Ensure Dxgi duplicator works correctly in session 0

webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.cc

 /*
  *  Copyright (c) 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.
  */
 
 #include "webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.h"
 
 #include <windows.h>
 
 #include <algorithm>
 #include <string>
 
 #include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
 #include "webrtc/base/timeutils.h"
+#include "webrtc/base/win32.h"
 #include "webrtc/modules/desktop_capture/desktop_capture_types.h"
 #include "webrtc/modules/desktop_capture/win/dxgi_frame.h"
 #include "webrtc/modules/desktop_capture/win/screen_capture_utils.h"
 #include "webrtc/system_wrappers/include/sleep.h"
 
 namespace webrtc {
 
+namespace {
+
+bool IsRunningInSession0() {
+  DWORD session_id = 0;
+  if (!::ProcessIdToSessionId(::GetCurrentProcessId(), &session_id)) {
+    LOG(LS_WARNING) << "Failed to retrieve current session Id, no priviledge?";
+    return true;
+  }
+  return session_id == 0;
+}
+
+}  // namespace
+
 // static
 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;
 }
 
 DxgiDuplicatorController::DxgiDuplicatorController() = default;
 
 DxgiDuplicatorController::~DxgiDuplicatorController() {
   rtc::CritScope lock(&lock_);
   Deinitialize();
 }
 
 bool DxgiDuplicatorController::IsSupported() {
-  rtc::CritScope lock(&lock_);
-  return Initialize();
+  bool result = false;
+  {
+    rtc::CritScope lock(&lock_);
+    result = Initialize();
+  }
+
+  if (result) {
+    return true;
+  }
+
+  if (IsRunningInSession0()) {
+    LOG(LS_WARNING) << "Current binary is running in session 0. DXGI "
+                       "components cannot be initialized. Fallback to use "
+                       "Windows version to decide the support of DirectX "
+                       "capturer. It may be inaccurate.";
+    return rtc::IsWindows8OrLater();

[Sergey Ulanov, 2017/06/26 23:41:41]

In this case DX capturer is effectively unsupported, but 
DxgiDuplicatorController::IsSupported() still returns true. This doesn't look
right to me. Does this case need to be handled here? Can we handle in the
chromoting host directly?

[Hzj_jie, 2017/06/27 04:37:33]

A very good point, I have moved this logic into
https://codereview.chromium.org/2941623003/.

+  }
+
+  return false;
 }
 
 bool DxgiDuplicatorController::RetrieveD3dInfo(D3dInfo* info) {
-  rtc::CritScope lock(&lock_);
-  if (!Initialize()) {
-    return false;
+  bool result = false;
+  {
+    rtc::CritScope lock(&lock_);
+    result = Initialize();
   }
-  *info = d3d_info_;
-  return true;
+
+  if (result) {
+    *info = d3d_info_;
+    return true;
+  }
+
+  if (IsRunningInSession0()) {
+    LOG(LS_WARNING) << "Current binary is running in session 0. Initialization "
+                       "of DXGI components are expected to fail. But "
+                       "retrieving feature level is still supported.";
+    *info = d3d_info_;
+    return true;
+  }
+
+  return false;
 }
 
 DxgiDuplicatorController::Result
 DxgiDuplicatorController::Duplicate(DxgiFrame* frame) {
   return DoDuplicate(frame, -1);
 }
 
 DxgiDuplicatorController::Result
 DxgiDuplicatorController::DuplicateMonitor(DxgiFrame* frame, int monitor_id) {
   RTC_DCHECK_GE(monitor_id, 0);
@@ skipping 33 matching lines @@
   // size.
   // TODO(zijiehe): Confirm whether IDXGIOutput::GetDesc() and
   // IDXGIOutputDuplication::GetDesc() can detect the resolution change without
   // reinitialization.
   if (resolution_change_detector_.IsChanged(
           GetScreenRect(kFullDesktopScreenId, std::wstring()).size())) {
     Deinitialize();
   }
 
   if (!Initialize()) {
+    if (succeeded_duplications_ == 0 && IsRunningInSession0()) {
+      LOG(LS_WARNING) << "Current binary is running in session 0. DXGI "
+                         "components cannot be initialized.";
+      return Result::UNSUPPORTED_SESSION;
+    }
+
     // Cannot initialize COM components now, display mode may be changing.
     return Result::INITIALIZATION_FAILED;
   }
 
   if (!frame->Prepare(SelectedDesktopSize(monitor_id), monitor_id)) {
     return Result::FRAME_PREPARE_FAILED;
   }
 
   frame->frame()->mutable_updated_region()->Clear();
 
   if (DoDuplicateUnlocked(frame->context(), monitor_id, frame->frame())) {
+    succeeded_duplications_++;
     return Result::SUCCEEDED;
   }
   if (monitor_id >= ScreenCountUnlocked()) {
     // It's a user error to provide a |monitor_id| larger than screen count. We
     // do not need to deinitialize.
     return Result::INVALID_MONITOR_ID;
   }
 
