Re: [libvirt] [PATCH v2 2/2] Add asyncio event loop implementation

+class Callback(object): + '''Base class for holding callback + + :param virEventAsyncIOImpl impl: the implementation in which we run + :param cb: the callback itself + :param opaque: the opaque tuple passed by libvirt + ''' + # pylint: disable=too-few-public-methods + + _iden_counter = itertools.count() + + def __init__(self, impl, cb, opaque, *args, **kwargs): + super().__init__(*args, **kwargs) + self.iden = next(self._iden_counter) + self.impl = impl + self.cb = cb + self.opaque = opaque + + assert self.iden not in self.impl.callbacks, \ + 'found {} callback: {!r}'.format( + self.iden, self.impl.callbacks[self.iden]) + self.impl.callbacks[self.iden] = self + + def __repr__(self): + return '<{} iden={}>'.format(self.__clas__.__name__, self.iden)

+class TimeoutCallback(Callback): + '''Callback for timer''' + def __init__(self, *args, timeout, **kwargs): + super().__init__(*args, **kwargs) + self.timeout = timeout + self._task = None + + def __repr__(self): + return '<{} iden={} timeout={}>'.format( + self.__class__.__name__, self.iden, self.timeout) + + @asyncio.coroutine + def _timer(self): + '''An actual timer running on the event loop. + + This is a coroutine. + ''' + while True: + assert self.timeout >= 0, \ + 'invalid timeout {} for running timer'.format(self.timeout)

+ + try: + if self.timeout > 0: + timeout = self.timeout * 1e-3 + self.impl.log.debug('sleeping %r', timeout) + yield from asyncio.sleep(timeout) + else: + # scheduling timeout for next loop iteration + yield + + except asyncio.CancelledError: + self.impl.log.debug('timer %d cancelled', self.iden) + break + + self.cb(self.iden, self.opaque) + self.impl.log.debug('timer %r callback ended', self.iden) + + def update(self, *, timeout=None): + '''Start or the timer, possibly updating timeout''' + if timeout is not None: + self.timeout = timeout +

+ if self.timeout >= 0 and self._task is None: + self.impl.log.debug('timer %r start', self.iden) + self._task = ensure_future(self._timer(), + loop=self.impl.loop) + + elif self.timeout < 0 and self._task is not None: + self.impl.log.debug('timer %r stop', self.iden) + self._task.cancel() # pylint: disable=no-member + self._task = None + + def close(self): + '''Stop the timer and call ff callback''' + self.timeout = -1 + self.update() + super().close()

diff --git a/setup.py b/setup.py index 120ddd5..bac9010 100755 --- a/setup.py +++ b/setup.py @@ -14,6 +14,7 @@ import sys import os import os.path import re +import shutil import time MIN_LIBVIRT = "0.9.11" @@ -50,6 +51,12 @@ def have_libvirt_lxc(): except DistutilsExecError: return False +def have_libvirtaio(): + # This depends on asyncio, which in turn depends on "yield from" syntax. + # The asyncio module itself is in standard library since 3.4, but there is + # an out-of-tree version compatible with 3.3. + return sys.version_info >= (3, 3) + def get_pkgconfig_data(args, mod, required=True): """Run pkg-config to and return content associated with it""" f = os.popen("%s %s %s" % (get_pkgcfg(), " ".join(args), mod)) @@ -124,6 +131,9 @@ def get_module_lists(): c_modules.append(modulelxc) py_modules.append("libvirt_lxc") + if have_libvirtaio(): + py_modules.append("libvirtaio") + return c_modules, py_modules @@ -141,6 +151,8 @@ class my_build(build): self.spawn([sys.executable, "generator.py", "libvirt-qemu", apis[1]]) if have_libvirt_lxc(): self.spawn([sys.executable, "generator.py", "libvirt-lxc", apis[2]]) + if have_libvirtaio(): + shutil.copy('libvirtaio.py', 'build') build.run(self)