#!/usr/bin/stap
#
# Copyright (C) 2011 Red Hat, Inc.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library.  If not, see
# <http://www.gnu.org/licenses/>.
#
# Author: Daniel P. Berrange <berrange@redhat.com>
#
# This script will monitor all operation of the libvirt event loop
# in both client and server. Example output is:
#
#  0.000 begin
#  2.359 18185 + handle 1 4 1
#  2.360 18185 + handle 2 6 1
#  2.360 18185 * handle 2 0
#  2.360 14370 > handle 3 1
#  2.360 14370 + handle 33 16 1
#  2.361 14370 ~ 7 -1
#  2.361 14370 > handle 33 1
#  2.361 14370 * handle 33 1
#  2.361 14370 * handle 33 1
#  2.361 14370 * handle 33 3
#  2.361 14370 ~ 7 -1
#  2.361 14370 > handle 1 1
#  2.361 14370 ~ 7 -1
#  2.361 14370 > handle 33 2
#  2.361 14370 * handle 33 1
#  2.361 14370 ~ 7 -1
#  2.361 18185 * handle 2 1
#  2.362 18185 * handle 2 0
#  2.362 14370 > handle 33 1
#  2.362 14370 * handle 33 1
#  2.362 14370 * handle 33 1
#  2.362 14370 ~ 7 -1
#  2.367 14370 * handle 33 3
#  2.367 14370 > handle 1 1
#  2.367 14370 ~ 7 -1
#  2.367 14370 > handle 33 2
#  2.367 14370 * handle 33 1
#  2.367 14370 ~ 7 -1
#  2.370 18185 - timeout 1
#  2.370 14370 ! handle 33
#  2.371 14370 - handle 33
#  2.371 14370 ~ 6 -1
#
# Legend:
#   +   Add
#   -   Remove
#   *   Update
#   >   dispatch
#   !   purge
#   ~   Iterate
#
#

# Show all updates to registered timeouts/handles
global showUpdates = 1

# Show when handles/timeouts are dispatched
global showDispatch = 1

# Show iterations of the event loop
global showIter = 1

global start

# Print a string, with a timestamp relative to the start of the script
function print_ts(msg)
{
  now = gettimeofday_ns() / (1000*1000)
  delta = (now - start)

  printf("%3d.%03d %s\n", (delta / 1000), (delta % 1000), msg);
}

probe begin {
  start = gettimeofday_ns() / (1000*1000)
  print_ts("begin");
}

probe libvirt.event_poll.add_handle {
  print_ts(sprintf("%d + handle %d %d %d", pid(), watch, fd, events));
}
probe libvirt.event_poll.remove_handle {
  print_ts(sprintf("%d - handle %d", pid(), watch));
}
probe libvirt.event_poll.update_handle {
  if (showUpdates)
    print_ts(sprintf("%d * handle %d %d", pid(), watch, events));
}
probe libvirt.event_poll.purge_handle {
  print_ts(sprintf("%d ! handle %d", pid(), watch));
}
probe libvirt.event_poll.dispatch_handle {
  if (showDispatch)
    print_ts(sprintf("%d > handle %d %d", pid(), watch, events));
}

probe libvirt.event_poll.add_timeout {
  print_ts(sprintf("%d + timeout %d %d", pid(), timer, frequency));
}
probe libvirt.event_poll.remove_timeout {
  print_ts(sprintf("%d - timeout %d", pid(), timer));
}
probe libvirt.event_poll.update_timeout {
  if (showUpdates)
    print_ts(sprintf("%d * timeout %d %d", pid(), timer, frequency));
}
probe libvirt.event_poll.purge_timeout {
  print_ts(sprintf("%d ! timeout %d", pid(), timer));
}

probe libvirt.event_poll.dispatch_timeout {
  if (showDispatch)
    print_ts(sprintf("%d > timeout %d", pid(), timer));
}

probe libvirt.event_poll.run {
  if (showIter)
    print_ts(sprintf("%d ~ %d %d", pid(), nfds, timeout));
}