Fix lock behavior on RTCAudioSession.

In addition:
- Introduces RTCAudioSessionTest
- iOS/Mac gtests now have an autoreleasepool
- Moves ScopedAutoreleasePool to rtc_base_approved
- Introduces route change button in AppRTCDemo

BUG=webrtc:5649

Review URL: https://codereview.webrtc.org/1782363002

Cr-Commit-Position: refs/heads/master@{#11971}

webrtc/base/objc/RTCDispatcher.h

@@ -16,6 +16,8 @@ typedef NS_ENUM(NSInteger, RTCDispatcherQueueType) {
   // Used for starting/stopping AVCaptureSession, and assigning
   // capture session to AVCaptureVideoPreviewLayer.
   RTCDispatcherTypeCaptureSession,
+  // Used for operations on AVAudioSession.
+  RTCDispatcherTypeAudioSession,
 };
 
 /** Dispatcher that asynchronously dispatches blocks to a specific

webrtc/base/objc/RTCDispatcher.m

@@ -10,15 +10,17 @@
 
 #import "RTCDispatcher.h"
 
+static dispatch_queue_t kAudioSessionQueue = nil;
 static dispatch_queue_t kCaptureSessionQueue = nil;
 
-@implementation RTCDispatcher {
-  dispatch_queue_t _captureSessionQueue;
-}
+@implementation RTCDispatcher
 
 + (void)initialize {
   static dispatch_once_t onceToken;
   dispatch_once(&onceToken, ^{
+    kAudioSessionQueue = dispatch_queue_create(
+        "org.webrtc.RTCDispatcherAudioSession",
+        DISPATCH_QUEUE_SERIAL);
     kCaptureSessionQueue = dispatch_queue_create(
         "org.webrtc.RTCDispatcherCaptureSession",
         DISPATCH_QUEUE_SERIAL);
@@ -39,6 +41,8 @@ static dispatch_queue_t kCaptureSessionQueue = nil;
       return dispatch_get_main_queue();
     case RTCDispatcherTypeCaptureSession:
       return kCaptureSessionQueue;
+    case RTCDispatcherTypeAudioSession:
+      return kAudioSessionQueue;
   }
 }
 

webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallView.h

@@ -21,6 +21,9 @@
 // Called when the camera switch button is pressed.
 - (void)videoCallViewDidSwitchCamera:(ARDVideoCallView *)view;
 
+// Called when the route change button is pressed.
+- (void)videoCallViewDidChangeRoute:(ARDVideoCallView *)view;
+
 // Called when the hangup button is pressed.
 - (void)videoCallViewDidHangup:(ARDVideoCallView *)view;
 

webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallView.m

@@ -23,6 +23,7 @@ static CGFloat const kStatusBarHeight = 20;
 @end
 
 @implementation ARDVideoCallView {
+  UIButton *_routeChangeButton;
   UIButton *_cameraSwitchButton;
   UIButton *_hangupButton;
   CGSize _remoteVideoSize;
@@ -48,12 +49,23 @@ static CGFloat const kStatusBarHeight = 20;
     _statsView.hidden = YES;
     [self addSubview:_statsView];
 
+    _routeChangeButton = [UIButton buttonWithType:UIButtonTypeCustom];
+    _routeChangeButton.backgroundColor = [UIColor whiteColor];
+    _routeChangeButton.layer.cornerRadius = kButtonSize / 2;
+    _routeChangeButton.layer.masksToBounds = YES;
+    UIImage *image = [UIImage imageNamed:@"ic_surround_sound_black_24dp.png"];
+    [_routeChangeButton setImage:image forState:UIControlStateNormal];
+    [_routeChangeButton addTarget:self
+                           action:@selector(onRouteChange:)
+                 forControlEvents:UIControlEventTouchUpInside];
+    [self addSubview:_routeChangeButton];
+
     // TODO(tkchin): don't display this if we can't actually do camera switch.
     _cameraSwitchButton = [UIButton buttonWithType:UIButtonTypeCustom];
     _cameraSwitchButton.backgroundColor = [UIColor whiteColor];
     _cameraSwitchButton.layer.cornerRadius = kButtonSize / 2;
     _cameraSwitchButton.layer.masksToBounds = YES;
-    UIImage *image = [UIImage imageNamed:@"ic_switch_video_black_24dp.png"];
+    image = [UIImage imageNamed:@"ic_switch_video_black_24dp.png"];
     [_cameraSwitchButton setImage:image forState:UIControlStateNormal];
     [_cameraSwitchButton addTarget:self
                       action:@selector(onCameraSwitch:)
@@ -140,6 +152,12 @@ static CGFloat const kStatusBarHeight = 20;
       CGRectGetMaxX(cameraSwitchFrame) + kButtonPadding;
   _cameraSwitchButton.frame = cameraSwitchFrame;
 
