[Windows 10] systray.AddMenuItem() intermittently fails when run inside go function

[ldstein]

Hi all,

I'm experiencing an issue where systray.AddMenuItem() intermittently stops working. I first noticed the problem in v1.0.0 and exists in all versions up to and including v1.0.4.

It occurs intermittently - if I run ~10 instances of the exe, ~2 tray icons will be missing a menu:

I noticed this only occurs when systray is run inside a go function (unfortunately a requirement for the App I'm working on).

The issue does not exist in v0.9.0. Would love to update to a newer version, but not really an option at this point in my project (and v0.9.0 is working fine for my immediate requirements).

Any thoughts / ideas /pointers on what might the problem be?

Testing Environment

• Windows 10 Pro x64 1903
• Go 1.14.1 windows/amd64
• TDM-GCC 9.2.0

main.go
This fork of v1.0.4 contains a modified example demonstrating the issue

package main

import (
	"sync"

	"github.com/getlantern/systray"
	"github.com/getlantern/systray/example/icon"
)

func main() {
	var wg sync.WaitGroup
	wg.Add(1)
	go runSystray(&wg)
	wg.Wait()
}

func runSystray(wg *sync.WaitGroup) {
	onReady := func() {
		systray.SetIcon(icon.Data)
		systray.SetTitle("Awsome App")
		systray.SetTooltip("Lantern")
		mQuitOrig := systray.AddMenuItem("Quit", "Quit App")
		go func() {
			<-mQuitOrig.ClickedCh
			systray.Quit()
		}()
	}

	onExit := func() {
		wg.Done()
	}

	systray.Run(onReady, onExit)
}

[ldstein]

Just a quick update - I discovered I can work around this issue by adding a ~400ms delay before calling systray.SetIcon().

With a delay of 0-300ms, systray.addMenuItem() would regularly not work.
With a delay of 400ms, systray.addMenuItem() appears to work consistently.

I settled on 500ms as a bit of extra safety margin.

Note, I've only tested on a single PC so far.

package main

import (
	"sync"
	"time"

	"github.com/getlantern/systray"
	"github.com/getlantern/systray/example/icon"
)

func main() {
	var wg sync.WaitGroup
	wg.Add(1)
	go runSystray(&wg)
	wg.Wait()
}

func runSystray(wg *sync.WaitGroup) {
	onReady := func() {		
		time.Sleep(500 * time.Millisecond) // Add 500ms delay to fix issue with systray.AddMenuItem() not always working.
		systray.SetIcon(icon.Data)
		systray.SetTitle("Awsome App")
		systray.SetTooltip("Lantern")
		mQuitOrig := systray.AddMenuItem("Quit", "Quit App")
		go func() {
			<-mQuitOrig.ClickedCh
			systray.Quit()
		}()
	}

	onExit := func() {
		wg.Done()
	}

	systray.Run(onReady, onExit)
}