Annotate rest of WebRTC with @Nullable.

Bug: webrtc:8881
Change-Id: Ic199efa73a0b3b9437df1e8fe5a1814a70380993
Reviewed-on: https://webrtc-review.googlesource.com/64884
Reviewed-by: Paulina Hensman <phensman@webrtc.org>
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22639}

examples/androidnativeapi/java/org/webrtc/examples/androidnativeapi/MainActivity.java

@@ -13,16 +13,17 @@ package org.webrtc.examples.androidnativeapi;
 import android.app.Activity;
 import android.os.Bundle;
 import android.widget.Button;
+import javax.annotation.Nullable;
 import org.webrtc.ContextUtils;
 import org.webrtc.EglBase;
 import org.webrtc.GlRectDrawer;
 import org.webrtc.SurfaceViewRenderer;
 
 public class MainActivity extends Activity {
-  private CallClient callClient;
-  private EglBase eglBase;
-  private SurfaceViewRenderer localRenderer;
-  private SurfaceViewRenderer remoteRenderer;
+  private @Nullable CallClient callClient;
+  private @Nullable EglBase eglBase;
+  private @Nullable SurfaceViewRenderer localRenderer;
+  private @Nullable SurfaceViewRenderer remoteRenderer;
 
   @Override
   protected void onCreate(Bundle savedInstance) {

examples/unityplugin/java/src/org/webrtc/UnityUtility.java

@@ -12,6 +12,7 @@ package org.webrtc;
 
 import android.content.Context;
 import java.util.List;
+import javax.annotation.Nullable;
 
 public class UnityUtility {
   private static final String VIDEO_CAPTURER_THREAD_NAME = "VideoCapturerThread";
@@ -26,7 +27,7 @@ public class UnityUtility {
     return Camera2Enumerator.isSupported(ContextUtils.getApplicationContext());
   }
 
-  private static VideoCapturer createCameraCapturer(CameraEnumerator enumerator) {
+  private static @Nullable VideoCapturer createCameraCapturer(CameraEnumerator enumerator) {
     final String[] deviceNames = enumerator.getDeviceNames();
 
     for (String deviceName : deviceNames) {

modules/audio_device/android/java/src/org/webrtc/voiceengine/WebRtcAudioEffects.java

@@ -19,6 +19,7 @@ import android.media.audiofx.NoiseSuppressor;
 import android.os.Build;
 import java.util.List;
 import java.util.UUID;
+import javax.annotation.Nullable;
 import org.webrtc.Logging;
 
 // This class wraps control of three different platform effects. Supported
@@ -40,12 +41,12 @@ public class WebRtcAudioEffects {
   // Contains the available effect descriptors returned from the
   // AudioEffect.getEffects() call. This result is cached to avoid doing the
   // slow OS call multiple times.
-  private static Descriptor[] cachedEffects = null;
+  private static @Nullable Descriptor[] cachedEffects = null;
 
   // Contains the audio effect objects. Created in enable() and destroyed
   // in release().
-  private AcousticEchoCanceler aec = null;
-  private NoiseSuppressor ns = null;
+  private @Nullable AcousticEchoCanceler aec = null;
+  private @Nullable NoiseSuppressor ns = null;
 
   // Affects the final state given to the setEnabled() method on each effect.
   // The default state is set to "disabled" but each effect can also be enabled
@@ -291,7 +292,7 @@ public class WebRtcAudioEffects {
 
   // Returns the cached copy of the audio effects array, if available, or
   // queries the operating system for the list of effects.
-  private static Descriptor[] getAvailableEffects() {
+  private static @Nullable Descriptor[] getAvailableEffects() {
     if (cachedEffects != null) {
       return cachedEffects;
     }

modules/audio_device/android/java/src/org/webrtc/voiceengine/WebRtcAudioManager.java

@@ -20,6 +20,7 @@ import android.media.AudioTrack;
 import android.os.Build;
 import java.util.Timer;
 import java.util.TimerTask;
+import javax.annotation.Nullable;
 import org.webrtc.ContextUtils;
 import org.webrtc.Logging;
 
