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
Change-Id: I5911d01984695550b6c9afe7a8eb535bf5e320a1
This commit is contained in:
Chalard Jean
2020-05-20 16:11:50 +09:00
parent 551b6e094b
commit a5ff113bff
3 changed files with 87 additions and 10 deletions

View File

@@ -711,6 +711,13 @@ public class ConnectivityDiagnosticsManager {
* 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 @@ public class ConnectivityDiagnosticsManager {
* 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,

View File

@@ -3855,13 +3855,22 @@ public class ConnectivityManager {
* 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) {
@@ -3875,8 +3884,8 @@ public class ConnectivityManager {
* 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
@@ -3907,8 +3916,8 @@ public class ConnectivityManager {
* 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
@@ -3934,8 +3943,8 @@ public class ConnectivityManager {
* 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
@@ -4004,6 +4013,15 @@ public class ConnectivityManager {
* 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
@@ -4015,7 +4033,7 @@ public class ConnectivityManager {
* 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) {
@@ -4072,10 +4090,20 @@ public class ConnectivityManager {
* 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,
@@ -4089,10 +4117,21 @@ public class ConnectivityManager {
* 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,
@@ -4126,10 +4165,21 @@ public class ConnectivityManager {
* <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,
@@ -4151,9 +4201,19 @@ public class ConnectivityManager {
* 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) {
@@ -4165,9 +4225,19 @@ public class ConnectivityManager {
* 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,
@@ -4259,7 +4329,6 @@ public class ConnectivityManager {
* Cannot be null.
*/
public void unregisterNetworkCallback(@NonNull PendingIntent operation) {
checkPendingIntentNotNull(operation);
releaseNetworkRequest(operation);
}

View File

@@ -6422,7 +6422,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
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