os, net, internal/poll: return consistent error for closed socket

In the past we returned "use of closed network connection" when using
a closed network descriptor in some way. In CL 36799 that was changed
to return "use of closed file or network connection". Because programs
have no access to a value of this error type (see issue #4373) they
resort to doing direct string comparisons (see issue #19252). This CL
restores the old error string so that we don't break programs
unnecessarily with the 1.9 release.

This adds a test to the net package for the expected string.

For symmetry check that the os package returns the expected error,
which for os already exists as os.ErrClosed.

Updates #4373.
Fixed #19252.

Change-Id: I5b83fd12cfa03501a077cad9336499b819f4a38b
Reviewed-on: https://go-review.googlesource.com/39997
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This commit is contained in:
Ian Lance Taylor 2017-04-07 15:53:19 -07:00
parent 2fb2ebc32e
commit fb4b4342fe
19 changed files with 143 additions and 99 deletions

View file

@ -87,20 +87,18 @@ func newFile(fd uintptr, name string, pollable bool) *File {
pollable = false
}
if pollable {
if err := f.pfd.Init(); err != nil {
// An error here indicates a failure to register
// with the netpoll system. That can happen for
// a file descriptor that is not supported by
// epoll/kqueue; for example, disk files on
// GNU/Linux systems. We assume that any real error
// will show up in later I/O.
} else {
// We successfully registered with netpoll, so put
// the file into nonblocking mode.
if err := syscall.SetNonblock(fdi, true); err == nil {
f.nonblock = true
}
if err := f.pfd.Init("file", pollable); err != nil {
// An error here indicates a failure to register
// with the netpoll system. That can happen for
// a file descriptor that is not supported by
// epoll/kqueue; for example, disk files on
// GNU/Linux systems. We assume that any real error
// will show up in later I/O.
} else if pollable {
// We successfully registered with netpoll, so put
// the file into nonblocking mode.
if err := syscall.SetNonblock(fdi, true); err == nil {
f.nonblock = true
}
}