os_core/os_task.c

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/***********************************
* Operation System Kernel File
* Function: Task management
* 
*              
* File:   os_task.c
* Author: Book Chen
* Date: 2008.07.18
************************************
*/
#include "includes.h"

OS_TCB OsTask[OS_TASK_MAX];   // Declare total tasks in OS
OS_TASK_CONTROL OsTaskCtrl;   // Task control 

void OsTaskInit(void);
INT8U OsTaskCreat(void (*Task)(void),OS_STK *Ptos,INT8U Id,INT8U Priority);
INT8U OsTaskFreeTaskListCheck(void);
OS_TCB *OsTaskFreeTaskGet(void);
void OsTaskFreeTaskPut(OS_TCB *pOsTcb);
INT8U OsTaskSuspendTaskListCheck(INT8U Id);
OS_TCB *OsTaskSuspendTaskGet(INT8U Id);
void OsTaskSuspendTaskPut(OS_TCB *pOsTcb);
INT8U OsTaskReadyListCheck(INT8U Priority);
void OsTaskReadyTaskPut(OS_TCB *pOsTcb);
OS_TCB *OsTaskReadyTaskGet(INT8U Priority);
  
void OsTaskInit(void){
    INT8U i; 
    
    OsTaskCtrl.Status=0;
    OsTaskCtrl.FreeTaskNumber=0;
    OsTaskCtrl.SuspendTaskNumber=0;
    OsTaskCtrl.FreeList=(OS_TCB *)0;           // Initial free task list 
    OsTaskCtrl.SuspendList=(OS_TCB *)0;        // Initial pending task list
    for(i=0;i<TASK_PRIORITY_MAX;i++){
        OsTaskCtrl.ReadyListHead[i]=(OS_TCB *)0;
        OsTaskCtrl.ReadyListTail[i]=(OS_TCB *)0;
        OsTaskCtrl.ReadyTaskNumber[i]=0;        
    }
    for(i=0;i<OS_TASK_MAX;i++){                 // pust all task in free task list
        OsTask[i].Status=OS_TASK_FREE;  
        OsTask[i].Id=0;
        OsTask[i].Priority=0;
        OsTask[i].Prev=(OS_TCB *)0;           
        OsTask[i].Next=(OS_TCB *)0;
        OsTaskFreeTaskPut(&OsTask[i]);
    }                                    
}
INT8U OsTaskCreat(void (*Task)(void),OS_STK *Ptos,INT8U Id,INT8U Priority){
    OS_TCB *pOsTcb;
    
    if(OSRunning==1) OS_ENTER_CRITICAL();
    if(OsTaskFreeTaskListCheck()==FALSE) return FALSE; 
    pOsTcb=OsTaskFreeTaskGet();
    pOsTcb->Id=Id;    
    if(Priority<TASK_PRIORITY_MAX) pOsTcb->Priority=Priority;
    else pOsTcb->Priority=0;
    pOsTcb->Function=Task;
    pOsTcb->TimeDelay=0;
    pOsTcb->pEvent=(OS_EVENT *)0;     
    pOsTcb->pStack=OSTaskStkInit(Task,(void *)0,Ptos,0);     
    OsTaskReadyTaskPut(pOsTcb);
    if(OSRunning==1) OS_EXIT_CRITICAL();
    return TRUE;
}
INT8U OsTaskFreeTaskListCheck(void){
    if(OsTaskCtrl.FreeList==(OS_TCB *)0) return FALSE; 
    else return TRUE;
}
OS_TCB *OsTaskFreeTaskGet(void){
    OS_TCB *pOsTcb;
    
    if(OsTaskCtrl.FreeTaskNumber==0) return (OS_TCB *)0;  
    pOsTcb=OsTaskCtrl.FreeList;
    OsTaskCtrl.FreeList=OsTaskCtrl.FreeList->Next;
    OsTaskCtrl.FreeList->Prev=(OS_TCB *)0; 
    OsTaskCtrl.FreeTaskNumber--; 
    return pOsTcb;
}
void OsTaskFreeTaskPut(OS_TCB *pOsTcb){
    if(OsTaskCtrl.FreeList==(OS_TCB *)0){
        pOsTcb->Status=OS_TASK_FREE;
        OsTaskCtrl.FreeList=pOsTcb;
        OsTaskCtrl.FreeList->Prev=(OS_TCB *)0;        
        OsTaskCtrl.FreeList->Next=(OS_TCB *)0;
    } 
    else{
        pOsTcb->Status=OS_TASK_FREE;
        OsTaskCtrl.FreeList->Prev=pOsTcb;
        pOsTcb->Next=OsTaskCtrl.FreeList;          
        pOsTcb->Prev=(OS_TCB *)0;    
        OsTaskCtrl.FreeList=pOsTcb; 
        if(OsTaskCtrl.FreeTaskNumber<OS_TASK_MAX) OsTaskCtrl.FreeTaskNumber++;  
    }    
}
INT8U OsTaskSuspendTaskListCheck(INT8U Id){
    OS_TCB *pOsTcb;
    
    if(OsTaskCtrl.SuspendList==(OS_TCB *)0) return FALSE; 
    pOsTcb=OsTaskCtrl.SuspendList;
    while(pOsTcb!=(OS_TCB *)0){
        if(pOsTcb->Id==Id) break;
        else pOsTcb=pOsTcb->Next;
    }    
    if(pOsTcb==(OS_TCB *)0) return FALSE; 
    else return 1;
}
OS_TCB *OsTaskSuspendTaskGet(INT8U Id){
    OS_TCB *pOsTcb;
        
