Bug 818933 - Provide a hardware release API so that we don't have to rely on CC of CameraControl objects. r=mhabicher

dom/camera/CameraControlImpl.cpp

@@ -367,6 +367,13 @@ CameraControlImpl::GetPreviewStreamVideoMode(CameraRecorderOptions* aOptions, ns
   return mCameraThread->Dispatch(getPreviewStreamVideoModeTask, NS_DISPATCH_NORMAL);
 }
 
+nsresult
+CameraControlImpl::ReleaseHardware(nsICameraReleaseCallback* onSuccess, nsICameraErrorCallback* onError)
+{
+  nsCOMPtr<nsIRunnable> releaseHardwareTask = new ReleaseHardwareTask(this, onSuccess, onError);
+  return mCameraThread->Dispatch(releaseHardwareTask, NS_DISPATCH_NORMAL);
+}
+
 bool
 CameraControlImpl::ReceiveFrame(void* aBuffer, ImageFormat aFormat, FrameBuilder aBuilder)
 {

dom/camera/CameraControlImpl.h

@@ -27,6 +27,7 @@ class StopRecordingTask;
 class SetParameterTask;
 class GetParameterTask;
 class GetPreviewStreamVideoModeTask;
+class ReleaseHardwareTask;
 
 class DOMCameraPreview;
 class RecorderProfileManager;
@@ -43,6 +44,7 @@ class CameraControlImpl : public ICameraControl
   friend class SetParameterTask;
   friend class GetParameterTask;
   friend class GetPreviewStreamVideoModeTask;
+  friend class ReleaseHardwareTask;
 
 public:
   CameraControlImpl(uint32_t aCameraId, nsIThread* aCameraThread, uint64_t aWindowId);
@@ -55,6 +57,7 @@ public:
   nsresult StartRecording(dom::CameraStartRecordingOptions* aOptions, nsIFile* aFolder, const nsAString& aFilename, nsICameraStartRecordingCallback* onSuccess, nsICameraErrorCallback* onError);
   nsresult StopRecording();
   nsresult GetPreviewStreamVideoMode(dom::CameraRecorderOptions* aOptions, nsICameraPreviewStreamCallback* onSuccess, nsICameraErrorCallback* onError);
+  nsresult ReleaseHardware(nsICameraReleaseCallback* onSuccess, nsICameraErrorCallback* onError);
 
   nsresult Set(uint32_t aKey, const nsAString& aValue);
   nsresult Get(uint32_t aKey, nsAString& aValue);
@@ -117,6 +120,7 @@ protected:
   virtual nsresult PushParametersImpl() = 0;
   virtual nsresult PullParametersImpl() = 0;
   virtual nsresult GetPreviewStreamVideoModeImpl(GetPreviewStreamVideoModeTask* aGetPreviewStreamVideoMode) = 0;
+  virtual nsresult ReleaseHardwareImpl(ReleaseHardwareTask* aReleaseHardware) = 0;
   virtual already_AddRefed<RecorderProfileManager> GetRecorderProfileManagerImpl() = 0;
 
   void OnShutterInternal();
@@ -610,7 +614,73 @@ public:
   nsCOMPtr<nsICameraErrorCallback> mOnErrorCb;
 };
 
