database locked occasionally

[Alsan]

I'm trying to write a program to auto tag my collections. It'll call the tmsu through shell execution, then combining fd to loop through all files in my collections. It worked as expected, except the tmsu returns database locked error occasionally.

Here's my program fragment:

func runCommand(filename string, command string, ch chan output) {
  // fmt.Println(cmd)
  fields := strings.Fields(command)
  cmd := exec.Command(fields[0], fields[1:]...)
  out, err := cmd.CombinedOutput()
  ch <- output{out, err}
}

...

ch := make(chan output)
go runCommand(fn, cmd, ch)

select {
case <-time.After(2 * time.Second):
  errs.PrintToStdErrAndExit(fmt.Sprintf("timeout: %s", cmd))
case x := <-ch:
  if x.err != nil {
    errs.PrintToStdErrAndExit(fmt.Sprintf("error: %s", string(x.out)))
  } else {
    fmt.Println(fn)
  }
}

Any suggestion on optimizing the program?