cmd/go: factor the I/O-retry logic out of renameio
Factor the try-on-failure variants are now in the package
cmd/go/internal/robustio.
Add to them a RemoveAll variant using the same retry loop,
and use it to attempt to address the observed flakes in
TestLinkXImportPathEscape.
Fixes #19491
Updates #25965
Updates #28387
Updates #32188
Change-Id: I9db1a0c7537b8aaadccab1b9eca734595668ba29
Reviewed-on: https://go-review.googlesource.com/c/go/+/181541
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go
index 8a6beb8..9d82ac7 100644
--- a/src/cmd/go/go_test.go
+++ b/src/cmd/go/go_test.go
@@ -29,6 +29,7 @@
"cmd/go/internal/cache"
"cmd/go/internal/cfg"
+ "cmd/go/internal/robustio"
"cmd/internal/sys"
)
@@ -685,7 +686,7 @@
if tg.wd != "" && !filepath.IsAbs(path) {
path = filepath.Join(tg.pwd(), path)
}
- tg.must(os.RemoveAll(path))
+ tg.must(robustio.RemoveAll(path))
tg.temps = append(tg.temps, path)
}
@@ -887,7 +888,7 @@
}
return nil
})
- return os.RemoveAll(dir)
+ return robustio.RemoveAll(dir)
}
// failSSH puts an ssh executable in the PATH that always fails.
@@ -1181,7 +1182,7 @@
case "svn":
// SVN doesn't believe in text files so we can't just edit the config.
// Check out a different repo into the wrong place.
- tg.must(os.RemoveAll(tg.path("src/code.google.com/p/rsc-svn")))
+ tg.must(robustio.RemoveAll(tg.path("src/code.google.com/p/rsc-svn")))
tg.run("get", "-d", "-u", "code.google.com/p/rsc-svn2/trunk")
tg.must(os.Rename(tg.path("src/code.google.com/p/rsc-svn2"), tg.path("src/code.google.com/p/rsc-svn")))
default:
@@ -1693,7 +1694,7 @@
goarch := strings.TrimSpace(tg.getStdout())
tg.setenv("GOARCH", goarch)
fixbin := filepath.Join(goroot, "pkg", "tool", goos+"_"+goarch, "fix") + exeSuffix
- tg.must(os.RemoveAll(fixbin))
+ tg.must(robustio.RemoveAll(fixbin))
tg.run("install", "cmd/fix")
tg.wantExecutable(fixbin, "did not install cmd/fix to $GOROOT/pkg/tool")
tg.must(os.Remove(fixbin))
@@ -2065,13 +2066,13 @@
tg.grepStderr("created GOPATH="+regexp.QuoteMeta(tg.path("home/go"))+"; see 'go help gopath'", "did not create GOPATH")
// no warning if directory already exists
- tg.must(os.RemoveAll(tg.path("home/go")))
+ tg.must(robustio.RemoveAll(tg.path("home/go")))
tg.tempDir("home/go")
tg.run("get", "github.com/golang/example/hello")
tg.grepStderrNot(".", "expected no output on standard error")
// error if $HOME/go is a file
- tg.must(os.RemoveAll(tg.path("home/go")))
+ tg.must(robustio.RemoveAll(tg.path("home/go")))
tg.tempFile("home/go", "")
tg.runFail("get", "github.com/golang/example/hello")
tg.grepStderr(`mkdir .*[/\\]go: .*(not a directory|cannot find the path)`, "expected error because $HOME/go is a file")
@@ -2872,7 +2873,7 @@
files, err := filepath.Glob(filepath.Join(runtime.GOROOT(), "pkg", "*_race"))
tg.must(err)
for _, file := range files {
- tg.check(os.RemoveAll(file))
+ tg.check(robustio.RemoveAll(file))
}
tg.tempFile("src/foo/foo.go", `
package foo
@@ -3925,10 +3926,10 @@
tg.run("get", "go-get-issue-9357.appspot.com")
tg.run("get", "-u", "go-get-issue-9357.appspot.com")
- tg.must(os.RemoveAll(tg.path("src/go-get-issue-9357.appspot.com")))
+ tg.must(robustio.RemoveAll(tg.path("src/go-get-issue-9357.appspot.com")))
tg.run("get", "go-get-issue-9357.appspot.com")
- tg.must(os.RemoveAll(tg.path("src/go-get-issue-9357.appspot.com")))
+ tg.must(robustio.RemoveAll(tg.path("src/go-get-issue-9357.appspot.com")))
tg.run("get", "-u", "go-get-issue-9357.appspot.com")
}
@@ -4513,8 +4514,9 @@
tg := testgo(t)
defer tg.cleanup()
tg.parallel()
+ tg.makeTempdir()
tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
- exe := "./linkx" + exeSuffix
+ exe := tg.path("linkx" + exeSuffix)
tg.creatingTemp(exe)
tg.run("build", "-o", exe, "-ldflags", "-X=my.pkg.Text=linkXworked", "my.pkg/main")
out, err := exec.Command(exe).CombinedOutput()
@@ -4750,7 +4752,7 @@
check(t, symGoTool, newRoot)
})
- tg.must(os.RemoveAll(tg.path("new/pkg")))
+ tg.must(robustio.RemoveAll(tg.path("new/pkg")))
// Binaries built in the new tree should report the
// new tree when they call runtime.GOROOT.
