rtc关机闹钟4 AlarmManagerService.java

vim base/services/core/java/com/android/server/AlarmManagerService.java

AlarmManager 调用 IAlarmManager, AlarmManagerService 是IAlarmManager的实现

private final IBinder mService = new IAlarmManager.Stub() {
        @Override
        public void set(int type, long triggerAtTime, long windowLength, long interval, int flags,
                PendingIntent operation, WorkSource workSource,
                AlarmManager.AlarmClockInfo alarmClock) {
            final int callingUid = Binder.getCallingUid();
            if (workSource != null) {
                getContext().enforcePermission(
                        android.Manifest.permission.UPDATE_DEVICE_STATS,
                        Binder.getCallingPid(), callingUid, "AlarmManager.set");
            }

            // No incoming callers can request either WAKE_FROM_IDLE or
            // ALLOW_WHILE_IDLE_UNRESTRICTED -- we will apply those later as appropriate.
            flags &= ~(AlarmManager.FLAG_WAKE_FROM_IDLE
                    | AlarmManager.FLAG_ALLOW_WHILE_IDLE_UNRESTRICTED);

            // Only the system can use FLAG_IDLE_UNTIL -- this is used to tell the alarm
            // manager when to come out of idle mode, which is only for DeviceIdleController.
            if (callingUid != Process.SYSTEM_UID) {
                flags &= ~AlarmManager.FLAG_IDLE_UNTIL;
            }

            // If the caller is a core system component, and not calling to do work on behalf
            // of someone else, then always set ALLOW_WHILE_IDLE_UNRESTRICTED.  This means we
            // will allow these alarms to go off as normal even while idle, with no timing
            // restrictions.
            if (callingUid < Process.FIRST_APPLICATION_UID && workSource == null) {
                flags |= AlarmManager.FLAG_ALLOW_WHILE_IDLE_UNRESTRICTED;
            }

            // If this is an exact time alarm, then it can't be batched with other alarms.
            if (windowLength == AlarmManager.WINDOW_EXACT) {
                flags |= AlarmManager.FLAG_STANDALONE;
            }

            // If this alarm is for an alarm clock, then it must be standalone and we will
            // use it to wake early from idle if needed.
            if (alarmClock != null) {
                flags |= AlarmManager.FLAG_WAKE_FROM_IDLE | AlarmManager.FLAG_STANDALONE;
            }

            setImpl(type, triggerAtTime, windowLength, interval, operation,
                    flags, workSource, alarmClock, callingUid);
        }

void setImpl(int type, long triggerAtTime, long windowLength, long interval,
            PendingIntent operation, int flags, WorkSource workSource,
            AlarmManager.AlarmClockInfo alarmClock, int callingUid) {
        if (operation == null) {
            Slog.w(TAG, "set/setRepeating ignored because there is no intent");
            return;
        }

        // Sanity check the window length.  This will catch people mistakenly
        // trying to pass an end-of-window timestamp rather than a duration.
        if (windowLength > AlarmManager.INTERVAL_HALF_DAY) {
            Slog.w(TAG, "Window length " + windowLength
                    + "ms suspiciously long; limiting to 1 hour");
            windowLength = AlarmManager.INTERVAL_HOUR;
        }

        // Sanity check the recurrence interval.  This will catch people who supply
        // seconds when the API expects milliseconds.
        final long minInterval = mConstants.MIN_INTERVAL;
        if (interval > 0 && interval < minInterval) {
            Slog.w(TAG, "Suspiciously short interval " + interval
                    + " millis; expanding to " + (minInterval/1000)
                    + " seconds");
            interval = minInterval;
        }

        if (type < RTC_WAKEUP || type > ELAPSED_REALTIME) {
            throw new IllegalArgumentException("Invalid alarm type " + type);
        }

        if (triggerAtTime < 0) {
            final long what = Binder.getCallingPid();
            Slog.w(TAG, "Invalid alarm trigger time! " + triggerAtTime + " from uid=" + callingUid
                    + " pid=" + what);
            triggerAtTime = 0;
        }

        final long nowElapsed = SystemClock.elapsedRealtime();
        final long nominalTrigger = convertToElapsed(triggerAtTime, type);
        // Try to prevent spamming by making sure we aren't firing alarms in the immediate future
        final long minTrigger = nowElapsed + mConstants.MIN_FUTURITY;
        final long triggerElapsed = (nominalTrigger > minTrigger) ? nominalTrigger : minTrigger;

        final long maxElapsed;
        if (windowLength == AlarmManager.WINDOW_EXACT) {
            maxElapsed = triggerElapsed;
        } else if (windowLength < 0) {
            maxElapsed = maxTriggerTime(nowElapsed, triggerElapsed, interval);
            // Fix this window in place, so that as time approaches we don't collapse it.
            windowLength = maxElapsed - triggerElapsed;
        } else {
            maxElapsed = triggerElapsed + windowLength;
        }

        synchronized (mLock) {
            if (DEBUG_BATCH) {
                Slog.v(TAG, "set(" + operation + ") : type=" + type
                        + " triggerAtTime=" + triggerAtTime + " win=" + windowLength
                        + " tElapsed=" + triggerElapsed + " maxElapsed=" + maxElapsed
                        + " interval=" + interval + " flags=0x" + Integer.toHexString(flags));
            }
            setImplLocked(type, triggerAtTime, triggerElapsed, windowLength, maxElapsed,
                    interval, operation, flags, true, workSource, alarmClock, callingUid);
        }
    }

