Deadlock when resizing on Windows

[fallenwood]

When resizing on windows, the ghostty window is likely to stuck.
The stacktrace shows that it's waiting forever on BlockingQueue in MainThread, with the mutex held in push, which means it's impossible to notify the queue with pop .
Also the pop method is designed to be called on MainThread :(

It's not reproducible on linux as the breakpoint set on the highlighed line never hits.

Workaround:
Instead of waiting forever, a finite wait works for me

// mailbox.zig
-                _ = mb.queue.push(msg, .{ .forever = {} });               
+                _ = mb.queue.push(msg, .{ .ns = 100 });

[mitchellh]

Can you get me the stack traces of all threads? Its very likely this is possible on other platforms too just not happening for whatever reason and I'd like to look into it.

[fallenwood]

Can you get me the stack traces of all threads? Its very likely this is possible on other platforms too just not happening for whatever reason and I'd like to look into it.

Sure, here is the full callstack of main thread

ntdll.dll!00007ffa67063374() (Unknown Source:0)
ntdll.dll!00007ffa66f5f574() (Unknown Source:0)
KernelBase.dll!00007ffa6455d8f8() (Unknown Source:0)
ghostty.exe!wait(builtin.StackTrace * self, Thread.Condition.WindowsImpl * mutex, Thread.Mutex * timeout, ?u64 *) Line 168 (c:\Programs\zig\lib\std\Thread\Condition.zig:168)
ghostty.exe!wait(Thread.Condition * self, Thread.Mutex * mutex) Line 72 (c:\Programs\zig\lib\std\Thread\Condition.zig:72)
ghostty.exe!push(datastruct.blocking_queue.BlockingQueue(termio.message.Message,64) * self, termio.message.Message * value, datastruct.blocking_queue.BlockingQueue(App.Message,64).Timeout * timeout) Line 116 (d:\Workspace\ghostty\src\datastruct\blocking_queue.zig:116)
ghostty.exe!send(termio.mailbox.Mailbox * self, termio.message.Message * msg, Thread.Mutex * mutex) Line 94 (d:\Workspace\ghostty\src\termio\mailbox.zig:94)
ghostty.exe!queueMessage(termio.Termio * self, termio.message.Message * msg, termio.Termio.queueMessage__enum_67818 mutex) Line 278 (d:\Workspace\ghostty\src\termio\Termio.zig:278)
ghostty.exe!resize(builtin.StackTrace * self, Surface * size, renderer.size.ScreenSize *) Line 1554 (d:\Workspace\ghostty\src\Surface.zig:1554)
ghostty.exe!sizeCallback(builtin.StackTrace * self, Surface * size, apprt.structs.SurfaceSize *) Line 1519 (d:\Workspace\ghostty\src\Surface.zig:1519)
[Inline Frame] ghostty.exe!sizeCallback() Line 863 (d:\Workspace\ghostty\src\apprt\glfw.zig:863)
ghostty.exe!sizeCallbackWrapper(cimport.struct_GLFWwindow * handle, int width, int height) Line 1270 (c:\Users\<username>\AppData\Local\zig\p\12206ed982e709e565d536ce930701a8c07edfd2cfdce428683f3f2a601d37696a62\src\Window.zig:1270)
ghostty.exe!_glfwInputWindowSize(_GLFWwindow * window, int width, int height) Line 96 (c:\Users\<username>\AppData\Local\zig\p\1220736fa4ba211162c7a0e46cc8fe04d95921927688bff64ab5da7420d098a7272d\src\window.c:96)
ghostty.exe!windowProc(HWND__ * hWnd, unsigned int uMsg, unsigned __int64 wParam, __int64 lParam) Line 1027 (c:\Users\<username>\AppData\Local\zig\p\1220736fa4ba211162c7a0e46cc8fe04d95921927688bff64ab5da7420d098a7272d\src\win32_window.c:1027)
user32.dll!00007ffa651b5801() (Unknown Source:0)
user32.dll!00007ffa651b52dc() (Unknown Source:0)
opengl32.dll!00007ffa2429bcf3() (Unknown Source:0)
user32.dll!00007ffa651b5801() (Unknown Source:0)
user32.dll!00007ffa651b509c() (Unknown Source:0)
user32.dll!00007ffa651e4eb3() (Unknown Source:0)
ntdll.dll!00007ffa67063744() (Unknown Source:0)
win32u.dll!00007ffa64451334() (Unknown Source:0)
user32.dll!00007ffa651b4c82() (Unknown Source:0)
user32.dll!00007ffa651b1dcf() (Unknown Source:0)
user32.dll!00007ffa651b1a54() (Unknown Source:0)
uxtheme.dll!00007ffa5e152c64() (Unknown Source:0)
uxtheme.dll!00007ffa5e152bb1() (Unknown Source:0)
user32.dll!00007ffa651b30aa() (Unknown Source:0)
