Android关闭屏幕，但不休眠

最新推荐文章于 2024-04-23 09:00:30 发布

原创最新推荐文章于 2024-04-23 09:00:30 发布 · 4.8k 阅读

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#安卓 #android

本文详细解析了Android系统中PowerManagerService的updatePowerStateLocked方法的实现原理。该方法通过多个阶段更新设备的电源状态，包括基本状态更新、唤醒锁状态更新等。此外，还介绍了如何根据电源状态变化调整显示和休眠行为。

修改：frameworks\base\services\core\java\com\android\server\power\PowerManagerService.java

updatePowerStateLocked()方法

private void updatePowerStateLocked() {
        if (!mSystemReady || mDirty == 0) {
            return;
        }
        if (!Thread.holdsLock(mLock)) {
            Slog.wtf(TAG, "Power manager lock was not held when calling updatePowerStateLocked");
        }

        Trace.traceBegin(Trace.TRACE_TAG_POWER, "updatePowerState");
        try {
            // Phase 0: Basic state updates.
            updateIsPoweredLocked(mDirty);
            updateStayOnLocked(mDirty);
            updateScreenBrightnessBoostLocked(mDirty);

            // Phase 1: Update wakefulness.
            // Loop because the wake lock and user activity computations are influenced
            // by changes in wakefulness.
            final long now = SystemClock.uptimeMillis();
            int dirtyPhase2 = 0;
            for (;;) {
                int dirtyPhase1 = mDirty;
                dirtyPhase2 |= dirtyPhase1;
                mDirty = 0;

                updateWakeLockSummaryLocked(dirtyPhase1);
                updateUserActivitySummaryLocked(now, dirtyPhase1);
                if (!updateWakefulnessLocked(dirtyPhase1)) {
                    break;
                }
            }

            // Phase 2: Lock profiles that became inactive/not kept awake.
            updateProfilesLocked(now);

            // Phase 3: Update display power state.
            final boolean displayBecameReady = updateDisplayPowerStateLocked(dirtyPhase2);

            // Phase 4: Update dream state (depends on display ready signal).
            updateDreamLocked(dirtyPhase2, displayBecameReady);

            // Phase 5: Send notifications, if needed.
            finishWakefulnessChangeIfNeededLocked();

            // Phase 6: Update suspend blocker.
            // Because we might release the last suspend blocker here, we need to make sure
            // we finished everything else first!
            //updateSuspendBlockerLocked();     //注释掉这一行就可以了
        } finally {
            Trace.traceEnd(Trace.TRACE_TAG_POWER);
        }
    }