pmsysstate.cpp

此代码为WCE5.0下电源管理的源代码

        // read the default power state and the flags -- both values
        // must be present
        dwSize = sizeof(dwDefaultDx);
        dwStatus = keyHandle->RegFindValue(_T("Default"), &dwDefaultDx, &dwSize, &dwType);
        if(dwStatus != ERROR_SUCCESS) {
            PMLOGMSG(ZONE_WARN, 
                (_T("%s: can't read default Dx from '%s', status is %d\r\n"),
                pszFname, szPath, dwStatus));
            dwRetStatus = dwStatus;
        }
        if(dwDefaultDx < D0 || dwDefaultDx > D4) {
            PMLOGMSG(ZONE_WARN,
                (_T("%s: invalid Dx value for '%s': %d\r\n"), pszFname,
                pszName, dwDefaultDx));
            dwRetStatus = ERROR_INVALID_DATA;
        }

        if(dwRetStatus == ERROR_SUCCESS) {
            dwSize = sizeof(dwFlags);
            dwStatus =keyHandle->RegFindValue( _T("Flags"), &dwFlags, &dwSize, &dwType);
            if(dwStatus != ERROR_SUCCESS) {
                PMLOGMSG(ZONE_WARN, 
                    (_T("%s: can't read flags from '%s', status is %d\r\n"),
                    pszFname, szPath, dwStatus));
                dwRetStatus = dwStatus;
            }
        }

        PMLOGMSG(dwRetStatus == ERROR_SUCCESS && ZONE_REGISTRY,
            (_T("%s: state '%s' devices max is D%d, flags 0x%08x\r\n"),
            pszFname, pszName, dwDefaultDx, dwFlags));
        if(dwRetStatus == ERROR_SUCCESS && ppsps != NULL) {
            // allocate and initialize a system power state
            PSYSTEM_POWER_STATE psps = SystemPowerStateCreate(pszName);
            if(psps == NULL) {
                dwRetStatus = ERROR_OUTOFMEMORY;
            } else {
                // initialize the structure
                psps->defaultCeilingDx = (CEDEVICE_POWER_STATE) dwDefaultDx;
                psps->dwFlags = dwFlags;
                *ppsps = psps;
            }
        }
    }

    // read device power modifiers for all associated devices
    if(dwRetStatus == ERROR_SUCCESS && ppdpr != NULL) {
        PDEVICE_POWER_RESTRICTION pdpr = RegReadDeviceRestrictions(keyHandle);
        *ppdpr = pdpr;
    }

    g_pSysRegistryAccess->LeaveLock();
    
    return dwRetStatus;
}

// This routine allows applications to determine what the current system
// power state name is.  It also passes back flag bits which provide some
// information about the state.
EXTERN_C DWORD WINAPI 
PmGetSystemPowerState(LPWSTR pBuffer, DWORD dwBufChars, PDWORD pdwFlags)
{
    DWORD dwStatus = ERROR_INVALID_PARAMETER;
    SETFNAME(_T("PmGetSystemPowerState"));
    
    PMLOGMSG(ZONE_API, (_T("+%s: buf 0x%08x, size %d, pflags 0x%08x\r\n"),
        pszFname, pBuffer, dwBufChars, pdwFlags));

    PMLOCK();

    __try {
        if(dwBufChars < (_tcslen(gpSystemPowerState->pszName) + 1)) {
            dwStatus = ERROR_INSUFFICIENT_BUFFER;
        } else {
            _tcscpy(pBuffer, gpSystemPowerState->pszName);
            *pdwFlags = gpSystemPowerState->dwFlags;
            dwStatus = ERROR_SUCCESS;
        }
    }
    __except(EXCEPTION_EXECUTE_HANDLER) {
        dwStatus = ERROR_INVALID_PARAMETER;
    }

    PMUNLOCK();

    PMLOGMSG(ZONE_API, (_T("-%s: returning %d\r\n"), pszFname, dwStatus));

    return dwStatus;
}

// This routine wraps system power state transitions.  It can be called
// from within the PM or (indirectly) by applications.  The fInternal
// flag indicates whether the invocation is from the PM or an application.
// If apps don't know the name of the state in which they're interested,
// the PM will find a mapping for them.  This routine serializes system power
// state changes using a critical section.  Drivers should not change system 
// power states while handling device power state transitions.  If they do, 
// they may deadlock the power manager.
DWORD
PmSetSystemPowerState_I(LPCWSTR pwsState, DWORD dwStateHint, DWORD dwOptions, 
                        BOOL fInternal)
{
    TCHAR szStateName[MAX_PATH];
    DWORD dwStatus = ERROR_SUCCESS;
    SETFNAME(_T("PmSetSystemPowerState_I"));