ghostty.exe!windowProc(HWND__ * hWnd, unsigned int uMsg, unsigned __int64 wParam, __int64 lParam) Line 1247 (c:\Users\<username>\AppData\Local\zig\p\1220736fa4ba211162c7a0e46cc8fe04d95921927688bff64ab5da7420d098a7272d\src\win32_window.c:1247)
user32.dll!00007ffa651b5801() (Unknown Source:0)
user32.dll!00007ffa651b52dc() (Unknown Source:0)
opengl32.dll!00007ffa2429bcf3() (Unknown Source:0)
user32.dll!00007ffa651b5801() (Unknown Source:0)
user32.dll!00007ffa651b509c() (Unknown Source:0)
user32.dll!00007ffa651f0cf3() (Unknown Source:0)
ntdll.dll!00007ffa67063744() (Unknown Source:0)
win32u.dll!00007ffa64451334() (Unknown Source:0)
user32.dll!00007ffa651b1bbb() (Unknown Source:0)
user32.dll!00007ffa651b1a54() (Unknown Source:0)
uxtheme.dll!00007ffa5e15138d() (Unknown Source:0)
uxtheme.dll!00007ffa5e14f45a() (Unknown Source:0)
uxtheme.dll!00007ffa5e15331f() (Unknown Source:0)
uxtheme.dll!00007ffa5e152bb1() (Unknown Source:0)
user32.dll!00007ffa651b30aa() (Unknown Source:0)
ghostty.exe!windowProc(HWND__ * hWnd, unsigned int uMsg, unsigned __int64 wParam, __int64 lParam) Line 1247 (c:\Users\<username>\AppData\Local\zig\p\1220736fa4ba211162c7a0e46cc8fe04d95921927688bff64ab5da7420d098a7272d\src\win32_window.c:1247)
user32.dll!00007ffa651b5801() (Unknown Source:0)
user32.dll!00007ffa651b52dc() (Unknown Source:0)
opengl32.dll!00007ffa2429bcf3() (Unknown Source:0)
user32.dll!00007ffa651b5801() (Unknown Source:0)
user32.dll!00007ffa651b509c() (Unknown Source:0)
user32.dll!00007ffa651e4eb3() (Unknown Source:0)
ntdll.dll!00007ffa67063744() (Unknown Source:0)
win32u.dll!00007ffa64451334() (Unknown Source:0)
user32.dll!00007ffa651b1bbb() (Unknown Source:0)
user32.dll!00007ffa651b1a54() (Unknown Source:0)
uxtheme.dll!00007ffa5e15138d() (Unknown Source:0)
uxtheme.dll!00007ffa5e189919() (Unknown Source:0)
uxtheme.dll!00007ffa5e15331f() (Unknown Source:0)
uxtheme.dll!00007ffa5e152bb1() (Unknown Source:0)
user32.dll!00007ffa651b30aa() (Unknown Source:0)
ghostty.exe!windowProc(HWND__ * hWnd, unsigned int uMsg, unsigned __int64 wParam, __int64 lParam) Line 1247 (c:\Users\<username>\AppData\Local\zig\p\1220736fa4ba211162c7a0e46cc8fe04d95921927688bff64ab5da7420d098a7272d\src\win32_window.c:1247)
user32.dll!00007ffa651b5801() (Unknown Source:0)
user32.dll!00007ffa651b52dc() (Unknown Source:0)
opengl32.dll!00007ffa2429bcf3() (Unknown Source:0)
user32.dll!00007ffa651b5801() (Unknown Source:0)
user32.dll!00007ffa651b334d() (Unknown Source:0)
ghostty.exe!_glfwPollEventsWin32() Line 2039 (c:\Users\<username>\AppData\Local\zig\p\1220736fa4ba211162c7a0e46cc8fe04d95921927688bff64ab5da7420d098a7272d\src\win32_window.c:2039)
ghostty.exe!_glfwWaitEventsWin32() Line 2120 (c:\Users\<username>\AppData\Local\zig\p\1220736fa4ba211162c7a0e46cc8fe04d95921927688bff64ab5da7420d098a7272d\src\win32_window.c:2120)
ghostty.exe!glfwWaitEvents() Line 1132 (c:\Users\<username>\AppData\Local\zig\p\1220736fa4ba211162c7a0e46cc8fe04d95921927688bff64ab5da7420d098a7272d\src\window.c:1132)
[Inline Frame] ghostty.exe!waitEvents() Line 427 (c:\Users\<username>\AppData\Local\zig\p\12206ed982e709e565d536ce930701a8c07edfd2cfdce428683f3f2a601d37696a62\src\main.zig:427)
ghostty.exe!run(builtin.StackTrace * self, apprt.glfw.App *) Line 124 (d:\Workspace\ghostty\src\apprt\glfw.zig:124)
ghostty.exe!main(builtin.StackTrace *) Line 111 (d:\Workspace\ghostty\src\main_ghostty.zig:111)
[Inline Frame] ghostty.exe!callMain() Line 524 (c:\Programs\zig\lib\std\start.zig:524)
[Inline Frame] ghostty.exe!callMainWithArgs() Line 482 (c:\Programs\zig\lib\std\start.zig:482)
ghostty.exe!main(int c_argc, char * * c_argv, char * * c_envp) Line 497 (c:\Programs\zig\lib\std\start.zig:497)
ghostty.exe!__tmainCRTStartup() Line 267 (c:\Programs\zig\lib\libc\mingw\crt\crtexe.c:267)
ghostty.exe!WinMainCRTStartup() Line 159 (c:\Programs\zig\lib\libc\mingw\crt\crtexe.c:159)
kernel32.dll!00007ffa65e2e8d7() (Unknown Source:0)
ntdll.dll!00007ffa66fdfbcc() (Unknown Source:0)