@@ -102,7 +103,7 @@ public class WebRtcAudioManager {
     private static final int TIMER_PERIOD_IN_SECONDS = 30;
 
     private final AudioManager audioManager;
-    private Timer timer;
+    private @Nullable Timer timer;
 
     public VolumeLogger(AudioManager audioManager) {
       this.audioManager = audioManager;

modules/audio_device/android/java/src/org/webrtc/voiceengine/WebRtcAudioRecord.java

@@ -19,6 +19,7 @@ import java.lang.System;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.concurrent.TimeUnit;
+import javax.annotation.Nullable;
 import org.webrtc.Logging;
 import org.webrtc.ThreadUtils;
 
@@ -51,12 +52,12 @@ public class WebRtcAudioRecord {
 
   private final long nativeAudioRecord;
 
-  private WebRtcAudioEffects effects = null;
+  private @Nullable WebRtcAudioEffects effects = null;
 
   private ByteBuffer byteBuffer;
 
-  private AudioRecord audioRecord = null;
-  private AudioRecordThread audioThread = null;
+  private @Nullable AudioRecord audioRecord = null;
+  private @Nullable AudioRecordThread audioThread = null;
 
   private static volatile boolean microphoneMute = false;
   private byte[] emptyBytes;
@@ -73,7 +74,7 @@ public class WebRtcAudioRecord {
     void onWebRtcAudioRecordError(String errorMessage);
   }
 
-  private static WebRtcAudioRecordErrorCallback errorCallback = null;
+  private static @Nullable WebRtcAudioRecordErrorCallback errorCallback = null;
 
   public static void setErrorCallback(WebRtcAudioRecordErrorCallback errorCallback) {
     Logging.d(TAG, "Set error callback");
@@ -123,7 +124,7 @@ public class WebRtcAudioRecord {
     void onWebRtcAudioRecordSamplesReady(AudioSamples samples);
   }
 
-  private static WebRtcAudioRecordSamplesReadyCallback audioSamplesReadyCallback = null;
+  private static @Nullable WebRtcAudioRecordSamplesReadyCallback audioSamplesReadyCallback = null;
 
   public static void setOnAudioSamplesReady(WebRtcAudioRecordSamplesReadyCallback callback) {
     audioSamplesReadyCallback = callback;

modules/audio_device/android/java/src/org/webrtc/voiceengine/WebRtcAudioTrack.java

@@ -20,6 +20,7 @@ import android.media.AudioTrack;
 import android.os.Process;
 import java.lang.Thread;
 import java.nio.ByteBuffer;
+import javax.annotation.Nullable;
 import org.webrtc.ContextUtils;
 import org.webrtc.Logging;
 import org.webrtc.ThreadUtils;
@@ -79,8 +80,8 @@ public class WebRtcAudioTrack {
 
   private ByteBuffer byteBuffer;
 
-  private AudioTrack audioTrack = null;
-  private AudioTrackThread audioThread = null;
+  private @Nullable AudioTrack audioTrack = null;
+  private @Nullable AudioTrackThread audioThread = null;
 
   // Samples to be played are replaced by zeros if |speakerMute| is set to true.
   // Can be used to ensure that the speaker is fully muted.
@@ -107,8 +108,8 @@ public class WebRtcAudioTrack {
     void onWebRtcAudioTrackError(String errorMessage);
   }
 
-  private static WebRtcAudioTrackErrorCallback errorCallbackOld = null;
-  private static ErrorCallback errorCallback = null;
+  private static @Nullable WebRtcAudioTrackErrorCallback errorCallbackOld = null;
+  private static @Nullable ErrorCallback errorCallback = null;
 
