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      1 // Copyright 2012 The Go Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style
      3 // license that can be found in the LICENSE file.
      4 
      5 // +build darwin dragonfly freebsd linux netbsd openbsd solaris
      6 
      7 package runtime_test
      8 
      9 import (
     10 	"bytes"
     11 	"internal/testenv"
     12 	"io/ioutil"
     13 	"os"
     14 	"os/exec"
     15 	"path/filepath"
     16 	"runtime"
     17 	"syscall"
     18 	"testing"
     19 )
     20 
     21 func TestCrashDumpsAllThreads(t *testing.T) {
     22 	switch runtime.GOOS {
     23 	case "darwin", "dragonfly", "freebsd", "linux", "netbsd", "openbsd", "solaris":
     24 	default:
     25 		t.Skipf("skipping; not supported on %v", runtime.GOOS)
     26 	}
     27 
     28 	// We don't use executeTest because we need to kill the
     29 	// program while it is running.
     30 
     31 	testenv.MustHaveGoBuild(t)
     32 
     33 	checkStaleRuntime(t)
     34 
     35 	dir, err := ioutil.TempDir("", "go-build")
     36 	if err != nil {
     37 		t.Fatalf("failed to create temp directory: %v", err)
     38 	}
     39 	defer os.RemoveAll(dir)
     40 
     41 	if err := ioutil.WriteFile(filepath.Join(dir, "main.go"), []byte(crashDumpsAllThreadsSource), 0666); err != nil {
     42 		t.Fatalf("failed to create Go file: %v", err)
     43 	}
     44 
     45 	cmd := exec.Command("go", "build", "-o", "a.exe")
     46 	cmd.Dir = dir
     47 	out, err := testEnv(cmd).CombinedOutput()
     48 	if err != nil {
     49 		t.Fatalf("building source: %v\n%s", err, out)
     50 	}
     51 
     52 	cmd = exec.Command(filepath.Join(dir, "a.exe"))
     53 	cmd = testEnv(cmd)
     54 	cmd.Env = append(cmd.Env, "GOTRACEBACK=crash")
     55 	var outbuf bytes.Buffer
     56 	cmd.Stdout = &outbuf
     57 	cmd.Stderr = &outbuf
     58 
     59 	rp, wp, err := os.Pipe()
     60 	if err != nil {
     61 		t.Fatal(err)
     62 	}
     63 	cmd.ExtraFiles = []*os.File{wp}
     64 
     65 	if err := cmd.Start(); err != nil {
     66 		t.Fatalf("starting program: %v", err)
     67 	}
     68 
     69 	if err := wp.Close(); err != nil {
     70 		t.Logf("closing write pipe: %v", err)
     71 	}
     72 	if _, err := rp.Read(make([]byte, 1)); err != nil {
     73 		t.Fatalf("reading from pipe: %v", err)
     74 	}
     75 
     76 	if err := cmd.Process.Signal(syscall.SIGQUIT); err != nil {
     77 		t.Fatalf("signal: %v", err)
     78 	}
     79 
     80 	// No point in checking the error return from Wait--we expect
     81 	// it to fail.
     82 	cmd.Wait()
     83 
     84 	// We want to see a stack trace for each thread.
     85 	// Before https://golang.org/cl/2811 running threads would say
     86 	// "goroutine running on other thread; stack unavailable".
     87 	out = outbuf.Bytes()
     88 	n := bytes.Count(out, []byte("main.loop("))
     89 	if n != 4 {
     90 		t.Errorf("found %d instances of main.loop; expected 4", n)
     91 		t.Logf("%s", out)
     92 	}
     93 }
     94 
     95 const crashDumpsAllThreadsSource = `
     96 package main
     97 
     98 import (
     99 	"fmt"
    100 	"os"
    101 	"runtime"
    102 )
    103 
    104 func main() {
    105 	const count = 4
    106 	runtime.GOMAXPROCS(count + 1)
    107 
    108 	chans := make([]chan bool, count)
    109 	for i := range chans {
    110 		chans[i] = make(chan bool)
    111 		go loop(i, chans[i])
    112 	}
    113 
    114 	// Wait for all the goroutines to start executing.
    115 	for _, c := range chans {
    116 		<-c
    117 	}
    118 
    119 	// Tell our parent that all the goroutines are executing.
    120 	if _, err := os.NewFile(3, "pipe").WriteString("x"); err != nil {
    121 		fmt.Fprintf(os.Stderr, "write to pipe failed: %v\n", err)
    122 		os.Exit(2)
    123 	}
    124 
    125 	select {}
    126 }
    127 
    128 func loop(i int, c chan bool) {
    129 	close(c)
    130 	for {
    131 		for j := 0; j < 0x7fffffff; j++ {
    132 		}
    133 	}
    134 }
    135 `
    136