Minimize chance of race condition bug that misses alarms by clearing/rescheduling alarms.

This was properly fixed in the provider but this tries to minimize the bug until that fix is rolled out everywhere.

Bug:7221716
Change-Id: I4cb32b48caf31c8372770b74d7983e54480b755a

2 files changed, 67 insertions, 2 deletions

diff --git a/src/com/android/calendar/alerts/AlertService.java b/src/com/android/calendar/alerts/AlertService.java
index ac1ca26d..8c2d3d2e 100644
--- a/src/com/android/calendar/alerts/AlertService.java
+++ b/src/com/android/calendar/alerts/AlertService.java
@@ -177,8 +177,19 @@ public class AlertService extends Service {
                 action.equals(android.provider.CalendarContract.ACTION_EVENT_REMINDER) ||
                 action.equals(Intent.ACTION_LOCALE_CHANGED)) {
             updateAlertNotification(this);
-        } else if (action.equals(Intent.ACTION_BOOT_COMPLETED)
-                || action.equals(Intent.ACTION_TIME_CHANGED)) {
+        } else if (action.equals(Intent.ACTION_BOOT_COMPLETED)) {
+            // The provider usually initiates this setting up of alarms on startup,
+            // but there was a bug (b/7221716) where a race condition caused this step to be
+            // skipped, resulting in missed alarms.  This is a stopgap to minimize this bug
+            // for devices that don't have the provider fix, by initiating this a 2nd time here.
+            // However, it would still theoretically be possible to hit the race condition
+            // the 2nd time and still miss alarms.
+            //
+            // TODO: Remove this when the provider fix is rolled out everywhere.
+            Intent intent = new Intent();
+            intent.setClass(this, InitAlarmsService.class);
+            startService(intent);
+        } else if (action.equals(Intent.ACTION_TIME_CHANGED)) {
             doTimeChanged();
         } else if (action.equals(AlertReceiver.ACTION_DISMISS_OLD_REMINDERS)) {
             dismissOldAlerts(this);
diff --git a/src/com/android/calendar/alerts/InitAlarmsService.java b/src/com/android/calendar/alerts/InitAlarmsService.java
new file mode 100644
index 00000000..7655dc8c
--- /dev/null
+++ b/src/com/android/calendar/alerts/InitAlarmsService.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.calendar.alerts;
+
+import android.app.IntentService;
+import android.content.ContentValues;
+import android.content.Intent;
+import android.net.Uri;
+import android.os.SystemClock;
+import android.provider.CalendarContract;
+import android.util.Log;
+
+/**
+ * Service for clearing all scheduled alerts from the CalendarAlerts table and
+ * rescheduling them.  This is expected to be called only on boot up, to restore
+ * the AlarmManager alarms that were lost on device restart.
+ */
+public class InitAlarmsService extends IntentService {
+    private static final String TAG = "InitAlarmsService";
+    private static final String SCHEDULE_ALARM_REMOVE_PATH = "schedule_alarms_remove";
+    private static final Uri SCHEDULE_ALARM_REMOVE_URI = Uri.withAppendedPath(
+            CalendarContract.CONTENT_URI, SCHEDULE_ALARM_REMOVE_PATH);
+
+    // Delay for rescheduling the alarms must be great enough to minimize race
+    // conditions with the provider's boot up actions.
+    private static final long DELAY_MS = 30000;
+
+    public InitAlarmsService() {
+        super("InitAlarmsService");
+    }
+
+    @Override
+    protected void onHandleIntent(Intent intent) {
+        // Delay to avoid race condition of in-progress alarm scheduling in provider.
+        SystemClock.sleep(DELAY_MS);
+        Log.d(TAG, "Clearing and rescheduling alarms.");
+        getContentResolver().update(SCHEDULE_ALARM_REMOVE_URI, new ContentValues(), null,
+                null);
+    }
+}