Document the limitation to a hundred callbacks.
Some developers have been surprised by this limitation and had trouble
figuring out what the issue was. Add documentation to address this.
This also includes a drive-by removal of a duplicate check.
Bug: 149867479
Test: doc-only change
Original-Change: https://android-review.googlesource.com/1313813
Merged-In: I5911d01984695550b6c9afe7a8eb535bf5e320a1
Change-Id: I5911d01984695550b6c9afe7a8eb535bf5e320a1
diff --git a/core/java/android/net/ConnectivityDiagnosticsManager.java b/core/java/android/net/ConnectivityDiagnosticsManager.java
index 275e38c..704f31d 100644
--- a/core/java/android/net/ConnectivityDiagnosticsManager.java
+++ b/core/java/android/net/ConnectivityDiagnosticsManager.java
@@ -711,6 +711,13 @@
* not currently registered. If a ConnectivityDiagnosticsCallback instance is registered with
* multiple NetworkRequests, an IllegalArgumentException will be thrown.
*
+ * <p>To avoid performance issues due to apps leaking callbacks, the system will limit the
+ * number of outstanding requests to 100 per app (identified by their UID), shared with
+ * callbacks in {@link ConnectivityManager}. Registering a callback with this method will count
+ * toward this limit. If this limit is exceeded, an exception will be thrown. To avoid hitting
+ * this issue and to conserve resources, make sure to unregister the callbacks with
+ * {@link #unregisterConnectivityDiagnosticsCallback}.
+ *
* @param request The NetworkRequest that will be used to match with Networks for which
* callbacks will be fired
* @param e The Executor to be used for running the callback method invocations
@@ -718,6 +725,7 @@
* System
* @throws IllegalArgumentException if the same callback instance is registered with multiple
* NetworkRequests
+ * @throws RuntimeException if the app already has too many callbacks registered.
*/
public void registerConnectivityDiagnosticsCallback(
@NonNull NetworkRequest request,
diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index ba34899..a29f878 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -3794,13 +3794,22 @@
* or the ability to modify system settings as determined by
* {@link android.provider.Settings.System#canWrite}.</p>
*
+ * <p>To avoid performance issues due to apps leaking callbacks, the system will limit the
+ * number of outstanding requests to 100 per app (identified by their UID), shared with
+ * all variants of this method, of {@link #registerNetworkCallback} as well as
+ * {@link ConnectivityDiagnosticsManager#registerConnectivityDiagnosticsCallback}.
+ * Requesting a network with this method will count toward this limit. If this limit is
+ * exceeded, an exception will be thrown. To avoid hitting this issue and to conserve resources,
+ * make sure to unregister the callbacks with
+ * {@link #unregisterNetworkCallback(NetworkCallback)}.
+ *
* @param request {@link NetworkRequest} describing this request.
* @param networkCallback The {@link NetworkCallback} to be utilized for this request. Note
* the callback must not be shared - it uniquely specifies this request.
* The callback is invoked on the default internal Handler.
* @throws IllegalArgumentException if {@code request} contains invalid network capabilities.
* @throws SecurityException if missing the appropriate permissions.
- * @throws RuntimeException if request limit per UID is exceeded.
+ * @throws RuntimeException if the app already has too many callbacks registered.
*/
public void requestNetwork(@NonNull NetworkRequest request,
@NonNull NetworkCallback networkCallback) {
@@ -3814,8 +3823,8 @@
* but runs all the callbacks on the passed Handler.
*
* <p>This method has the same permission requirements as
- * {@link #requestNetwork(NetworkRequest, NetworkCallback)} and throws the same exceptions in
- * the same conditions.
+ * {@link #requestNetwork(NetworkRequest, NetworkCallback)}, is subject to the same limitations,
+ * and throws the same exceptions in the same conditions.
*
* @param request {@link NetworkRequest} describing this request.
* @param networkCallback The {@link NetworkCallback} to be utilized for this request. Note
@@ -3846,8 +3855,8 @@
* for that purpose. Calling this method will attempt to bring up the requested network.
*
* <p>This method has the same permission requirements as
- * {@link #requestNetwork(NetworkRequest, NetworkCallback)} and throws the same exceptions in
- * the same conditions.
+ * {@link #requestNetwork(NetworkRequest, NetworkCallback)}, is subject to the same limitations,
+ * and throws the same exceptions in the same conditions.
*
* @param request {@link NetworkRequest} describing this request.
* @param networkCallback The {@link NetworkCallback} to be utilized for this request. Note
@@ -3873,8 +3882,8 @@
* on the passed Handler.