+  // Place route button to the right of camera button.
+  CGRect routeChangeFrame = _cameraSwitchButton.frame;
+  routeChangeFrame.origin.x =
+      CGRectGetMaxX(routeChangeFrame) + kButtonPadding;
+  _routeChangeButton.frame = routeChangeFrame;
+
   [_statusLabel sizeToFit];
   _statusLabel.center =
       CGPointMake(CGRectGetMidX(bounds), CGRectGetMidY(bounds));
@@ -160,6 +178,10 @@ static CGFloat const kStatusBarHeight = 20;
   [_delegate videoCallViewDidSwitchCamera:self];
 }
 
+- (void)onRouteChange:(id)sender {
+  [_delegate videoCallViewDidChangeRoute:self];
+}
+
 - (void)onHangup:(id)sender {
   [_delegate videoCallViewDidHangup:self];
 }

webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallViewController.m

@@ -10,6 +10,9 @@
 
 #import "ARDVideoCallViewController.h"
 
+#import "webrtc/base/objc/RTCDispatcher.h"
+#import "webrtc/modules/audio_device/ios/objc/RTCAudioSession.h"
+
 #import "RTCAVFoundationVideoSource.h"
 #import "RTCLogging.h"
 
@@ -27,6 +30,7 @@
   ARDAppClient *_client;
   RTCVideoTrack *_remoteVideoTrack;
   RTCVideoTrack *_localVideoTrack;
+  AVAudioSessionPortOverride _portOverride;
 }
 
 @synthesize videoCallView = _videoCallView;
@@ -117,6 +121,26 @@
   [self switchCamera];
 }
 
+- (void)videoCallViewDidChangeRoute:(ARDVideoCallView *)view {
+  AVAudioSessionPortOverride override = AVAudioSessionPortOverrideNone;
+  if (_portOverride == AVAudioSessionPortOverrideNone) {
+    override = AVAudioSessionPortOverrideSpeaker;
+  }
+  [RTCDispatcher dispatchAsyncOnType:RTCDispatcherTypeAudioSession
+                               block:^{
+    RTCAudioSession *session = [RTCAudioSession sharedInstance];
+    [session lockForConfiguration];
+    NSError *error = nil;
+    if ([session overrideOutputAudioPort:override error:&error]) {
+      _portOverride = override;
+    } else {
+      RTCLogError(@"Error overriding output port: %@",
+                  error.localizedDescription);
+    }
+    [session unlockForConfiguration];
+  }];
+}
+
 - (void)videoCallViewDidEnableStats:(ARDVideoCallView *)view {
   _client.shouldGetStats = YES;
   _videoCallView.statsView.hidden = NO;

webrtc/modules/audio_device/ios/objc/RTCAudioSession+Private.h

@@ -14,9 +14,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface RTCAudioSession ()
 
-/** The lock that guards access to AVAudioSession methods. */
-@property(nonatomic, strong) NSRecursiveLock *lock;
-
 /** The delegates. */
 @property(nonatomic, readonly) NSSet *delegates;
 

webrtc/modules/audio_device/ios/objc/RTCAudioSession.mm

@@ -11,6 +11,7 @@
 #import "webrtc/modules/audio_device/ios/objc/RTCAudioSession.h"
 
 #include "webrtc/base/checks.h"
+#include "webrtc/base/criticalsection.h"
 
 #import "webrtc/base/objc/RTCLogging.h"
 #import "webrtc/modules/audio_device/ios/objc/RTCAudioSession+Private.h"
@@ -22,15 +23,15 @@ NSInteger const kRTCAudioSessionErrorLockRequired = -1;
 // TODO(tkchin): Consider more granular locking. We're not expecting a lot of
 // lock contention so coarse locks should be fine for now.
 @implementation RTCAudioSession {
+  rtc::CriticalSection _crit;
   AVAudioSession *_session;
   NSHashTable *_delegates;
   NSInteger _activationCount;
+  NSInteger _lockRecursionCount;
   BOOL _isActive;
-  BOOL _isLocked;
 }
 
 @synthesize session = _session;
-@synthesize lock = _lock;
 
 + (instancetype)sharedInstance {
   static dispatch_once_t onceToken;
@@ -45,7 +46,7 @@ NSInteger const kRTCAudioSessionErrorLockRequired = -1;
   if (self = [super init]) {
     _session = [AVAudioSession sharedInstance];
     _delegates = [NSHashTable weakObjectsHashTable];
-    _lock = [[NSRecursiveLock alloc] init];
+
     NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
     [center addObserver:self
                selector:@selector(handleInterruptionNotification:)
@@ -86,7 +87,7 @@ NSInteger const kRTCAudioSessionErrorLockRequired = -1;
 