   @Deprecated
   public static void setErrorCallback(WebRtcAudioTrackErrorCallback errorCallback) {

rtc_base/BUILD.gn

@@ -1383,18 +1383,5 @@ if (is_android) {
       "java/src/org/webrtc/Size.java",
       "java/src/org/webrtc/ThreadUtils.java",
     ]
-
-    # TODO(crbug.com/824679): Find out why this fails in Chromium
-    if (!build_with_chromium) {
-      javac_args = [
-        "-Xep:ParameterNotNullable:ERROR",
-        "-Xep:FieldMissingNullable:ERROR",
-        "-Xep:ReturnMissingNullable:ERROR",
-      ]
-    }
-
-    deps = [
-      "//third_party/jsr-305:jsr_305_javalib",
-    ]
   }
 }

sdk/android/BUILD.gn

@@ -845,16 +845,9 @@ rtc_android_library("libjingle_peerconnection_java") {
     ]
   }
 
-  javac_args = [
-    "-Xep:ParameterNotNullable:ERROR",
-    "-Xep:FieldMissingNullable:ERROR",
-    "-Xep:ReturnMissingNullable:ERROR",
-  ]
-
   deps = [
     "../../modules/audio_device:audio_device_java",
     "../../rtc_base:base_java",
-    "//third_party/jsr-305:jsr_305_javalib",
   ]
 }
 

sdk/android/instrumentationtests/src/org/webrtc/Camera2CapturerTest.java

@@ -27,6 +27,7 @@ import android.support.test.filters.MediumTest;
 import android.support.test.filters.SmallTest;
 import java.io.IOException;
 import java.util.concurrent.CountDownLatch;
+import javax.annotation.Nullable;
 import org.chromium.base.test.BaseJUnit4ClassRunner;
 import org.junit.After;
 import org.junit.Before;
@@ -46,7 +47,7 @@ public class Camera2CapturerTest {
     final LooperThread looperThread;
     final CountDownLatch openDoneSignal;
     final Object cameraDeviceLock;
-    CameraDevice cameraDevice; // Guarded by cameraDeviceLock
+    @Nullable CameraDevice cameraDevice; // Guarded by cameraDeviceLock
     boolean openSucceeded; // Guarded by cameraDeviceLock
 
     private class LooperThread extends Thread {

sdk/android/instrumentationtests/src/org/webrtc/CameraVideoCapturerTestFixtures.java

@@ -25,6 +25,7 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
+import javax.annotation.Nullable;
 import org.chromium.base.test.BaseJUnit4ClassRunner;
 import org.junit.runner.RunWith;
 import org.webrtc.CameraEnumerationAndroid.CaptureFormat;
@@ -103,7 +104,7 @@ class CameraVideoCapturerTestFixtures {
 
   static private class FakeCapturerObserver implements CameraVideoCapturer.CapturerObserver {
     private int framesCaptured = 0;
-    private VideoFrame videoFrame;
+    private @Nullable VideoFrame videoFrame;
     final private Object frameLock = new Object();
     final private Object capturerStartLock = new Object();
     private Boolean capturerStartResult;
@@ -290,7 +291,7 @@ class CameraVideoCapturerTestFixtures {
       return cameraEnumerator.createCapturer(name, eventsHandler);
     }
 
-    public String getNameOfFrontFacingDevice() {
+    public @Nullable String getNameOfFrontFacingDevice() {
       for (String deviceName : cameraEnumerator.getDeviceNames()) {
         if (cameraEnumerator.isFrontFacing(deviceName)) {
           return deviceName;
@@ -300,7 +301,7 @@ class CameraVideoCapturerTestFixtures {
       return null;
     }
 
-    public String getNameOfBackFacingDevice() {
+    public @Nullable String getNameOfBackFacingDevice() {
       for (String deviceName : cameraEnumerator.getDeviceNames()) {
         if (cameraEnumerator.isBackFacing(deviceName)) {
           return deviceName;

sdk/android/instrumentationtests/src/org/webrtc/DefaultVideoEncoderFactoryTest.java

@@ -18,6 +18,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
+import javax.annotation.Nullable;
 import org.chromium.base.test.BaseJUnit4ClassRunner;
 import org.junit.Before;
 import org.junit.Test;
@@ -51,7 +52,7 @@ public class DefaultVideoEncoderFactoryTest {
     }
 
