Handle Android stop capturer race.

webrtc/api/java/jni/androidvideocapturer_jni.cc

 /*
  *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 71 matching lines @@
           ? surface_texture_helper_->GetJavaSurfaceTextureHelper()
           : nullptr,
       application_context_, j_frame_observer);
   CHECK_EXCEPTION(jni()) << "error during VideoCapturer.startCapture";
 }
 
 void AndroidVideoCapturerJni::Stop() {
   LOG(LS_INFO) << "AndroidVideoCapturerJni stop";
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   {
+    // TODO(nisse): Consider moving this block until *after* the call to
+    // stopCapturer. stopCapturer should ensure that we get no
+    // more frames, and then we shouldn't need the if (!capturer_)
+    // checks in OnMemoryBufferFrame and OnTextureFrame.
     rtc::CritScope cs(&capturer_lock_);
     // Destroying |invoker_| will cancel all pending calls to |capturer_|.
     invoker_ = nullptr;
     capturer_ = nullptr;
   }
   jmethodID m = GetMethodID(jni(), *j_video_capturer_class_,
                             "stopCapture", "()V");
   jni()->CallVoidMethod(*j_video_capturer_, m);
   CHECK_EXCEPTION(jni()) << "error during VideoCapturer.stopCapture";
   LOG(LS_INFO) << "AndroidVideoCapturerJni stop done";
@@ skipping 63 matching lines @@
 
 void AndroidVideoCapturerJni::OnMemoryBufferFrame(void* video_frame,
                                                   int length,
                                                   int width,
                                                   int height,
                                                   int rotation,
                                                   int64_t timestamp_ns) {
   RTC_DCHECK(rotation == 0 || rotation == 90 || rotation == 180 ||
              rotation == 270);
   rtc::CritScope cs(&capturer_lock_);
-
+  if (!capturer_) {
+    LOG(LS_WARNING) << "OnMemoryBufferFrame() called for closed capturer.";
+    return;
+  }
   int adapted_width;
   int adapted_height;
   int crop_width;
   int crop_height;
   int crop_x;
   int crop_y;
 
   if (!capturer_->AdaptFrame(width, height, timestamp_ns,
                              &adapted_width, &adapted_height,
                              &crop_width, &crop_height, &crop_x, &crop_y)) {
@@ skipping 59 matching lines @@
 }
 
 void AndroidVideoCapturerJni::OnTextureFrame(int width,
                                              int height,
                                              int rotation,
                                              int64_t timestamp_ns,
                                              const NativeHandleImpl& handle) {
   RTC_DCHECK(rotation == 0 || rotation == 90 || rotation == 180 ||
              rotation == 270);
   rtc::CritScope cs(&capturer_lock_);
-
+  if (!capturer_) {
+    LOG(LS_WARNING) << "OnTextureFrame() called for closed capturer.";
+    return;
+  }
   int adapted_width;
   int adapted_height;
   int crop_width;
   int crop_height;
   int crop_x;
   int crop_y;
 
   if (!capturer_->AdaptFrame(width, height, timestamp_ns,
                              &adapted_width, &adapted_height,
                              &crop_width, &crop_height, &crop_x, &crop_y)) {
@@ skipping 68 matching lines @@
 
 JOW(void, VideoCapturer_00024NativeObserver_nativeOnOutputFormatRequest)
     (JNIEnv* jni, jclass, jlong j_capturer, jint j_width, jint j_height,
         jint j_fps) {
   LOG(LS_INFO) << "NativeObserver_nativeOnOutputFormatRequest";
   reinterpret_cast<AndroidVideoCapturerJni*>(j_capturer)->OnOutputFormatRequest(
       j_width, j_height, j_fps);
 }
 
 }  // namespace webrtc_jni