@@ -5101,7 +5103,7 @@
if len(matches) == 0 {
t.Fatal("no WORK directory")
}
- tg.must(os.RemoveAll(matches[1]))
+ tg.must(robustio.RemoveAll(matches[1]))
}
func TestParallelNumber(t *testing.T) {
diff --git a/src/cmd/go/go_windows_test.go b/src/cmd/go/go_windows_test.go
index d65d91f..3999166 100644
--- a/src/cmd/go/go_windows_test.go
+++ b/src/cmd/go/go_windows_test.go
@@ -12,6 +12,8 @@
"path/filepath"
"strings"
"testing"
+
+ "cmd/go/internal/robustio"
)
func TestAbsolutePath(t *testing.T) {
@@ -21,7 +23,7 @@
if err != nil {
t.Fatal(err)
}
- defer os.RemoveAll(tmp)
+ defer robustio.RemoveAll(tmp)
file := filepath.Join(tmp, "a.go")
err = ioutil.WriteFile(file, []byte{}, 0644)
diff --git a/src/cmd/go/internal/renameio/renameio.go b/src/cmd/go/internal/renameio/renameio.go
index a34ce59..d573cc6 100644
--- a/src/cmd/go/internal/renameio/renameio.go
+++ b/src/cmd/go/internal/renameio/renameio.go
@@ -12,6 +12,8 @@
"os"
"path/filepath"
"strconv"
+
+ "cmd/go/internal/robustio"
)
const patternSuffix = ".tmp"
@@ -61,7 +63,7 @@
return err
}
- return rename(f.Name(), filename)
+ return robustio.Rename(f.Name(), filename)
}
// ReadFile is like ioutil.ReadFile, but on Windows retries spurious errors that
@@ -74,7 +76,7 @@
// - syscall.ERROR_FILE_NOT_FOUND
// - internal/syscall/windows.ERROR_SHARING_VIOLATION
func ReadFile(filename string) ([]byte, error) {
- return readFile(filename)
+ return robustio.ReadFile(filename)
}
// tempFile creates a new temporary file with given permission bits.
diff --git a/src/cmd/go/internal/renameio/renameio_test.go b/src/cmd/go/internal/renameio/renameio_test.go
index e06dee3..81dba6d 100644
--- a/src/cmd/go/internal/renameio/renameio_test.go
+++ b/src/cmd/go/internal/renameio/renameio_test.go
@@ -19,6 +19,8 @@
"syscall"
"testing"
"time"
+
+ "cmd/go/internal/robustio"
)
func TestConcurrentReadsAndWrites(t *testing.T) {
@@ -58,7 +60,7 @@
chunk := buf[offset*8 : (offset+chunkWords)*8]
if err := WriteFile(path, chunk, 0666); err == nil {
atomic.AddInt64(&writeSuccesses, 1)
- } else if isEphemeralError(err) {
+ } else if robustio.IsEphemeralError(err) {
var (
errno syscall.Errno
dup bool
@@ -74,10 +76,10 @@
}
time.Sleep(time.Duration(rand.Intn(100)) * time.Microsecond)
- data, err := ioutil.ReadFile(path)
+ data, err := ReadFile(path)
if err == nil {
atomic.AddInt64(&readSuccesses, 1)
- } else if isEphemeralError(err) {
+ } else if robustio.IsEphemeralError(err) {
var (
errno syscall.Errno
dup bool
diff --git a/src/cmd/go/internal/robustio/robustio.go b/src/cmd/go/internal/robustio/robustio.go
new file mode 100644
index 0000000..76e47ad
--- /dev/null
+++ b/src/cmd/go/internal/robustio/robustio.go
@@ -0,0 +1,53 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package robustio wraps I/O functions that are prone to failure on Windows,
+// transparently retrying errors up to an arbitrary timeout.
+//
+// Errors are classified heuristically and retries are bounded, so the functions
+// in this package do not completely eliminate spurious errors. However, they do
+// significantly reduce the rate of failure in practice.
+//
+// If so, the error will likely wrap one of:
+// The functions in this package do not completely eliminate spurious errors,
+// but substantially reduce their rate of occurrence in practice.
+package robustio
+
+// Rename is like os.Rename, but on Windows retries errors that may occur if the
+// file is concurrently read or overwritten.
+//
+// (See golang.org/issue/31247 and golang.org/issue/32188.)
+func Rename(oldpath, newpath string) error {
+ return rename(oldpath, newpath)
+}
+
+// ReadFile is like ioutil.ReadFile, but on Windows retries errors that may
+// occur if the file is concurrently replaced.
+//
+// (See golang.org/issue/31247 and golang.org/issue/32188.)
