Merge pull request #565 from provenance-io/egaxhaj/remove-lock-on-sta…

…te-listening

remove listener lock as there is no concurrency

CHANGELOG.md

@@ -39,6 +39,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## Unreleased
 
+### Improvements
+
+* [PR 565](https://github.com/provenance-io/cosmos-sdk/pull/565) Removes locks around state listening. There's no concurrency risk.
+
 ### Bug Fixes
 
 * [PR 564](https://github.com/provenance-io/cosmos-sdk/pull/564) Fix protobufjs parse error by using object form vs. array for `additional_bindings` rpc tag.

store/rootmulti/store.go

@@ -61,8 +61,6 @@ type Store struct {
 	interBlockCache types.MultiStorePersistentCache
 
 	listeners map[types.StoreKey]*types.MemoryListener
-
-	listenersMx sync.Mutex
 }
 
 var (
@@ -382,8 +380,6 @@ func (rs *Store) TracingEnabled() bool {
 
 // AddListeners adds a listener for the KVStore belonging to the provided StoreKey
 func (rs *Store) AddListeners(keys []types.StoreKey) {
-	rs.listenersMx.Lock()
-	defer rs.listenersMx.Unlock()
 	for i := range keys {
 		listener := rs.listeners[keys[i]]
 		if listener == nil {
@@ -405,8 +401,6 @@ func (rs *Store) ListeningEnabled(key types.StoreKey) bool {
 // not the state in the store itself. This is a mutating and destructive operation.
 // This method has been synchronized.
 func (rs *Store) PopStateCache() []*types.StoreKVPair {
-	rs.listenersMx.Lock()
-	defer rs.listenersMx.Unlock()
 	var cache []*types.StoreKVPair
 	for key := range rs.listeners {
 		ls := rs.listeners[key]
@@ -490,8 +484,6 @@ func (rs *Store) CacheWrapWithTrace(_ io.Writer, _ types.TraceContext) types.Cac
 // CacheMultiStore creates ephemeral branch of the multi-store and returns a CacheMultiStore.
 // It implements the MultiStore interface.
 func (rs *Store) CacheMultiStore() types.CacheMultiStore {
-	rs.listenersMx.Lock()
-	defer rs.listenersMx.Unlock()
 	stores := make(map[types.StoreKey]types.CacheWrapper)
 	for k, v := range rs.stores {
 		store := types.KVStore(v)
@@ -510,8 +502,6 @@ func (rs *Store) CacheMultiStore() types.CacheMultiStore {
 // any store cannot be loaded. This should only be used for querying and
 // iterating at past heights.
 func (rs *Store) CacheMultiStoreWithVersion(version int64) (types.CacheMultiStore, error) {
-	rs.listenersMx.Lock()
-	defer rs.listenersMx.Unlock()
 	cachedStores := make(map[types.StoreKey]types.CacheWrapper)
 	for key, store := range rs.stores {
 		var cacheStore types.KVStore
@@ -566,8 +556,6 @@ func (rs *Store) GetStore(key types.StoreKey) types.Store {
 // NOTE: The returned KVStore may be wrapped in an inter-block cache if it is
 // set on the root store.
 func (rs *Store) GetKVStore(key types.StoreKey) types.KVStore {
-	rs.listenersMx.Lock()
-	defer rs.listenersMx.Unlock()
 	s := rs.stores[key]
 	if s == nil {
 		panic(fmt.Sprintf("store does not exist for key: %s", key.Name()))