安卓修改屏幕超时后，系统不进入休眠的方法。

修改系统行为，让屏幕超时后，不去休眠。
frameworks\base\services\core\java\com\android\server\power\PowerManagerService，电源管理类，屏蔽休眠在此方法中修改。关键函数如下

@VisibleForTestingvoid setWakefulnessLocked(int wakefulness, int reason) {    if (mWakefulness != wakefulness) {        mWakefulness = wakefulness;        mWakefulnessChanging = true;        mDirty |= DIRTY_WAKEFULNESS;        if (mNotifier != null) {            mNotifier.onWakefulnessChangeStarted(wakefulness, reason);        }    }}

重点屏蔽调用这个函数的方法，即在调用这几个函数的方法开头处，如果不需要休眠，则直接返回false。
setWakefulnessLocked(WAKEFULNESS_AWAKE, 0);//这个不用屏蔽
setWakefulnessLocked(WAKEFULNESS_DOZING, reason);
setWakefulnessLocked(WAKEFULNESS_DREAMING, 0);
setWakefulnessLocked(WAKEFULNESS_ASLEEP, PowerManager.GO_TO_SLEEP_REASON_TIMEOUT);

比方说调用setWakefulnessLocked(WAKEFULNESS_ASLEEP, PowerManager.GO_TO_SLEEP_REASON_TIMEOUT);方法的方法是reallyGoToSleepNoUpdateLocked()，则在方法开头处就根据情况直接返回，不去执行休眠方法。

// Done dozing, drop everything and go to sleep.    private boolean reallyGoToSleepNoUpdateLocked(long eventTime, int uid) {        if (DEBUG_SPEW) {            Slog.d(TAG, "reallyGoToSleepNoUpdateLocked: eventTime=" + eventTime                    + ", uid=" + uid);        }        if (eventTime < mLastWakeTime || mWakefulness == WAKEFULNESS_ASLEEP                || !mBootCompleted || !mSystemReady) {            return false;        }// add by zzh @{boolean needSleep = SystemProperties.getBoolean("persist.sys.powersave.open", true);if (!needSleep) {Log.i("zzh", "reallyGoToSleepNoUpdateLocked no need sleep");return false;}// @}        Trace.traceBegin(Trace.TRACE_TAG_POWER, "reallyGoToSleep");        try {            Slog.i(TAG, "Sleeping (uid " + uid +")...");            setWakefulnessLocked(WAKEFULNESS_ASLEEP, PowerManager.GO_TO_SLEEP_REASON_TIMEOUT);        } finally {            Trace.traceEnd(Trace.TRACE_TAG_POWER);        }        return true;    }

以上修改完成后，我们仍然可以知道屏幕什么时候超时，这样我们可以在超时后做一些自己的逻辑，比如通知app层，去做灭屏（只是单纯将屏幕亮度设为0）。屏幕超时后具体执行休眠代码的位置：

/**     * Handler for asynchronous operations performed by the power manager.     */    private final class PowerManagerHandler extends Handler {        public PowerManagerHandler(Looper looper) {            super(looper, null, true /*async*/);        }        @Override        public void handleMessage(Message msg) {            switch (msg.what) {                case MSG_USER_ACTIVITY_TIMEOUT:                    // add by zzh @{boolean needSleep = SystemProperties.getBoolean("persist.sys.powersave.open", true);                    // @}// condition and else block add by zzhif (needSleep)handleUserActivityTimeout();elsesendTimeoutBroadcast();                    break;                case MSG_SANDMAN:                    handleSandman();                    break;                case MSG_SCREEN_BRIGHTNESS_BOOST_TIMEOUT:                    handleScreenBrightnessBoostTimeout();                    break;                case MSG_CHECK_FOR_LONG_WAKELOCKS:                    checkForLongWakeLocks();                    break;            }        }    }// add by zzhpublic void sendTimeoutBroadcast() {Log.i("xxx zzh", "sendTimeoutBroadcast execute"); mContext.sendBroadcast(new Intent("company.power.save.timout"));}

更多相关文章

随机推荐