Avoid timer ticks on frozen windows

src/cascadia/LocalTests_TerminalApp/pch.h

@@ -68,6 +68,8 @@ Author(s):
 // Manually include til after we include Windows.Foundation to give it winrt superpowers
 #include "til.h"
 
+#include <SafeDispatcherTimer.h>
+
 // Common includes for most tests:
 #include "../../inc/conattrs.hpp"
 #include "../../types/inc/utils.hpp"

src/cascadia/TerminalApp/ColorHelper.cpp

@@ -1,6 +1,4 @@
-#include "pch.h"
 #include "ColorHelper.h"
-#include <limits>
 
 using namespace winrt::TerminalApp;
 

src/cascadia/TerminalApp/ColorHelper.h

@@ -1,7 +1,6 @@
 #pragma once
-#include "pch.h"
 
-#include <winrt/windows.ui.core.h>
+#include <winrt/Windows.UI.h>
 
 namespace winrt::TerminalApp
 {

src/cascadia/TerminalApp/TerminalAppLib.vcxproj

@@ -237,7 +237,9 @@
     </ClCompile>
     <ClCompile Include="Pane.cpp" />
     <ClCompile Include="Pane.LayoutSizeNode.cpp" />
-    <ClCompile Include="ColorHelper.cpp" />
+    <ClCompile Include="ColorHelper.cpp">
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+    </ClCompile>
     <ClCompile Include="DebugTapConnection.cpp" />
     <ClCompile Include="pch.cpp">
       <PrecompiledHeader>Create</PrecompiledHeader>

src/cascadia/TerminalApp/TerminalTab.cpp

@@ -121,12 +121,7 @@ namespace winrt::TerminalApp::implementation
     void TerminalTab::_BellIndicatorTimerTick(const Windows::Foundation::IInspectable& /*sender*/, const Windows::Foundation::IInspectable& /*e*/)
     {
         ShowBellIndicator(false);
-        // Just do a sanity check that the timer still exists before we stop it
-        if (_bellIndicatorTimer.has_value())
-        {
-            _bellIndicatorTimer->Stop();
-            _bellIndicatorTimer = std::nullopt;
-        }
+        _bellIndicatorTimer.Stop();
     }
 
     // Method Description:
@@ -356,14 +351,13 @@ namespace winrt::TerminalApp::implementation
     {
         ASSERT_UI_THREAD();
 
-        if (!_bellIndicatorTimer.has_value())
+        if (!_bellIndicatorTimer)
         {
-            DispatcherTimer bellIndicatorTimer;
-            bellIndicatorTimer.Interval(std::chrono::milliseconds(2000));
-            bellIndicatorTimer.Tick({ get_weak(), &TerminalTab::_BellIndicatorTimerTick });
-            bellIndicatorTimer.Start();
-            _bellIndicatorTimer.emplace(std::move(bellIndicatorTimer));
+            _bellIndicatorTimer.Interval(std::chrono::milliseconds(2000));
+            _bellIndicatorTimer.Tick({ get_weak(), &TerminalTab::_BellIndicatorTimerTick });
         }
+
+        _bellIndicatorTimer.Start();
     }
 
     // Method Description:

src/cascadia/TerminalApp/TerminalTab.h

@@ -152,7 +152,7 @@ namespace winrt::TerminalApp::implementation
 
         void _Setup();
 
-        std::optional<Windows::UI::Xaml::DispatcherTimer> _bellIndicatorTimer;
+        SafeDispatcherTimer _bellIndicatorTimer;
         void _BellIndicatorTimerTick(const Windows::Foundation::IInspectable& sender, const Windows::Foundation::IInspectable& e);
 
         void _MakeTabViewItem() override;

src/cascadia/TerminalApp/Toast.h

@@ -34,5 +34,5 @@ class Toast : public std::enable_shared_from_this<Toast>
 
 private:
     winrt::Microsoft::UI::Xaml::Controls::TeachingTip _tip;
-    winrt::Windows::UI::Xaml::DispatcherTimer _timer;
+    SafeDispatcherTimer _timer;
 };

src/cascadia/TerminalApp/pch.h

@@ -83,6 +83,8 @@ TRACELOGGING_DECLARE_PROVIDER(g_hTerminalAppProvider);
 // Manually include til after we include Windows.Foundation to give it winrt superpowers
 #include "til.h"
 
