Add reference counter of DxgiDuplicatorController to unload DXGI components

On Windows, only four applications can use DXGI duplication APIs concurrently.
So this change adds a reference counter of DxgiDuplicatorController to unload
DXGI components when the reference counter reaches 0.

BUG=webrtc:7808

Review-Url: https://codereview.webrtc.org/2933893003
Cr-Commit-Position: refs/heads/master@{#18668}

webrtc/modules/desktop_capture/screen_capturer_win.cc

@@ -24,10 +24,9 @@ namespace webrtc {
 
 namespace {
 
-std::unique_ptr<DesktopCapturer> CreateScreenCapturerWinDirectx(
-    const DesktopCaptureOptions& options) {
+std::unique_ptr<DesktopCapturer> CreateScreenCapturerWinDirectx() {
   std::unique_ptr<DesktopCapturer> capturer(
-      new ScreenCapturerWinDirectx(options));
+      new ScreenCapturerWinDirectx());
   capturer.reset(new BlankDetectorDesktopCapturerWrapper(
       std::move(capturer), RgbaColor(0, 0, 0, 0)));
   return capturer;
@@ -39,10 +38,14 @@ std::unique_ptr<DesktopCapturer> CreateScreenCapturerWinDirectx(
 std::unique_ptr<DesktopCapturer> DesktopCapturer::CreateRawScreenCapturer(
     const DesktopCaptureOptions& options) {
   std::unique_ptr<DesktopCapturer> capturer(new ScreenCapturerWinGdi(options));
-  if (options.allow_directx_capturer() &&
-      ScreenCapturerWinDirectx::IsSupported()) {
-    capturer.reset(new FallbackDesktopCapturerWrapper(
-        CreateScreenCapturerWinDirectx(options), std::move(capturer)));
+  if (options.allow_directx_capturer()) {
+    // |dxgi_duplicator_controller| should be alive in this scope to ensure it
+    // won't unload DxgiDuplicatorController.
+    auto dxgi_duplicator_controller = DxgiDuplicatorController::Instance();
+    if (ScreenCapturerWinDirectx::IsSupported()) {
+      capturer.reset(new FallbackDesktopCapturerWrapper(
+          CreateScreenCapturerWinDirectx(), std::move(capturer)));
+    }
   }
 
   if (options.allow_use_magnification_api()) {

webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.cc

@@ -16,6 +16,7 @@
 #include <string>
 
 #include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
 #include "webrtc/base/timeutils.h"
 #include "webrtc/modules/desktop_capture/desktop_capture_types.h"
 #include "webrtc/modules/desktop_capture/win/dxgi_frame.h"
@@ -25,18 +26,30 @@
 namespace webrtc {
 
 // static
-DxgiDuplicatorController* DxgiDuplicatorController::Instance() {
+rtc::scoped_refptr<DxgiDuplicatorController>
+DxgiDuplicatorController::Instance() {
   // The static instance won't be deleted to ensure it can be used by other
   // threads even during program exiting.
   static DxgiDuplicatorController* instance = new DxgiDuplicatorController();
-  return instance;
+  return rtc::scoped_refptr<DxgiDuplicatorController>(instance);
 }
 
-DxgiDuplicatorController::DxgiDuplicatorController() = default;
+DxgiDuplicatorController::DxgiDuplicatorController()
+    : refcount_(0) {}
 
-DxgiDuplicatorController::~DxgiDuplicatorController() {
-  rtc::CritScope lock(&lock_);
-  Deinitialize();
+void DxgiDuplicatorController::AddRef() {
+  int refcount = (++refcount_);
+  RTC_DCHECK(refcount > 0);
+}
+
+void DxgiDuplicatorController::Release() {
+  int refcount = (--refcount_);
+  RTC_DCHECK(refcount >= 0);
+  if (refcount == 0) {
+    LOG(LS_WARNING) << "Count of references reaches zero, "
+                       "DxgiDuplicatorController will be unloaded.";
+    Unload();
+  }
 }
 
 bool DxgiDuplicatorController::IsSupported() {
@@ -129,6 +142,11 @@ DxgiDuplicatorController::DoDuplicate(DxgiFrame* frame, int monitor_id) {
   return Result::DUPLICATION_FAILED;
 }
 
+void DxgiDuplicatorController::Unload() {
+  rtc::CritScope lock(&lock_);
+  Deinitialize();
+}
+
 void DxgiDuplicatorController::Unregister(const Context* const context) {
   rtc::CritScope lock(&lock_);
   if (ContextExpired(context)) {

webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.h

@@ -13,10 +13,11 @@
 
 #include <D3DCommon.h>
 
-#include <memory>
+#include <atomic>
 #include <vector>
 
 #include "webrtc/base/criticalsection.h"
+#include "webrtc/base/scoped_ref_ptr.h"
 #include "webrtc/modules/desktop_capture/desktop_geometry.h"
 #include "webrtc/modules/desktop_capture/resolution_change_detector.h"
 #include "webrtc/modules/desktop_capture/shared_desktop_frame.h"
@@ -66,12 +67,7 @@ class DxgiDuplicatorController {
   };
 
   // Returns the singleton instance of DxgiDuplicatorController.
-  static DxgiDuplicatorController* Instance();
-
-  // Destructs current instance. We need to make sure COM components and their
-  // containers are destructed in correct order. This function calls
-  // Deinitialize() to do the real work.
-  ~DxgiDuplicatorController();
+  static rtc::scoped_refptr<DxgiDuplicatorController> Instance();
 
   // All the following public functions implicitly call Initialize() function.
 
