From d1dda43839002de5bce712befe70721215d56426 Mon Sep 17 00:00:00 2001
From: "David G. Young" <davidgyoung@gmail.com>
Date: Tue, 19 May 2015 00:10:23 -0400
Subject: [PATCH] Avoid 500 alarm limit by rescheduling alarms.

---
 .../service/scanner/CycledLeScanner.java      | 34 ++++++++++++-------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScanner.java b/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScanner.java
index 7e9e73faf..8c5270240 100644
--- a/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScanner.java
+++ b/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScanner.java
@@ -268,7 +268,6 @@ private void finishScanCycle() {
         }
     }
 
-
     protected BluetoothAdapter getBluetoothAdapter() {
         if (mBluetoothAdapter == null) {
             // Initializes Bluetooth adapter.
@@ -296,22 +295,33 @@ protected void setWakeUpAlarm() {
         if (milliseconds < mScanPeriod) {
             milliseconds = mScanPeriod;
         }
+
         AlarmManager alarmManager = (AlarmManager) mContext.getSystemService(Context.ALARM_SERVICE);
-        Intent intent = new Intent();
-        intent.setClassName(mContext, StartupBroadcastReceiver.class.getName());
-        intent.putExtra("wakeup", true);
-        cancelWakeUpAlarm();
-        mWakeUpOperation = PendingIntent.getBroadcast(mContext, 0, intent, PendingIntent.FLAG_CANCEL_CURRENT);
-        alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + milliseconds, mWakeUpOperation);
-        LogManager.d(TAG, "Set a wakeup alarm to go off in %s ms: %s", milliseconds, mWakeUpOperation);
+        alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + milliseconds, getWakeUpOperation());
+        LogManager.d(TAG, "Set a wakeup alarm to go off in %s ms: %s", milliseconds, getWakeUpOperation());
+    }
+
+    protected PendingIntent getWakeUpOperation() {
+        if (mWakeUpOperation == null) {
+            Intent wakeupIntent = new Intent();
+            //intent.setFlags(Intent.FLAG_UPDATE_CURRENT);
+            wakeupIntent.setClassName(mContext, StartupBroadcastReceiver.class.getName());
+            wakeupIntent.putExtra("wakeup", true);
+            mWakeUpOperation = PendingIntent.getBroadcast(mContext, 0, wakeupIntent, PendingIntent.FLAG_UPDATE_CURRENT);
+        }
+        return mWakeUpOperation;
     }
 
     protected void cancelWakeUpAlarm() {
         LogManager.d(TAG, "cancel wakeup alarm: %s", mWakeUpOperation);
-        if (mWakeUpOperation != null) {
-            AlarmManager alarmManager = (AlarmManager) mContext.getSystemService(Context.ALARM_SERVICE);
-            alarmManager.cancel(mWakeUpOperation);
-        }
+        // We actually don't cancel the wakup alarm... we just reschedule for a long time in the
+        // future.  This is to get around a limit on 500 alarms you can start per app on Samsung
+        // devices.
+        long milliseconds = Long.MAX_VALUE; // 2.9 million years from now
+        AlarmManager alarmManager = (AlarmManager) mContext.getSystemService(Context.ALARM_SERVICE);
+        alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + milliseconds, getWakeUpOperation());
+        LogManager.d(TAG, "Set a wakeup alarm to go off in %s ms: %s", milliseconds, getWakeUpOperation());
+
     }
 
     private long getNextScanStartTime() {