When using the RPC client in my test suite (with -race enabled), I do a lot of Subscribe/Unsubscribe operations, at some point (randomly) the race detector returns the following warning:
WARNING: DATA RACE
Read at 0x00c0009dbe30 by goroutine 31:
runtime.mapiterinit()
/usr/local/go/src/runtime/map.go:804 +0x0
github.com/tendermint/tendermint/rpc/client.(*WSEvents).redoSubscriptionsAfter()
/go/pkg/mod/github.com/tendermint/tendermint@v0.31.5/rpc/client/httpclient.go:364 +0xc0
github.com/tendermint/tendermint/rpc/client.(*WSEvents).eventListener()
/go/pkg/mod/github.com/tendermint/tendermint@v0.31.5/rpc/client/httpclient.go:393 +0x3c6
Turns out that the redoSubscriptionAfter is not protecting the access to subscriptions.
The following change protects the read access to the subscription map behind the mutex