mailbox.c

最近在國外網站抓到的作業系統 以Arm為基礎去開發的

//*************************************************************************
//
//  Copyright (C) SEIKO EPSON CORP. 1997
//  All Rights Reserved
//
//  Filename : mailbox.c
//  Function : Mailbox functions
//  Revision :
//          1997/08/01  H.Matsuoka  start
//          1999/08/09  H.Matsuoka  BUG FIX(mail box link list)
//          1999/08/27  H.Matsuoka  BUG FIX(critical section)
//          1999/11/25  H.Matsuoka  Add isnd_msg
//          2000/02/23  H.Matsuoka  Fix suspend status problem
//          2000/11/30  Y.Taka      Add Enter/Return_critical_section
//          2001/01/22  Y.Taka      Add trcv_msg()
//          2001/03/08  Y.Taka      Change critical section
//
//*************************************************************************
#include "Ros33.h"
#include "internal.h"

//****************************************************************************
//***    3.3 Synchronization and Communication Functions                   ***
//****************************************************************************

//********************************************************************
//  Send Message to Mailbox
//  [Parameters]
//      ID      mbxid   MailboxID
//      T_MSG   *pk_msg Start Address of Message Packet
//  [Return Parameters]
//      ER      ercd    ErrorCode
//********************************************************************
ER snd_msg
    (
    ID      mbxid,
    T_MSG*  pk_msg
    )
{
    T_TSKCB*    pTskcb;
    T_MLBXCB*   pMlbxcb;
   // UW psr;
    UW psr;
    
#ifndef NO_ERROR_CHECK    
    if(mbxid <= 0)
    {
        return E_ID;
    }
    
    if(mbxid > MLBX_NUM)
    {
        return E_NOEXS;
    }

    if(pk_msg->pNxt != 0)
    {
        return E_PAR;
    }
#endif

	psr = ent_cri();

    pMlbxcb = &g_sMlbxcb[mbxid-1];

    if(pMlbxcb->pNxtTsk != (UW*)pMlbxcb) {      // exist mail wait task
        pTskcb = (T_TSKCB*)pMlbxcb->pNxtTsk;
        
        *(pTskcb->pMsg) = pk_msg;

        pTskcb->ubStatus &= ~TTS_WAI;  
        pTskcb->ubWaitStat &= ~TTW_MBX;

        if(pTskcb->ubIntinfo  == 0)          /* interrupt information */
        {
            ((T_SAVEDREG_MIN*)(pTskcb->uwSP))->returnvalue = E_OK; //gfd
        }

        /* clear time out task link */
        vfnDelInitMember((T_NODE*)&(pTskcb->pNxtTmoTsk));

        vfnDelAddMember((T_NODE*)&g_sReadyQueue[pTskcb->bPriority], 
                           (T_NODE*)pTskcb);

        int_dispatch();         // dispatch & disable interrupt

    } else {                // add messege to mail list
    	pMlbxcb->count++;
        if(pMlbxcb->pMsg == 0)
        {
            pMlbxcb->pMsg = pk_msg;
        } else {            // 1999/08/09  H.Matsuoka  BUG FIX
                            // (mail box link list)

            T_MSG*  pTemp; 
            pTemp = pMlbxcb->pMsg;
            while(pTemp->pNxt != 0) 
            {
                pTemp = pTemp->pNxt;
            }
            pTemp->pNxt = pk_msg;
        }

    }

    ret_cri(psr);

#ifndef NO_RETURN_VALUE
    return E_OK;
#endif
}


//********************************************************************
//  Receive Message from Mailbox
//  [Parameters]
//      ID      mbxid   MailboxID
//      TMO     tmout   Timeout
//  [Return Parameters]
//      ER      ercd    ErrorCode
//      T_MSG   *pk_msg Start Address of Message Packet
//********************************************************************
ER trcv_msg
    (
    T_MSG** ppk_msg,
    ID      mbxid,
    TMO     tmout
    )
{
    T_TSKCB*    pTskcb;
    T_MLBXCB*   pMlbxcb;
    UW psr;
    
#ifndef NO_ERROR_CHECK    
    if((g_ubIntNestCnt != 0)        // issued from task-independent portions
    || (g_ubSysStat & TSS_DDSP))    // task in dispatch disabled state
    {   
        return E_CTX;
    }

    if(mbxid <= 0)
    {
        return E_ID;
    }
    
    if(mbxid > MLBX_NUM)
    {
        return E_NOEXS;
    }
    if(tmout <= -2)
    {
        return E_PAR;
    }
#endif
    
	psr = ent_cri();

    pMlbxcb = &g_sMlbxcb[mbxid-1];

    if(pMlbxcb->pMsg == 0)  // message nothing
    {
        if (tmout == TMO_POL)
        {
			ret_cri(psr);
            return E_TMOUT;
        }

	g_pCurTsk->pMsg = ppk_msg;
        g_pCurTsk->ubStatus |= TTS_WAI;  
        g_pCurTsk->ubWaitStat |= TTW_MBX;
        
        vfnDelAddMember((T_NODE*)pMlbxcb, (T_NODE*)g_pCurTsk);
        
        /* set time out */
        if(tmout != TMO_FEVR) {
            g_pCurTsk->utime = g_sSysTime.utime;
            if (g_sSysTime.ltime > g_sSysTime.ltime + tmout)
                g_pCurTsk->utime +=  1;
            g_pCurTsk->ltime = g_sSysTime.ltime + tmout;
            vfnAddTimer((T_NODE*)&(g_pCurTsk->pNxtTmoTsk));
        }

        int_dispatch();        // dispatch & disable interrupt
		ret_cri(psr);
	    MOV_R1TOR0;		// mov r1(from the returnvalue in the stack) to ro (in asm)
        return;                // return value is E_OK or E_RLWAI

    } else {
        *ppk_msg = pMlbxcb->pMsg;
        pMlbxcb->pMsg = pMlbxcb->pMsg->pNxt;
        pMlbxcb->count--;
    }

	ret_cri(psr);
#ifndef NO_RETURN_VALUE
    return E_OK;
#endif
}