-// Error result runnable
+// Return the result of releasing the camera hardware.  Runs on the main thread.
+class ReleaseHardwareResult : public nsRunnable
+{
+public:
+  ReleaseHardwareResult(nsICameraReleaseCallback* onSuccess, uint64_t aWindowId)
+    : mOnSuccessCb(onSuccess)
+    , mWindowId(aWindowId)
+  {
+    DOM_CAMERA_LOGT("%s:%d : this=%p\n", __func__, __LINE__, this);
+  }
+
+  virtual ~ReleaseHardwareResult()
+  {
+    DOM_CAMERA_LOGT("%s:%d : this=%p\n", __func__, __LINE__, this);
+  }
+
+  NS_IMETHOD Run()
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+
+    if (mOnSuccessCb && nsDOMCameraManager::IsWindowStillActive(mWindowId)) {
+      mOnSuccessCb->HandleEvent();
+    }
+    return NS_OK;
+  }
+
+protected:
+  nsCOMPtr<nsICameraReleaseCallback> mOnSuccessCb;
+  uint64_t mWindowId;
+};
+
+// Release the camera hardware.
+class ReleaseHardwareTask : public nsRunnable
+{
+public:
+  ReleaseHardwareTask(CameraControlImpl* aCameraControl, nsICameraReleaseCallback* onSuccess, nsICameraErrorCallback* onError)
+    : mCameraControl(aCameraControl)
+    , mOnSuccessCb(onSuccess)
+    , mOnErrorCb(onError)
+  {
+    DOM_CAMERA_LOGT("%s:%d : this=%p\n", __func__, __LINE__, this);
+  }
+
+  virtual ~ReleaseHardwareTask()
+  {
+    DOM_CAMERA_LOGT("%s:%d : this=%p\n", __func__, __LINE__, this);
+  }
+
+  NS_IMETHOD Run()
+  {
+    DOM_CAMERA_LOGT("%s:%d\n", __func__, __LINE__);
+    nsresult rv = mCameraControl->ReleaseHardwareImpl(this);
+    DOM_CAMERA_LOGT("%s:%d\n", __func__, __LINE__);
+
+    if (NS_FAILED(rv) && mOnErrorCb) {
+      rv = NS_DispatchToMainThread(new CameraErrorResult(mOnErrorCb, NS_LITERAL_STRING("FAILURE"), mCameraControl->GetWindowId()));
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+    return rv;
+  }
+
+  nsRefPtr<CameraControlImpl> mCameraControl;
+  nsCOMPtr<nsICameraReleaseCallback> mOnSuccessCb;
+  nsCOMPtr<nsICameraErrorCallback> mOnErrorCb;
+};
+
+// Report that the video recorder state has changed.
 class CameraRecorderStateChange : public nsRunnable
 {
 public:

dom/camera/DOMCameraControl.cpp

@@ -373,6 +373,12 @@ nsDOMCameraControl::GetPreviewStreamVideoMode(const JS::Value& aOptions, nsICame
   return mCameraControl->GetPreviewStreamVideoMode(&options, onSuccess, onError);
 }
 
+NS_IMETHODIMP
+nsDOMCameraControl::ReleaseHardware(nsICameraReleaseCallback* onSuccess, nsICameraErrorCallback* onError)
+{
+  return mCameraControl->ReleaseHardware(onSuccess, onError);
+}
+
 class GetCameraResult : public nsRunnable
 {
 public:

dom/camera/DOMCameraPreview.cpp

@@ -212,7 +212,7 @@ DOMCameraPreview::Start()
    * This reference is removed in SetStateStopped().
    */
   NS_ADDREF_THIS();
-  mState = STARTING;
+  DOM_CAMERA_SETSTATE(STARTING);
   mCameraControl->StartPreview(this);
 }
 
@@ -221,7 +221,7 @@ DOMCameraPreview::SetStateStarted()
 {
   NS_ASSERTION(NS_IsMainThread(), "SetStateStarted() not called from main thread");
 
-  mState = STARTED;
+  DOM_CAMERA_SETSTATE(STARTED);
   DOM_CAMERA_LOGI("Preview stream started\n");
 }
 
@@ -249,7 +249,7 @@ DOMCameraPreview::StopPreview()
   }
 
   DOM_CAMERA_LOGI("Stopping preview stream\n");
-  mState = STOPPING;
+  DOM_CAMERA_SETSTATE(STOPPING);
   mCameraControl->StopPreview();
   mInput->EndTrack(TRACK_VIDEO);
   mInput->Finish();
@@ -265,7 +265,7 @@ DOMCameraPreview::SetStateStopped()
     mInput->EndTrack(TRACK_VIDEO);
     mInput->Finish();
   }
-  mState = STOPPED;
+  DOM_CAMERA_SETSTATE(STOPPED);
   DOM_CAMERA_LOGI("Preview stream stopped\n");
 
