StorageSubscription.Unsubscribe race

[ggwpez]

Hi there,

i am using gsrpc in a project and noticed that a race occurs when trying to unsubscribe from a StorageSubscription while a second one is running.
This is weird since i never spawned a go-routine myself.

Place the following test in main_test.go and execute go test -v -count=1 -race -run=TestClient_Subscribe .:

func TestClient_Subscribe(t *testing.T) {
	// Setup and chain connection
	api, err := gsrpc.NewSubstrateAPI(config.Default().RPCURL)
	require.NoError(t, err)
	meta, err := api.RPC.State.GetMetadataLatest()
	require.NoError(t, err)
	// Use "Time" if you run an older node version.
	key, err := types.CreateStorageKey(meta, "Timestamp", "Now")
	require.NoError(t, err)

	// Subscribe once
	sub1, err := api.RPC.State.SubscribeStorageRaw([]types.StorageKey{key})
	require.NoError(t, err)

	// Subscribe twice
	_, err = api.RPC.State.SubscribeStorageRaw([]types.StorageKey{key})
	require.NoError(t, err)

	// Unsubscribing produces a race!
	sub1.Unsubscribe()
}

Test output: race.txt.
The problem seems to occur between

go-substrate-rpc-client/gethrpc/subscription.go

Line 304 in fee0d0e

chosen, recv, _ = reflect.Select(cases)

and

go-substrate-rpc-client/rpc/state/subscribe_storage.go

Line 59 in 03ce7c5

close(s.channel)

Any help with this would be much appreciated, thanks for your time 🙏

[NunoAlexandre]

@ggwpez did you happen to resolve this issue?

[ggwpez]

@ggwpez did you happen to resolve this issue?

No, we just refrained from running the race tests in our project…
I saw that this is old code copied from geth, maybe it could help to update it? I dont know.
Instead it could also use a fork as subrepo here, to keep track which files were changed from the geth code.
@NunoAlexandre

[cdamian]

Will most likely create a geth fork and use that given another issue reported here - #362