commit 7e43aee3016006fb74760d1936fb1ce6d2d08560
author Shenghou Ma <minux@golang.org> Tue Feb 03 12:59:40 2015 -0500
committer Minux Ma <minux@golang.org> Fri Feb 06 19:21:40 2015 +0000
tree 3d02d331f52d0b36802b8de880f2cf7eec703ecb
parent 4ce06f4b5caab3874f30f14551aa3f8e08f2de3e

net: document that user shouldn't modify returned Addr

Ideally, those methods should return a copy of the Addr, but
due to the Go 1 API guarantee, we cannot make that change now:
there might exist client code that uses the returned Addr as
map index and thus relies on the fact that different invocation
of the method returns the same pointer. Changing this behavior
will lead to hidden behaviour change in those programs.

Update #9654.

Change-Id: Iad4235f2ed7789b3a3c8e0993b9718cf0534ea2b
Reviewed-on: https://go-review.googlesource.com/3851
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/net/net.go

diff --git a/src/net/net.go b/src/net/net.go
index c850d2b..339c972 100644
--- a/src/net/net.go
+++ b/src/net/net.go
@@ -135,6 +135,8 @@
 }
 
 // LocalAddr returns the local network address.
+// The Addr returned is shared by all invocations of LocalAddr, so
+// do not modify it.
 func (c *conn) LocalAddr() Addr {
 	if !c.ok() {
 		return nil
@@ -143,6 +145,8 @@
 }
 
 // RemoteAddr returns the remote network address.
+// The Addr returned is shared by all invocations of RemoteAddr, so
+// do not modify it.
 func (c *conn) RemoteAddr() Addr {
 	if !c.ok() {
 		return nil

src/net/tcpsock_plan9.go

diff --git a/src/net/tcpsock_plan9.go b/src/net/tcpsock_plan9.go
index 52019d7..ae21942 100644
--- a/src/net/tcpsock_plan9.go
+++ b/src/net/tcpsock_plan9.go
@@ -157,6 +157,8 @@
 }
 
 // Addr returns the listener's network address, a *TCPAddr.
+// The Addr returned is shared by all invocations of Addr, so
+// do not modify it.
 func (l *TCPListener) Addr() Addr { return l.fd.laddr }
 
 // SetDeadline sets the deadline associated with the listener.

src/net/tcpsock_posix.go

diff --git a/src/net/tcpsock_posix.go b/src/net/tcpsock_posix.go
index dd78aef..aaff0ac 100644
--- a/src/net/tcpsock_posix.go
+++ b/src/net/tcpsock_posix.go
@@ -258,6 +258,8 @@
 }
 
 // Addr returns the listener's network address, a *TCPAddr.
+// The Addr returned is shared by all invocations of Addr, so
+// do not modify it.
 func (l *TCPListener) Addr() Addr { return l.fd.laddr }
 
 // SetDeadline sets the deadline associated with the listener.

src/net/unixsock_plan9.go

diff --git a/src/net/unixsock_plan9.go b/src/net/unixsock_plan9.go
index c60c1d8..64a511d 100644
--- a/src/net/unixsock_plan9.go
+++ b/src/net/unixsock_plan9.go
@@ -115,6 +115,8 @@
 }
 
 // Addr returns the listener's network address.
+// The Addr returned is shared by all invocations of Addr, so
+// do not modify it.
 func (l *UnixListener) Addr() Addr { return nil }
 
 // SetDeadline sets the deadline associated with the listener.

src/net/unixsock_posix.go

diff --git a/src/net/unixsock_posix.go b/src/net/unixsock_posix.go
index 3c2e78b..d7127d9 100644
--- a/src/net/unixsock_posix.go
+++ b/src/net/unixsock_posix.go
@@ -321,6 +321,8 @@
 }
 
 // Addr returns the listener's network address.
+// The Addr returned is shared by all invocations of Addr, so
+// do not modify it.
 func (l *UnixListener) Addr() Addr { return l.fd.laddr }
 
 // SetDeadline sets the deadline associated with the listener.