【发布时间】：2018-05-27 13:16:26
【问题描述】：
我刚刚将我的代码从 asynctask 切换到 rxjava2 并且我在我的关系上随机收到此异常：
在 Galaxy s6 中调用 Camera.release() 后正在使用相机 边缘
以下是我的代码-
类相机：
public class Cameras {
private static final String TAG = Cameras.class.getSimpleName();
private static final String SP_CAMERA_ID = "camera_id";
private static final int NO_NEXT_TASK = 0;
private static final int NEXT_TASK_RELEASE_COMPLETE = 1;
private static final int NEXT_TASK_SWITCH_COMPLETE = 2;
private static final int NEXT_TASK_START_PREVIEW = 3;
private Camera camera;
private int currentCameraId = -1;
private Camera.PreviewCallback previewCallback;
private byte[] buffer1, buffer2, buffer3;
private SurfaceTexture surfaceTexture;
private Listener listener;
public interface Listener {
void onCameraOpened(Camera.Size size, int angle);
}
private boolean cameraReleased = false;
public Cameras(Camera.PreviewCallback previewCallback, Listener listener) {
this.listener = listener;
this.previewCallback = previewCallback;
this.currentCameraId = Spin.INSTANCE.getSp().getInt(SP_CAMERA_ID, -1);
getCameraList();
}
private void getCameraList() {
int numberOfCameras = Camera.getNumberOfCameras();
Camera.CameraInfo camInfo = new Camera.CameraInfo();
for (int i = 0; i < numberOfCameras; i++) {
Camera.getCameraInfo(i, camInfo);
cams.add(camInfo.facing);
}
if (Camera.CameraInfo.CAMERA_FACING_BACK != currentCameraId
&& Camera.CameraInfo.CAMERA_FACING_FRONT != currentCameraId) {
currentCameraId = cams.get(cams.size() == 2 ? 1 : 0);
}
}
public boolean isSwitchCamAvailable() {
return Camera.getNumberOfCameras() > 1;
}
public void open(SurfaceTexture surfaceTexture) {
this.surfaceTexture = surfaceTexture;
init(NEXT_TASK_START_PREVIEW);
}
private void init(final int nextTask) {
if (cams.isEmpty()) {
Toast.makeText(Spin.getContext(), "Device have no camera", Toast.LENGTH_SHORT).show();
return;
}
cameraReleased = false;
if (Looper.getMainLooper().getThread() == Thread.currentThread()) {
Observable.defer(new Callable<ObservableSource<?>>() {
@Override
public ObservableSource<?> call() throws Exception {
synchronized (this) {
try {
camera = Camera.open(currentCameraId);
} catch (RuntimeException e) {
e.printStackTrace();
}
}
return Completable.complete().toObservable();
}
}).doOnComplete(() -> {
initComplete(nextTask);
Log.d("Complete", "Complete");
})
.subscribeOn(Schedulers.computation())
.observeOn(AndroidSchedulers.mainThread()).subscribe();
} else {
try {
synchronized (this) {
this.camera = Camera.open(currentCameraId);
}
initComplete(nextTask);
} catch (RuntimeException ignored) {
}
}
}
private void initComplete(int nextTask) {
if (camera == null) {
return;
}
//noinspection SynchronizeOnNonFinalField
synchronized (camera) {
try {
Camera.Parameters params = camera.getParameters();
Camera.Size size = getClosestFrameSize(params, 640);
params.setPreviewSize(size.width, size.height);
camera.setParameters(params);
camera.setPreviewCallbackWithBuffer(previewCallback);
int bufferSize = size.width * size.height
* ImageFormat.getBitsPerPixel(ImageFormat.NV21) / 8;
buffer1 = new byte[bufferSize];
buffer2 = new byte[bufferSize];
buffer3 = new byte[bufferSize];
camera.addCallbackBuffer(buffer1);
camera.addCallbackBuffer(buffer2);
camera.addCallbackBuffer(buffer3);
camera.setPreviewTexture(surfaceTexture);
int angle = rotateStream();
camera.setDisplayOrientation(angle);
if (currentCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT && angle > 0)
angle = 360 - angle;
listener.onCameraOpened(size, angle);
routNextTask(nextTask);
} catch (IOException | RuntimeException e) {
e.printStackTrace();
}
}
}
private Camera.Size getClosestFrameSize(Camera.Parameters params, int width) {
Camera.Size result = null;
List<Camera.Size> sizes = params.getSupportedPreviewSizes();
Camera.Size currentSize = null;
int closestDistance = 0;
int currentDistance = 0;
for (int i = 0; i < sizes.size(); ++i) {
if (null == result) {
result = sizes.get(i);
closestDistance = Math.abs(result.width - width);