   /**

dom/camera/DOMCameraPreview.h

@@ -12,7 +12,6 @@
 #include "nsDOMMediaStream.h"
 #include "CameraCommon.h"
 
-
 namespace mozilla {
 
 typedef void (*FrameBuilder)(mozilla::layers::Image* aImage, void* aBuffer, uint32_t aWidth, uint32_t aHeight);
@@ -38,7 +37,7 @@ public:
 
   void Start();   // called by the MediaStreamListener to start preview
   void Started(); // called by the CameraControl when preview is started
-  void StopPreview();    // called by the MediaStreamListener to stop preview
+  void StopPreview(); // called by the MediaStreamListener to stop preview
   void Stopped(bool aForced = false);
                   // called by the CameraControl when preview is stopped
   void Error();   // something went wrong, NS_RELEASE needed
@@ -57,6 +56,23 @@ protected:
   };
   uint32_t mState;
 
+  // Helper function, used in conjunction with the macro below, to make
+  //  it easy to track state changes, which must happen only on the main
+  //  thread.
+  void
+  SetState(uint32_t aNewState, const char* aFileOrFunc, int aLine)
+  {
+#ifdef PR_LOGGING
+    const char* states[] = { "stopped", "starting", "started", "stopping" };
+    MOZ_ASSERT(mState < sizeof(states) / sizeof(states[0]));
+    MOZ_ASSERT(aNewState < sizeof(states) / sizeof(states[0]));
+    DOM_CAMERA_LOGI("SetState: (this=%p) '%s' --> '%s' : %s:%d\n", this, states[mState], states[aNewState], aFileOrFunc, aLine);
+#endif
+
+    NS_ASSERTION(NS_IsMainThread(), "Preview state set OFF OF main thread!");
+    mState = aNewState;
+  }
+
   uint32_t mWidth;
   uint32_t mHeight;
   uint32_t mFramesPerSecond;
@@ -76,4 +92,6 @@ private:
 
 } // namespace mozilla
 
+#define DOM_CAMERA_SETSTATE(newState)   SetState((newState), __func__, __LINE__)
+
 #endif // DOM_CAMERA_DOMCAMERAPREVIEW_H

dom/camera/GonkCameraControl.cpp

@@ -282,7 +282,7 @@ nsGonkCameraControl::Init()
 nsGonkCameraControl::~nsGonkCameraControl()
 {
   DOM_CAMERA_LOGT("%s:%d : this=%p, mHwHandle = %d\n", __func__, __LINE__, this, mHwHandle);
-  GonkCameraHardware::ReleaseHandle(mHwHandle);
+  ReleaseHardwareImpl(nullptr);
   if (mRwLock) {
     PRRWLock* lock = mRwLock;
     mRwLock = nullptr;
@@ -1309,6 +1309,32 @@ nsGonkCameraControl::GetPreviewStreamVideoModeImpl(GetPreviewStreamVideoModeTask
   return NS_OK;
 }
 
+nsresult
+nsGonkCameraControl::ReleaseHardwareImpl(ReleaseHardwareTask* aReleaseHardware)
+{
+  DOM_CAMERA_LOGT("%s:%d : this=%p\n", __func__, __LINE__, this);
+
+  // if we're recording, stop recording
+  if (mRecorder) {
+    DOM_CAMERA_LOGI("shutting down existing video recorder\n");
+    mRecorder->stop();
+    mRecorder = nullptr;
+  }
+
+  // stop the preview
+  StopPreviewInternal(true /* forced */);
+
+  // release the hardware handle
+  GonkCameraHardware::ReleaseHandle(mHwHandle);
+
+  if (aReleaseHardware && aReleaseHardware->mOnSuccessCb) {
+    nsCOMPtr<nsIRunnable> releaseHardwareResult = new ReleaseHardwareResult(aReleaseHardware->mOnSuccessCb, mWindowId);
+    return NS_DispatchToMainThread(releaseHardwareResult);
+  }
+
+  return NS_OK;
+}
+
 already_AddRefed<GonkRecorderProfileManager>
 nsGonkCameraControl::GetGonkRecorderProfileManager()
 {

