diff --git a/common/io/reader.go b/common/io/reader.go
index cd6524118..8a2abf032 100644
--- a/common/io/reader.go
+++ b/common/io/reader.go
@@ -33,6 +33,7 @@ type AdaptiveReader struct {
 }
 
 // NewAdaptiveReader creates a new AdaptiveReader.
+// The AdaptiveReader instance doesn't take the ownership of reader.
 func NewAdaptiveReader(reader io.Reader) *AdaptiveReader {
 	return &AdaptiveReader{
 		reader:   reader,
diff --git a/common/io/writer.go b/common/io/writer.go
index 8901bd52d..2df487ce8 100644
--- a/common/io/writer.go
+++ b/common/io/writer.go
@@ -26,7 +26,7 @@ func NewAdaptiveWriter(writer io.Writer) *AdaptiveWriter {
 	}
 }
 
-// Write implements Writer.Write().
+// Write implements Writer.Write(). Write() takes ownership of the given buffer.
 func (this *AdaptiveWriter) Write(buffer *alloc.Buffer) error {
 	nBytes, err := this.writer.Write(buffer.Value)
 	if nBytes < buffer.Len() {
diff --git a/common/protocol/raw/server.go b/common/protocol/raw/server.go
index 57cfb25d7..206d9b42c 100644
--- a/common/protocol/raw/server.go
+++ b/common/protocol/raw/server.go
@@ -24,12 +24,15 @@ type ServerSession struct {
 	responseWriter  io.Writer
 }
 
+// NewServerSession creates a new ServerSession, using the given UserValidator.
+// The ServerSession instance doesn't take ownership of the validator.
 func NewServerSession(validator protocol.UserValidator) *ServerSession {
 	return &ServerSession{
 		userValidator: validator,
 	}
 }
 
+// Release implements common.Releaseable.
 func (this *ServerSession) Release() {
 	this.userValidator = nil
 	this.requestBodyIV = nil