+func ReadFile(filename string) ([]byte, error) {
+ return readFile(filename)
+}
+
+// RemoveAll is like os.RemoveAll, but on Windows retries errors that may occur
+// if an executable file in the directory has recently been executed.
+//
+// (See golang.org/issue/19491.)
+func RemoveAll(path string) error {
+ return removeAll(path)
+}
+
+// IsEphemeralError reports whether err is one of the errors that the functions
+// in this package attempt to mitigate.
+//
+// Errors considered ephemeral include:
+// - syscall.ERROR_ACCESS_DENIED
+// - syscall.ERROR_FILE_NOT_FOUND
+// - internal/syscall/windows.ERROR_SHARING_VIOLATION
+//
+// This set may be expanded in the future; programs must not rely on the
+// non-ephemerality of any given error.
+func IsEphemeralError(err error) bool {
+ return isEphemeralError(err)
+}
diff --git a/src/cmd/go/internal/renameio/rename.go b/src/cmd/go/internal/robustio/robustio_other.go
similarity index 83%
rename from src/cmd/go/internal/renameio/rename.go
rename to src/cmd/go/internal/robustio/robustio_other.go
index 9862ebd..91ca56c 100644
--- a/src/cmd/go/internal/renameio/rename.go
+++ b/src/cmd/go/internal/robustio/robustio_other.go
@@ -4,7 +4,7 @@
//+build !windows
-package renameio
+package robustio
import (
"io/ioutil"
@@ -19,6 +19,10 @@
return ioutil.ReadFile(filename)
}
+func removeAll(path string) error {
+ return os.RemoveAll(path)
+}
+
func isEphemeralError(err error) bool {
return false
}
diff --git a/src/cmd/go/internal/renameio/rename_windows.go b/src/cmd/go/internal/robustio/robustio_windows.go
similarity index 88%
rename from src/cmd/go/internal/renameio/rename_windows.go
rename to src/cmd/go/internal/robustio/robustio_windows.go
index 7da8c9c..a3d94e5 100644
--- a/src/cmd/go/internal/renameio/rename_windows.go
+++ b/src/cmd/go/internal/robustio/robustio_windows.go
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-package renameio
+package robustio
import (
"errors"
@@ -14,9 +14,10 @@
"time"
)
+const arbitraryTimeout = 500 * time.Millisecond
+
// retry retries ephemeral errors from f up to an arbitrary timeout
// to work around spurious filesystem errors on Windows
-// (see golang.org/issue/31247 and golang.org/issue/32188).
func retry(f func() (err error, mayRetry bool)) error {
var (
bestErr error
@@ -40,7 +41,7 @@
if start.IsZero() {
start = time.Now()
- } else if d := time.Since(start) + nextSleep; d >= 500*time.Millisecond {
+ } else if d := time.Since(start) + nextSleep; d >= arbitraryTimeout {
break
}
time.Sleep(nextSleep)
@@ -61,8 +62,6 @@
//
// Empirical error rates with MoveFileEx are lower under modest concurrency, so
// for now we're sticking with what the os package already provides.
-//
-// TODO(bcmills): For Go 1.14, should we try changing os.Rename itself to do this?
func rename(oldpath, newpath string) (err error) {
return retry(func() (err error, mayRetry bool) {
err = os.Rename(oldpath, newpath)
@@ -71,8 +70,6 @@
}
// readFile is like ioutil.ReadFile, but retries ephemeral errors.
-//
-// TODO(bcmills): For Go 1.14, should we try changing ioutil.ReadFile itself to do this?
func readFile(filename string) ([]byte, error) {
var b []byte
err := retry(func() (err error, mayRetry bool) {
@@ -86,6 +83,13 @@
return b, err
}
+func removeAll(path string) error {
+ return retry(func() (err error, mayRetry bool) {
+ err = os.RemoveAll(path)
+ return err, isEphemeralError(err)
+ })
+}
+
// isEphemeralError returns true if err may be resolved by waiting.
func isEphemeralError(err error) bool {
var errno syscall.Errno
diff --git a/src/cmd/go/script_test.go b/src/cmd/go/script_test.go
index 8733159..4dcb4b4 100644
--- a/src/cmd/go/script_test.go
+++ b/src/cmd/go/script_test.go
@@ -27,6 +27,7 @@
"cmd/go/internal/cfg"
"cmd/go/internal/imports"
"cmd/go/internal/par"
+ "cmd/go/internal/robustio"
"cmd/go/internal/txtar"
"cmd/go/internal/work"
)
@@ -388,7 +389,7 @@
var b work.Builder
b.Init()
ts.cmdExec(neg, append(b.GccCmd(".", ""), args...))
- os.RemoveAll(b.WorkDir)
+ robustio.RemoveAll(b.WorkDir)
}
// cd changes to a different directory.
@@ -669,8 +670,8 @@
}
for _, arg := range args {
file := ts.mkabs(arg)
- removeAll(file) // does chmod and then attempts rm
- ts.check(os.RemoveAll(file)) // report error
+ removeAll(file) // does chmod and then attempts rm
+ ts.check(robustio.RemoveAll(file)) // report error
}
}
