AI 144307: am: CL 144306 Fix SDK issue 1716562 - Broadcast mechanism documentation should be improved.
Original author: ctate
Merged from: //branches/cupcake/...
Automated import of CL 144307
diff --git a/core/java/android/app/AlarmManager.java b/core/java/android/app/AlarmManager.java
index b4c0e31..53c7935 100644
--- a/core/java/android/app/AlarmManager.java
+++ b/core/java/android/app/AlarmManager.java
@@ -29,6 +29,17 @@
* if it is not already running. Registered alarms are retained while the
* device is asleep (and can optionally wake the device up if they go off
* during that time), but will be cleared if it is turned off and rebooted.
+ *
+ * <p>The Alarm Manager holds a CPU wake lock as long as the alarm receiver's
+ * onReceive() method is executing. This guarantees that the phone will not sleep
+ * until you have finished handling the broadcast. Once onReceive() returns, the
+ * Alarm Manager releases this wake lock. This means that the phone will in some
+ * cases sleep as soon as your onReceive() method completes. If your alarm receiver
+ * called {@link android.content.Context#startService Context.startService()}, it
+ * is possible that the phone will sleep before the requested service is launched.
+ * To prevent this, your BroadcastReceiver and Service will need to implement a
+ * separate wake lock policy to ensure that the phone continues running until the
+ * service becomes available.
*
* <p><b>Note: The Alarm Manager is intended for cases where you want to have
* your application code run at a specific time, even if your application is
diff --git a/core/java/android/content/BroadcastReceiver.java b/core/java/android/content/BroadcastReceiver.java
index a41627a..b391c57d 100644
--- a/core/java/android/content/BroadcastReceiver.java
+++ b/core/java/android/content/BroadcastReceiver.java
@@ -44,14 +44,14 @@
* <ul>
* <li> <b>Normal broadcasts</b> (sent with {@link Context#sendBroadcast(Intent)
* Context.sendBroadcast}) are completely asynchronous. All receivers of the
- * broadcast are run, in an undefined order, often at the same time. This is
- * more efficient, but means that receivers can not use the result or abort
+ * broadcast are run in an undefined order, often at the same time. This is
+ * more efficient, but means that receivers cannot use the result or abort
* APIs included here.
* <li> <b>Ordered broadcasts</b> (sent with {@link Context#sendOrderedBroadcast(Intent, String)
* Context.sendOrderedBroadcast}) are delivered to one receiver at a time.
* As each receiver executes in turn, it can propagate a result to the next
* receiver, or it can completely abort the broadcast so that it won't be passed
- * to other receivers. The order receivers runs in can be controlled with the
+ * to other receivers. The order receivers run in can be controlled with the
* {@link android.R.styleable#AndroidManifestIntentFilter_priority
* android:priority} attribute of the matching intent-filter; receivers with
* the same priority will be run in an arbitrary order.
@@ -61,8 +61,8 @@
* situations revert to delivering the broadcast one receiver at a time. In
* particular, for receivers that may require the creation of a process, only
* one will be run at a time to avoid overloading the system with new processes.
- * In this situation, however, the non-ordered semantics hold: these receivers
- * can not return results or abort their broadcast.</p>
+ * In this situation, however, the non-ordered semantics hold: these receivers still
+ * cannot return results or abort their broadcast.</p>
*
* <p>Note that, although the Intent class is used for sending and receiving
* these broadcasts, the Intent broadcast mechanism here is completely separate
@@ -156,7 +156,7 @@
* more important processes.
*
* <p>This means that for longer-running operations you will often use
- * an {@link android.app.Service} in conjunction with a BroadcastReceiver to keep
+ * a {@link android.app.Service} in conjunction with a BroadcastReceiver to keep
* the containing process active for the entire time of your operation.
*/
public abstract class BroadcastReceiver {
@@ -167,7 +167,7 @@
* This method is called when the BroadcastReceiver is receiving an Intent
* broadcast. During this time you can use the other methods on
* BroadcastReceiver to view/modify the current result values. The function
- * is normally called from the main thread of its process, so you should
+ * is normally called within the main thread of its process, so you should
* never perform long-running operations in it (there is a timeout of
* 10 seconds that the system allows before considering the receiver to
* be blocked and a candidate to be killed). You cannot launch a popup dialog
@@ -183,6 +183,14 @@
* to interact with a service that is already running, you can use
* {@link #peekService}.
*
+ * <p>The Intent filters used in {@link android.content.Context#registerReceiver}
+ * and in application manifests are <em>not</em> guaranteed to be exclusive. They
+ * are hints to the operating system about how to find suitable recipients. It is
+ * possible for senders to force delivery to specific recipients, bypassing filter
+ * resolution. For this reason, {@link #onReceive(Context, Intent) onReceive()}
+ * implementations should respond only to known actions, ignoring any unexpected
+ * Intents that they may receive.
+ *
* @param context The Context in which the receiver is running.
* @param intent The Intent being received.
*/
diff --git a/core/java/android/content/Context.java b/core/java/android/content/Context.java
index 9a0dc9f..600dfa4 100644
--- a/core/java/android/content/Context.java
+++ b/core/java/android/content/Context.java
@@ -738,7 +738,7 @@
public abstract void removeStickyBroadcast(Intent intent);
/**
- * Register an BroadcastReceiver to be run in the main activity thread. The
+ * Register a BroadcastReceiver to be run in the main activity thread. The
* <var>receiver</var> will be called with any broadcast Intent that
* matches <var>filter</var>, in the main application thread.
*
@@ -762,11 +762,12 @@
*
* <p>See {@link BroadcastReceiver} for more information on Intent broadcasts.
*
- * <p class="note">Note: this method <em>can not be called from an
- * {@link BroadcastReceiver} component</em>. It is okay, however, to use
- * this method from another BroadcastReceiver that has itself been registered with
- * {@link #registerReceiver}, since the lifetime of such an BroadcastReceiver
- * is tied to another object (the one that registered it).</p>
+ * <p class="note">Note: this method <em>cannot be called from a
+ * {@link BroadcastReceiver} component;</em> that is, from a BroadcastReceiver
+ * that is declared in an application's manifest. It is okay, however, to call
+ * this method from another BroadcastReceiver that has itself been registered
+ * at run time with {@link #registerReceiver}, since the lifetime of such a
+ * registered BroadcastReceiver is tied to the object that registered it.</p>
*
* @param receiver The BroadcastReceiver to handle the broadcast.
* @param filter Selects the Intent broadcasts to be received.