Potential deadlock or goleak in util/progress/progress.go#157

[xuxiaofan1203]

Like the test in packege flightcontrol below:

func TestNoCancel(t *testing.T) {
	t.Parallel()
	g := &Group[string]{}
	eg, ctx := errgroup.WithContext(context.Background())
	var r1, r2 string
	var counter int64
	f := testFunc(100*time.Millisecond, "bar", &counter)
	eg.Go(func() error {
		ret1, err := g.Do(ctx, "foo", f)
		if err != nil {
			return err
		}
		r1 = ret1
		return nil
	})
	eg.Go(func() error {
		ret2, err := g.Do(ctx, "foo", f)
		if err != nil {
			return err
		}
		r2 = ret2
		return nil
	})
	err := eg.Wait()
	assert.NoError(t, err)
	assert.Equal(t, "bar", r1)
	assert.Equal(t, "bar", r2)
	assert.Equal(t, counter, int64(1))
}

When executes this code segment

eg.Go(func() error {
		ret1, err := g.Do(ctx, "foo", f)
		if err != nil {
			return err
		}
		r1 = ret1
		return nil
	})

if err=nil, the cancel in Go doesn't execute.Then g.Do() executes, and the call chains are g.do() -> newcall() -> go c.progressState.run(pr) -> pr.Read() -> Wait() in Read(): due to cancel doesn't execute, and pr.cond.Broadcast() doesn't execute as well. As a result, there isn't a signal() or broadcast() can awaken the Wait()

Broadcast() in function Read and in function pipe are be blocked at <-ctx.Done()
go func() {
		select {
		case <-done:
		case <-ctx.Done():
			pr.mu.Lock()
			pr.cond.Broadcast()
			pr.mu.Unlock()
		}
}()
go func() {
		<-ctx.Done()
		pr.mu.Lock()
		pr.cond.Broadcast()
		pr.mu.Unlock()
}()

[tonistiigi]

Hard to understand what case you are really pointing to. Can you provide an example(you can add sleeps if you want to cause a specific race) or propose a fix.

[imeoer]

A similar problem occurs when the push.Push method is called concurrently, not sure if it is related to us using the same context.Context between multiple goroutines.