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

Prevent deadlock in binderDied in validation layer

Browse Source 
In binderDied, we hold the validation layer lock as we call unloadModel,
which blocks on callbacks, violating our lock ordering.

As a temporary fix, cache the currently loaded models, and unload them.

Bug: 237602275
Test: Compiles
Change-Id: I5091cb152765ea1f78958108a331d75951b8b717
This commit is contained in:
Atneya Nair
2022-07-25 16:31:05 -07:00
parent d4384a5ff2
commit 0fd2afe084
1 changed files with 32 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerMiddlewareValidation.java
View File

@@ -37,6 +37,7 @@ import android.os.IBinder;
import android.os.RemoteException;
import android.os.ServiceSpecificException;
import android.util.Log;
import android.util.SparseArray;
import com.android.internal.util.Preconditions;
@@ -829,17 +830,41 @@ public class SoundTriggerMiddlewareValidation implements ISoundTriggerMiddleware
@Override
public void binderDied() {
// This is called whenever our client process dies.
SparseArray<ModelState.Activity> cachedMap =
new SparseArray<ModelState.Activity>();
synchronized (SoundTriggerMiddlewareValidation.this) {
try {
// Gracefully stop all active recognitions and unload the models.
// Copy the relevant state under the lock, so we can call back without
// holding a lock. This exposes us to a potential race, but the client is
// dead so we don't expect one.
// TODO(240613068) A more resilient fix for this.
for (Map.Entry<Integer, ModelState> entry :
mLoadedModels.entrySet()) {
if (entry.getValue().activityState == ModelState.Activity.ACTIVE) {
mDelegate.stopRecognition(entry.getKey());
}
mDelegate.unloadModel(entry.getKey());
cachedMap.put(entry.getKey(), entry.getValue().activityState);
}
// Detach.
}
try {
// Gracefully stop all active recognitions and unload the models.
for (int i = 0; i < cachedMap.size(); i++) {
if (cachedMap.valueAt(i) == ModelState.Activity.ACTIVE) {
mDelegate.stopRecognition(cachedMap.keyAt(i));
}
mDelegate.unloadModel(cachedMap.keyAt(i));
}
} catch (Exception e) {
throw handleException(e);
}
synchronized (SoundTriggerMiddlewareValidation.this) {
// Check if state updated unexpectedly to log race conditions.
for (Map.Entry<Integer, ModelState> entry : mLoadedModels.entrySet()) {
if (cachedMap.get(entry.getKey()) != entry.getValue().activityState) {
Log.e(TAG, "Unexpected state update in binderDied. Race occurred!");
}
}
if (mLoadedModels.size() != cachedMap.size()) {
Log.e(TAG, "Unexpected state update in binderDied. Race occurred!");
}
try {
// Detach
detachInternal();
} catch (Exception e) {
throw handleException(e);