+#include <SafeDispatcherTimer.h>
+
 #include <cppwinrt_utils.h>
 #include <wil/cppwinrt_helpers.h> // must go after the CoreDispatcher type is defined
 

src/cascadia/TerminalControl/TermControl.cpp

@@ -57,10 +57,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         _isInternalScrollBarUpdate{ false },
         _autoScrollVelocity{ 0 },
         _autoScrollingPointerPoint{ std::nullopt },
-        _autoScrollTimer{},
         _lastAutoScrollUpdateTime{ std::nullopt },
-        _cursorTimer{},
-        _blinkTimer{},
         _searchBox{ nullptr }
     {
         InitializeComponent();
@@ -1087,10 +1084,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         if (blinkTime != INFINITE)
         {
             // Create a timer
-            DispatcherTimer cursorTimer;
-            cursorTimer.Interval(std::chrono::milliseconds(blinkTime));
-            cursorTimer.Tick({ get_weak(), &TermControl::_CursorTimerTick });
-            _cursorTimer.emplace(std::move(cursorTimer));
+            _cursorTimer.Interval(std::chrono::milliseconds(blinkTime));
+            _cursorTimer.Tick({ get_weak(), &TermControl::_CursorTimerTick });
             // As of GH#6586, don't start the cursor timer immediately, and
             // don't show the cursor initially. We'll show the cursor and start
             // the timer when the control is first focused.
@@ -1105,13 +1100,12 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             _core.CursorOn(_focused || _displayCursorWhileBlurred());
             if (_displayCursorWhileBlurred())
             {
-                _cursorTimer->Start();
+                _cursorTimer.Start();
             }
         }
         else
         {
-            // The user has disabled cursor blinking
-            _cursorTimer = std::nullopt;
+            _cursorTimer.Destroy();
         }
 
         // Set up blinking attributes
@@ -1120,16 +1114,14 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         if (animationsEnabled && blinkTime != INFINITE)
         {
             // Create a timer
-            DispatcherTimer blinkTimer;
-            blinkTimer.Interval(std::chrono::milliseconds(blinkTime));
-            blinkTimer.Tick({ get_weak(), &TermControl::_BlinkTimerTick });
-            blinkTimer.Start();
-            _blinkTimer.emplace(std::move(blinkTimer));
+            _blinkTimer.Interval(std::chrono::milliseconds(blinkTime));
+            _blinkTimer.Tick({ get_weak(), &TermControl::_BlinkTimerTick });
+            _blinkTimer.Start();
         }
         else
         {
             // The user has disabled blinking
-            _blinkTimer = std::nullopt;
+            _blinkTimer.Destroy();
         }
 
         // Now that the renderer is set up, update the appearance for initialization
@@ -1498,7 +1490,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             // Manually show the cursor when a key is pressed. Restarting
             // the timer prevents flickering.
             _core.CursorOn(_core.SelectionMode() != SelectionInteractionMode::Mark);
-            _cursorTimer->Start();
+            _cursorTimer.Start();
         }
 
         return handled;
@@ -1973,12 +1965,12 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         {
             // When the terminal focuses, show the cursor immediately
             _core.CursorOn(_core.SelectionMode() != SelectionInteractionMode::Mark);
-            _cursorTimer->Start();
+            _cursorTimer.Start();
         }
 
         if (_blinkTimer)
         {
-            _blinkTimer->Start();
+            _blinkTimer.Start();
         }
 
