Android/frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Make IOnAssociationsChangedListener.onAssociationsChanged() blocking

Browse Source 
Make IOnAssociationsChangedListener.onAssociationsChanged() blocking
(not "oneway") to make sure that the clients of the
addOnAssociationsChangedListener() API (@SystemAPI guarded by a
"signature" permission) are able to prevent race conditions that may
arise if their own clients (applications) effectively get notified
about the changes before system services do.

This is safe for 2 reasons:
1. The addOnAssociationsChangedListener() API is only available to the
   system components (guarded by a "signature" permission).
   See android.permission.MANAGE_COMPANION_DEVICES.
2. On the Java side addOnAssociationsChangedListener() in CDM takes an
   Executor, and the proxy implementation of onAssociationsChanged()
   simply "posts" a job to it.
   See CompanionDeviceManager.OnAssociationsChangedListenerProxy class.

Bug: 214016641
Test: atest --iterations 10 CtsCompanionDeviceManagerCoreTestCases:AssociationsChangedListenerTest
Test: atest CtsCompanionDeviceManagerCoreTestCases
Test: atest CtsCompanionDeviceManagerUiAutomationTestCases
Test: atest CtsOsTestCases:CompanionDeviceManagerTest
Change-Id: I7c664e9b9c848f8f0291ff46a56ff47bae7db346
This commit is contained in:
Sergey Nikolaienkov
2022-01-12 08:56:11 +01:00
parent bac69433f6
commit 11ec828ecd
1 changed files with 18 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
core/java/android/companion/IOnAssociationsChangedListener.aidl
View File

@@ -20,5 +20,22 @@ import android.companion.AssociationInfo;
/** @hide */
interface IOnAssociationsChangedListener {
oneway void onAssociationsChanged(in List<AssociationInfo> associations);
/*
* IMPORTANT: This method is intentionally NOT "oneway".
*
* The method is intentionally "blocking" to make sure that the clients of the
* addOnAssociationsChangedListener() API (@SystemAPI guarded by a "signature" permission) are
* able to prevent race conditions that may arise if their own clients (applications)
* effectively get notified about the changes before system services do.
*
* This is safe for 2 reasons:
* 1. The addOnAssociationsChangedListener() is only available to the system components
* (guarded by a "signature" permission).
* See android.permission.MANAGE_COMPANION_DEVICES.
* 2. On the Java side addOnAssociationsChangedListener() in CDM takes an Executor, and the
* proxy implementation of onAssociationsChanged() simply "post" a Runnable to it.
* See CompanionDeviceManager.OnAssociationsChangedListenerProxy class.
*/
void onAssociationsChanged(in List<AssociationInfo> associations);
}