    pOsTcb=OsTaskCtrl.SuspendList;
    if(OsTaskCtrl.SuspendList==(OS_TCB *)0) return (OS_TCB *)0;
    while(pOsTcb!=(OS_TCB *)0){
        if(pOsTcb->Id==Id){
            if(pOsTcb==OsTaskCtrl.SuspendList){
                OsTaskCtrl.SuspendList=(OS_TCB *)0;
            }
            else{
                pOsTcb->Prev->Next=pOsTcb->Next;
                pOsTcb->Next->Prev=pOsTcb->Prev;        
            }    
            break;
        }
        else pOsTcb=pOsTcb->Next;
    }                
    if(pOsTcb==(OS_TCB *)0) return (OS_TCB *)0;  
    OsTaskCtrl.SuspendTaskNumber--;   
    return pOsTcb;
}
void OsTaskSuspendTaskPut(OS_TCB *pOsTcb){  
    if(OsTaskCtrl.SuspendList==(OS_TCB *)0){
        pOsTcb->Status=OS_TASK_SUSPEND;
        OsTaskCtrl.SuspendList=pOsTcb;
        OsTaskCtrl.SuspendList->Prev=(OS_TCB *)0;        
        OsTaskCtrl.SuspendList->Next=(OS_TCB *)0;
        OsTaskCtrl.SuspendTaskNumber=1;
    } 
    else{
        pOsTcb->Status=OS_TASK_SUSPEND;
        OsTaskCtrl.SuspendList->Prev=pOsTcb;
        pOsTcb->Next=OsTaskCtrl.SuspendList;          
        pOsTcb->Prev=(OS_TCB *)0;    
        OsTaskCtrl.SuspendList=pOsTcb; 
        OsTaskCtrl.SuspendTaskNumber++;  
    }    
}
INT8U OsTaskReadyListCheck(INT8U Priority){  // check if ready task list empty   
    if(OsTaskCtrl.ReadyListHead[Priority]==(OS_TCB *)0) return FALSE; //empty
    else return TRUE; // not empty  
}
void OsTaskReadyTaskPut(OS_TCB *pOsTcb){
    INT8U  Priority;    
    OS_TCB **pListHead;
    OS_TCB **pListTail;
    OS_TCB *pHead;
    OS_TCB *pTail;
    INT8U  *pListNumber;
    
    if(pOsTcb->Priority>=TASK_PRIORITY_MAX) return;  // no support priority level
    pOsTcb->Next=(OS_TCB *)0;                        // clean linking relationship        
    pOsTcb->Prev=(OS_TCB *)0;                        // clean linking relationship       
    pOsTcb->Status=OS_TASK_READY;        // task status ready for run
    pOsTcb->PendingType=OS_PENDING_NONE; // reset pending type
    pOsTcb->TimeDelay=0;                 // reset delay timer
    pOsTcb->pEvent=(OS_EVENT *)0;        // reset event    
    Priority=pOsTcb->Priority;                       // get task priority  
    pListHead=&OsTaskCtrl.ReadyListHead[Priority];   // get task list head related to priority
    pListTail=&OsTaskCtrl.ReadyListTail[Priority];   // get task list head related to priority
    pHead=OsTaskCtrl.ReadyListHead[Priority];        // get head os_tcb
    pTail=OsTaskCtrl.ReadyListTail[Priority];        // get tail os_tcb
    pListNumber=(INT8U *)&OsTaskCtrl.ReadyTaskNumber[Priority]; // get list task number
    if(pHead==(OS_TCB *)0){ // if list is empty, add task os_tcb to list head
        *pListHead=pOsTcb;      
        *pListTail=pOsTcb;
        *pListNumber=1;      
    }
    else{                   // if list is not empty, add task os_tcb to list head
        pHead->Prev=pOsTcb; 
        pOsTcb->Next=pHead;
        *pListHead=pOsTcb;
        *pListNumber+=1;    
    }
}
OS_TCB *OsTaskReadyTaskGet(INT8U Priority){ // get a task os_tcb from task list 
    OS_TCB **pListHead;
    OS_TCB **pListTail;
    OS_TCB *pHead;
    OS_TCB *pTail;
    OS_TCB *pOsTcb;
    INT8U  *pListNumber;
   
    pHead=OsTaskCtrl.ReadyListHead[Priority];        
    if(pHead==(OS_TCB *)0) return (OS_TCB *)0;
    pListHead=&OsTaskCtrl.ReadyListHead[Priority];
    pListTail=&OsTaskCtrl.ReadyListTail[Priority];
    pTail=OsTaskCtrl.ReadyListTail[Priority];
    pListNumber=(INT8U *)&OsTaskCtrl.ReadyTaskNumber[Priority];    
    if(pHead==pTail){
        pOsTcb=pTail;
        *pListHead=(OS_TCB *)0;
        *pListTail=(OS_TCB *)0;
        *pListNumber=0;
        pOsTcb->Next=(OS_TCB *)0;        
        pOsTcb->Prev=(OS_TCB *)0;
        return pOsTcb;
    }
    else{
        pOsTcb=pTail;        
        pTail=pTail->Prev;
        pTail->Next=(OS_TCB *)0;
        *pListTail=pTail;
        *pListNumber-=1;
        pOsTcb->Next=(OS_TCB *)0;        
        pOsTcb->Prev=(OS_TCB *)0;
        return pOsTcb;
    }    
}

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