1 /*
2  * Copyright (C) 2017 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License
15  */
16 
17 package android.telephony.ims.stub;
18 
19 import android.annotation.NonNull;
20 import android.annotation.SystemApi;
21 import android.os.RemoteException;
22 import android.util.Log;
23 
24 import com.android.ims.internal.IImsEcbm;
25 import com.android.ims.internal.IImsEcbmListener;
26 import com.android.internal.telephony.util.TelephonyUtils;
27 
28 import java.util.Objects;
29 import java.util.concurrent.CancellationException;
30 import java.util.concurrent.CompletableFuture;
31 import java.util.concurrent.CompletionException;
32 import java.util.concurrent.Executor;
33 
34 
35 /**
36  * Base implementation of ImsEcbm, which implements stub versions of the methods
37  * in the IImsEcbm AIDL. Override the methods that your implementation of ImsEcbm supports.
38  *
39  * DO NOT remove or change the existing APIs, only add new ones to this Base implementation or you
40  * will break other implementations of ImsEcbm maintained by other ImsServices.
41  *
42  * @hide
43  */
44 @SystemApi
45 public class ImsEcbmImplBase {
46     private static final String TAG = "ImsEcbmImplBase";
47 
48     private final Object mLock = new Object();
49     private IImsEcbmListener mListener;
50     private Executor mExecutor = Runnable::run;
51 
52     private final IImsEcbm mImsEcbm = new IImsEcbm.Stub() {
53         @Override
54         public void setListener(IImsEcbmListener listener) {
55             executeMethodAsync(() -> {
56                 if (mListener != null && !mListener.asBinder().isBinderAlive()) {
57                     Log.w(TAG, "setListener: discarding dead Binder");
58                     mListener = null;
59                 }
60                 if (mListener != null && listener != null && Objects.equals(
61                         mListener.asBinder(), listener.asBinder())) {
62                     return;
63                 }
64                 if (listener == null) {
65                     mListener = null;
66                 } else if (listener != null && mListener == null) {
67                     mListener = listener;
68                 } else {
69                     // Warn that the listener is being replaced while active
70                     Log.w(TAG, "setListener is being called when there is already an active "
71                             + "listener");
72                     mListener = listener;
73                 }
74             }, "setListener");
75         }
76 
77         @Override
78         public void exitEmergencyCallbackMode() {
79             executeMethodAsync(() -> ImsEcbmImplBase.this.exitEmergencyCallbackMode(),
80                     "exitEmergencyCallbackMode");
81         }
82 
83         // Call the methods with a clean calling identity on the executor and wait indefinitely for
84         // the future to return.
85         private void executeMethodAsync(Runnable r, String errorLogName) {
86             try {
87                 CompletableFuture.runAsync(
88                         () -> TelephonyUtils.runWithCleanCallingIdentity(r), mExecutor).join();
89             } catch (CancellationException | CompletionException e) {
90                 Log.w(TAG, "ImsEcbmImplBase Binder - " + errorLogName + " exception: "
91                         + e.getMessage());
92             }
93         }
94     };
95 
96     /** @hide */
getImsEcbm()97     public IImsEcbm getImsEcbm() {
98         return mImsEcbm;
99     }
100 
101     /**
102      * This method should be implemented by the IMS provider. Framework will trigger this method to
103      * request to come out of ECBM mode
104      */
exitEmergencyCallbackMode()105     public void exitEmergencyCallbackMode() {
106         Log.d(TAG, "exitEmergencyCallbackMode() not implemented");
107     }
108 
109     /**
110      * Notifies the framework when the device enters Emergency Callback Mode.
111      *
112      * @throws RuntimeException if the connection to the framework is not available.
113      */
enteredEcbm()114     public final void enteredEcbm() {
115         Log.d(TAG, "Entered ECBM.");
116         IImsEcbmListener listener;
117         synchronized (mLock) {
118             listener = mListener;
119         }
120         if (listener != null) {
121             try {
122                 listener.enteredECBM();
123             } catch (RemoteException e) {
124                 throw new RuntimeException(e);
125             }
126         }
127     }
128 
129     /**
130      * Notifies the framework when the device exits Emergency Callback Mode.
131      *
132      * @throws RuntimeException if the connection to the framework is not available.
133      */
exitedEcbm()134     public final void exitedEcbm() {
135         Log.d(TAG, "Exited ECBM.");
136         IImsEcbmListener listener;
137         synchronized (mLock) {
138             listener = mListener;
139         }
140         if (listener != null) {
141             try {
142                 listener.exitedECBM();
143             } catch (RemoteException e) {
144                 throw new RuntimeException(e);
145             }
146         }
147     }
148 
149     /**
150      * Set default Executor from MmTelFeature.
151      * @param executor The default executor for the framework to use when executing the methods
152      * overridden by the implementation of ImsEcbm.
153      * @hide
154      */
setDefaultExecutor(@onNull Executor executor)155     public final void setDefaultExecutor(@NonNull Executor executor) {
156         mExecutor = executor;
157     }
158 }
159