   // If the |monitor_id| is valid, but DoDuplicateUnlocked() failed, something
   // must be wrong from capturer APIs. We should Deinitialize().
@@ skipping 27 matching lines @@
 
 bool DxgiDuplicatorController::DoInitialize() {
   RTC_DCHECK(desktop_rect_.is_empty());
   RTC_DCHECK(duplicators_.empty());
 
   d3d_info_.min_feature_level = static_cast<D3D_FEATURE_LEVEL>(0);
   d3d_info_.max_feature_level = static_cast<D3D_FEATURE_LEVEL>(0);
 
   std::vector<D3dDevice> devices = D3dDevice::EnumDevices();
   if (devices.empty()) {
+    LOG(LS_WARNING) << "No D3dDevice found.";
     return false;
   }
 
   for (size_t i = 0; i < devices.size(); i++) {
-    duplicators_.emplace_back(devices[i]);
-    if (!duplicators_.back().Initialize()) {
-      return false;
-    }
-
     D3D_FEATURE_LEVEL feature_level =
         devices[i].d3d_device()->GetFeatureLevel();
     if (d3d_info_.max_feature_level == 0 ||
         feature_level > d3d_info_.max_feature_level) {
       d3d_info_.max_feature_level = feature_level;
     }
     if (d3d_info_.min_feature_level == 0 ||
         feature_level < d3d_info_.min_feature_level) {
       d3d_info_.min_feature_level = feature_level;
     }
 
+    DxgiAdapterDuplicator duplicator(devices[i]);
+    if (!duplicator.Initialize()) {
+      LOG(LS_WARNING) << "Failed to initialize DxgiAdapterDuplicator on "
+                         "adapter "
+                      << i;
+      continue;

[Sergey Ulanov, 2017/06/26 23:41:41]

Why do we need to keep trying initialization after initialization of a single
adapter fails? Maybe document add a comment somewhere? I also don't understand
how it's related to this change.

[Hzj_jie, 2017/06/27 04:37:33]

This issue happens when a virtual adapter is installed on to the system, but the
virtual adapter does not support DX11 or upper. I encountered this issue when
D3D gear was installed.
But if there are two physical video cards, and both of them are connecting to
monitors. IMO, it's safe to assume they support a same DX version. It's very
hard to imagine someone is using a DX 11 video card with a DX 10 one, which has
a 3-year gap.
Comments have been added.

+    }
+    RTC_DCHECK(!duplicator.desktop_rect().is_empty());
+    duplicators_.push_back(std::move(duplicator));
+
     desktop_rect_.UnionWith(duplicators_.back().desktop_rect());
   }
   TranslateRect();
 
   HDC hdc = GetDC(nullptr);
   // Use old DPI value if failed.
   if (hdc) {
     dpi_.set(GetDeviceCaps(hdc, LOGPIXELSX), GetDeviceCaps(hdc, LOGPIXELSY));
     ReleaseDC(nullptr, hdc);
   }
 
   identity_++;
-  return true;
+
+  if (duplicators_.empty()) {
+    LOG(LS_WARNING) << "Cannot initialize any DxgiAdapterDuplicator instance.";
+  }
+
+  return !duplicators_.empty();
 }
 
 void DxgiDuplicatorController::Deinitialize() {
   desktop_rect_ = DesktopRect();
   duplicators_.clear();
   resolution_change_detector_.Reset();
 }
 
 bool DxgiDuplicatorController::ContextExpired(
     const Context* const context) const {
@@ skipping 164 matching lines @@
 void DxgiDuplicatorController::TranslateRect() {
   const DesktopVector position =
       DesktopVector().subtract(desktop_rect_.top_left());
   desktop_rect_.Translate(position);
   for (auto& duplicator : duplicators_) {
     duplicator.TranslateRect(position);
   }
 }
 
 }  // namespace webrtc