High CPU usage on Windows when using a wxNotebook with long tab titles. (Issue #25797)
Quin Gillespie
trypsynth created an issue (wxWidgets/wxWidgets#25797)Description
Bug description:
When I run the provided code sample on Windows, I see the CPU usage of my app rising quite high, and my screen reader navigation lags. If I shorten the length of the title strings, the CPU usage goes way down.
Expected vs observed behaviour:
CPU usage should remain low, as we're doing nothing intensive.
Patch or snippet allowing to reproduce the problem:
\#include <memory> #include <wx/bookctrl.h> #include <wx/wx.h> class app : public wxApp { public: bool OnInit() override { frame = new wxFrame(nullptr, wxID_ANY, "Test"); auto* panel = new wxPanel(frame); notebook = new wxNotebook(panel, wxID_ANY); auto* sizer = new wxBoxSizer(wxVERTICAL); sizer->Add(notebook, 1, wxEXPAND | wxALL, 10); panel->SetSizer(sizer); auto* panel1 = create_tab_panel("This is a test."); auto* panel2 = create_tab_panel("This is a test."); notebook->AddPage(panel1, "This is a test of a very long title This is a test of a very long title This is a test of a very long title"); notebook->AddPage(panel2, "This is a test of a very long title This is a test of a very long title This is a test of a very long title"); frame->Show(true); return true; } wxPanel* create_tab_panel(const wxString& content) { wxPanel* panel = new wxPanel(notebook, wxID_ANY); auto* sizer = new wxBoxSizer(wxVERTICAL); long style = wxTE_MULTILINE | wxTE_READONLY | wxTE_RICH2 | wxTE_DONTWRAP; auto* text_ctrl = new wxTextCtrl(panel, wxID_ANY, "", wxDefaultPosition, wxDefaultSize, style); sizer->Add(text_ctrl, 1, wxEXPAND | wxALL, 5); panel->SetSizer(sizer); text_ctrl->SetValue(content); return panel; } private: wxFrame* frame{nullptr}; wxNotebook* notebook{nullptr}; }; wxIMPLEMENT_APP(app);
To Reproduce:
Run the compiled code sample, and then view CPU usage in task manager. Depending on how many cores you have, you'll see different usage values as wxWidgets only is allowed to use one core, but it's trying to use most of it.
Platform and version information
- wxWidgets version you use: 3.3.1
- wxWidgets port you use: wxMSW
- OS and its version: Windows 10 21H2 (AMD64) build 19044.6218
—
Reply to this email directly, view it on GitHub, or unsubscribe.
You are receiving this because you are subscribed to this thread.
Quin Gillespie
trypsynth left a comment (wxWidgets/wxWidgets#25797)Adding this:
#ifdef __WXMSW__ notebook->MSWDisableComposited(); #endif
makes the behavior go away.
—
Reply to this email directly, view it on GitHub, or unsubscribe.
You are receiving this because you are subscribed to this thread.
VZ
vadz left a comment (wxWidgets/wxWidgets#25797)Probably not worth investigating in light of #25663.
—
Reply to this email directly, view it on GitHub, or unsubscribe.
You are receiving this because you are subscribed to this thread.
Quin Gillespie
trypsynth left a comment (wxWidgets/wxWidgets#25797)Ah thanks, hadn't seen that. That should fix this :) thanks
—
Reply to this email directly, view it on GitHub, or unsubscribe.
You are receiving this because you are subscribed to this thread.
VZ
vadz left a comment (wxWidgets/wxWidgets#25797)Please check that #25808 fixes this if you can.
—
Reply to this email directly, view it on GitHub, or unsubscribe.
You are receiving this because you are subscribed to this thread.
VZ
Closed #25797 as completed via b5a9fa3.
—
Reply to this email directly, view it on GitHub, or unsubscribe.
You are receiving this because you are subscribed to this thread.