    PMLOGMSG(ZONE_API, (_T("+%s: name %s, hint 0x%08x, options 0x%08x, fInternal %d\r\n"),
        pszFname, pwsState != NULL ? pwsState : _T("<NULL>"), dwStateHint, dwOptions,
        fInternal));

    PMENTERUPDATE();

    // if the user passes a null state name, use the hints flag to try
    // to find a match.
    if(pwsState != NULL) {
        // copy the parameter but watch out for bad pointers
        __try {
            _tcsncpy(szStateName, pwsState, dim(szStateName) - 1);
            szStateName[dim(szStateName) - 1] = 0;
        }
        __except(EXCEPTION_EXECUTE_HANDLER) {
            PMLOGMSG(ZONE_WARN, (_T("%s: exception copying state name\r\n"), 
                pszFname));
            dwStatus = ERROR_INVALID_PARAMETER;
        }
    } else {
        // try to match the hint flag to a system state
        dwStatus = PlatformMapPowerStateHint(dwStateHint, szStateName, dim(szStateName));
    }
    
    // go ahead and do the update?
    if(dwStatus == ERROR_SUCCESS) {
        BOOL fForce;
        
        if((dwOptions & POWER_FORCE) != 0) {
            fForce = TRUE;
        } else {
            fForce = FALSE;
        }
        dwStatus = PlatformSetSystemPowerState(szStateName, fForce, fInternal);
    }

    PMLEAVEUPDATE();

    PMLOGMSG(ZONE_API, (_T("-%s: returning dwStatus %d\r\n"), pszFname, dwStatus));

    return dwStatus;
}

// Applications can call this routine to modify the system power state.
// If they don't know the name of the state in which they're interested,
// the PM will find a mapping for them.  Drivers should not change system 
// power states while handling device power state transitions.  If they do, 
// they may deadlock the power manager.
EXTERN_C DWORD WINAPI 
PmSetSystemPowerState(LPCWSTR pwsState, DWORD dwStateHint, DWORD dwOptions)
{
    TCHAR szState[MAX_PATH];
    LPTSTR pszStateName = NULL;
    DWORD dwStatus = ERROR_SUCCESS;
    SETFNAME(_T("PmSetSystemPowerState"));

    PMLOGMSG(ZONE_API, (_T("+%s: name %s, hint 0x%08x, options 0x%08x\r\n"),
        pszFname, pwsState != NULL ? pwsState : _T("<NULL>"), dwStateHint, dwOptions));

    // if the user passes a null state name, use the hints flag to try
    // to find a match.
    if(pwsState != NULL) {
        // copy the parameter but watch out for bad pointers
        __try {
            DWORD dwIndex;
            for(dwIndex = 0; pwsState[dwIndex] != 0 && dwIndex < (dim(szState) - 1); dwIndex++) {
                szState[dwIndex] = _totlower(pwsState[dwIndex]);
            }
            szState[dwIndex] = 0;
            pszStateName = szState;

            // don't pass on truncated system power state names
            if(pwsState[dwIndex] != 0) {
                PMLOGMSG(ZONE_WARN, 
                    (_T("%s: system power state name '%s' exceeds %d characters\r\n"), 
                    pszFname, pwsState, dim(szState) - 1));
                dwStatus = ERROR_INVALID_PARAMETER;
            }
        }
        __except(EXCEPTION_EXECUTE_HANDLER) {
            PMLOGMSG(ZONE_WARN, (_T("%s: exception copying state name\r\n"), 
                pszFname));
            dwStatus = ERROR_INVALID_PARAMETER;
        }
    }

    // carry out the power state change
    if(dwStatus == ERROR_SUCCESS) {
        dwStatus = PmSetSystemPowerState_I(pszStateName, dwStateHint, dwOptions, FALSE);
    }

    PMLOGMSG(ZONE_API, (_T("-%s: returning dwStatus %d\r\n"), pszFname, dwStatus));

    return dwStatus;
}