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authorGoogler <noreply@google.com>2018-04-27 10:37:02 -0700
committerAdin Scannell <ascannell@google.com>2018-04-28 01:44:26 -0400
commitd02b74a5dcfed4bfc8f2f8e545bca4d2afabb296 (patch)
tree54f95eef73aee6bacbfc736fffc631be2605ed53 /pkg/syserror
parentf70210e742919f40aa2f0934a22f1c9ba6dada62 (diff)
Check in gVisor.
PiperOrigin-RevId: 194583126 Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463
Diffstat (limited to 'pkg/syserror')
-rw-r--r--pkg/syserror/BUILD18
-rw-r--r--pkg/syserror/syserror.go151
-rw-r--r--pkg/syserror/syserror_test.go136
3 files changed, 305 insertions, 0 deletions
diff --git a/pkg/syserror/BUILD b/pkg/syserror/BUILD
new file mode 100644
index 000000000..68ddec786
--- /dev/null
+++ b/pkg/syserror/BUILD
@@ -0,0 +1,18 @@
+package(licenses = ["notice"]) # Apache 2.0
+
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+ name = "syserror",
+ srcs = ["syserror.go"],
+ importpath = "gvisor.googlesource.com/gvisor/pkg/syserror",
+ visibility = ["//visibility:public"],
+)
+
+go_test(
+ name = "syserror_test",
+ srcs = ["syserror_test.go"],
+ deps = [
+ ":syserror",
+ ],
+)
diff --git a/pkg/syserror/syserror.go b/pkg/syserror/syserror.go
new file mode 100644
index 000000000..6f8a7a319
--- /dev/null
+++ b/pkg/syserror/syserror.go
@@ -0,0 +1,151 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package syserror contains syscall error codes exported as error interface
+// instead of Errno. This allows for fast comparison and returns when the
+// comparand or return value is of type error because there is no need to
+// convert from Errno to an interface, i.e., runtime.convT2I isn't called.
+package syserror
+
+import (
+ "errors"
+ "syscall"
+)
+
+// The following variables have the same meaning as their syscall equivalent.
+var (
+ E2BIG = error(syscall.E2BIG)
+ EACCES = error(syscall.EACCES)
+ EAGAIN = error(syscall.EAGAIN)
+ EBADF = error(syscall.EBADF)
+ EBUSY = error(syscall.EBUSY)
+ ECHILD = error(syscall.ECHILD)
+ ECONNREFUSED = error(syscall.ECONNREFUSED)
+ ECONNRESET = error(syscall.ECONNRESET)
+ EEXIST = error(syscall.EEXIST)
+ EFAULT = error(syscall.EFAULT)
+ EFBIG = error(syscall.EFBIG)
+ EIDRM = error(syscall.EIDRM)
+ EINTR = error(syscall.EINTR)
+ EINVAL = error(syscall.EINVAL)
+ EIO = error(syscall.EIO)
+ EISDIR = error(syscall.EISDIR)
+ ELIBBAD = error(syscall.ELIBBAD)
+ ELOOP = error(syscall.ELOOP)
+ EMFILE = error(syscall.EMFILE)
+ ENAMETOOLONG = error(syscall.ENAMETOOLONG)
+ ENOATTR = ENODATA
+ ENODATA = error(syscall.ENODATA)
+ ENODEV = error(syscall.ENODEV)
+ ENOENT = error(syscall.ENOENT)
+ ENOEXEC = error(syscall.ENOEXEC)
+ ENOLCK = error(syscall.ENOLCK)
+ ENOLINK = error(syscall.ENOLINK)
+ ENOMEM = error(syscall.ENOMEM)
+ ENOSPC = error(syscall.ENOSPC)
+ ENOSYS = error(syscall.ENOSYS)
+ ENOTDIR = error(syscall.ENOTDIR)
+ ENOTEMPTY = error(syscall.ENOTEMPTY)
+ ENOTSUP = error(syscall.ENOTSUP)
+ ENOTTY = error(syscall.ENOTTY)
+ ENXIO = error(syscall.ENXIO)
+ EOPNOTSUPP = error(syscall.EOPNOTSUPP)
+ EOVERFLOW = error(syscall.EOVERFLOW)
+ EPERM = error(syscall.EPERM)
+ EPIPE = error(syscall.EPIPE)
+ ERANGE = error(syscall.ERANGE)
+ EROFS = error(syscall.EROFS)
+ ESPIPE = error(syscall.ESPIPE)
+ ESRCH = error(syscall.ESRCH)
+ ETIMEDOUT = error(syscall.ETIMEDOUT)
+ EUSERS = error(syscall.EUSERS)
+ EWOULDBLOCK = error(syscall.EWOULDBLOCK)
+ EXDEV = error(syscall.EXDEV)
+)
+
+var (
+ // ErrWouldBlock is an internal error used to indicate that an operation
+ // cannot be satisfied immediately, and should be retried at a later
+ // time, possibly when the caller has received a notification that the
+ // operation may be able to complete. It is used by implementations of
+ // the kio.File interface.
