walk.NewMainWindow hangs in win.SendMessage

[tmm1]

I integrated the notifyicon example into a complex app with many goroutines, and walk.NewMainWindow never returns the rest of my code (including walk.NewNotifyIcon) never executes:

goroutine 1 [syscall, locked to thread]:
syscall.Syscall6(0x7fff83c90ef0, 0x4, 0x60344, 0x432, 0x0, 0xc0423a1650, 0x0, 0x0, 0x0, 0x75, ...)
	src/runtime/syscall_windows.go:174 +0x69
github.com/lxn/win.SendMessage(0x60344, 0x432, 0x0, 0xc0423a1650, 0xc4a1e4)
	src/github.com/lxn/win/user32.go:2641 +0x7b
github.com/lxn/walk.(*WindowBase).SendMessage(0xc04206b440, 0x432, 0x0, 0xc0423a1650, 0x458830)
	src/github.com/lxn/walk/window.go:601 +0x52
github.com/lxn/walk.(*ToolTip).addTool(0xc04206b440, 0x1400900, 0xc0421b6840, 0x0, 0x350a0a8c, 0x1)
	src/github.com/lxn/walk/tooltip.go:200 +0xce
github.com/lxn/walk.(*ToolTip).AddTool(0xc04206b440, 0x1400900, 0xc0421b6840, 0x495d8b8, 0xc0423a1738)
	src/github.com/lxn/walk/tooltip.go:179 +0x4b
github.com/lxn/walk.(*WidgetBase).init(0xc0421b6840, 0x13ff600, 0xc0421b6840, 0x13ff600, 0xc0421b6840)
	src/github.com/lxn/walk/widget.go:117 +0x4e
github.com/lxn/walk.InitWindow(0x495d6c0, 0xc0421b6840, 0x13fbfa0, 0xc042029500, 0xe67e61, 0x1c, 0x1000050000000, 0x0, 0x0)
	src/github.com/lxn/walk/window.go:453 +0x941
github.com/lxn/walk.InitWidget(0x13ff600, 0xc0421b6840, 0x13fbfa0, 0xc042029500, 0xe67e61, 0x1c, 0x1000050000000, 0xe2dea0, 0xe4b1a0)
	src/github.com/lxn/walk/widget.go:96 +0xc5
github.com/lxn/walk.NewCompositeWithStyle(0x13fbfa0, 0xc042029500, 0xc000000000, 0x13fbfa0, 0xc042029500, 0x13fe620)
	src/github.com/lxn/walk/composite.go:28 +0xf5
github.com/lxn/walk.NewComposite(0x13fe620, 0xc042029500, 0xc042029500, 0x13fe620, 0xc042029500)
	src/github.com/lxn/walk/composite.go:43 +0x68
github.com/lxn/walk.(*FormBase).init(0xc042029500, 0x495d408, 0xc042029500, 0x495d408, 0xc042029500)
	src/github.com/lxn/walk/form.go:107 +0x78
github.com/lxn/walk.InitWindow(0x13fbfa0, 0xc042029500, 0x0, 0x0, 0xe68b66, 0x1d, 0x1000000cf0000, 0x0, 0x0)
	src/github.com/lxn/walk/window.go:445 +0x9c5
github.com/lxn/walk.NewMainWindow(0x0, 0x0, 0x0)
	src/github.com/lxn/walk/mainwindow.go:34 +0xba
main.runMenu(0x0, 0x0)
	main.go:49 +0x56
main.main()
	main.go:182 +0x3df

I thought maybe this is because the main window wasn't being created from the main thread, but I tried to call runtime.LockOSThread() and it made no difference.

[tmm1]

I'm not sure what was causing this, but I moved the walk.NewMainWindow() call to be the first thing in my main() and now it works. I think perhaps one of my other dependencies was interacting with the windows api as well and conflicting somehow.

[tmm1]

I figured out why this is happening.. one of my dependencies uses go-ole, which calls Lock/UnlockOSThread itself. This causes the main thread to get unlocked due to a golang bug.

See golang/go#20458 which has been fixed in hyangah/go@97af9ea for golang 1.10