*
* <p>This method has the same permission requirements as
- * {@link #requestNetwork(NetworkRequest, NetworkCallback, int)} and throws the same exceptions
- * in the same conditions.
+ * {@link #requestNetwork(NetworkRequest, NetworkCallback)}, is subject to the same limitations,
+ * and throws the same exceptions in the same conditions.
*
* @param request {@link NetworkRequest} describing this request.
* @param networkCallback The {@link NetworkCallback} to be utilized for this request. Note
@@ -3943,6 +3952,15 @@
* is unknown prior to bringing up the network so the framework does not
* know how to go about satisfying a request with these capabilities.
*
+ * <p>To avoid performance issues due to apps leaking callbacks, the system will limit the
+ * number of outstanding requests to 100 per app (identified by their UID), shared with
+ * all variants of this method, of {@link #registerNetworkCallback} as well as
+ * {@link ConnectivityDiagnosticsManager#registerConnectivityDiagnosticsCallback}.
+ * Requesting a network with this method will count toward this limit. If this limit is
+ * exceeded, an exception will be thrown. To avoid hitting this issue and to conserve resources,
+ * make sure to unregister the callbacks with {@link #unregisterNetworkCallback(PendingIntent)}
+ * or {@link #releaseNetworkRequest(PendingIntent)}.
+ *
* <p>This method requires the caller to hold either the
* {@link android.Manifest.permission#CHANGE_NETWORK_STATE} permission
* or the ability to modify system settings as determined by
@@ -3954,7 +3972,7 @@
* comes from {@link PendingIntent#getBroadcast}. Cannot be null.
* @throws IllegalArgumentException if {@code request} contains invalid network capabilities.
* @throws SecurityException if missing the appropriate permissions.
- * @throws RuntimeException if request limit per UID is exceeded.
+ * @throws RuntimeException if the app already has too many callbacks registered.
*/
public void requestNetwork(@NonNull NetworkRequest request,
@NonNull PendingIntent operation) {
@@ -4010,10 +4028,20 @@
* either the application exits or {@link #unregisterNetworkCallback(NetworkCallback)} is
* called.
*
+ * <p>To avoid performance issues due to apps leaking callbacks, the system will limit the
+ * number of outstanding requests to 100 per app (identified by their UID), shared with
+ * all variants of this method, of {@link #requestNetwork} as well as
+ * {@link ConnectivityDiagnosticsManager#registerConnectivityDiagnosticsCallback}.
+ * Requesting a network with this method will count toward this limit. If this limit is
+ * exceeded, an exception will be thrown. To avoid hitting this issue and to conserve resources,
+ * make sure to unregister the callbacks with
+ * {@link #unregisterNetworkCallback(NetworkCallback)}.
+ *
* @param request {@link NetworkRequest} describing this request.
* @param networkCallback The {@link NetworkCallback} that the system will call as suitable
* networks change state.
* The callback is invoked on the default internal Handler.
+ * @throws RuntimeException if the app already has too many callbacks registered.
*/
@RequiresPermission(android.Manifest.permission.ACCESS_NETWORK_STATE)
public void registerNetworkCallback(@NonNull NetworkRequest request,
@@ -4027,10 +4055,21 @@
* either the application exits or {@link #unregisterNetworkCallback(NetworkCallback)} is
* called.
*
+ * <p>To avoid performance issues due to apps leaking callbacks, the system will limit the
+ * number of outstanding requests to 100 per app (identified by their UID), shared with
+ * all variants of this method, of {@link #requestNetwork} as well as
+ * {@link ConnectivityDiagnosticsManager#registerConnectivityDiagnosticsCallback}.
+ * Requesting a network with this method will count toward this limit. If this limit is
+ * exceeded, an exception will be thrown. To avoid hitting this issue and to conserve resources,
+ * make sure to unregister the callbacks with
+ * {@link #unregisterNetworkCallback(NetworkCallback)}.
+ *
+ *
* @param request {@link NetworkRequest} describing this request.
* @param networkCallback The {@link NetworkCallback} that the system will call as suitable
* networks change state.
* @param handler {@link Handler} to specify the thread upon which the callback will be invoked.
+ * @throws RuntimeException if the app already has too many callbacks registered.
*/
@RequiresPermission(android.Manifest.permission.ACCESS_NETWORK_STATE)
public void registerNetworkCallback(@NonNull NetworkRequest request,
@@ -4064,10 +4103,21 @@
* <p>
* The request may be released normally by calling
* {@link #unregisterNetworkCallback(android.app.PendingIntent)}.