+ ErrWouldBlock = errors.New("request would block")
+
+ // ErrInterrupted is returned if a request is interrupted before it can
+ // complete.
+ ErrInterrupted = errors.New("request was interrupted")
+
+ // ErrExceedsFileSizeLimit is returned if a request would exceed the
+ // file's size limit.
+ ErrExceedsFileSizeLimit = errors.New("exceeds file size limit")
+)
+
+// errorMap is the map used to convert generic errors into errnos.
+var errorMap = map[error]syscall.Errno{}
+
+// errorUnwrappers is an array of unwrap functions to extract typed errors.
+var errorUnwrappers = []func(error) (syscall.Errno, bool){}
+
+// AddErrorTranslation allows modules to populate the error map by adding their
+// own translations during initialization. Returns if the error translation is
+// accepted or not. A pre-existing translation will not be overwritten by the
+// new translation.
+func AddErrorTranslation(from error, to syscall.Errno) bool {
+ if _, ok := errorMap[from]; ok {
+ return false
+ }
+
+ errorMap[from] = to
+ return true
+}
+
+// AddErrorUnwrapper registers an unwrap method that can extract a concrete error
+// from a typed, but not initialized, error.
+func AddErrorUnwrapper(unwrap func(e error) (syscall.Errno, bool)) {
+ errorUnwrappers = append(errorUnwrappers, unwrap)
+}
+
+// TranslateError translates errors to errnos, it will return false if
+// the error was not registered.
+func TranslateError(from error) (syscall.Errno, bool) {
+ err, ok := errorMap[from]
+ if ok {
+ return err, ok
+ }
+ // Try to unwrap the error if we couldn't match an error
+ // exactly. This might mean that a package has its own
+ // error type.
+ for _, unwrap := range errorUnwrappers {
+ err, ok := unwrap(from)
+ if ok {
+ return err, ok
+ }
+ }
+ return 0, false
+}
+
+// ConvertIntr converts the provided error code (err) to another one (intr) if
+// the first error corresponds to an interrupted operation.
