os_core/os_event.c

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/***********************************
* Operation System Kernel File
* function: provide event entry for semaphore,mutex,flags....
* 
* File:   os_event.c
* Author: Book Chen
* Date: 2008.07.18
************************************
*/
#include "includes.h"

OS_EVENT OsEvent[OS_EVENT_MAX];
OS_EVENT *EventFreeList;
OS_EVENT_CONTROL OsEventCtrl;

void OsEventInit(void);
INT8U OsEventFreeListCheck(void);
void OsEventFreeEventPut(OS_EVENT *pOsEvent);
OS_EVENT *OsEventFreeEventGet(void);

void OsEventInit(void){
    INT8U i;
    
    OsEventCtrl.EntryNumber=0;
    EventFreeList=(OS_EVENT *)0;
    for(i=0;i<OS_EVENT_MAX;i++) OsEventFreeEventPut(&OsEvent[i]);
}
INT8U OsEventFreeListCheck(void){
    if(EventFreeList==(OS_EVENT *)0) return FALSE;
    else return TRUE;
}
void OsEventFreeEventPut(OS_EVENT *pOsEvent){   
    pOsEvent->Next=(OS_EVENT *)0;
    pOsEvent->Prev=(OS_EVENT *)0; 
    if(OsEventCtrl.EntryNumber==0){
        EventFreeList=pOsEvent;
        OsEventCtrl.EntryNumber=1;
    }
    else{
        pOsEvent->Next=EventFreeList;
        EventFreeList->Prev=pOsEvent;
        EventFreeList=pOsEvent;
        OsEventCtrl.EntryNumber++;    
    }
}
OS_EVENT *OsEventFreeEventGet(void){
    OS_EVENT *pOsEvent;

    if(EventFreeList==(OS_EVENT *)0) return (OS_EVENT *)0;
    if(EventFreeList->Next==(OS_EVENT *)0){
        pOsEvent=EventFreeList;
        EventFreeList=(OS_EVENT *)0;
        OsEventCtrl.EntryNumber=0;
    }
    else{
        pOsEvent=EventFreeList;
        EventFreeList=EventFreeList->Next;
        EventFreeList->Prev=(OS_EVENT *)0;
        OsEventCtrl.EntryNumber--;    
    }
    pOsEvent->Prev=(OS_EVENT *)0;
    pOsEvent->Next=(OS_EVENT *)0;
    return pOsEvent;
}
void OsEventPendingTaskPut(OS_EVENT *pOsEvent,OS_TCB *pOsTcb){ // add a pending task to event waiting list tail
    OS_TCB *pTcb;

    pOsTcb->Next=(OS_TCB *)0; // clear link list relationship
    pOsTcb->Prev=(OS_TCB *)0; // clear link list relationship
    if(pOsEvent->ListHead==(INT32U *)0){      
        pOsEvent->ListHead=(INT32U *)pOsTcb;
        pOsEvent->EntryNumber=1;
    }
    else{
        pTcb=(OS_TCB *)pOsEvent->ListHead;
        while(pTcb->Next!=(OS_TCB *)0) pTcb=pTcb->Next; // find last task in event pending list
        pTcb->Next=pOsTcb;
        pOsTcb->Prev=pTcb;        
        pOsEvent->EntryNumber++;
    }
}
OS_TCB *OsEventPendingTaskGet(OS_EVENT *pOsEvent){ // get the 1st task in event pending list
    OS_TCB *pTcb;

    if(pOsEvent->ListHead==(INT32U *)0) return (OS_TCB *)0;
    pTcb=(OS_TCB *)pOsEvent->ListHead;
    if(pTcb->Next==(OS_TCB *)0){     
        pOsEvent->ListHead=(INT32U *)0;
        pOsEvent->EntryNumber=0;
        return pTcb;
    }
    else{
        pOsEvent->ListHead=(INT32U *)pTcb->Next;
        pTcb->Next->Prev=(OS_TCB *)0;
        pOsEvent->EntryNumber--;
        return pTcb;
    }
}

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