Android AlarmManager的运行间隔太短，无法预测。接近预期时间的最小合理间隔是多少？

Question

首先，我知道关于这方面的其他问题，例如：scheduling alarm for every second in android 5.1或How to use Android AlarmManager with small intervals like 1 minute?

因此，它基本上说，这种行为的小间隔是由于系统优化的目的。但是什么是小呢？它说的是每隔几秒钟设置一次警报器。但是几分钟呢？同样的问题？什么时间间隔将开始行为更接近预定的时间？几个小时？几天？它们似乎讨论了使用setRepeating设置重复间隔。

所以这就是我在挣扎的地方。我试着每5分钟(300000毫秒)设置一次警报，这是否仍然太小？我正试图通过set，甚至setExact或setWindow来实现这一目标。在第一次警报触发后，我设置了300000 ms的新警报。下面是我最初设置的方式：

//initially somewhere I call:
IntervalScheduler.createAlarm(context!!, 300000)
...

//which is this:
object IntervalScheduler
{
    fun createAlarm(ctx: Context, milliseconds: Long)
    {
        val intent = Intent(ctx, AlarmReceiver::class.java)
        val alarmManager = ctx.getSystemService(Context.ALARM_SERVICE) as AlarmManager
        val pendingIntent = PendingIntent.getBroadcast(ctx, 0, intent, PendingIntent.FLAG_CANCEL_CURRENT)
        if (Build.VERSION.SDK_INT >= KITKAT)
        {
            // doesn't help
            //alarmManager.setExact(AlarmManager.RTC_WAKEUP, milliseconds, 60000, pendingIntent)

            // this doesn't help as well - trying to give it a window of 1 minute
            alarmManager.setWindow(AlarmManager.RTC_WAKEUP, milliseconds, 60000, pendingIntent) // doesn't help
        }
        else
        {
            alarmManager.set(AlarmManager.RTC_WAKEUP, milliseconds, pendingIntent)
        }
    }
}

// this gets called fine
class AlarmReceiver: BroadcastReceiver()
{
    override fun onReceive(context: Context?, intent: Intent?)
    {
        Log.i("NOTE","Notifying")
        // create next alarm
        IntervalScheduler.createAlarm(context!!, 300000)
    }
}

以下是生成的日志：

09-21 22:21:53.846 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:22:54.812 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:23:55.023 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:24:00.655 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:24:06.085 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:24:11.616 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:24:17.193 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:24:22.674 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:24:28.164 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:24:33.852 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:25:34.815 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:26:57.604 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:28:14.842 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:29:14.968 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:30:15.275 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:31:15.459 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:32:15.644 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:33:15.834 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:34:15.941 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:35:16.143 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:36:17.804 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:37:17.969 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:37:23.686 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:37:29.131 26982-26982/com.sykes I/NOTE: Notifying
09-21 22:37:34.749 26982-26982/com.sykes I/NOTE: Notifying

离这儿不到5分钟。事实上，它很少超过一分钟。就像最后4个电话是在同一分钟内发生的。系统有时会优化5分钟至6-5秒？

这还像预期的那样吗？如果设定为3600000小时(1小时)还是86400000小时(24小时)，它会更接近预期吗？

Answer 1

发现我做错了什么。我用警报类型调用set (和所有其他变体)，并传递给它300000 (5分钟)。我没有意识到警报器应该在几毫秒内触发。我一直在想，从现在开始，等待的时间是毫秒。所以在此之前：

alarmManager.set(AlarmManager.RTC_WAKEUP, milliseconds, pendingIntent)

解决办法是：

alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + milliseconds, pendingIntent)

小心你。这并不意味着我能让它在短时间内正常工作。我把它做得很好--即使是很长的时间间隔。

PS。我不知道这对堆叠溢出是否有用。