move lock into qtkit code to remove racing condition.

BUG=147104
Review URL: https://codereview.chromium.org/10911314

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@159347 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 24 insertions, 23 deletions

diff --git a/media/video/capture/mac/video_capture_device_mac.h b/media/video/capture/mac/video_capture_device_mac.h
index ffb1790..95d78e0 100644
--- a/media/video/capture/mac/video_capture_device_mac.h
+++ b/media/video/capture/mac/video_capture_device_mac.h
@@ -10,7 +10,6 @@
 #include <string>
 
 #include "base/compiler_specific.h"
-#include "base/synchronization/lock.h"
 #include "media/video/capture/video_capture_device.h"
 #include "media/video/capture/video_capture_types.h"
 
@@ -56,7 +55,6 @@ class VideoCaptureDeviceMac : public VideoCaptureDevice {
   VideoCaptureDevice::Name device_name_;
   VideoCaptureDevice::EventHandler* observer_;
   InternalState state_;
-  base::Lock lock_;
 
   VideoCaptureDeviceQTKit* capture_device_;
 
diff --git a/media/video/capture/mac/video_capture_device_mac.mm b/media/video/capture/mac/video_capture_device_mac.mm
index 315d07e..5fc614f 100644
--- a/media/video/capture/mac/video_capture_device_mac.mm
+++ b/media/video/capture/mac/video_capture_device_mac.mm
@@ -49,7 +49,6 @@ VideoCaptureDeviceMac::~VideoCaptureDeviceMac() {
 
 void VideoCaptureDeviceMac::Allocate(int width, int height, int frame_rate,
                                      EventHandler* observer) {
-  base::AutoLock auto_lock(lock_);
   if (state_ != kIdle) {
     return;
   }
@@ -57,6 +56,8 @@ void VideoCaptureDeviceMac::Allocate(int width, int height, int frame_rate,
   NSString* deviceId =
       [NSString stringWithUTF8String:device_name_.unique_id.c_str()];
 
+  [capture_device_ setFrameReceiver:this];
+
   if (![capture_device_ setCaptureDevice:deviceId]) {
     SetErrorState("Could not open capture device.");
     return;
@@ -86,19 +87,16 @@ void VideoCaptureDeviceMac::Start() {
     SetErrorState("Could not start capture device.");
     return;
   }
-  base::AutoLock auto_lock(lock_);
   state_ = kCapturing;
 }
 
 void VideoCaptureDeviceMac::Stop() {
   DCHECK_EQ(state_, kCapturing);
   [capture_device_ stopCapture];
-  base::AutoLock auto_lock(lock_);
   state_ = kAllocated;
 }
 
 void VideoCaptureDeviceMac::DeAllocate() {
-  base::AutoLock auto_lock(lock_);
   if (state_ != kAllocated && state_ != kCapturing) {
     return;
   }
@@ -106,6 +104,8 @@ void VideoCaptureDeviceMac::DeAllocate() {
     [capture_device_ stopCapture];
   }
   [capture_device_ setCaptureDevice:nil];
+  [capture_device_ setFrameReceiver:nil];
+
   state_ = kIdle;
 }
 
@@ -138,16 +138,12 @@ void VideoCaptureDeviceMac::ReceiveFrame(
     const uint8* video_frame,
     int video_frame_length,
     const VideoCaptureCapability& frame_info) {
-  base::AutoLock auto_lock(lock_);
-  if (state_ == kCapturing) {
-    observer_->OnIncomingCapturedFrame(video_frame, video_frame_length,
-                                       base::Time::Now());
-  }
+  observer_->OnIncomingCapturedFrame(video_frame, video_frame_length,
+                                     base::Time::Now());
 }
 
 void VideoCaptureDeviceMac::SetErrorState(const std::string& reason) {
   DLOG(ERROR) << reason;
-  base::AutoLock auto_lock(lock_);
   state_ = kError;
   observer_->OnError();
 }
diff --git a/media/video/capture/mac/video_capture_device_qtkit_mac.h b/media/video/capture/mac/video_capture_device_qtkit_mac.h
index 526c855..5739c2e 100644
--- a/media/video/capture/mac/video_capture_device_qtkit_mac.h
+++ b/media/video/capture/mac/video_capture_device_qtkit_mac.h
@@ -14,7 +14,6 @@ namespace media {
   class VideoCaptureDeviceMac;
 }
 
