📄 os_core.lst
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837 1 ptcb1->OSTCBNext = (OS_TCB *)0; /* Last OS_TCB
- */
838 1 OSTCBFreeList = &OSTCBTbl[0];
839 1 }
840 /*$PAGE*/
841 /*
842 *********************************************************************************************************
843 * SCHEDULER
844 *
845 * Description: This function is called by other uC/OS-II services to determine whether a new, high
846 * priority task has been made ready to run. This function is invoked by TASK level code
847 * and is not used to reschedule tasks from ISRs (see OSIntExit() for ISR rescheduling).
848 *
849 * Arguments : none
850 *
851 * Returns : none
852 *
853 * Notes : 1) This function is INTERNAL to uC/OS-II and your application should not call it.
854 * 2) Rescheduling is prevented when the scheduler is locked (see OS_SchedLock())
855 *********************************************************************************************************
856 */
857
858 void OS_Sched (void)
859 {
860 1
861 1 INT8U y;
862 1
863 1
864 1 OS_ENTER_CRITICAL();
865 1 if ((OSIntNesting == 0) && (OSLockNesting == 0)) { /* Sched. only if all ISRs done & not locked */
866 2 y = OSUnMapTbl[OSRdyGrp]; /* Get pointer to HPT ready to run */
867 2 OSPrioHighRdy = (INT8U)((y << 3) + OSUnMapTbl[OSRdyTbl[y]]);
C51 COMPILER V7.50 OS_CORE 08/08/2005 12:35:30 PAGE 16
868 2 if (OSPrioHighRdy != OSPrioCur) { /* No Ctx Sw if current task is highest rdy */
869 3 OSTCBHighRdy = OSTCBPrioTbl[OSPrioHighRdy];
870 3 OSCtxSwCtr++; /* Increment context switch counter */
871 3 OS_TASK_SW(); /* Perform a context switch */
872 3 }
873 2 }
874 1 OS_EXIT_CRITICAL();
875 1 }
876 /*$PAGE*/
877 /*
878 *********************************************************************************************************
879 * IDLE TASK
880 *
881 * Description: This task is internal to uC/OS-II and executes whenever no other higher priority tasks
882 * executes because they are ALL waiting for event(s) to occur.
883 *
884 * Arguments : none
885 *
886 * Returns : none
887 *
888 * Note(s) : 1) OSTaskIdleHook() is called after the critical section to ensure that interrupts will be
889 * enabled for at least a few instructions. On some processors (ex. Philips XA), enabling
890 * and then disabling interrupts didn't allow the processor enough time to have interrupts
891 * enabled before they were disabled again. uC/OS-II would thus never recognize
892 * interrupts.
893 * 2) This hook has been added to allow you to do such things as STOP the CPU to conserve
894 * power.
895 *********************************************************************************************************
896 */
897
898 void OS_TaskIdle (void *ppdata)
899 {
900 1
901 1
902 1
903 1 ppdata = ppdata; /* Prevent compiler warning for not using 'pdata' *
-/
904 1 for (;;) {
905 2 OS_ENTER_CRITICAL();
906 2 OSIdleCtr++;
907 2 OS_EXIT_CRITICAL();
908 2 OSTaskIdleHook(); /* Call user definable HOOK */
909 2 }
910 1 }
911 /*$PAGE*/
912 /*
913 *********************************************************************************************************
914 * STATISTICS TASK
915 *
916 * Description: This task is internal to uC/OS-II and is used to compute some statistics about the
917 * multitasking environment. Specifically, OS_TaskStat() computes the CPU usage.
918 * CPU usage is determined by:
919 *
920 * OSIdleCtr
921 * OSCPUUsage = 100 * (1 - ------------) (units are in %)
922 * OSIdleCtrMax
923 *
924 * Arguments : pdata this pointer is not used at this time.
925 *
926 * Returns : none
927 *
928 * Notes : 1) This task runs at a priority level higher than the idle task. In fact, it runs at the
C51 COMPILER V7.50 OS_CORE 08/08/2005 12:35:30 PAGE 17
929 * next higher priority, OS_IDLE_PRIO-1.
930 * 2) You can disable this task by setting the configuration #define OS_TASK_STAT_EN to 0.
931 * 3) We delay for 5 seconds in the beginning to allow the system to reach steady state and
932 * have all other tasks created before we do statistics. You MUST have at least a delay
933 * of 2 seconds to allow for the system to establish the maximum value for the idle
934 * counter.
