SylixOS中的线程【13】--- 线程安全模式

为防止某些关键过程操作线程被删除或重启，SylixOS提供线程安全模式相关接口。线程进入安全模式后, 任何对本线程的删除或重启操作都会推迟到线程退出安全模式时进行。

ULONG  API_ThreadSafe (VOID)

ULONG  API_ThreadUnsafe (VOID)

BOOL    API_ThreadIsSafe (LW_OBJECT_HANDLE    ulId)

ssize_t  _TyWrite (TY_DEV_ID  ptyDev, 
                   PCHAR      pcBuffer, 
                   size_t     stNBytes)
{
             INTREG     iregInterLevel;
             
    REGISTER INT        iBytesput;
    REGISTER ssize_t    sstNbStart = stNBytes;
    
    REGISTER ULONG      ulError;
    
    if (pcBuffer == LW_NULL) {
        _ErrorHandle(EINVAL);
        return  (PX_ERROR);
    }
    
    if (stNBytes == 0) {
        return  (0);
    }
    
    LW_THREAD_SAFE();                                                   
    
    while (stNBytes > 0) {
        ulError = API_SemaphoreBPend(ptyDev->TYDEV_hWrtSyncSemB, ptyDev->TYDEV_ulWTimeout);
        if (ulError) {
            LW_THREAD_UNSAFE();
            _ErrorHandle(ERROR_IO_DEVICE_TIMEOUT);                      
            return  (sstNbStart - stNBytes);
        }
        
        TYDEV_LOCK(ptyDev, LW_THREAD_UNSAFE(); return (PX_ERROR));      
        
        if (ptyDev->TYDEV_iAbortFlag & OPT_WABORT) {                    
            ptyDev->TYDEV_iAbortFlag &= ~OPT_WABORT;                    
            TYDEV_UNLOCK(ptyDev);                                       
            LW_THREAD_UNSAFE();
            _ErrorHandle(ERROR_IO_ABORT);                               
            return  (sstNbStart - stNBytes);
        }
        
        if (ptyDev->TYDEV_tydevwrstat.TYDEVWRSTAT_bCanceled) {          
            ptyDev->TYDEV_tydevwrstat.TYDEVWRSTAT_bCanceled = LW_FALSE; 
            TYDEV_UNLOCK(ptyDev);                                       
            LW_THREAD_UNSAFE();
            _ErrorHandle(ERROR_IO_CANCELLED);
            return  (sstNbStart - stNBytes);
        }
        
        LW_SPIN_LOCK_QUICK(&ptyDev->TYDEV_slLock, &iregInterLevel);     
        iBytesput = rngBufPut(ptyDev->TYDEV_vxringidWrBuf, 
                              pcBuffer, 
                              (INT)stNBytes);                           
        LW_SPIN_UNLOCK_QUICK(&ptyDev->TYDEV_slLock, iregInterLevel);    
        
        _TyTxStartup(ptyDev);                                           
        
        stNBytes -= (size_t)iBytesput;                                  
        pcBuffer += iBytesput;                                          
    
        LW_SPIN_LOCK_QUICK(&ptyDev->TYDEV_slLock, &iregInterLevel);     
        if (rngFreeBytes(ptyDev->TYDEV_vxringidWrBuf) > 0) {
            LW_SPIN_UNLOCK_QUICK(&ptyDev->TYDEV_slLock, iregInterLevel);
            API_SemaphoreBPost(ptyDev->TYDEV_hWrtSyncSemB);             
        
        } else {
            LW_SPIN_UNLOCK_QUICK(&ptyDev->TYDEV_slLock, iregInterLevel);
        }
        
        TYDEV_UNLOCK(ptyDev);                                           
    }
    
    LW_THREAD_UNSAFE();                                                 
    
    return  (sstNbStart);
}