/*
* Copyright 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.server.camera;
import android.app.ActivityManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.UserInfo;
import android.hardware.ICameraService;
import android.hardware.ICameraServiceProxy;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Process;
import android.os.RemoteException;
import android.os.UserManager;
import android.util.Slog;
import com.android.server.ServiceThread;
import com.android.server.SystemService;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* CameraService is the system_server analog to the camera service running in mediaserver.
*
* @hide
*/
public class CameraService extends SystemService implements Handler.Callback {
private static final String TAG = "CameraService_proxy";
/**
* This must match the ICameraService.aidl definition
*/
private static final String CAMERA_SERVICE_BINDER_NAME = "media.camera";
public static final String CAMERA_SERVICE_PROXY_BINDER_NAME = "media.camera.proxy";
// Event arguments to use with the camera service notifySystemEvent call:
public static final int NO_EVENT = 0; // NOOP
public static final int USER_SWITCHED = 1; // User changed, argument is the new user handle
// Handler message codes
private static final int MSG_SWITCH_USER = 1;
private static final int RETRY_DELAY_TIME = 20; //ms
private final Context mContext;
private final ServiceThread mHandlerThread;
private final Handler mHandler;
private UserManager mUserManager;
private final Object mLock = new Object();
private Set<Integer> mEnabledCameraUsers;
private int mLastUser;
private final BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if (action == null) return;
switch (action) {
case Intent.ACTION_USER_ADDED:
case Intent.ACTION_USER_REMOVED:
case Intent.ACTION_USER_INFO_CHANGED:
case Intent.ACTION_MANAGED_PROFILE_ADDED:
case Intent.ACTION_MANAGED_PROFILE_REMOVED:
synchronized(mLock) {
// Return immediately if we haven't seen any users start yet
if (mEnabledCameraUsers == null) return;
switchUserLocked(mLastUser);
}
break;
default:
break; // do nothing
}
}
};
private final ICameraServiceProxy.Stub mCameraServiceProxy = new ICameraServiceProxy.Stub() {
@Override
public void pingForUserUpdate() {
notifySwitchWithRetries(30);
}
};
public CameraService(Context context) {
super(context);
mContext = context;
mHandlerThread = new ServiceThread(TAG, Process.THREAD_PRIORITY_DISPLAY, /*allowTo*/false);
mHandlerThread.start();
mHandler = new Handler(mHandlerThread.getLooper(), this);
}
@Override
public boolean handleMessage(Message msg) {
switch(msg.what) {
case MSG_SWITCH_USER: {
notifySwitchWithRetries(msg.arg1);
} break;
default: {
Slog.e(TAG, "CameraService error, invalid message: " + msg.what);
} break;
}
return true;
}
@Override
public void onStart() {
mUserManager = UserManager.get(mContext);
if (mUserManager == null) {
// Should never see this unless someone messes up the SystemServer service boot order.
throw new IllegalStateException("UserManagerService must start before CameraService!");
}
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_USER_ADDED);
filter.addAction(Intent.ACTION_USER_REMOVED);
filter.addAction(Intent.ACTION_USER_INFO_CHANGED);
filter.addAction(Intent.ACTION_MANAGED_PROFILE_ADDED);
filter.addAction(Intent.ACTION_MANAGED_PROFILE_REMOVED);
mContext.registerReceiver(mIntentReceiver, filter);
publishBinderService(CAMERA_SERVICE_PROXY_BINDER_NAME, mCameraServiceProxy);
}
@Override
public void onStartUser(int userHandle) {
synchronized(mLock) {
if (mEnabledCameraUsers == null) {
// Initialize mediaserver, or update mediaserver if we are recovering from a crash.
switchUserLocked(userHandle);
}
}
}
@Override
public void onSwitchUser(int userHandle) {
synchronized(mLock) {
switchUserLocked(userHandle);
}
}
private void switchUserLocked(int userHandle) {
Set<Integer> currentUserHandles = getEnabledUserHandles(userHandle);
mLastUser = userHandle;
if (mEnabledCameraUsers == null || !mEnabledCameraUsers.equals(currentUserHandles)) {
// Some user handles have been added or removed, update mediaserver.
mEnabledCameraUsers = currentUserHandles;
notifyMediaserver(USER_SWITCHED, currentUserHandles);
}
}
private Set<Integer> getEnabledUserHandles(int currentUserHandle) {
List<UserInfo> userProfiles = mUserManager.getEnabledProfiles(currentUserHandle);
Set<Integer> handles = new HashSet<>(userProfiles.size());
for (UserInfo i : userProfiles) {
handles.add(i.id);
}
return handles;
}
private void notifySwitchWithRetries(int retries) {
synchronized(mLock) {
if (mEnabledCameraUsers == null) {
return;
}
if (notifyMediaserver(USER_SWITCHED, mEnabledCameraUsers)) {
retries = 0;
}
}
if (retries <= 0) {
return;
}
Slog.i(TAG, "Could not notify camera service of user switch, retrying...");
mHandler.sendMessageDelayed(mHandler.obtainMessage(MSG_SWITCH_USER, retries - 1, 0, null),
RETRY_DELAY_TIME);
}
private boolean notifyMediaserver(int eventType, Set<Integer> updatedUserHandles) {
// Forward the user switch event to the native camera service running in the mediaserver
// process.
IBinder cameraServiceBinder = getBinderService(CAMERA_SERVICE_BINDER_NAME);
if (cameraServiceBinder == null) {
Slog.w(TAG, "Could not notify mediaserver, camera service not available.");
return false; // Camera service not active, cannot evict user clients.
}
ICameraService cameraServiceRaw = ICameraService.Stub.asInterface(cameraServiceBinder);
try {
cameraServiceRaw.notifySystemEvent(eventType, toArray(updatedUserHandles));
} catch (RemoteException e) {
Slog.w(TAG, "Could not notify mediaserver, remote exception: " + e);
// Not much we can do if camera service is dead.
return false;
}
return true;
}
private static int[] toArray(Collection<Integer> c) {
int len = c.size();
int[] ret = new int[len];
int idx = 0;
for (Integer i : c) {
ret[idx++] = i;
}
return ret;
}
}