;
}
if (OSIntNesting == 0)
{ /* Reschedule only if all ISRs complete ... */
if (OSLockNesting == 0)
{ /* ... and not locked. */
OS_SchedNew();
if (OSPrioHighRdy != OSPrioCur)
{ /* No Ctx Sw if current task is highest rdy */
OSTCBHighRdy = OSTCBPrioTbl[OSPrioHighRdy];
#if OS_TASK_PROFILE_EN > 0
OSTCBHighRdy->OSTCBCtxSwCtr++; /* Inc. # of context switches to this task */
#endif
OSCtxSwCtr++; /* Keep track of the number of ctx switches */
OSCtxSw();//OSIntCtxSw(); /* Perform interrupt level ctx switch */
}
}
}
OS_EXIT_CRITICAL();
}
// printf("out OSIntExit\n");
}
/*$PAGE*/
/*
*********************************************************************************************************
* PREVENT SCHEDULING
*
* Description: This function is used to prevent rescheduling to take place. This allows your application
* to prevent context switches until you are ready to permit context switching.
*
* Arguments : none
*
* Returns : none
*
* Notes : 1) You MUST invoke OSSchedLock() and OSSchedUnlock() in pair. In other words, for every
* call to OSSchedLock() you MUST have a call to OSSchedUnlock().
*********************************************************************************************************
*/
#if OS_SCHED_LOCK_EN > 0
void OSSchedLock (void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
if (OSRunning == TRUE) { /* Make sure multitasking is running */
OS_ENTER_CRITICAL();
if (OSLockNesting < 255u) { /* Prevent OSLockNesting from wrapping back to 0 */
OSLockNesting++; /* Increment lock nesting level */
}
OS_EXIT_CRITICAL();
}
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* ENABLE SCHEDULING
*
* Description: This function is used to re-allow rescheduling.
*
* Arguments : none
*
* Returns : none
*
* Notes : 1) You MUST invoke OSSchedLock() and OSSchedUnlock() in pair. In other words, for every
* call to OSSchedLock() you MUST have a call to OSSchedUnlock().
*********************************************************************************************************
*/
#if OS_SCHED_LOCK_EN > 0
void OSSchedUnlock (void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
if (OSRunning == TRUE) { /* Make sure multitasking is running */
OS_ENTER_CRITICAL();
if (OSLockNesting > 0) { /* Do not decrement if already 0 */
OSLockNesting--; /* Decrement lock nesting level */
if (OSLockNesting == 0) { /* See if scheduler is enabled and ... */
if (OSIntNesting == 0) { /* ... not in an ISR */
OS_EXIT_CRITICAL();
OS_Sched(); /* See if a HPT is ready */
} else {
OS_EXIT_CRITICAL();
}
} else {
OS_EXIT_CRITICAL();
}
} else {
OS_EXIT_CRITICAL();
}
}
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* START MULTITASKING
*
* Description: This function is used to start the multitasking process which lets uC/OS-II manages the
* task that you have created. Before you can call OSStart(), you MUST have called OSInit()
* and you MUST have created at least one task.
*
* Arguments : none
*
* Returns : none
*
* Note : OSStartHighRdy() MUST:
* a) Call OSTaskSwHook() then,
* b) Set OSRunning to TRUE.
* c) Load the context of the task pointed to by OSTCBHighRdy.
* d_ Execute the task.