+ *
+ * <p>To avoid performance issues due to apps leaking callbacks, the system will limit the
+ * number of outstanding requests to 100 per app (identified by their UID), shared with
+ * all variants of this method, of {@link #requestNetwork} as well as
+ * {@link ConnectivityDiagnosticsManager#registerConnectivityDiagnosticsCallback}.
+ * Requesting a network with this method will count toward this limit. If this limit is
+ * exceeded, an exception will be thrown. To avoid hitting this issue and to conserve resources,
+ * make sure to unregister the callbacks with {@link #unregisterNetworkCallback(PendingIntent)}
+ * or {@link #releaseNetworkRequest(PendingIntent)}.
+ *
* @param request {@link NetworkRequest} describing this request.
* @param operation Action to perform when the network is available (corresponds
* to the {@link NetworkCallback#onAvailable} call. Typically
* comes from {@link PendingIntent#getBroadcast}. Cannot be null.
+ * @throws RuntimeException if the app already has too many callbacks registered.
*/
@RequiresPermission(android.Manifest.permission.ACCESS_NETWORK_STATE)
public void registerNetworkCallback(@NonNull NetworkRequest request,
@@ -4089,9 +4139,19 @@
* will continue to be called until either the application exits or
* {@link #unregisterNetworkCallback(NetworkCallback)} is called.
*
+ * <p>To avoid performance issues due to apps leaking callbacks, the system will limit the
+ * number of outstanding requests to 100 per app (identified by their UID), shared with
+ * all variants of this method, of {@link #requestNetwork} as well as
+ * {@link ConnectivityDiagnosticsManager#registerConnectivityDiagnosticsCallback}.
+ * Requesting a network with this method will count toward this limit. If this limit is
+ * exceeded, an exception will be thrown. To avoid hitting this issue and to conserve resources,
+ * make sure to unregister the callbacks with
+ * {@link #unregisterNetworkCallback(NetworkCallback)}.
+ *
* @param networkCallback The {@link NetworkCallback} that the system will call as the
* system default network changes.
* The callback is invoked on the default internal Handler.
+ * @throws RuntimeException if the app already has too many callbacks registered.
*/
@RequiresPermission(android.Manifest.permission.ACCESS_NETWORK_STATE)
public void registerDefaultNetworkCallback(@NonNull NetworkCallback networkCallback) {
@@ -4103,9 +4163,19 @@
* will continue to be called until either the application exits or
* {@link #unregisterNetworkCallback(NetworkCallback)} is called.
*
+ * <p>To avoid performance issues due to apps leaking callbacks, the system will limit the
+ * number of outstanding requests to 100 per app (identified by their UID), shared with
+ * all variants of this method, of {@link #requestNetwork} as well as
+ * {@link ConnectivityDiagnosticsManager#registerConnectivityDiagnosticsCallback}.
+ * Requesting a network with this method will count toward this limit. If this limit is
+ * exceeded, an exception will be thrown. To avoid hitting this issue and to conserve resources,
+ * make sure to unregister the callbacks with
+ * {@link #unregisterNetworkCallback(NetworkCallback)}.
+ *
* @param networkCallback The {@link NetworkCallback} that the system will call as the
* system default network changes.
* @param handler {@link Handler} to specify the thread upon which the callback will be invoked.
+ * @throws RuntimeException if the app already has too many callbacks registered.
*/
@RequiresPermission(android.Manifest.permission.ACCESS_NETWORK_STATE)
public void registerDefaultNetworkCallback(@NonNull NetworkCallback networkCallback,
@@ -4197,7 +4267,6 @@
* Cannot be null.
*/
public void unregisterNetworkCallback(@NonNull PendingIntent operation) {
- checkPendingIntentNotNull(operation);
releaseNetworkRequest(operation);
}
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 0ab5718..2958fd2 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -6426,7 +6426,7 @@
final boolean shouldFilter = requiresVpnIsolation(nai, newNc, nai.linkProperties);
final String iface = nai.linkProperties.getInterfaceName();
// For VPN uid interface filtering, old ranges need to be removed before new ranges can
- // be added, due to the range being expanded and stored as invidiual UIDs. For example
+ // be added, due to the range being expanded and stored as individual UIDs. For example
// the UIDs might be updated from [0, 99999] to ([0, 10012], [10014, 99999]) which means
// prevRanges = [0, 99999] while newRanges = [0, 10012], [10014, 99999]. If prevRanges
// were added first and then newRanges got removed later, there would be only one uid