         // Only update the appearance here if an unfocused config exists - if an
@@ -2021,13 +2013,13 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
         if (_cursorTimer && !_displayCursorWhileBlurred())
         {
-            _cursorTimer->Stop();
+            _cursorTimer.Stop();
             _core.CursorOn(false);
         }
 
         if (_blinkTimer)
         {
-            _blinkTimer->Stop();
+            _blinkTimer.Stop();
         }
 
         // Check if there is an unfocused config we should set the appearance to
@@ -2278,7 +2270,16 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
             // Disconnect the TSF input control so it doesn't receive EditContext events.
             TSFInputControl().Close();
+
+            // At the time of writing, closing the last tab of a window inexplicably
+            // does not lead to the destruction of the remaining TermControl instance(s).
+            // On Win10 we don't destroy window threads due to bugs in DesktopWindowXamlSource.
+            // In turn, we leak TermControl instances. This results in constant HWND messages
+            // while the thread is supposed to be idle. Stop these timers avoids this.
             _autoScrollTimer.Stop();
+            _bellLightTimer.Stop();
+            _cursorTimer.Stop();
+            _blinkTimer.Stop();
 
             if (!_detached)
             {
@@ -3129,20 +3130,13 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             _bellDarkAnimation.Duration(winrt::Windows::Foundation::TimeSpan(std::chrono::milliseconds(TerminalWarningBellInterval)));
         }
 
-        // Similar to the animation, only initialize the timer here
-        if (!_bellLightTimer)
-        {
-            _bellLightTimer = {};
-            _bellLightTimer.Interval(std::chrono::milliseconds(TerminalWarningBellInterval));
-            _bellLightTimer.Tick({ get_weak(), &TermControl::_BellLightOff });
-        }
-
         Windows::Foundation::Numerics::float2 zeroSize{ 0, 0 };
         // If the grid has 0 size or if the bell timer is
         // already active, do nothing
         if (RootGrid().ActualSize() != zeroSize && !_bellLightTimer.IsEnabled())
         {
-            // Start the timer, when the timer ticks we switch off the light
+            _bellLightTimer.Interval(std::chrono::milliseconds(TerminalWarningBellInterval));
+            _bellLightTimer.Tick({ get_weak(), &TermControl::_BellLightOff });
             _bellLightTimer.Start();
 
             // Switch on the light and animate the intensity to fade out
@@ -3162,15 +3156,12 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     void TermControl::_BellLightOff(const Windows::Foundation::IInspectable& /* sender */,
                                     const Windows::Foundation::IInspectable& /* e */)
     {
-        if (_bellLightTimer)
-        {
-            // Stop the timer and switch off the light
-            _bellLightTimer.Stop();
+        // Stop the timer and switch off the light
+        _bellLightTimer.Stop();
 
-            if (!_IsClosing())
-            {
-                VisualBellLight::SetIsTarget(RootGrid(), false);
-            }
+        if (!_IsClosing())
+        {
+            VisualBellLight::SetIsTarget(RootGrid(), false);
         }
     }
 
@@ -3729,9 +3720,9 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         {
             // If we should be ALWAYS displaying the cursor, turn it on and start blinking.
             _core.CursorOn(true);
-            if (_cursorTimer.has_value())
+            if (_cursorTimer)
             {
-                _cursorTimer->Start();
+                _cursorTimer.Start();
             }
         }
         else
@@ -3740,9 +3731,9 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             // blinking. (if we're focused, then we're already doing the right
             // thing)
             const auto focused = FocusState() != FocusState::Unfocused;
-            if (!focused && _cursorTimer.has_value())
+            if (!focused && _cursorTimer)
             {
-                _cursorTimer->Stop();
+                _cursorTimer.Stop();
             }
             _core.CursorOn(focused);
         }

