Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

internal/process/process_test.go

@@ -0,0 +1,81 @@
+//go:build !windows
+
+package process
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"sync/atomic"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/influxdata/telegraf/testutil"
+)
+
+// test that a restarting process resets pipes properly
+func TestRestartingRebindsPipes(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping long running test in short mode")
+	}
+
+	exe, err := os.Executable()
+	require.NoError(t, err)
+
+	p, err := New([]string{exe, "-external"}, []string{"INTERNAL_PROCESS_MODE=application"})
+	p.RestartDelay = 100 * time.Nanosecond
+	p.Log = testutil.Logger{}
+	require.NoError(t, err)
+
+	linesRead := int64(0)
+	p.ReadStdoutFn = func(r io.Reader) {
+		scanner := bufio.NewScanner(r)
+
+		for scanner.Scan() {
+			atomic.AddInt64(&linesRead, 1)
+		}
+	}
+
+	require.NoError(t, p.Start())
+
+	for atomic.LoadInt64(&linesRead) < 1 {
+		time.Sleep(1 * time.Millisecond)
+	}
+
+	require.NoError(t, syscall.Kill(p.Pid(), syscall.SIGKILL))
+
+	for atomic.LoadInt64(&linesRead) < 2 {
+		time.Sleep(1 * time.Millisecond)
+	}
+
+	// the mainLoopWg.Wait() call p.Stop() makes takes multiple seconds to complete
+	p.Stop()
+}
+
+var external = flag.Bool("external", false,
+	"if true, run externalProcess instead of tests")
+
+func TestMain(m *testing.M) {
+	flag.Parse()
+	runMode := os.Getenv("INTERNAL_PROCESS_MODE")
+	if *external && runMode == "application" {
+		externalProcess()
+		os.Exit(0)
+	}
+	code := m.Run()
+	os.Exit(code)
+}
+
+// externalProcess is an external "misbehaving" process that won't exit
+// cleanly.
+func externalProcess() {
+	wait := make(chan int)
+	fmt.Fprintln(os.Stdout, "started")
+	<-wait
+	os.Exit(2) //nolint:revive // os.Exit called intentionally
+}