935 *********************************************************************************************************
936 */
937
938 #if OS_TASK_STAT_EN > 0
void OS_TaskStat (void *ppdata)
{
INT32U run;
INT32U max;
INT8S usage;
ppdata = ppdata; /* Prevent compiler warning for not using 'pdata' *
-/
while (OSStatRdy == FALSE) {
OSTimeDly(2 * OS_TICKS_PER_SEC); /* 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 */
OSTimeDly(OS_TICKS_PER_SEC); /* Accumulate OSIdleCtr for the next second */
}
}
#endif
974 /*$PAGE*/
975 /*
976 *********************************************************************************************************
977 * INITIALIZE TCB
978 *
979 * Description: This function is internal to uC/OS-II and is used to initialize a Task Control Block when
980 * a task is created (see OSTaskCreate() and OSTaskCreateExt()).
981 *
982 * Arguments : prio is the priority of the task being created
983 *
984 * ptos is a pointer to the task's top-of-stack assuming that the CPU registers
985 * have been placed on the stack. Note that the top-of-stack corresponds to a
986 * 'high' memory location is OS_STK_GROWTH is set to 1 and a 'low' memory
987 * location if OS_STK_GROWTH is set to 0. Note that stack growth is CPU
988 * specific.
989 *
C51 COMPILER V7.50 OS_CORE 08/08/2005 12:35:30 PAGE 18
990 * pbos is a pointer to the bottom of stack. A NULL pointer is passed if called by
991 * 'OSTaskCreate()'.
992 *
993 * id is the task's ID (0..65535)
994 *
995 * stk_size is the size of the stack (in 'stack units'). If the stack units are INT8Us
996 * then, 'stk_size' contains the number of bytes for the stack. If the stack
997 * units are INT32Us then, the stack contains '4 * stk_size' bytes. The stack
998 * units are established by the #define constant OS_STK which is CPU
999 * specific. 'stk_size' is 0 if called by 'OSTaskCreate()'.
1000 *
1001 * pext is a pointer to a user supplied memory area that is used to extend the task
1002 * control block. This allows you to store the contents of floating-point
1003 * registers, MMU registers or anything else you could find useful during a
1004 * context switch. You can even assign a name to each task and store this name
1005 * in this TCB extension. A NULL pointer is passed if called by OSTaskCreate().
1006 *
1007 * opt options as passed to 'OSTaskCreateExt()' or,
1008 * 0 if called from 'OSTaskCreate()'.
1009 *
1010 * Returns : OS_NO_ERR if the call was successful
1011 * OS_NO_MORE_TCB if there are no more free TCBs to be allocated and thus, the task cannot
1012 * be created.
1013 *
1014 * Note : This function is INTERNAL to uC/OS-II and your application should not call it.
1015 *********************************************************************************************************
1016 */
1017
1018 INT8U OS_TCBInit (INT8U prio, OS_STK *ptos, OS_STK *pbos, INT16U id, INT32U stk_size, void *pext, INT16U
-opt)
1019 {
1020 1
1021 1 OS_TCB *ptcb;
1022 1
1023 1
1024 1 OS_ENTER_CRITICAL();
1025 1 ptcb = OSTCBFreeList; /* Get a free TCB from the free TCB list */
1026 1 if (ptcb != (OS_TCB *)0) {
1027 2 OSTCBFreeList = ptcb->OSTCBNext; /* Update pointer to free TCB list */
1028 2 OS_EXIT_CRITICAL();
1029 2 ptcb->OSTCBStkPtr = ptos; /* Load Stack pointer in TCB */
1030 2 ptcb->OSTCBPrio = (INT8U)prio; /* Load task priority into TCB */
1031 2 ptcb->OSTCBStat = OS_STAT_RDY; /* Task is ready to run */
1032 2 ptcb->OSTCBDly = 0; /* Task is not delayed */
1033 2
1034 2 #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; /* Store task options */
ptcb->OSTCBId = id; /* Store task ID */
#else
1041 2 pext = pext; /* Prevent compiler warning if not used */
1042 2 stk_size = stk_size;
1043 2 pbos = pbos;
1044 2 opt = opt;
1045 2 id = id;
1046 2 #endif
1047 2
1048 2 #if OS_TASK_DEL_EN > 0
ptcb->OSTCBDelReq = OS_NO_ERR;
#endif
C51 COMPILER V7.50 OS_CORE 08/08/2005 12:35:30 PAGE 19
1051 2
1052 2 ptcb->OSTCBY = prio >> 3; /* Pre-compute X, Y, BitX and BitY */
1053 2 ptcb->OSTCBBitY = OSMapTbl[ptcb->OSTCBY];
1054 2 ptcb->OSTCBX = prio & 0x07;
1055 2 ptcb->OS⌨️ 快捷键说明
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