src/cascadia/TerminalControl/TermControl.h

@@ -236,16 +236,16 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         // viewport. View is then scrolled to 'follow' the cursor.
         double _autoScrollVelocity;
         std::optional<Windows::UI::Input::PointerPoint> _autoScrollingPointerPoint;
-        Windows::UI::Xaml::DispatcherTimer _autoScrollTimer;
+        SafeDispatcherTimer _autoScrollTimer;
         std::optional<std::chrono::high_resolution_clock::time_point> _lastAutoScrollUpdateTime;
         bool _pointerPressedInBounds{ false };
 
         winrt::Windows::UI::Composition::ScalarKeyFrameAnimation _bellLightAnimation{ nullptr };
         winrt::Windows::UI::Composition::ScalarKeyFrameAnimation _bellDarkAnimation{ nullptr };
-        Windows::UI::Xaml::DispatcherTimer _bellLightTimer{ nullptr };
+        SafeDispatcherTimer _bellLightTimer;
 
-        std::optional<Windows::UI::Xaml::DispatcherTimer> _cursorTimer;
-        std::optional<Windows::UI::Xaml::DispatcherTimer> _blinkTimer;
+        SafeDispatcherTimer _cursorTimer;
+        SafeDispatcherTimer _blinkTimer;
 
         winrt::Windows::UI::Xaml::Controls::SwapChainPanel::LayoutUpdated_revoker _layoutUpdatedRevoker;
         bool _showMarksInScrollbar{ false };

src/cascadia/TerminalControl/pch.h

@@ -73,7 +73,8 @@ TRACELOGGING_DECLARE_PROVIDER(g_hTerminalControlProvider);
 #include <til/mutex.h>
 #include <til/winrt.h>
 
-#include "ThrottledFunc.h"
+#include <SafeDispatcherTimer.h>
+#include <ThrottledFunc.h>
 
 #include <cppwinrt_utils.h>
 #include <wil/cppwinrt_helpers.h> // must go after the CoreDispatcher type is defined

src/cascadia/WinRTUtils/WinRTUtils.vcxproj

@@ -19,6 +19,7 @@
   <Import Project="$(OpenConsoleDir)src\cppwinrt.build.pre.props" />
   <!-- ========================= Headers ======================== -->
   <ItemGroup>
+    <ClInclude Include="inc\SafeDispatcherTimer.h" />
     <ClInclude Include="pch.h" />
     <ClInclude Include="inc\ScopedResourceLoader.h" />
     <ClInclude Include="inc\LibraryResources.h" />
@@ -52,4 +53,4 @@
   <!-- ========================= Globals ======================== -->
   <Import Project="$(OpenConsoleDir)src\cppwinrt.build.post.props" />
   <Import Project="$(OpenConsoleDir)src\common.nugetversions.targets" />
-</Project>
+</Project>

src/cascadia/WinRTUtils/WinRTUtils.vcxproj.filters

@@ -2,21 +2,21 @@
 <Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup>
     <Natvis Include="$(SolutionDir)tools\ConsoleTypes.natvis" />
+    <Natvis Include="$(MSBuildThisFileDirectory)..\..\natvis\wil.natvis" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="pch.cpp" />
     <ClCompile Include="LibraryResources.cpp" />
     <ClCompile Include="ScopedResourceLoader.cpp" />
+    <ClCompile Include="Utils.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="pch.h" />
-    <ClInclude Include="ScopedResourceLoader.h" />
     <ClInclude Include="inc\LibraryResources.h" />
+    <ClInclude Include="inc\SafeDispatcherTimer.h" />
+    <ClInclude Include="inc\ScopedResourceLoader.h" />
     <ClInclude Include="inc\ThrottledFunc.h" />
     <ClInclude Include="inc\Utils.h" />
     <ClInclude Include="inc\WtExeUtils.h" />
   </ItemGroup>
-  <ItemGroup>
-    <None Include="packages.config" />
-  </ItemGroup>
 </Project>