     @Override
-    public VideoEncoder createEncoder(VideoCodecInfo info) {
+    public @Nullable VideoEncoder createEncoder(VideoCodecInfo info) {
       return null;
     }
 

sdk/android/instrumentationtests/src/org/webrtc/HardwareVideoDecoderTest.java

@@ -21,6 +21,7 @@ import java.util.List;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.TimeUnit;
+import javax.annotation.Nullable;
 import org.chromium.base.test.params.BaseJUnit4RunnerDelegate;
 import org.chromium.base.test.params.ParameterAnnotations.ClassParameter;
 import org.chromium.base.test.params.ParameterAnnotations.UseRunnerDelegate;
@@ -118,7 +119,7 @@ public final class HardwareVideoDecoderTest {
     return new HardwareVideoDecoderFactory(eglContext);
   }
 
-  private VideoDecoder createDecoder() {
+  private @Nullable VideoDecoder createDecoder() {
     VideoDecoderFactory factory =
         createDecoderFactory(useEglContext ? eglBase.getEglBaseContext() : null);
     return factory.createDecoder(codecType);

sdk/android/instrumentationtests/src/org/webrtc/HardwareVideoEncoderTest.java

@@ -26,6 +26,7 @@ import java.util.List;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.TimeUnit;
+import javax.annotation.Nullable;
 import org.chromium.base.test.params.BaseJUnit4RunnerDelegate;
 import org.chromium.base.test.params.ParameterAnnotations.ClassParameter;
 import org.chromium.base.test.params.ParameterAnnotations.UseRunnerDelegate;
@@ -291,7 +292,7 @@ public class HardwareVideoEncoderTest {
         eglContext, ENABLE_INTEL_VP8_ENCODER, ENABLE_H264_HIGH_PROFILE);
   }
 
-  private VideoEncoder createEncoder() {
+  private @Nullable VideoEncoder createEncoder() {
     VideoEncoderFactory factory =
         createEncoderFactory(useEglContext ? eglBase.getEglBaseContext() : null);
     VideoCodecInfo[] supportedCodecs = factory.getSupportedCodecs();

sdk/android/instrumentationtests/src/org/webrtc/NetworkMonitorTest.java

@@ -35,6 +35,7 @@ import android.support.test.annotation.UiThreadTest;
 import android.support.test.filters.MediumTest;
 import android.support.test.filters.SmallTest;
 import android.support.test.rule.UiThreadTestRule;
+import javax.annotation.Nullable;
 import org.chromium.base.test.BaseJUnit4ClassRunner;
 import org.junit.Before;
 import org.junit.Rule;
@@ -147,7 +148,7 @@ public class NetworkMonitorTest {
   }
 
   private static final Object lock = new Object();
-  private static Handler uiThreadHandler = null;
+  private static @Nullable Handler uiThreadHandler = null;
 
   private NetworkMonitorAutoDetect receiver;
   private MockConnectivityManagerDelegate connectivityDelegate;
@@ -155,10 +156,11 @@ public class NetworkMonitorTest {
 
   private static Handler getUiThreadHandler() {
     synchronized (lock) {
-      if (uiThreadHandler == null) {
-        uiThreadHandler = new Handler(Looper.getMainLooper());
+      Handler handler = uiThreadHandler;
+      if (handler != null) {
+        return handler;
       }
-      return uiThreadHandler;
+      return uiThreadHandler = new Handler(Looper.getMainLooper());
     }
   }
 

sdk/android/instrumentationtests/src/org/webrtc/PeerConnectionTest.java

@@ -34,6 +34,7 @@ import java.util.Queue;
 import java.util.TreeSet;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import javax.annotation.Nullable;
 import org.chromium.base.test.BaseJUnit4ClassRunner;
 import org.chromium.base.test.util.DisabledTest;
 import org.junit.Before;
@@ -48,7 +49,7 @@ import org.webrtc.PeerConnection.SignalingState;
 @RunWith(BaseJUnit4ClassRunner.class)
 public class PeerConnectionTest {
   private static final int TIMEOUT_SECONDS = 20;
-  private TreeSet<String> threadsBeforeTest = null;
+  private @Nullable TreeSet<String> threadsBeforeTest = null;
 
