virt-manager/virtManager/asyncjob.py
Cole Robinson 6869760732 asyncjob: Fix issues with multiple dialogs (bz 1003101)
Basically, drop usage of nested main loops. As has been documented in
other commit messages, we use nested main loops in ways they aren't
supposed to be used. They gave us async behavior that would block
callers, but had weird behavior in some edge cases.

Switch to having async dialogs be 100% async, requiring the user to
pass in a completion callback which is triggered after the async
action is complete.
2013-09-06 21:30:19 -04:00

364 lines
11 KiB
Python

#
# Copyright (C) 2006 Red Hat, Inc.
# Copyright (C) 2006 Hugh O. Brock <hbrock@redhat.com>
#
# 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., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301 USA.
#
import logging
import threading
import traceback
# pylint: disable=E0611
from gi.repository import Gdk
from gi.repository import GLib
from gi.repository import Gtk
# pylint: enable=E0611
import libvirt
import urlgrabber
from virtManager.baseclass import vmmGObjectUI
class vmmMeter(urlgrabber.progress.BaseMeter):
def __init__(self, cb_pulse, cb_fraction, cb_done):
urlgrabber.progress.BaseMeter.__init__(self)
self.started = False
self._vmm_pulse = cb_pulse
self._vmm_fraction = cb_fraction
self._vmm_done = cb_done
def _do_start(self, now=None):
if self.text is not None:
text = self.text
else:
text = self.basename
if self.size is None:
out = " %5sB" % (0)
self._vmm_pulse(out, text)
else:
out = "%3i%% %5sB" % (0, 0)
self._vmm_fraction(0, out, text)
self.started = True
def _do_update(self, amount_read, now=None):
if self.text is not None:
text = self.text
else:
text = self.basename
fread = urlgrabber.progress.format_number(amount_read)
if self.size is None:
out = " %5sB" % (fread)
self._vmm_pulse(out, text)
else:
frac = self.re.fraction_read()
out = "%3i%% %5sB" % (frac * 100, fread)
self._vmm_fraction(frac, out, text)
def _do_end(self, amount_read, now=None):
if self.text is not None:
text = self.text
else:
text = self.basename
fread = urlgrabber.progress.format_number(amount_read)
if self.size is None:
out = " %5sB" % (fread)
self._vmm_pulse(out, text)
else:
out = "%3i%% %5sB" % (100, fread)
self._vmm_done(out, text)
self.started = False
def cb_wrapper(callback, asyncjob, *args, **kwargs):
try:
callback(asyncjob, *args, **kwargs)
except Exception, e:
# If job is cancelled, don't report error to user.
if (isinstance(e, libvirt.libvirtError) and
asyncjob.can_cancel() and
asyncjob.job_canceled):
return
asyncjob.set_error(str(e), "".join(traceback.format_exc()))
def _simple_async_done_cb(error, details, errorintro,
errorcb, parent, finish_cb):
if error:
if errorcb:
errorcb(error, details)
else:
error = errorintro + ": " + error
parent.err.show_err(error,
details=details)
if finish_cb:
finish_cb()
def _simple_async(callback, args, title, text, parent, errorintro,
show_progress, simplecb, errorcb, finish_cb):
"""
@show_progress: Whether to actually show a progress dialog
@simplecb: If true, build a callback wrapper that ignores the asyncjob
param that's passed to every cb by default
"""
docb = callback
if simplecb:
def tmpcb(job, *args, **kwargs):
ignore = job
callback(*args, **kwargs)
docb = tmpcb
asyncjob = vmmAsyncJob(docb, args,
_simple_async_done_cb,
(errorintro, errorcb, parent, finish_cb),
title, text, parent.topwin,
show_progress=show_progress)
asyncjob.run()
def idle_wrapper(fn):
def wrapped(self, *args, **kwargs):
return self.idle_add(fn, self, *args, **kwargs)
return wrapped
class vmmAsyncJob(vmmGObjectUI):
"""
Displays a progress bar while executing the "callback" method.
"""
@staticmethod
def simple_async(callback, args, title, text, parent, errorintro,
simplecb=True, errorcb=None, finish_cb=None):
_simple_async(callback, args,
title, text, parent, errorintro, True,
simplecb, errorcb, finish_cb)
@staticmethod
def simple_async_noshow(callback, args, parent, errorintro,
simplecb=True, errorcb=None, finish_cb=None):
_simple_async(callback, args,
"", "", parent, errorintro, False,
simplecb, errorcb, finish_cb)
def __init__(self,
callback, args, finish_cb, finish_args,
title, text, parent,
show_progress=True, cancel_cb=None):
"""
@show_progress: If False, don't actually show a progress dialog
@cancel_cb: Cancel callback if operation supports it.
(cb, arg1, arg2, ...)
"""
vmmGObjectUI.__init__(self, "vmm-progress.ui", "vmm-progress")
self.topwin.set_transient_for(parent)
self.show_progress = bool(show_progress)