+func ConvertIntr(err, intr error) error {
+ if err == ErrInterrupted {
+ return intr
+ }
+ return err
+}
+
+func init() {
+ AddErrorTranslation(ErrWouldBlock, syscall.EWOULDBLOCK)
+ AddErrorTranslation(ErrInterrupted, syscall.EINTR)
+ AddErrorTranslation(ErrExceedsFileSizeLimit, syscall.EFBIG)
+}
diff --git a/pkg/syserror/syserror_test.go b/pkg/syserror/syserror_test.go
new file mode 100644
index 000000000..fb7d8d5ee
--- /dev/null
+++ b/pkg/syserror/syserror_test.go
@@ -0,0 +1,136 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package syserror_test
+
+import (
+ "errors"
+ "syscall"
+ "testing"
+
+ "gvisor.googlesource.com/gvisor/pkg/syserror"
+)
+
+var globalError error
+
+func returnErrnoAsError() error {
+ return syscall.EINVAL
+}
+
+func returnError() error {
+ return syserror.EINVAL
+}
+
+func BenchmarkReturnErrnoAsError(b *testing.B) {
+ for i := b.N; i > 0; i-- {
+ returnErrnoAsError()
+ }
+}
+
+func BenchmarkReturnError(b *testing.B) {
+ for i := b.N; i > 0; i-- {
+ returnError()
+ }
+}
+
+func BenchmarkCompareErrno(b *testing.B) {
+ j := 0
+ for i := b.N; i > 0; i-- {
+ if globalError == syscall.EINVAL {
+ j++
+ }
+ }
+}
+
+func BenchmarkCompareError(b *testing.B) {
+ j := 0
+ for i := b.N; i > 0; i-- {
+ if globalError == syserror.EINVAL {
+ j++
+ }
+ }
+}
+
+func BenchmarkSwitchErrno(b *testing.B) {
+ j := 0
+ for i := b.N; i > 0; i-- {
+ switch globalError {
+ case syscall.EINVAL:
+ j += 1
+ case syscall.EINTR:
+ j += 2
+ case syscall.EAGAIN:
+ j += 3
+ }
+ }
+}
+
+func BenchmarkSwitchError(b *testing.B) {
+ j := 0
+ for i := b.N; i > 0; i-- {
+ switch globalError {
+ case syserror.EINVAL:
+ j += 1
+ case syserror.EINTR:
+ j += 2
+ case syserror.EAGAIN:
+ j += 3
+ }
+ }
+}
+
+type translationTestTable struct {
+ fn string
+ errIn error
+ syscallErrorIn syscall.Errno
+ expectedBool bool
+ expectedTranslation syscall.Errno
+}
+
+func TestErrorTranslation(t *testing.T) {
+ myError := errors.New("My test error")
+ myError2 := errors.New("Another test error")
+ testTable := []translationTestTable{
+ {"TranslateError", myError, 0, false, 0},
+ {"TranslateError", myError2, 0, false, 0},
+ {"AddErrorTranslation", myError, syscall.EAGAIN, true, 0},
+ {"AddErrorTranslation", myError, syscall.EAGAIN, false, 0},
+ {"AddErrorTranslation", myError, syscall.EPERM, false, 0},
+ {"TranslateError", myError, 0, true, syscall.EAGAIN},
+ {"TranslateError", myError2, 0, false, 0},
+ {"AddErrorTranslation", myError2, syscall.EPERM, true, 0},
+ {"AddErrorTranslation", myError2, syscall.EPERM, false, 0},
+ {"AddErrorTranslation", myError2, syscall.EAGAIN, false, 0},
+ {"TranslateError", myError, 0, true, syscall.EAGAIN},
+ {"TranslateError", myError2, 0, true, syscall.EPERM},
+ }
+ for _, tt := range testTable {
+ switch tt.fn {
+ case "TranslateError":
+ err, ok := syserror.TranslateError(tt.errIn)
+ if ok != tt.expectedBool {
+ t.Fatalf("%v(%v) => %v expected %v", tt.fn, tt.errIn, ok, tt.expectedBool)
+ } else if err != tt.expectedTranslation {
+ t.Fatalf("%v(%v) (error) => %v expected %v", tt.fn, tt.errIn, err, tt.expectedTranslation)
+ }
+ case "AddErrorTranslation":
+ ok := syserror.AddErrorTranslation(tt.errIn, tt.syscallErrorIn)
+ if ok != tt.expectedBool {
+ t.Fatalf("%v(%v) => %v expected %v", tt.fn, tt.errIn, ok, tt.expectedBool)
+ }
+ default:
+ t.Fatalf("Unknown function %v", tt.fn)
+ }
+ }
+}