    private void setImplLocked(int type, long when, long whenElapsed, long windowLength,
            long maxWhen, long interval, PendingIntent operation, int flags,
            boolean doValidate, WorkSource workSource, AlarmManager.AlarmClockInfo alarmClock,
            int uid) {
        Alarm a = new Alarm(type, when, whenElapsed, windowLength, maxWhen, interval,
                operation, workSource, flags, alarmClock, uid);
        removeLocked(operation);
        setImplLocked(a, false, doValidate);
    }

    private void setImplLocked(Alarm a, boolean rebatching, boolean doValidate) {
        if ((a.flags&AlarmManager.FLAG_IDLE_UNTIL) != 0) {
            // This is a special alarm that will put the system into idle until it goes off.
            // The caller has given the time they want this to happen at, however we need
            // to pull that earlier if there are existing alarms that have requested to
            // bring us out of idle at an earlier time.
            if (mNextWakeFromIdle != null && a.whenElapsed > mNextWakeFromIdle.whenElapsed) {
                a.when = a.whenElapsed = a.maxWhenElapsed = mNextWakeFromIdle.whenElapsed;
            }
            // Add fuzz to make the alarm go off some time before the actual desired time.
            final long nowElapsed = SystemClock.elapsedRealtime();
            final int fuzz = fuzzForDuration(a.whenElapsed-nowElapsed);
            if (fuzz > 0) {
                if (mRandom == null) {
                    mRandom = new Random();
                }
                final int delta = mRandom.nextInt(fuzz);
                a.whenElapsed -= delta;
                if (false) {
                    Slog.d(TAG, "Alarm when: " + a.whenElapsed);
                    Slog.d(TAG, "Delta until alarm: " + (a.whenElapsed-nowElapsed));
                    Slog.d(TAG, "Applied fuzz: " + fuzz);
                    Slog.d(TAG, "Final delta: " + delta);
                    Slog.d(TAG, "Final when: " + a.whenElapsed);
                }
                a.when = a.maxWhenElapsed = a.whenElapsed;
            }

        } else if (mPendingIdleUntil != null) {
            // We currently have an idle until alarm scheduled; if the new alarm has
            // not explicitly stated it wants to run while idle, then put it on hold.
            if ((a.flags&(AlarmManager.FLAG_ALLOW_WHILE_IDLE
                    | AlarmManager.FLAG_ALLOW_WHILE_IDLE_UNRESTRICTED
                    | AlarmManager.FLAG_WAKE_FROM_IDLE))
                    == 0) {
                mPendingWhileIdleAlarms.add(a);
                return;
            }
        }

        int whichBatch = ((a.flags&AlarmManager.FLAG_STANDALONE) != 0)
                ? -1 : attemptCoalesceLocked(a.whenElapsed, a.maxWhenElapsed);
        if (whichBatch < 0) {
            Batch batch = new Batch(a);
            addBatchLocked(mAlarmBatches, batch);
        } else {
            Batch batch = mAlarmBatches.get(whichBatch);
            if (batch.add(a)) {
                // The start time of this batch advanced, so batch ordering may
                // have just been broken.  Move it to where it now belongs.
                mAlarmBatches.remove(whichBatch);
                addBatchLocked(mAlarmBatches, batch);
            }
        }

        if (a.alarmClock != null) {
            mNextAlarmClockMayChange = true;
        }

        boolean needRebatch = false;

        if ((a.flags&AlarmManager.FLAG_IDLE_UNTIL) != 0) {
            mPendingIdleUntil = a;
            mConstants.updateAllowWhileIdleMinTimeLocked();
            needRebatch = true;
        } else if ((a.flags&AlarmManager.FLAG_WAKE_FROM_IDLE) != 0) {
            if (mNextWakeFromIdle == null || mNextWakeFromIdle.whenElapsed > a.whenElapsed) {
                mNextWakeFromIdle = a;
                // If this wake from idle is earlier than whatever was previously scheduled,
                // and we are currently idling, then we need to rebatch alarms in case the idle
                // until time needs to be updated.
                if (mPendingIdleUntil != null) {
                    needRebatch = true;
                }
            }
        }

        if (!rebatching) {
            if (DEBUG_VALIDATE) {
                if (doValidate && !validateConsistencyLocked()) {
                    Slog.v(TAG, "Tipping-point operation: type=" + a.type + " when=" + a.when
                            + " when(hex)=" + Long.toHexString(a.when)
                            + " whenElapsed=" + a.whenElapsed
                            + " maxWhenElapsed=" + a.maxWhenElapsed
                            + " interval=" + a.repeatInterval + " op=" + a.operation
                            + " flags=0x" + Integer.toHexString(a.flags));
                    rebatchAllAlarmsLocked(false);
                    needRebatch = false;
                }
            }

            if (needRebatch) {
                rebatchAllAlarmsLocked(false);
            }

            rescheduleKernelAlarmsLocked();
            updateNextAlarmClockLocked();
        }
    }