*********************************************************************************************************
*/
void OSStart (void)
{
if (OSRunning == FALSE)
{
OS_SchedNew(); /* Find highest priority's task priority number */
OSPrioCur = OSPrioHighRdy;
OSTCBHighRdy = OSTCBPrioTbl[OSPrioHighRdy]; /* Point to highest priority task ready to run */
OSTCBCur = OSTCBHighRdy;
//printf("OSStart:%d %lx %lx %lx\n", OSPrioHighRdy, OSTCBPrioTbl, OSTCBHighRdy, OSTCBCur);
OSStartHighRdy(); /* Execute target specific code to start task */
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* STATISTICS INITIALIZATION
*
* Description: This function is called by your application to establish CPU usage by first determining
* how high a 32-bit counter would count to in 1 second if no other tasks were to execute
* during that time. CPU usage is then determined by a low priority task which keeps track
* of this 32-bit counter every second but this time, with other tasks running. CPU usage is
* determined by:
*
* OSIdleCtr
* CPU Usage (%) = 100 * (1 - ------------)
* OSIdleCtrMax
*
* Arguments : none
*
* Returns : none
*********************************************************************************************************
*/
#if OS_TASK_STAT_EN > 0
void OSStatInit (void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
OSTimeDly(2); /* Synchronize with clock tick */
OS_ENTER_CRITICAL();
OSIdleCtr = 0L; /* Clear idle counter */
OS_EXIT_CRITICAL();
OSTimeDly(OS_TICKS_PER_SEC / 10); /* Determine MAX. idle counter value for 1/10 second */
OS_ENTER_CRITICAL();
OSIdleCtrMax = OSIdleCtr; /* Store maximum idle counter count in 1/10 second */
OSStatRdy = TRUE;
OS_EXIT_CRITICAL();
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* PROCESS SYSTEM TICK
*
* Description: This function is used to signal to uC/OS-II the occurrence of a 'system tick' (also known
* as a 'clock tick'). This function should be called by the ticker ISR but, can also be
* called by a high priority task.
*
* Arguments : none
*
* Returns : none
*********************************************************************************************************
*/
void OSTimeTick (void)
{
OS_TCB *ptcb;
#if OS_TIME_TICK_HOOK_EN > 0
OSTimeTickHook(); /* Call user definable hook */
#endif
#if OS_TIME_GET_SET_EN > 0
OS_ENTER_CRITICAL(); /* Update the 32-bit tick counter */
OSTime++;
OS_EXIT_CRITICAL();
#endif
// printf("into OSTimeTick\n");
if (OSRunning == TRUE)
{
ptcb = OSTCBList; /* Point at first TCB in TCB list */
while (ptcb->OSTCBPrio != OS_IDLE_PRIO)
{ /* Go through all TCBs in TCB list */
OS_ENTER_CRITICAL();
if (ptcb->OSTCBDly != 0)
{ /* No, Delayed or waiting for event with TO */
if (--ptcb->OSTCBDly == 0)
{ /* Decrement nbr of ticks to end of delay */
/* Check for timeout */
if ((ptcb->OSTCBStat & OS_STAT_PEND_ANY) != OS_STAT_RDY)
{
ptcb->OSTCBStat &= ~OS_STAT_PEND_ANY; /* Yes, Clear status flag */
ptcb->OSTCBPendTO = TRUE; /* Indicate PEND timeout */
}
else
{
ptcb->OSTCBPendTO = FALSE;
}
if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) == OS_STAT_RDY)
{ /* Is task suspended? */
OSRdyGrp |= ptcb->OSTCBBitY; /* No, Make ready */
OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
}
}
}
ptcb = ptcb->OSTCBNext; /* Point at next TCB in TCB list */
OS_EXIT_CRITICAL();
}
}
// printf("out OSTimeTick\n");
}
/*$PAGE*/
/*
*********************************************************************************************************
* GET VERSION
*
* Description: This function is used to return the version number of uC/OS-II. The returned value
* corresponds to uC/OS-II's version number multiplied by 100. In other words, version 2.00
* would be returned as 200.
*
* Arguments : none
*
* Returns : the version number of uC/OS-II multiplied by 100.
*********************************************************************************************************
*/
INT16U OSVersion (void)
{
return (OS_VERSION);
}
/*$PAGE*/
/*
*********************************************************************************************************
* DUMMY FUNCTION
*
* Description: This function doesn't do anything. It is called by OSTaskDel().
*
* Arguments : none
*
* Returns : none
*********************************************************************************************************
*/
#if OS_TASK_DEL_EN > 0
void OS_Dummy (void)
{
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* MAKE TASK READY TO RUN BASED ON EVENT OCCURING
*
* Description: This function is called by other uC/OS-II services and is used to ready a task that was
* waiting for an event to occur.
*
* Arguments : pevent is a pointer to the event control block corresponding to the event.
*
* msg is a pointer to a message. This pointer is used by message oriented services
* such as MAILBOXEs and QUEUEs. The pointer is not used when called by other
* service functions.
*
* msk is a mask that is used to clear the status byte of the TCB. For example,
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