[mitchellh]

Sorry I meant all threads. Can you get me the stacks of all threads? I want to see what the rest are doing.

[fallenwood]

Sorry I meant all threads. Can you get me the stacks of all threads? I want to see what the rest are doing.

Ah my bad, here are the callstacks

ghostty_callstacks.zip

[fallenwood]

After reading deeper into the source, I found the wakeupCallback in renderer/Thread.zig is not called (the break point not hit), while self.wakeup.wait(&self.loop, &self.wakeup_c, Thread, self, wakeupCallback); did called.

It also lead to a crash that, after resizing, left click the area newlly created, the app crashed for Debug build at Surface.zig

        const pin = pin: {
            const pt_viewport = self.posToViewport(pos.x, pos.y);
            const pin = screen.pages.pin(.{
                .viewport = .{
                    .x = pt_viewport.x,
                    .y = pt_viewport.y,
                },
            }) orelse {
                // Weird... our viewport x/y that we just converted isn't
                // found in our pages. This is probably a bug but we don't
                // want to crash in releases because its harmless. So, we
                // only assert in debug mode.
                if (comptime std.debug.runtime_safety) unreachable;  <--------------------
                break :click;
            };

            break :pin try screen.pages.trackPin(pin);
        };

Also I believe that's why there is nothing show from cmd.exe in the terminal window

---

It blocks on, and there is nothing show in ghostty window

    // Start blinking the cursor.
    self.cursor_h.run(
        &self.loop,
        &self.cursor_c,
        CURSOR_BLINK_INTERVAL,
        Thread,
        self,
        cursorTimerCallback,
    );

[gaocegege]

I’m not entirely sure if this is the right place to ask, but I’m wondering how to get Ghostty on Windows. I couldn’t find any information about it in the documentation or on the download page. Could someone point me in the right direction?

[fallenwood]

I’m not entirely sure if this is the right place to ask, but I’m wondering how to get Ghostty on Windows. I couldn’t find any information about it in the documentation or on the download page. Could someone point me in the right direction?

just build from source with zig 0.13, either natively on windows or cross build from linux
but as you can see from the screenshot, it does not work now, lots of bugs need to fix

[melutovich]

@gaocegege The github readme in the Roadmap says Windows support is not yet done
#2563

[mitchellh]

Yes, if this is a Windows-only issue I will close it. But if this deadlock can potentially impact other platforms I need to look into it. That's why I've kept this open until that's verified.