fs: add --dump goroutines and --dump openfiles

These are developer flags useful for tracking down resource leaks.

cmd/cmd.go

@@ -10,10 +10,12 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"os/exec"
 	"path"
 	"regexp"
 	"runtime"
 	"runtime/pprof"
+	"strconv"
 	"time"
 
 	"github.com/pkg/errors"
@@ -322,6 +324,26 @@ func Run(Retry bool, showStats bool, cmd *cobra.Command, f func() error) {
 		accounting.Stats.Log()
 	}
 	fs.Debugf(nil, "%d go routines active\n", runtime.NumGoroutine())
+
+	// dump all running go-routines
+	if fs.Config.Dump&fs.DumpGoRoutines != 0 {
+		err = pprof.Lookup("goroutine").WriteTo(os.Stdout, 1)
+		if err != nil {
+			fs.Errorf(nil, "Failed to dump goroutines: %v", err)
+		}
+	}
+
+	// dump open files
+	if fs.Config.Dump&fs.DumpOpenFiles != 0 {
+		c := exec.Command("lsof", "-p", strconv.Itoa(os.Getpid()))
+		c.Stdout = os.Stdout
+		c.Stderr = os.Stderr
+		err = c.Run()
+		if err != nil {
+			fs.Errorf(nil, "Failed to list open files: %v", err)
+		}
+	}
+
 	if accounting.Stats.Errored() {
 		resolveExitCode(accounting.Stats.GetLastError())
 	}

docs/content/docs.md

@@ -953,6 +953,17 @@ only.
 Dump the filters to the output.  Useful to see exactly what include
 and exclude options are filtering on.
 
+#### --dump goroutines ####
+
+This dumps a list of the running go-routines at the end of the command
+to standard output.
+
+#### --dump openfiles ####
+
+This dumps a list of the open files at the end of the command.  It
+uses the `lsof` command to do that so you'll need that installed to
+use it.
+
 ### --memprofile=FILE ###
 
 Write memory profile to file. This can be analysed with `go tool pprof`.

fs/dump.go

@@ -18,6 +18,8 @@ const (
 	DumpResponses
 	DumpAuth
 	DumpFilters
+	DumpGoRoutines
+	DumpOpenFiles
 )
 
 var dumpFlags = []struct {
@@ -30,6 +32,8 @@ var dumpFlags = []struct {
 	{DumpResponses, "responses"},
 	{DumpAuth, "auth"},
 	{DumpFilters, "filters"},
+	{DumpGoRoutines, "goroutines"},
+	{DumpOpenFiles, "openfiles"},
 }
 
 // DumpFlagsList is a list of dump flags used in the help