-@class QTCaptureDecompressedVideoOutput;
 @class QTCaptureDeviceInput;
 @class QTCaptureSession;
 
@@ -25,12 +24,12 @@ namespace media {
   int frameWidth_;
   int frameHeight_;
 
+  NSLock *lock_;
   media::VideoCaptureDeviceMac *frameReceiver_;
 
   // QTKit variables.
   QTCaptureSession *captureSession_;
   QTCaptureDeviceInput *captureDeviceInput_;
-  QTCaptureDecompressedVideoOutput *captureDecompressedOutput_;
 }
 
 // Returns a dictionary of capture devices with friendly name and unique id.
@@ -39,6 +38,9 @@ namespace media {
 // Initializes the instance and registers the frame receiver.
 - (id)initWithFrameReceiver:(media::VideoCaptureDeviceMac *)frameReceiver;
 
+// Set the frame receiver.
+- (void)setFrameReceiver:(media::VideoCaptureDeviceMac *)frameReceiver;
+
 // Sets which capture device to use. Returns YES on sucess, NO otherwise.
 - (BOOL)setCaptureDevice:(NSString *)deviceId;
 
diff --git a/media/video/capture/mac/video_capture_device_qtkit_mac.mm b/media/video/capture/mac/video_capture_device_qtkit_mac.mm
index a7e2c58..096ce44 100644
--- a/media/video/capture/mac/video_capture_device_qtkit_mac.mm
+++ b/media/video/capture/mac/video_capture_device_qtkit_mac.mm
@@ -35,6 +35,7 @@
   self = [super init];
   if (self) {
     frameReceiver_ = frameReceiver;
+    lock_ = [[NSLock alloc] init];
   }
   return self;
 }
@@ -42,10 +43,15 @@
 - (void)dealloc {
   [captureSession_ release];
   [captureDeviceInput_ release];
-  [captureDecompressedOutput_ release];
   [super dealloc];
 }
 
+- (void)setFrameReceiver:(media::VideoCaptureDeviceMac *)frameReceiver {
+  [lock_ lock];
+  frameReceiver_ = frameReceiver;
+  [lock_ unlock];
+}
+
 - (BOOL)setCaptureDevice:(NSString *)deviceId {
   if (deviceId) {
     // Set the capture device.
@@ -73,10 +79,10 @@
     captureDeviceInput_ = [[QTCaptureDeviceInput alloc] initWithDevice:device];
     captureSession_ = [[QTCaptureSession alloc] init];
 
-    captureDecompressedOutput_ =
-        [[QTCaptureDecompressedVideoOutput alloc] init];
-    [captureDecompressedOutput_ setDelegate:self];
-    if (![captureSession_ addOutput:captureDecompressedOutput_ error:&error]) {
+    QTCaptureDecompressedVideoOutput *captureDecompressedOutput =
+        [[[QTCaptureDecompressedVideoOutput alloc] init] autorelease];
+    [captureDecompressedOutput setDelegate:self];
+    if (![captureSession_ addOutput:captureDecompressedOutput error:&error]) {
       DLOG(ERROR) << "Could not connect video capture output."
                   << [[error localizedDescription] UTF8String];
       return NO;
@@ -92,14 +98,10 @@
       // The device is still running.
       [self stopCapture];
     }
-    [captureDecompressedOutput_ setDelegate:nil];
-    [captureSession_ removeOutput:captureDecompressedOutput_];
     [captureSession_ release];
     captureSession_ = nil;
     [captureDeviceInput_ release];
     captureDeviceInput_ = nil;
-    [captureDecompressedOutput_ release];
-    captureDecompressedOutput_ = nil;
     return YES;
   }
 }
@@ -163,7 +165,9 @@
   didOutputVideoFrame:(CVImageBufferRef)videoFrame
      withSampleBuffer:(QTSampleBuffer *)sampleBuffer
        fromConnection:(QTCaptureConnection *)connection {
+  [lock_ lock];
   if(!frameReceiver_) {
+    [lock_ unlock];
     return;
   }
 
@@ -189,6 +193,7 @@
 
     CVPixelBufferUnlockBaseAddress(videoFrame, kLockFlags);
   }
+  [lock_ unlock];
 }
 
 @end