   @Before
   public void setUp() {
@@ -530,8 +531,8 @@ public class PeerConnectionTest {
 
   private static class SdpObserverLatch implements SdpObserver {
     private boolean success = false;
-    private SessionDescription sdp = null;
-    private String error = null;
+    private @Nullable SessionDescription sdp = null;
+    private @Nullable String error = null;
     private CountDownLatch latch = new CountDownLatch(1);
 
     public SdpObserverLatch() {}
@@ -572,11 +573,11 @@ public class PeerConnectionTest {
       return success;
     }
 
-    public SessionDescription getSdp() {
+    public @Nullable SessionDescription getSdp() {
       return sdp;
     }
 
-    public String getError() {
+    public @Nullable String getError() {
       return error;
     }
   }

sdk/android/instrumentationtests/src/org/webrtc/SurfaceTextureHelperTest.java

@@ -21,6 +21,7 @@ import android.support.test.filters.MediumTest;
 import android.support.test.filters.SmallTest;
 import java.nio.ByteBuffer;
 import java.util.concurrent.CountDownLatch;
+import javax.annotation.Nullable;
 import org.chromium.base.test.BaseJUnit4ClassRunner;
 import org.junit.Before;
 import org.junit.Test;
@@ -37,7 +38,7 @@ public class SurfaceTextureHelperTest {
     public float[] transformMatrix;
     private boolean hasNewFrame = false;
     // Thread where frames are expected to be received on.
-    private final Thread expectedThread;
+    private final @Nullable Thread expectedThread;
 
     MockTextureListener() {
       this.expectedThread = null;

webrtc.gni

@@ -501,11 +501,25 @@ if (is_android) {
       # Treat warnings as errors.
       javac_args += [ "-Werror" ]
 
+      # TODO(crbug.com/824679): Find out why this fails in Chromium
+      if (!build_with_chromium) {
+        javac_args += [
+          "-Xep:ParameterNotNullable:ERROR",
+          "-Xep:FieldMissingNullable:ERROR",
+          "-Xep:ReturnMissingNullable:ERROR",
+        ]
+      }
+
       # Add any arguments defined by the invoker.
       if (defined(invoker.javac_args)) {
         javac_args += invoker.javac_args
       }
 
+      if (!defined(deps)) {
+        deps = []
+      }
+      deps += [ "//third_party/jsr-305:jsr_305_javalib" ]
+
       no_build_hooks = true
     }
   }
@@ -524,6 +538,20 @@ if (is_android) {
       # Treat warnings as errors.
       javac_args = [ "-Werror" ]
 
+      # TODO(crbug.com/824679): Find out why this fails in Chromium
+      if (!build_with_chromium) {
+        javac_args += [
+          "-Xep:ParameterNotNullable:ERROR",
+          "-Xep:FieldMissingNullable:ERROR",
+          "-Xep:ReturnMissingNullable:ERROR",
+        ]
+      }
+
+      if (!defined(deps)) {
+        deps = []
+      }
+      deps += [ "//third_party/jsr-305:jsr_305_javalib" ]
+
       no_build_hooks = true
     }
   }
@@ -542,6 +570,20 @@ if (is_android) {
       # Treat warnings as errors.
       javac_args = [ "-Werror" ]
 
+      # TODO(crbug.com/824679): Find out why this fails in Chromium
+      if (!build_with_chromium) {
+        javac_args += [
+          "-Xep:ParameterNotNullable:ERROR",
+          "-Xep:FieldMissingNullable:ERROR",
+          "-Xep:ReturnMissingNullable:ERROR",
+        ]
+      }
+
+      if (!defined(deps)) {
+        deps = []
+      }
+      deps += [ "//third_party/jsr-305:jsr_305_javalib" ]
+
       no_build_hooks = true
     }
   }