On Fri, May 5, 2017 at 10:51 AM, Brian Dolbec <dol...@gentoo.org> wrote:
> On Fri, 5 May 2017 02:12:53 -0700 > Zac Medico <zmed...@gentoo.org> wrote: > > > Guarantee that newly added idle_add/call_soon callbacks have an > > opportunity to execute before the event loop decides to wait on > > self._thread_condition without a timeout. This fixes a case where > > the event loop would wait on self._thread_condition indefinitely, > > even though a callback scheduled by the AsynchronousTask._async_wait > > method needed to be executed first. > > > > X-Gentoo-bug: 617550 > > X-Gentoo-bug-url: https://bugs.gentoo.org/show_bug.cgi?id=617550 > > --- > > pym/portage/util/_eventloop/EventLoop.py | 18 ++++++++++++++++-- > > 1 file changed, 16 insertions(+), 2 deletions(-) > > > > diff --git a/pym/portage/util/_eventloop/EventLoop.py > > b/pym/portage/util/_eventloop/EventLoop.py index 712838e..b7c8762 > > 100644 --- a/pym/portage/util/_eventloop/EventLoop.py > > +++ b/pym/portage/util/_eventloop/EventLoop.py > > @@ -108,6 +108,15 @@ class EventLoop(object): > > self._poll_event_handler_ids = {} > > # Increment id for each new handler. > > self._event_handler_id = 0 > > + # New call_soon callbacks must have an opportunity to > > + # execute before it's safe to wait on > > self._thread_condition > > + # without a timeout, since delaying its execution > > indefinitely > > + # could lead to a deadlock. The following attribute > > stores the > > + # event handler id of the most recently added > > call_soon callback. > > + # If this attribute has changed since the last time > > that the > > + # call_soon callbacks have been called, then it's > > not safe to > > + # wait on self._thread_condition without a timeout. > > + self._call_soon_id = 0 > > # Use OrderedDict in order to emulate the FIFO queue > > behavior # of the AbstractEventLoop.call_soon method. > > self._idle_callbacks = OrderedDict() > > @@ -250,10 +259,15 @@ class EventLoop(object): > > > > if not event_handlers: > > with self._thread_condition: > > + prev_call_soon_id = > > self._call_soon_id if self._run_timeouts(): > > events_handled += 1 > > timeouts_checked = True > > - if not event_handlers and not > > events_handled and may_block: + > > + call_soon = > > bool(prev_call_soon_id != self._call_soon_id) + > > + if (not call_soon and not > > event_handlers > > + and not events_handled and > > may_block): # Block so that we don't waste cpu time by looping too > > # quickly. This makes > > EventLoop useful for code that needs # to wait for timeout callbacks > > regardless of whether or @@ -457,7 +471,7 @@ class EventLoop(object): > > @return: an integer ID > > """ > > with self._thread_condition: > > - source_id = self._new_source_id() > > + source_id = self._call_soon_id = > > self._new_source_id() self._idle_callbacks[source_id] = > > self._idle_callback_class( args=args, callback=callback, > > source_id=source_id) self._thread_condition.notify() > > > looks good > Thanks, merged: https://gitweb.gentoo.org/proj/portage.git/commit/?id=dac5089eb7908e9fd643f46c913515082077281e -- Thanks, Zac
