runtime: don't run TestCrashDumpsAllThreads in parallel

It sometimes seems to time out on slow systems, perhaps due to
being run at the same time as a lot of other work.

Also move the code to testdata/testprog, so that we don't have to
build it separately.

I hope that this
Fixes #35356

Change-Id: I875b858fa23836513ae14d3116461e22fffd5352
Reviewed-on: https://go-review.googlesource.com/c/go/+/312510
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>

diff --git a/src/runtime/crash_unix_test.go b/src/runtime/crash_unix_test.go
index b5cc910ad1fb9f0cbfcd879c8e956068897a9367..9469d5e6a649508fe09fc5e1e32e68c52c6c44a7 100644 (file)
--- a/src/runtime/crash_unix_test.go
+++ b/src/runtime/crash_unix_test.go
@@ -13,7 +13,6 @@ import (
        "io"
        "os"
        "os/exec"
-       "path/filepath"
        "runtime"
        "strings"
        "sync"
@@ -78,27 +77,14 @@ func TestCrashDumpsAllThreads(t *testing.T) {
                t.Skip("skipping; SIGQUIT is blocked, see golang.org/issue/19196")
        }
 
-       // We don't use executeTest because we need to kill the
-       // program while it is running.
-
        testenv.MustHaveGoBuild(t)
 
-       t.Parallel()
-
-       dir := t.TempDir()
-
-       if err := os.WriteFile(filepath.Join(dir, "main.go"), []byte(crashDumpsAllThreadsSource), 0666); err != nil {
-               t.Fatalf("failed to create Go file: %v", err)
-       }
-
-       cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
-       cmd.Dir = dir
-       out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
+       exe, err := buildTestProg(t, "testprog")
        if err != nil {
-               t.Fatalf("building source: %v\n%s", err, out)
+               t.Fatal(err)
        }
 
-       cmd = exec.Command(filepath.Join(dir, "a.exe"))
+       cmd := exec.Command(exe, "CrashDumpsAllThreads")
        cmd = testenv.CleanCmdEnv(cmd)
        cmd.Env = append(cmd.Env,
                "GOTRACEBACK=crash",
@@ -120,9 +106,12 @@ func TestCrashDumpsAllThreads(t *testing.T) {
        if err != nil {
                t.Fatal(err)
        }
+       defer rp.Close()
+
        cmd.ExtraFiles = []*os.File{wp}
 
        if err := cmd.Start(); err != nil {
+               wp.Close()
                t.Fatalf("starting program: %v", err)
        }
 
@@ -144,56 +133,14 @@ func TestCrashDumpsAllThreads(t *testing.T) {
        // We want to see a stack trace for each thread.
        // Before https://golang.org/cl/2811 running threads would say
        // "goroutine running on other thread; stack unavailable".
-       out = outbuf.Bytes()
-       n := bytes.Count(out, []byte("main.loop("))
+       out := outbuf.Bytes()
+       n := bytes.Count(out, []byte("main.crashDumpsAllThreadsLoop("))
        if n != 4 {
                t.Errorf("found %d instances of main.loop; expected 4", n)
                t.Logf("%s", out)
        }
 }
 
-const crashDumpsAllThreadsSource = `
-package main
-
-import (
-       "fmt"
-       "os"
-       "runtime"
-)
-
-func main() {
-       const count = 4
-       runtime.GOMAXPROCS(count + 1)
-
-       chans := make([]chan bool, count)
-       for i := range chans {
-               chans[i] = make(chan bool)
-               go loop(i, chans[i])
-       }
-
-       // Wait for all the goroutines to start executing.
-       for _, c := range chans {
-               <-c
-       }
-
-       // Tell our parent that all the goroutines are executing.
-       if _, err := os.NewFile(3, "pipe").WriteString("x"); err != nil {
-               fmt.Fprintf(os.Stderr, "write to pipe failed: %v\n", err)
-               os.Exit(2)
-       }
-
-       select {}
-}
-
-func loop(i int, c chan bool) {
-       close(c)
-       for {
-               for j := 0; j < 0x7fffffff; j++ {
-               }
-       }
-}
-`
-
 func TestPanicSystemstack(t *testing.T) {
        // Test that GOTRACEBACK=crash prints both the system and user
        // stack of other threads.

diff --git a/src/runtime/testdata/testprog/crashdump.go b/src/runtime/testdata/testprog/crashdump.go
new file mode 100644 (file)
index 0000000..bced397
--- /dev/null
+++ b/src/runtime/testdata/testprog/crashdump.go
@@ -0,0 +1,47 @@
+// Copyright 2021 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 main
+
+import (
+       "fmt"
+       "os"
+       "runtime"
+)
+
+func init() {
+       register("CrashDumpsAllThreads", CrashDumpsAllThreads)
+}
+
+func CrashDumpsAllThreads() {
+       const count = 4
+       runtime.GOMAXPROCS(count + 1)
+
+       chans := make([]chan bool, count)
+       for i := range chans {
+               chans[i] = make(chan bool)
+               go crashDumpsAllThreadsLoop(i, chans[i])
+       }
+
+       // Wait for all the goroutines to start executing.
+       for _, c := range chans {
+               <-c
+       }
+
+       // Tell our parent that all the goroutines are executing.
+       if _, err := os.NewFile(3, "pipe").WriteString("x"); err != nil {
+               fmt.Fprintf(os.Stderr, "write to pipe failed: %v\n", err)
+               os.Exit(2)
+       }
+
+       select {}
+}
+
+func crashDumpsAllThreadsLoop(i int, c chan bool) {
+       close(c)
+       for {
+               for j := 0; j < 0x7fffffff; j++ {
+               }
+       }
+}