dom/camera/GonkCameraControl.h

@@ -76,6 +76,7 @@ protected:
   nsresult PushParametersImpl();
   nsresult PullParametersImpl();
   nsresult GetPreviewStreamVideoModeImpl(GetPreviewStreamVideoModeTask* aGetPreviewStreamVideoMode);
+  nsresult ReleaseHardwareImpl(ReleaseHardwareTask* aReleaseHardware);
   already_AddRefed<RecorderProfileManager> GetRecorderProfileManagerImpl();
   already_AddRefed<GonkRecorderProfileManager> GetGonkRecorderProfileManager();
 

dom/camera/ICameraControl.h

@@ -30,6 +30,7 @@ public:
   virtual nsresult StartRecording(dom::CameraStartRecordingOptions* aOptions, nsIFile* aFolder, const nsAString& aFilename, nsICameraStartRecordingCallback* onSuccess, nsICameraErrorCallback* onError) = 0;
   virtual nsresult StopRecording() = 0;
   virtual nsresult GetPreviewStreamVideoMode(dom::CameraRecorderOptions* aOptions, nsICameraPreviewStreamCallback* onSuccess, nsICameraErrorCallback* onError) = 0;
+  virtual nsresult ReleaseHardware(nsICameraReleaseCallback* onSuccess, nsICameraErrorCallback* onError) = 0;
 
   virtual nsresult Set(uint32_t aKey, const nsAString& aValue) = 0;
   virtual nsresult Get(uint32_t aKey, nsAString& aValue) = 0;

dom/camera/nsIDOMCameraManager.idl

@@ -241,6 +241,12 @@ interface nsICameraRecorderStateChange : nsISupports
     void handleStateChange(in DOMString newState);
 };
 
+[scriptable, function, uuid(f84d607b-554c-413d-8810-cf848642765a)]
+interface nsICameraReleaseCallback : nsISupports
+{
+    void handleEvent();
+};
+
 [scriptable, function, uuid(a302c6c9-3776-4d1d-a395-f4105d47c3d3)]
 interface nsICameraErrorCallback : nsISupports
 {
@@ -251,7 +257,7 @@ interface nsICameraErrorCallback : nsISupports
     attributes here affect the preview, any pictures taken, and/or
     any video recorded by the camera.
 */
-[scriptable, uuid(70f45209-b69b-4937-bbac-57d82600e2af)]
+[scriptable, uuid(c8e7418d-8913-4b66-bd9f-562fba627266)]
 interface nsICameraControl : nsISupports
 {
     readonly attribute nsICameraCapabilities capabilities;
@@ -391,6 +397,17 @@ interface nsICameraControl : nsISupports
     /* call in or after the takePicture() onSuccess callback to
        resume the camera preview stream. */
     void resumePreview();
+
+    /* release the camera so that other applications can use it; you should
+       probably call this whenever the camera is not longer in the foreground
+       (depending on your usage model).
+
+       the callbacks are optional, unless you really need to know when
+       the hardware is ultimately released.
+
+       once this is called, the camera control object is to be considered
+       defunct; a new instance will need to be created to access the camera. */
+    [binaryname(ReleaseHardware)] void release([optional] in nsICameraReleaseCallback onSuccess, [optional] in nsICameraErrorCallback onError);
 };
 
 [scriptable, function, uuid(a267afbc-d91c-413a-8de5-0b94aecffa3e)]