cancel_cb = cancel_cb or (None, [])
self.cancel_cb = cancel_cb[0]
self.cancel_args = [self] + list(cancel_cb[1:])
self.job_canceled = False
self._finish_cb = finish_cb
self._finish_args = finish_args or ()
self._timer = None
self._error_info = None
self._data = None
self._is_pulsing = True
self._meter = None
self._bg_thread = threading.Thread(target=cb_wrapper,
args=[callback, self] + args)
self._bg_thread.daemon = True
logging.debug("Creating async job for function cb=%s", callback)
self.builder.connect_signals({
"on_async_job_delete_event" : self._on_window_delete,
"on_async_job_cancel_clicked" : self._on_cancel,
})
# UI state
self.topwin.set_title(title)
self.widget("pbar-text").set_text(text)
self.widget("cancel-async-job").set_visible(bool(self.cancel_cb))
####################
# Internal helpers #
####################
def _cleanup(self):
self._bg_thread = None
self.cancel_cb = None
self.cancel_args = None
self._meter = None
def _set_stage_text(self, text, canceling=False):
# This should be thread safe, since it's only ever called from
# pbar idle callbacks and cancel routine which is invoked from the
# main thread
if self.job_canceled and not canceling:
return
self.widget("pbar-stage").set_text(text)
def _hide_warning(self):
self.widget("warning-box").hide()
################
# UI listeners #
################
def _on_window_delete(self, ignore1=None, ignore2=None):
if not self.cancel_cb or not self._bg_thread.is_alive():
logging.debug("User closed progress window, but thread "
"still running and process isn't cancellable, "
"ignoring.")
return 1
res = self.err.warn_chkbox(
text1=_("Cancel the job?"),
buttons=Gtk.ButtonsType.YES_NO)
if not res:
logging.debug("User closed progress window, but chose not "
"cancel operation, ignoring.")
return 1
self._on_cancel()
def _on_cancel(self, ignore1=None, ignore2=None):
if not self.cancel_cb or not self._bg_thread.is_alive():
return
self.cancel_cb(*self.cancel_args)
if self.job_canceled:
self._hide_warning()
self._set_stage_text(_("Cancelling job..."), canceling=True)
##############
# Public API #
##############
def get_meter(self):
if not self._meter:
self._meter = vmmMeter(self._pbar_pulse,
self._pbar_fraction,
self._pbar_done)
return self._meter
def set_error(self, error, details):
self._error_info = (error, details)
def set_extra_data(self, data):
self._data = data
def get_extra_data(self):
return self._data
def can_cancel(self):
return bool(self.cancel_cb)
def show_warning(self, summary):
# This should only be called from cancel callbacks, not a the thread
markup = "<small>%s</small>" % summary
self.widget("warning-box").show()
self.widget("warning-text").set_markup(markup)
def _thread_finished(self):
GLib.source_remove(self._timer)
self.topwin.destroy()
self.cleanup()
error = None
details = None
if self._error_info:
error, details = self._error_info
self._finish_cb(error, details, *self._finish_args)
def run(self):
self._timer = GLib.timeout_add(100, self._exit_if_necessary)
if self.show_progress:
self.topwin.present()
if not self.cancel_cb and self.show_progress:
self.topwin.get_window().set_cursor(
Gdk.Cursor.new(Gdk.CursorType.WATCH))
self._bg_thread.start()
####################################################################
# All functions after this point are called from the timer loop or #
# the worker thread, so anything that touches Gtk needs to be #
# dispatches with idle_add #
####################################################################
def _exit_if_necessary(self):
if not self._bg_thread.is_alive():
self._thread_finished()
return False
if not self._is_pulsing or not self.show_progress:
return True
self._pbar_do_pulse()
return True
@idle_wrapper
def _pbar_do_pulse(self):
if not self.builder:
return
self.widget("pbar").pulse()
@idle_wrapper
def _pbar_pulse(self, progress="", stage=None):
self._is_pulsing = True
if not self.builder:
return
self.widget("pbar").set_text(progress)
self._set_stage_text(stage or _("Processing..."))
@idle_wrapper
def _pbar_fraction(self, frac, progress, stage=None):
self._is_pulsing = False
if not self.builder:
return
self._set_stage_text(stage or _("Processing..."))
self.widget("pbar").set_text(progress)
if frac > 1:
frac = 1.0
if frac < 0:
frac = 0
self.widget("pbar").set_fraction(frac)
@idle_wrapper
def _pbar_done(self, progress, stage=None):
self._is_pulsing = False
if not self.builder:
return
self._set_stage_text(stage or _("Completed"))
self.widget("pbar").set_text(progress)
self.widget("pbar").set_fraction(1)