os_core.c

uc/fs文件系统

}
/*$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;
#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;
#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)
{
    INT8U y;
    INT8U x;


    if (OSRunning == FALSE) {
        y             = OSUnMapTbl[OSRdyGrp];        /* Find highest priority's task priority number   */
        x             = OSUnMapTbl[OSRdyTbl[y]];
        OSPrioHighRdy = (INT8U)((y << 3) + x);
        OSPrioCur     = OSPrioHighRdy;
        OSTCBHighRdy  = OSTCBPrioTbl[OSPrioHighRdy]; /* Point to highest priority task ready to run    */
        OSTCBCur      = OSTCBHighRdy;
        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;
#endif    
    
    
    OSTimeDly(2);                                /* Synchronize with clock tick                        */
    OS_ENTER_CRITICAL();
    OSIdleCtr    = 0L;                           /* Clear idle counter                                 */
    OS_EXIT_CRITICAL();
    OSTimeDly(OS_TICKS_PER_SEC);                 /* Determine MAX. idle counter value for 1 second     */
    OS_ENTER_CRITICAL();
    OSIdleCtrMax = OSIdleCtr;                    /* Store maximum idle counter count in 1 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)
{
#if OS_CRITICAL_METHOD == 3                                /* Allocate storage for CPU status register     */
    OS_CPU_SR  cpu_sr;
#endif    
    OS_TCB    *ptcb;
    BOOLEAN    step;


#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
    if (OSRunning == TRUE) {    
#if OS_TICK_STEP_EN > 0
        switch (OSTickStepState) {                         /* Determine whether we need to process a tick  */
            case OS_TICK_STEP_DIS:                         /* Yes, stepping is disabled                    */
                 step = TRUE;
                 break;
        
            case OS_TICK_STEP_WAIT:                        /* No,  waiting for uC/OS-View to set ...       */
                 step = FALSE;                             /*      .. OSTickStepState to OS_TICK_STEP_ONCE */
                 break;

            case OS_TICK_STEP_ONCE:                        /* Yes, process tick once and wait for next ... */
                 step            = TRUE;                   /*      ... step command from uC/OS-View        */
                 OSTickStepState = OS_TICK_STEP_WAIT;
                 break;  

            default:                                       /* Invalid case, correct situation              */
                 step            = TRUE;
                 OSTickStepState = OS_TICK_STEP_DIS;
                 break;
        }
#else
        step = TRUE;
#endif
        if (step == 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) {                 /* Delayed or waiting for event with TO         */
                    if (--ptcb->OSTCBDly == 0) {           /* Decrement nbr of ticks to end of delay       */
                        if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) == OS_STAT_RDY) { /* Is task suspended?    */
                            OSRdyGrp               |= ptcb->OSTCBBitY; /* No,  Make task R-to-R (timed out)*/
                            OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
                        } else {                           /* Yes, Leave 1 tick to prevent loosing the ... */
                            ptcb->OSTCBDly = 1;            /* ... task when the suspension is removed.     */
                        }
                    }
                }
                ptcb = ptcb->OSTCBNext;                    /* Point at next TCB in TCB list                */
                OS_EXIT_CRITICAL();
            }
        }
    }
}
/*$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,
*                        OSSemPost() will pass OS_STAT_SEM, OSMboxPost() will pass OS_STAT_MBOX etc.
*
* Returns    : none
*
* Note       : This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/
#if OS_EVENT_EN > 0
INT8U  OS_EventTaskRdy (OS_EVENT *pevent, void *msg, INT8U msk)
{
    OS_TCB *ptcb;
    INT8U   x;
    INT8U   y;
    INT8U   bitx;
    INT8U   bity;
    INT8U   prio;


    y                      = OSUnMapTbl[pevent->OSEventGrp];   /* Find HPT waiting for message         */
    bity                   = OSMapTbl[y];
    x                      = OSUnMapTbl[pevent->OSEventTbl[y]];
    bitx                   = OSMapTbl[x];
    prio                   = (INT8U)((y << 3) + x);   /* Find priority of task getting the msg         */
    pevent->OSEventTbl[y] &= ~bitx;                   /* Remove this task from the waiting list        */
    if (pevent->OSEventTbl[y] == 0x00) {              
        pevent->OSEventGrp &= ~bity;                  /* Clr group bit if this was only task pending   */
    }
    ptcb                 =  OSTCBPrioTbl[prio];       /* Point to this task's OS_TCB                   */
    ptcb->OSTCBDly       =  0;                        /* Prevent OSTimeTick() from readying task       */
    ptcb->OSTCBEventPtr  = (OS_EVENT *)0;             /* Unlink ECB from this task                     */
#if ((OS_Q_EN > 0) && (OS_MAX_QS > 0)) || (OS_MBOX_EN > 0)
    ptcb->OSTCBMsg       = msg;                       /* Send message directly to waiting task         */
#else
    msg                  = msg;                       /* Prevent compiler warning if not used          */
#endif
    ptcb->OSTCBStat     &= ~msk;                      /* Clear bit associated with event type          */
    if (ptcb->OSTCBStat == OS_STAT_RDY) {             /* See if task is ready (could be susp'd)        */
        OSRdyGrp        |=  bity;                     /* Put task in the ready to run list             */
        OSRdyTbl[y]     |=  bitx;
    }
    return (prio);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                   MAKE TASK WAIT FOR EVENT TO OCCUR
*
* Description: This function is called by other uC/OS-II services to suspend a task because an event has
*              not occurred.
*
* Arguments  : pevent   is a pointer to the event control block for which the task will be waiting for.
*
* Returns    : none
*
* Note       : This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/