@@ -107,16 +103,32 @@ class DxgiDuplicatorController {
   // destructing.
   friend DxgiFrameContext::~DxgiFrameContext();
 
+  // scoped_refptr<DxgiDuplicatorController> accesses private AddRef() and
+  // Release() functions.
+  friend class rtc::scoped_refptr<DxgiDuplicatorController>;
+
   // A private constructor to ensure consumers to use
   // DxgiDuplicatorController::Instance().
   DxgiDuplicatorController();
 
+  // Not implemented: The singleton DxgiDuplicatorController instance should not
+  // be deleted.
+  ~DxgiDuplicatorController();
+
+  // RefCountedInterface implementations.
+  void AddRef();
+  void Release();
+
   // Does the real duplication work. Setting |monitor_id| < 0 to capture entire
   // screen. This function calls Initialize(). And if the duplication failed,
   // this function calls Deinitialize() to ensure the Dxgi components can be
   // reinitialized next time.
   Result DoDuplicate(DxgiFrame* frame, int monitor_id);
 
+  // Unload all the DXGI components and releases the resources. This function
+  // wraps Deinitialize() with |lock_|.
+  void Unload();
+
   // Unregisters Context from this instance and all DxgiAdapterDuplicator(s)
   // it owns.
   void Unregister(const Context* const context);
@@ -185,6 +197,9 @@ class DxgiDuplicatorController {
   // DxgiAdapterDuplicator and DxgiOutputDuplicator instances are initialized.
   void TranslateRect();
 
+  // The count of references which are now "living".
+  std::atomic_int refcount_;
+
   // This lock must be locked whenever accessing any of the following objects.
   rtc::CriticalSection lock_;
 

webrtc/modules/desktop_capture/win/screen_capturer_win_directx.cc

@@ -36,11 +36,10 @@ bool ScreenCapturerWinDirectx::RetrieveD3dInfo(D3dInfo* info) {
   return DxgiDuplicatorController::Instance()->RetrieveD3dInfo(info);
 }
 
-ScreenCapturerWinDirectx::ScreenCapturerWinDirectx(
-    const DesktopCaptureOptions& options)
-    : callback_(nullptr) {}
+ScreenCapturerWinDirectx::ScreenCapturerWinDirectx()
+    : controller_(DxgiDuplicatorController::Instance()) {}
 
-ScreenCapturerWinDirectx::~ScreenCapturerWinDirectx() {}
+ScreenCapturerWinDirectx::~ScreenCapturerWinDirectx() = default;
 
 void ScreenCapturerWinDirectx::Start(Callback* callback) {
   RTC_DCHECK(!callback_);
@@ -67,10 +66,9 @@ void ScreenCapturerWinDirectx::CaptureFrame() {
 
   DxgiDuplicatorController::Result result;
   if (current_screen_id_ == kFullDesktopScreenId) {
-    result = DxgiDuplicatorController::Instance()->Duplicate(
-        frames_.current_frame());
+    result = controller_->Duplicate(frames_.current_frame());
   } else {
-    result = DxgiDuplicatorController::Instance()->DuplicateMonitor(
+    result = controller_->DuplicateMonitor(
         frames_.current_frame(), current_screen_id_);
   }
 
@@ -106,7 +104,7 @@ void ScreenCapturerWinDirectx::CaptureFrame() {
 }
 
 bool ScreenCapturerWinDirectx::GetSourceList(SourceList* sources) {
-  int screen_count = DxgiDuplicatorController::Instance()->ScreenCount();
+  int screen_count = controller_->ScreenCount();
   for (int i = 0; i < screen_count; i++) {
     sources->push_back({i});
   }
@@ -123,7 +121,7 @@ bool ScreenCapturerWinDirectx::SelectSource(SourceId id) {
     return true;
   }
 
-  int screen_count = DxgiDuplicatorController::Instance()->ScreenCount();
+  int screen_count = controller_->ScreenCount();
   if (id >= 0 && id < screen_count) {
     current_screen_id_ = id;
     return true;

webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h

@@ -16,6 +16,7 @@
 #include <memory>
 #include <vector>
 
+#include "webrtc/base/scoped_ref_ptr.h"
 #include "webrtc/modules/desktop_capture/desktop_capturer.h"
 #include "webrtc/modules/desktop_capture/desktop_capture_options.h"
 #include "webrtc/modules/desktop_capture/desktop_region.h"
@@ -43,10 +44,11 @@ class ScreenCapturerWinDirectx : public DesktopCapturer {
   // consumers should not cache the result returned by this function.
   static bool RetrieveD3dInfo(D3dInfo* info);
 
-  explicit ScreenCapturerWinDirectx(const DesktopCaptureOptions& options);
+  explicit ScreenCapturerWinDirectx();
 
   ~ScreenCapturerWinDirectx() override;
 
+  // DesktopCapturer implementation.
   void Start(Callback* callback) override;
   void SetSharedMemoryFactory(
       std::unique_ptr<SharedMemoryFactory> shared_memory_factory) override;
@@ -55,6 +57,7 @@ class ScreenCapturerWinDirectx : public DesktopCapturer {
   bool SelectSource(SourceId id) override;
 
  private:
+  const rtc::scoped_refptr<DxgiDuplicatorController> controller_;
   ScreenCaptureFrameQueue<DxgiFrame> frames_;
   std::unique_ptr<SharedMemoryFactory> shared_memory_factory_;
   Callback* callback_ = nullptr;