continue;
}
currentSize = sizes.get(i);
currentDistance = Math.abs(currentSize.width - width);
if (currentDistance < closestDistance) {
closestDistance = currentDistance;
result = currentSize;
if (closestDistance == 0) break;
}
}
return result;
}
public void stopPreview() {
stopPreview(NO_NEXT_TASK);
}
private String nextTaskStr(final int nextTask) {
String nextTaskStr = null;
switch (nextTask) {
case NO_NEXT_TASK:
nextTaskStr = "NO_NEXT_TASK";
break;
case NEXT_TASK_RELEASE_COMPLETE:
nextTaskStr = "NEXT_TASK_RELEASE_COMPLETE";
break;
case NEXT_TASK_SWITCH_COMPLETE:
nextTaskStr = "NEXT_TASK_SWITCH_COMPLETE";
break;
case NEXT_TASK_START_PREVIEW:
nextTaskStr = "NEXT_TASK_START_PREVIEW";
break;
}
return nextTaskStr;
}
private void stopPreview(final int nextTask) {
if (null == camera) return;
if (Looper.getMainLooper().getThread() == Thread.currentThread()) {
Observable.defer(new Callable<ObservableSource<?>>() {
@Override
public ObservableSource<?> call() throws Exception {
synchronized (this) {
if ( (null != camera) && (!cameraReleased) ) {
if (LogDog.isEnabled) ;
camera.stopPreview();
}
}
return Completable.complete().toObservable();
}
}).doOnComplete(() -> {
routNextTask(nextTask);
Log.d("Complete", "Complete");
})
.subscribeOn(Schedulers.computation())
.observeOn(AndroidSchedulers.mainThread()).subscribe();
} else {
synchronized (this) {
if ( (null != camera) && (!cameraReleased) ) {
camera.stopPreview();
}
}
routNextTask(nextTask);
}
}
private void routNextTask(int nextTask) {
if (NO_NEXT_TASK == nextTask) return;
if (NEXT_TASK_SWITCH_COMPLETE == nextTask) {
switchCamComplete();
} else if (NEXT_TASK_RELEASE_COMPLETE == nextTask) {
releaseComplete();
} else if (NEXT_TASK_START_PREVIEW == nextTask) {
startPreview(null);
}
}
public void startPreview(Camera.PreviewCallback cpc) {
if (null == camera) return;
synchronized (this) {
camera.startPreview();
switchCamOnAir = false;
}
}
private void releaseCamera() {
synchronized (this) {
if (null == camera) return;
camera.setPreviewCallback(null);
camera.release();
camera = null;
cameraReleased = true;
}
}
public void release() {
synchronized (this) {
if (null == camera) return;
stopPreview(NEXT_TASK_RELEASE_COMPLETE);
}
}
private void releaseComplete() {
synchronized (this) {
if (camera != null) {
camera.release();
cameraReleased = true;
camera = null;
}
}
buffer1 = null;
buffer2 = null;
buffer3 = null;
}
private boolean switchCamOnAir = false;
public void switchCam() {
if (!isSwitchCamAvailable()) return;
if (null == camera) return;
if (switchCamOnAir) return;
this.switchCamOnAir = true;
stopPreview(NEXT_TASK_SWITCH_COMPLETE);
}
private void switchCamComplete() {
releaseCamera();
if (currentCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {
currentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
} else {
currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
}
Spin.INSTANCE.getSp().edit().putInt(SP_CAMERA_ID, currentCameraId).apply();
init(NEXT_TASK_START_PREVIEW);
}
public int rotateStream() {
Camera.CameraInfo info = new Camera.CameraInfo();
Camera.getCameraInfo(currentCameraId, info);
WindowManager wm = (WindowManager) Spin.getContext()
.getSystemService(Context.WINDOW_SERVICE);
int rotation = wm.getDefaultDisplay().getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0:
degrees = 0;
break;
case Surface.ROTATION_90:
degrees = 90;
break;
case Surface.ROTATION_180:
degrees = 180;
break;
case Surface.ROTATION_270:
degrees = 270;
break;
}
int result;
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360; // compensate the mirror
} else { // back-facing
result = (info.orientation - degrees + 360) % 360;
}
return result;
}
@SuppressWarnings("unused")
public int getDeviceDefaultOrientation() {
WindowManager windowManager = (WindowManager) Spin.getContext()
.getSystemService(Context.WINDOW_SERVICE);
Configuration config = Spin.getContext().getResources().getConfiguration();
