On Wed, Feb 28, 2018 at 01:20:24PM +0000, Daniel P. Berrangé wrote: > On Wed, Feb 28, 2018 at 09:05:26PM +0800, Peter Xu wrote: > > On Wed, Feb 28, 2018 at 09:23:56AM +0000, Daniel P. Berrangé wrote: > > > On Wed, Feb 28, 2018 at 01:06:32PM +0800, Peter Xu wrote: > > > > This is the part of work to allow the QIOTask to use a different > > > > gcontext rather than the default main gcontext, by providing > > > > qio_task_context_set() API. > > > > > > > > We have done some work before on doing similar things to add non-default > > > > gcontext support. The general idea is that we delete the old GSource > > > > from the main context, then re-add a new one to the new context when > > > > context changed to a non-default one. However this trick won't work > > > > easily for threaded QIOTasks since we can't easily stop a real thread > > > > and re-setup the whole thing from the very beginning. > > > > > > I think this entire usage pattern is really broken. We should not > > > provide a way to change the GMainContext on an existing task. We > > > should always just set the correct GMainContxt right from the start. > > > This will avoid much of the complexity you're introducing into this > > > patch series, and avoid having to expose GTasks to the callers of > > > the async methods at all. > > > > Yeah I agree with you that the threaded QIO patches are complicated. > > Then how about I introduce: > > > > - qio_task_thread_new(): to create QIO task and its thread (but not > > running) > > - qio_task_thread_run(): to run the thread > > > > Then I can setup the context correctly between the two in some way. > > > > After that, qio_task_run_in_thread() will be two calls of above two > > APIs. > > I don't see why it is not enough to just pass the right GMainContext > into qio_task_run_in_thread() immediately. There should not be any > need to split this into two parts. ALl that's needed here is for the > completion callback to rnu in the right context, which just means > passing the GMainContext from qio_task_run_in_thread, through to > qio_task_thread_worker via QIOTaskThreadData. Changing the GMainContext > after the thread is already created/running is not something we should > try todo.
I dropped patches 9-14 in version two and rewrote as you suggested, by introducing a chardev machine done notifier. Please have a looks. Thanks, -- Peter Xu
