(* Memory info for virtual domains.
   (C) Copyright 2008 Richard W.M. Jones, Red Hat Inc.
   http://libvirt.org/

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *)

open Printf

open Virt_mem_gettext.Gettext
open Virt_mem_utils
open Virt_mem_types

open Kernel_task_struct

let run debug { domname = domname; mem = mem }
    { utsname = utsname; tasks = tasks } =
  let utsname = Option.get utsname in
  let kernel_version = utsname.kernel_release in
  let init_task_addr = Option.get tasks in

  (* Starting at init_task, navigate through the linked list of
   * tasks (through tasks.next).  The main program has already made
   * sure these are mapped into memory.
   *)
  let tasks =
    let rec loop acc task =
      let next = task.task_struct_tasks'next in
      if next <> init_task_addr then (
	let task = get_task_struct kernel_version mem next in
	let task = {
	  task with
	    task_struct_comm = truncate_c_string task.task_struct_comm
	} in
	let acc = task :: acc in
	loop acc task
      ) else
	acc
    in
    loop [] (get_task_struct kernel_version mem init_task_addr) in

  (* Sort tasks by PID. *)
  let cmp { task_struct_pid = p1 } { task_struct_pid = p2 } = compare p1 p2 in
  let tasks = List.sort cmp tasks in

  printf "  PID STAT COMMAND\n";

  List.iter (
    fun task ->
      printf "%5Ld      %s\n" task.task_struct_pid task.task_struct_comm
  ) tasks

let summary = s_"list processes in virtual machine"
let description = s_"\
virt-ps prints a process listing for virtual machines running under
libvirt."

let () =
  Virt_mem.register "ps" summary description
    ~needs_utsname:true ~needs_tasks:true ~run