int rotation = windowManager.getDefaultDisplay().getRotation();
if (((rotation == Surface.ROTATION_0 || rotation == Surface.ROTATION_180) &&
config.orientation == Configuration.ORIENTATION_LANDSCAPE)
|| ((rotation == Surface.ROTATION_90 || rotation == Surface.ROTATION_270) &&
config.orientation == Configuration.ORIENTATION_PORTRAIT)) {
return Configuration.ORIENTATION_LANDSCAPE;
} else {
return Configuration.ORIENTATION_PORTRAIT;
}
}
}
cameras.java：
if (Looper.getMainLooper().getThread() == Thread.currentThread()) {
Observable.defer(new Callable<ObservableSource<?>>() {
@Override
public ObservableSource<?> call() throws Exception {
if (LogDog.isEnabled) LogDog.e("Debug::"+TAG + "::stopPreview()::AsyncTask::doInBackground()", " (camera != null) =" + (camera != null) );
synchronized (this) {
if ( (null != camera) && (!cameraReleased) ) {
if (LogDog.isEnabled) LogDog.e("Debug::" + TAG + "::stopPreview()::AsyncTask::doInBackground()", " XXX CALL camera.stopPreview()");
camera.stopPreview();
}
}
return Completable.complete().toObservable();
}
}).doOnComplete(() -> {
routNextTask(nextTask);
Log.d("Complete", "Complete");
})
.subscribeOn(Schedulers.computation())
.observeOn(AndroidSchedulers.mainThread()).subscribe();
不知道我做错了什么。有什么想法可以释放或分配相机，因此它可以正常工作吗？ 例外情况如下：
致命异常：主要 io.reactivex.exceptions.OnErrorNotImplementedException：相机是 在调用 Camera.release() 之后使用 在 io.reactivex.internal.functions.Functions$OnErrorMissingConsumer.accept(Functions.java:704) 在 io.reactivex.internal.functions.Functions$OnErrorMissingConsumer.accept(Functions.java:701) 在 io.reactivex.internal.observers.LambdaObserver.onError(LambdaObserver.java:74) 在 io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.checkTerminated(ObservableObserveOn.java:276) 在 io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.drainNormal(ObservableObserveOn.java:172) 在 io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.run(ObservableObserveOn.java:252) 在 io.reactivex.android.schedulers.HandlerScheduler$ScheduledRunnable.run(HandlerScheduler.java:109) 在 android.os.Handler.handleCallback(Handler.java:751) 在 android.os.Handler.dispatchMessage(Handler.java:95) 在 android.os.Looper.loop(Looper.java:154) 在 android.app.ActivityThread.main(ActivityThread.java:6119) 在 java.lang.reflect.Method.invoke（本机方法） 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 引起：java.lang.RuntimeException：Camera is being used after Camera.release() 被调用 在 android.hardware.Camera._stopPreview（本机方法） 在 android.hardware.Camera.stopPreview(Camera.java:730) 在 com.media.video.Cameras$2.call(Cameras.java:413) 在 com.media.video.Cameras$2.call(Cameras.java:406) 在 io.reactivex.internal.operators.observable.ObservableDefer.subscribeActual(ObservableDefer.java:32) 在 io.reactivex.Observable.subscribe(Observable.java:10842) 在 io.reactivex.internal.operators.observable.ObservableDoOnEach.subscribeActual(ObservableDoOnEach.java:42) 在 io.reactivex.Observable.subscribe(Observable.java:10842) 在 io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeTask.run(ObservableSubscribeOn.java:96) 在 io.reactivex.internal.schedulers.ScheduledDirectTask.call(ScheduledDirectTask.java:38) 在 io.reactivex.internal.schedulers.ScheduledDirectTask.call(ScheduledDirectTask.java:26) 在 java.util.concurrent.FutureTask.run(FutureTask.java:237) 在 java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:272) 在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607) 在 java.lang.Thread.run(Thread.java:761)
【问题讨论】：
-
请在调用#releaseComplete() / #startPreview() / #stopPreview() / init() 时添加一些调试日志。在此之后，引发异常并发布跟踪。
-
它是随机的。试图重现此崩溃但很难重现，随机发生。我的代码中还有一些调试日志，但没有在此处发布，因为它会使文件变大，而且通常人们有 TLDR 心态，所以可能不会看它。
-
你至少有一个堆栈跟踪吗？
-
我现在不遗憾但是有什么东西可以说明我可能做错了什么会导致崩溃/异常吗？
-
在我看来，这看起来像是一个线程问题。在 init 中，您在 ui 线程上执行时订阅了后台线程。因此订阅将发生在计算线程池上。在 observable 中，您在“this”上同步。这个'this'是'Callable'的this，而不是Cameras对象的this。同样适用于 stopPreview。也就是说，可能是在调用 init() 之前从不同的线程调用了 stopPreview。这将是一个经典的竞争条件，因为这两种方法都使用另一个对象来同步。对相机对象的访问是不同步的。
标签： android rx-java rx-java2 rx-android