Handle native event in wifi thread

To prevent deadlocks while processing native callback or death
as we're in the midst of performing some state changes, post
the native notification to the wifi thread.

Bug: 134987917
Test: Performed some basic tests (toggle wifi,softap, etc)
Test: atest com.android.server.wifi.HalDeviceManagerTest
Change-Id: Id24aa61ae51d254cfc937691475b19977e5c508d
(cherry-picked from ed9610cd4f703b8864fb2eb167bbbdce37561724)

2 files changed, 35 insertions, 15 deletions

diff --git a/service/java/com/android/server/wifi/HalDeviceManager.java b/service/java/com/android/server/wifi/HalDeviceManager.java
index bb53a6e88..d2ad47f48 100644
--- a/service/java/com/android/server/wifi/HalDeviceManager.java
+++ b/service/java/com/android/server/wifi/HalDeviceManager.java
@@ -37,6 +37,7 @@ import android.hidl.manager.V1_2.IServiceManager;
 import android.os.Handler;
 import android.os.HidlSupport.Mutable;
 import android.os.HwRemoteBinder;
+import android.os.Looper;
 import android.os.RemoteException;
 import android.util.Log;
 import android.util.LongSparseArray;
@@ -73,13 +74,19 @@ public class HalDeviceManager {
     public static final int START_HAL_RETRY_TIMES = 3;
 
     private final Clock mClock;
+    private final Handler mEventHandler;
+    private WifiDeathRecipient mIWifiDeathRecipient;
+    private ServiceManagerDeathRecipient mServiceManagerDeathRecipient;
 
     // cache the value for supporting vendor HAL or not
     private boolean mIsVendorHalSupported = false;
 
     // public API
-    public HalDeviceManager(Clock clock) {
+    public HalDeviceManager(Clock clock, Looper looper) {
         mClock = clock;
+        mEventHandler = new Handler(looper);
+        mIWifiDeathRecipient = new WifiDeathRecipient();
+        mServiceManagerDeathRecipient = new ServiceManagerDeathRecipient();
 
         mInterfaceAvailableForRequestListeners.put(IfaceType.STA, new HashMap<>());
         mInterfaceAvailableForRequestListeners.put(IfaceType.AP, new HashMap<>());
@@ -631,15 +638,19 @@ public class HalDeviceManager {
         mRttControllerLifecycleCallbacks.clear();
     }
 
-    private final HwRemoteBinder.DeathRecipient mServiceManagerDeathRecipient =
-            cookie -> {
+    private class ServiceManagerDeathRecipient implements HwRemoteBinder.DeathRecipient {
+        @Override
+        public void serviceDied(long cookie) {
+            mEventHandler.post(() -> {
                 Log.wtf(TAG, "IServiceManager died: cookie=" + cookie);
                 synchronized (mLock) {
                     mServiceManager = null;
                     // theoretically can call initServiceManager again here - but
                     // there's no point since most likely system is going to reboot
                 }
-            };
+            });
+        }
+    }
 
     private final IServiceNotification mServiceNotificationCallback =
             new IServiceNotification.Stub() {
@@ -718,8 +729,10 @@ public class HalDeviceManager {
         }
     }
 
-    private final HwRemoteBinder.DeathRecipient mIWifiDeathRecipient =
-            cookie -> {
+    private class WifiDeathRecipient implements HwRemoteBinder.DeathRecipient {
+        @Override
+        public void serviceDied(long cookie) {
+            mEventHandler.post(() -> {
                 Log.e(TAG, "IWifi HAL service died! Have a listener for it ... cookie=" + cookie);
                 synchronized (mLock) { // prevents race condition with surrounding method
                     mWifi = null;
@@ -727,7 +740,9 @@ public class HalDeviceManager {
                     teardownInternal();
                     // don't restart: wait for registration notification
                 }
-            };
+            });
+        }
+    }
 
     /**
      * Initialize IWifi and register death listener and event callback.
@@ -1264,21 +1279,26 @@ public class HalDeviceManager {
     private class WifiEventCallback extends IWifiEventCallback.Stub {
         @Override
         public void onStart() throws RemoteException {
-            if (VDBG) Log.d(TAG, "IWifiEventCallback.onStart");
-            // NOP: only happens in reaction to my calls - will handle directly
+            mEventHandler.post(() -> {
+                if (VDBG) Log.d(TAG, "IWifiEventCallback.onStart");
+                // NOP: only happens in reaction to my calls - will handle directly
+            });
         }
 
         @Override
         public void onStop() throws RemoteException {
-            if (VDBG) Log.d(TAG, "IWifiEventCallback.onStop");
-            // NOP: only happens in reaction to my calls - will handle directly
+            mEventHandler.post(() -> {
+                if (VDBG) Log.d(TAG, "IWifiEventCallback.onStop");
+                // NOP: only happens in reaction to my calls - will handle directly
+            });
         }
 
         @Override
         public void onFailure(WifiStatus status) throws RemoteException {
-            Log.e(TAG, "IWifiEventCallback.onFailure: " + statusString(status));
-            teardownInternal();
-
+            mEventHandler.post(() -> {
+                Log.e(TAG, "IWifiEventCallback.onFailure: " + statusString(status));
+                teardownInternal();
+            });
             // No need to do anything else: listeners may (will) re-start Wi-Fi
         }
     }
diff --git a/service/java/com/android/server/wifi/WifiInjector.java b/service/java/com/android/server/wifi/WifiInjector.java
index 178c98f6d..f33c7cf93 100644
--- a/service/java/com/android/server/wifi/WifiInjector.java
+++ b/service/java/com/android/server/wifi/WifiInjector.java
@@ -202,7 +202,7 @@ public class WifiInjector {
                 mCellularLinkLayerStatsCollector);
         // Modules interacting with Native.
         mWifiMonitor = new WifiMonitor(this);
-        mHalDeviceManager = new HalDeviceManager(mClock);
+        mHalDeviceManager = new HalDeviceManager(mClock, clientModeImplLooper);
         mWifiVendorHal =
                 new WifiVendorHal(mHalDeviceManager, mWifiCoreHandlerThread.getLooper());
         mSupplicantStaIfaceHal =