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// Copyright 2012 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 race
// This program is used to verify the race detector
// by running the tests and parsing their output.
// It does not check stack correctness, completeness or anything else:
// it merely verifies that if a test is expected to be racy
// then the race is detected.
package race_test
import (
"bufio"
"bytes"
"fmt"
"internal/testenv"
"io"
"log"
"math/rand"
"os"
"os/exec"
"path/filepath"
"strings"
"sync"
"sync/atomic"
"testing"
)
var (
passedTests = 0
totalTests = 0
falsePos = 0
falseNeg = 0
failingPos = 0
failingNeg = 0
failed = false
)
const (
visibleLen = 40
testPrefix = "=== RUN Test"
)
func TestRace(t *testing.T) {
testOutput, err := runTests(t)
if err != nil {
t.Fatalf("Failed to run tests: %v\n%v", err, string(testOutput))
}
reader := bufio.NewReader(bytes.NewReader(testOutput))
funcName := ""
var tsanLog []string
for {
s, err := nextLine(reader)
if err != nil {
fmt.Printf("%s\n", processLog(funcName, tsanLog))
break
}
if strings.HasPrefix(s, testPrefix) {
fmt.Printf("%s\n", processLog(funcName, tsanLog))
tsanLog = make([]string, 0, 100)
funcName = s[len(testPrefix):]
} else {
tsanLog = append(tsanLog, s)
}
}
if totalTests == 0 {
t.Fatalf("failed to parse test output")
}
fmt.Printf("\nPassed %d of %d tests (%.02f%%, %d+, %d-)\n",
passedTests, totalTests, 100*float64(passedTests)/float64(totalTests), falsePos, falseNeg)
fmt.Printf("%d expected failures (%d has not fail)\n", failingPos+failingNeg, failingNeg)
if failed {
t.Fail()
}
}
// nextLine is a wrapper around bufio.Reader.ReadString.
// It reads a line up to the next '\n' character. Error
// is non-nil if there are no lines left, and nil
// otherwise.
func nextLine(r *bufio.Reader) (string, error) {
s, err := r.ReadString('\n')
if err != nil {
if err != io.EOF {
log.Fatalf("nextLine: expected EOF, received %v", err)
}
return s, err
}
return s[:len(s)-1], nil
}
// processLog verifies whether the given ThreadSanitizer's log
// contains a race report, checks this information against
// the name of the testcase and returns the result of this
// comparison.
func processLog(testName string, tsanLog []string) string {
if !strings.HasPrefix(testName, "Race") && !strings.HasPrefix(testName, "NoRace") {
return ""
}
gotRace := false
for _, s := range tsanLog {
if strings.Contains(s, "DATA RACE") {
gotRace = true
break
}
}
failing := strings.Contains(testName, "Failing")
expRace := !strings.HasPrefix(testName, "No")
for len(testName) < visibleLen {
testName += " "
}
if expRace == gotRace {
passedTests++
totalTests++
if failing {
failed = true
failingNeg++
}
return fmt.Sprintf("%s .", testName)
}
pos := ""
if expRace {
falseNeg++
} else {
falsePos++
pos = "+"
}
if failing {
failingPos++
} else {
failed = true
}
totalTests++
return fmt.Sprintf("%s %s%s", testName, "FAILED", pos)
}
// runTests assures that the package and its dependencies is
// built with instrumentation enabled and returns the output of 'go test'
// which includes possible data race reports from ThreadSanitizer.
func runTests(t *testing.T) ([]byte, error) {
tests, err := filepath.Glob("./testdata/*_test.go")
if err != nil {
return nil, err
}
args := []string{"test", "-race", "-v"}
args = append(args, tests...)
cmd := exec.Command(testenv.GoToolPath(t), args...)
// The following flags turn off heuristics that suppress seemingly identical reports.
// It is required because the tests contain a lot of data races on the same addresses
// (the tests are simple and the memory is constantly reused).
for _, env := range os.Environ() {
if strings.HasPrefix(env, "GOMAXPROCS=") ||
strings.HasPrefix(env, "GODEBUG=") ||
strings.HasPrefix(env, "GORACE=") {
continue
}
cmd.Env = append(cmd.Env, env)
}
// We set GOMAXPROCS=1 to prevent test flakiness.
// There are two sources of flakiness:
// 1. Some tests rely on particular execution order.
// If the order is different, race does not happen at all.
// 2. Ironically, ThreadSanitizer runtime contains a logical race condition
// that can lead to false negatives if racy accesses happen literally at the same time.
// Tests used to work reliably in the good old days of GOMAXPROCS=1.
// So let's set it for now. A more reliable solution is to explicitly annotate tests
// with required execution order by means of a special "invisible" synchronization primitive
// (that's what is done for C++ ThreadSanitizer tests). This is issue #14119.
cmd.Env = append(cmd.Env,
"GOMAXPROCS=1",
"GORACE=suppress_equal_stacks=0 suppress_equal_addresses=0",
)
// There are races: we expect tests to fail and the exit code to be non-zero.
out, _ := cmd.CombinedOutput()
return out, nil
}
func TestIssue8102(t *testing.T) {
// If this compiles with -race, the test passes.
type S struct {
x interface{}
i int
}
c := make(chan int)
a := [2]*int{}
for ; ; c <- *a[S{}.i] {
if t != nil {
break
}
}
}
func TestIssue9137(t *testing.T) {
a := []string{"a"}
i := 0
a[i], a[len(a)-1], a = a[len(a)-1], "", a[:len(a)-1]
if len(a) != 0 || a[:1][0] != "" {
t.Errorf("mangled a: %q %q", a, a[:1])
}
}
func BenchmarkSyncLeak(b *testing.B) {
const (
G = 1000
S = 1000
H = 10
)
var wg sync.WaitGroup
wg.Add(G)
for g := 0; g < G; g++ {
go func() {
defer wg.Done()
hold := make([][]uint32, H)
for i := 0; i < b.N; i++ {
a := make([]uint32, S)
atomic.AddUint32(&a[rand.Intn(len(a))], 1)
hold[rand.Intn(len(hold))] = a
}
_ = hold
}()
}
wg.Wait()
}
func BenchmarkStackLeak(b *testing.B) {
done := make(chan bool, 1)
for i := 0; i < b.N; i++ {
go func() {
growStack(rand.Intn(100))
done <- true
}()
<-done
}
}
func growStack(i int) {
if i == 0 {
return
}
growStack(i - 1)
}