--- /dev/null
+// 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.
+
+// +build !plan9
+
+package renameio
+
+import (
+ "encoding/binary"
+ "errors"
+ "io/ioutil"
+ "math/rand"
+ "os"
+ "path/filepath"
+ "runtime"
+ "sync"
+ "sync/atomic"
+ "syscall"
+ "testing"
+ "time"
+
+ "honnef.co/go/tools/internal/robustio"
+)
+
+func TestConcurrentReadsAndWrites(t *testing.T) {
+ dir, err := ioutil.TempDir("", "renameio")
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer os.RemoveAll(dir)
+ path := filepath.Join(dir, "blob.bin")
+
+ const chunkWords = 8 << 10
+ buf := make([]byte, 2*chunkWords*8)
+ for i := uint64(0); i < 2*chunkWords; i++ {
+ binary.LittleEndian.PutUint64(buf[i*8:], i)
+ }
+
+ var attempts int64 = 128
+ if !testing.Short() {
+ attempts *= 16
+ }
+ const parallel = 32
+
+ var sem = make(chan bool, parallel)
+
+ var (
+ writeSuccesses, readSuccesses int64 // atomic
+ writeErrnoSeen, readErrnoSeen sync.Map
+ )
+
+ for n := attempts; n > 0; n-- {
+ sem <- true
+ go func() {
+ defer func() { <-sem }()
+
+ time.Sleep(time.Duration(rand.Intn(100)) * time.Microsecond)
+ offset := rand.Intn(chunkWords)
+ chunk := buf[offset*8 : (offset+chunkWords)*8]
+ if err := WriteFile(path, chunk, 0666); err == nil {
+ atomic.AddInt64(&writeSuccesses, 1)
+ } else if robustio.IsEphemeralError(err) {
+ var (
+ errno syscall.Errno
+ dup bool
+ )
+ if errors.As(err, &errno) {
+ _, dup = writeErrnoSeen.LoadOrStore(errno, true)
+ }
+ if !dup {
+ t.Logf("ephemeral error: %v", err)
+ }
+ } else {
+ t.Errorf("unexpected error: %v", err)
+ }
+
+ time.Sleep(time.Duration(rand.Intn(100)) * time.Microsecond)
+ data, err := ReadFile(path)
+ if err == nil {
+ atomic.AddInt64(&readSuccesses, 1)
+ } else if robustio.IsEphemeralError(err) {
+ var (
+ errno syscall.Errno
+ dup bool
+ )
+ if errors.As(err, &errno) {
+ _, dup = readErrnoSeen.LoadOrStore(errno, true)
+ }
+ if !dup {
+ t.Logf("ephemeral error: %v", err)
+ }
+ return
+ } else {
+ t.Errorf("unexpected error: %v", err)
+ return
+ }
+
+ if len(data) != 8*chunkWords {
+ t.Errorf("read %d bytes, but each write is a %d-byte file", len(data), 8*chunkWords)
+ return
+ }
+
+ u := binary.LittleEndian.Uint64(data)
+ for i := 1; i < chunkWords; i++ {
+ next := binary.LittleEndian.Uint64(data[i*8:])
+ if next != u+1 {
+ t.Errorf("wrote sequential integers, but read integer out of sequence at offset %d", i)
+ return
+ }
+ u = next
+ }
+ }()
+ }
+
+ for n := parallel; n > 0; n-- {
+ sem <- true
+ }
+
+ var minWriteSuccesses int64 = attempts
+ if runtime.GOOS == "windows" {
+ // Windows produces frequent "Access is denied" errors under heavy rename load.
+ // As long as those are the only errors and *some* of the writes succeed, we're happy.
+ minWriteSuccesses = attempts / 4
+ }
+
+ if writeSuccesses < minWriteSuccesses {
+ t.Errorf("%d (of %d) writes succeeded; want ≥ %d", writeSuccesses, attempts, minWriteSuccesses)
+ } else {
+ t.Logf("%d (of %d) writes succeeded (ok: ≥ %d)", writeSuccesses, attempts, minWriteSuccesses)
+ }
+
+ var minReadSuccesses int64 = attempts
+
+ switch runtime.GOOS {
+ case "windows":
+ // Windows produces frequent "Access is denied" errors under heavy rename load.
+ // As long as those are the only errors and *some* of the reads succeed, we're happy.
+ minReadSuccesses = attempts / 4
+
+ case "darwin":
+ // The filesystem on macOS 10.14 occasionally fails with "no such file or
+ // directory" errors. See https://golang.org/issue/33041. The flake rate is
+ // fairly low, so ensure that at least 75% of attempts succeed.
+ minReadSuccesses = attempts - (attempts / 4)
+ }
+
+ if readSuccesses < minReadSuccesses {
+ t.Errorf("%d (of %d) reads succeeded; want ≥ %d", readSuccesses, attempts, minReadSuccesses)
+ } else {
+ t.Logf("%d (of %d) reads succeeded (ok: ≥ %d)", readSuccesses, attempts, minReadSuccesses)
+ }
+}
projects / dotfiles / .git / blobdiff