 - (BOOL)isLocked {
   @synchronized(self) {
-    return _isLocked;
+    return _lockRecursionCount > 0;
   }
 }
 
@@ -103,24 +104,23 @@ NSInteger const kRTCAudioSessionErrorLockRequired = -1;
 }
 
 - (void)lockForConfiguration {
-  [_lock lock];
+  _crit.Enter();
   @synchronized(self) {
-    _isLocked = YES;
+    ++_lockRecursionCount;
   }
 }
 
 - (void)unlockForConfiguration {
   // Don't let threads other than the one that called lockForConfiguration
   // unlock.
-  if ([_lock tryLock]) {
+  if (_crit.TryEnter()) {
     @synchronized(self) {
-      _isLocked = NO;
+      --_lockRecursionCount;
     }
     // One unlock for the tryLock, and another one to actually unlock. If this
-    // was called without anyone calling lock, the underlying NSRecursiveLock
-    // should spit out an error.
-    [_lock unlock];
-    [_lock unlock];
+    // was called without anyone calling lock, we will hit an assertion.
+    _crit.Leave();
+    _crit.Leave();
   }
 }
 

webrtc/modules/audio_device/ios/objc/RTCAudioSessionTest.mm

@@ -0,0 +1,44 @@
+/*
+ *  Copyright 2016 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.
+ */
+
+#import <Foundation/Foundation.h>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+#import "webrtc/modules/audio_device/ios/objc/RTCAudioSession.h"
+
+@interface RTCAudioSessionTest : NSObject
+
+- (void)testLockForConfiguration;
+
+@end
+
+@implementation RTCAudioSessionTest
+
+- (void)testLockForConfiguration {
+  RTCAudioSession *session = [RTCAudioSession sharedInstance];
+
+  for (size_t i = 0; i < 2; i++) {
+    [session lockForConfiguration];
+    EXPECT_TRUE(session.isLocked);
+  }
+  for (size_t i = 0; i < 2; i++) {
+    EXPECT_TRUE(session.isLocked);
+    [session unlockForConfiguration];
+  }
+  EXPECT_FALSE(session.isLocked);
+}
+
+@end
+
+TEST(RTCAudioSessionTest, LockForConfiguration) {
+  RTCAudioSessionTest *test = [[RTCAudioSessionTest alloc] init];
+  [test testLockForConfiguration];
+}

webrtc/modules/modules.gyp

@@ -472,9 +472,13 @@
               ],
             }],
             ['OS=="ios"', {
+              'includes': [
+                '../build/objc_common.gypi',
+              ],
               'sources': [
                 'video_coding/codecs/h264/h264_video_toolbox_nalu_unittest.cc',
                 'audio_device/ios/audio_device_unittest_ios.cc',
+                'audio_device/ios/objc/RTCAudioSessionTest.mm',
               ],
               # This needs to be kept in sync with modules_unittests.isolate.
               'mac_bundle_resources': [

webrtc/webrtc_examples.gyp

@@ -281,14 +281,16 @@
           'conditions': [
             ['OS=="ios"', {
               'mac_bundle_resources': [
+                'examples/objc/AppRTCDemo/ios/resources/Roboto-Regular.ttf',
                 'examples/objc/AppRTCDemo/ios/resources/iPhone5@2x.png',
                 'examples/objc/AppRTCDemo/ios/resources/iPhone6@2x.png',
                 'examples/objc/AppRTCDemo/ios/resources/iPhone6p@3x.png',
-                'examples/objc/AppRTCDemo/ios/resources/Roboto-Regular.ttf',
                 'examples/objc/AppRTCDemo/ios/resources/ic_call_end_black_24dp.png',
                 'examples/objc/AppRTCDemo/ios/resources/ic_call_end_black_24dp@2x.png',
                 'examples/objc/AppRTCDemo/ios/resources/ic_clear_black_24dp.png',
                 'examples/objc/AppRTCDemo/ios/resources/ic_clear_black_24dp@2x.png',
+                'examples/objc/AppRTCDemo/ios/resources/ic_surround_sound_black_24dp.png',
+                'examples/objc/AppRTCDemo/ios/resources/ic_surround_sound_black_24dp@2x.png',
                 'examples/objc/AppRTCDemo/ios/resources/ic_switch_video_black_24dp.png',
                 'examples/objc/AppRTCDemo/ios/resources/ic_switch_video_black_24dp@2x.png',
                 'examples/objc/AppRTCDemo/ios/resources/mozart.mp3',