Standardize mutex unlocks as defers

blockchain/block.go

@@ -78,9 +78,9 @@ func (b *Block) NextBlock() (*Block, error) {
 // GetCreated returns a copy of the created coins list
 func (b *Block) GetCreated() []coin.Coin {
 	b.mutex.Lock()
+	defer b.mutex.Unlock()
 	cCopy := make([]coin.Coin, len(b.created))
 	copy(cCopy, b.created)
-	b.mutex.Unlock()
 	return cCopy
 }
 
@@ -102,9 +102,9 @@ func (b *Block) AddCreated(c []coin.Coin) error {
 // GetDestroyed returns a copy of the destroyed coins list
 func (b *Block) GetDestroyed() []coin.Coin {
 	b.mutex.Lock()
+	defer b.mutex.Unlock()
 	cCopy := make([]coin.Coin, len(b.destroyed))
 	copy(cCopy, b.destroyed)
-	b.mutex.Unlock()
 	return cCopy
 }
 
@@ -139,8 +139,8 @@ func (b *Block) GetHash() (BlockHash, error) {
 func (b *Block) GetPreviousHash() BlockHash {
 	var rtnBH BlockHash
 	b.mutex.Lock()
+	defer b.mutex.Unlock()
 	copy(rtnBH[:], b.previousHash[:])
-	b.mutex.Unlock()
 	return rtnBH
 }
 
@@ -148,7 +148,7 @@ func (b *Block) GetPreviousHash() BlockHash {
 func (b *Block) GetLifecycle() BlockLifecycle {
 	b.mutex.Lock()
 	blc := b.lifecycle
-	b.mutex.Unlock()
+	defer b.mutex.Unlock()
 	return blc
 }
 
@@ -276,7 +276,7 @@ func Deserialize(sBlock []byte) (*Block, error) {
 	b.id = sb.ID
 
 	b.lifecycle = Baked
-	b.mutex.Unlock()
+	defer b.mutex.Unlock()
 
 	return &b, nil
 }

fastRNG/stream.go

@@ -38,7 +38,7 @@ type Stream struct {
 	rng         csprng.Source
 	source      []byte
 	numStream   uint
-	mut         sync.Mutex
+	mutex       sync.Mutex
 	fortunaHash hash.Hash
 }
 
@@ -81,8 +81,8 @@ func (sg *StreamGenerator) newStream() *Stream {
 // If the # of open streams exceeds streamCount,
 // this function blocks (and prints a log warning) until a stream is available
 func (sg *StreamGenerator) GetStream() *Stream {
-	//Initialize a stream
 	var retStream *Stream
+
 	// If there is a stream waiting to be used, take that from the channel and return in
 	select {
 	case retStream = <-sg.waitingStreams:
@@ -112,9 +112,10 @@ func (sg *StreamGenerator) Close(stream *Stream) {
 // BlockSize into AES then run it until blockSize*scalingFactor bytes are read. Every time
 // BlockSize*scalingFactor bytes are read this functions blocks until it rereads csprng.Source.
 func (s *Stream) Read(b []byte) (int, error) {
-	s.mut.Lock()
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
 	if len(b)%aes.BlockSize != 0 {
-		s.mut.Unlock()
 		return 0, errors.New("requested read length is not byte aligned")
 	}
 
@@ -136,7 +137,6 @@ func (s *Stream) Read(b []byte) (int, error) {
 			extension = make([]byte, aes.BlockSize)
 			_, err := s.rng.Read(extension)
 			if err != nil {
-				s.mut.Unlock()
 				return 0, err
 			}
 			s.entropyCnt = s.streamGen.scalingFactor
@@ -149,7 +149,6 @@ func (s *Stream) Read(b []byte) (int, error) {
 
 	copy(s.source, dst)
 
-	s.mut.Unlock()
 	return len(b), nil
 }
 
@@ -161,11 +160,13 @@ func Fortuna(src, ext []byte, fortunaHash hash.Hash) cipher.Stream {
 	fortunaHash.Write(src)
 	fortunaHash.Write(ext)
 	key := fortunaHash.Sum(nil)
+
 	// Initialize a block cipher on that key
 	block, err := aes.NewCipher(key[:aes.BlockSize])
 	if err != nil {
 		jww.FATAL.Panicf(err.Error())
 	}
+
 	// Encrypt the counter and place into destination
 	return cipher.NewCTR(block, key[aes.BlockSize:2*aes.BlockSize])
 }
@@ -174,6 +175,5 @@ func Fortuna(src, ext []byte, fortunaHash hash.Hash) cipher.Stream {
 // csprng.Source interface.
 func (s *Stream) SetSeed(seed []byte) error {
 	jww.INFO.Printf("Stream does not utilise SetSeed().")
-
 	return nil
 }