Merge pull request #2076 from CortexFoundation/dev

core/state/snapshot: acquire the lock on Release

core/state/snapshot/snapshot.go

@@ -670,6 +670,9 @@ func diffToDisk(bottom *diffLayer) *diskLayer {
 
 // Release releases resources
 func (t *Tree) Release() {
+ t.lock.RLock()
+ defer t.lock.RUnlock()
+
  if dl := t.disklayer(); dl != nil {
  dl.Release()
  }
@@ -851,8 +854,8 @@ func (t *Tree) diskRoot() common.Hash {
 // generating is an internal helper function which reports whether the snapshot
 // is still under the construction.
 func (t *Tree) generating() (bool, error) {
- t.lock.Lock()
- defer t.lock.Unlock()
+ t.lock.RLock()
+ defer t.lock.RUnlock()
 
  layer := t.disklayer()
  if layer == nil {
@@ -865,8 +868,8 @@ func (t *Tree) generating() (bool, error) {
 
 // DiskRoot is an external helper function to return the disk layer root.
 func (t *Tree) DiskRoot() common.Hash {
- t.lock.Lock()
- defer t.lock.Unlock()
+ t.lock.RLock()
+ defer t.lock.RUnlock()
 
  return t.diskRoot()
 }