On Thu, Aug 23, 2018 at 04:31:20PM +0200, Marc-André Lureau wrote: > Hi, > > In commit 25679e5d58e "chardev: tcp: postpone async connection setup" > (and its follow up 99f2f54174a59), Peter moved chardev socket > connection to machine_done event. However, chardev created later will > no longer attempt to connect, and chardev created in tests do not have > machine_done event (breaking some of vhost-user-test). > > The goal was to move the "connect" source to the chardev frontend > context (the monitor thread context in his case). chr->gcontext is set > with qemu_chr_fe_set_handlers(). But there is no guarantee that the > function will be called in general, so we can't delay connection until > then: the chardev should still attempt to connect during open(), using > the main context. > > An alternative would be to specify the iothread during chardev > creation. Setting up monitor OOB would be quite different too, it > would take the same iothread as argument. > > 99f2f54174a595e is also a bit problematic, since it will behave > differently before and after machine_done (the first case gives a > chance to use a different context reliably, the second looks racy) > > In the end, I am not sure this is all necessary, as chardev callbacks > are called after qemu_chr_fe_set_handlers(), at which point the > context of sources are updated. In "char-socket: update all ioc > handlers when changing context", I moved also the hup handler to the > updated context. So unless the main thread is already stuck, we can > setup a different context for the chardev at that time. Or not? > > v2: > - fix a random socket chardev test failure
I have no problem on patch 3-5, but aren't patch 1-2 still breaking the context switch of chardev? Or did I misunderstood? Regards, -- Peter Xu