RE: Is there any way to let compositor set the data in client space and then return back to client?
Thanks pq. It is helpful for me. I will have a try with your idea. :) -Original Message- From: Pekka Paalanen [mailto:ppaala...@gmail.com] Sent: Saturday, February 08, 2014 5:56 PM To: Wang, Quanxian Cc: wayland-devel@lists.freedesktop.org Subject: Re: Is there any way to let compositor set the data in client space and then return back to client? On Sat, 8 Feb 2014 08:19:06 + Wang, Quanxian quanxian.w...@intel.com wrote: Hi, All I want to allocate some space in client, and let compositor set some data in this space and then return back to client. It seems like user data mechanism. Any way to implement that? Not really, it's nothing like user data. You have to make the client bind to a new protocol interface you designed, and then use events to pass the data to the client. If you need to pass significant amounts of data, you can use a mechanism similar to passing XKB keymaps, see wl_keyboard.keymap event. There the compositor creates the shm file. If you want the shm file created by the client, you pass the file descriptor in the other direction, similar to wl_shm.create_pool, have the server fill out the memory, and then send an event to say it's done or rely on a wl_display.sync roundtrip. Thanks, pq ___ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
RE: Is there any way to let compositor set the data in client space and then return back to client?
From: magc...@gmail.com [mailto:magc...@gmail.com] On Behalf Of Jasper St. Pierre Sent: Sunday, February 09, 2014 12:23 AM To: Wang, Quanxian Cc: wayland-devel@lists.freedesktop.org Subject: Re: Is there any way to let compositor set the data in client space and then return back to client? Well, there's not really anything that allows process A to arbitrarily modify process B's memory. The only thing that's close is memory-mapped files, and that's already what we use to share image data between the client and the compositor. There's also memfd, which is more secure than a memory-mapped tmpfile, simply because it allows sealing the fd, so you can be sure it will never change as you try to read from it. But memfd isn't a public API yet. What exactly are you trying to do here? [Wang, Quanxian] I want to create a protocol to get the output data from compositor, I don't know where to put it for client. So shared memory should be a good way to do that. Anyway, I need to check it how to make it happen. Thanks for your idea. On Sat, Feb 8, 2014 at 3:19 AM, Wang, Quanxian quanxian.w...@intel.commailto:quanxian.w...@intel.com wrote: Hi, All I want to allocate some space in client, and let compositor set some data in this space and then return back to client. It seems like user data mechanism. Any way to implement that? Thanks Regards Quanxian Wang ___ wayland-devel mailing list wayland-devel@lists.freedesktop.orgmailto:wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel -- Jasper ___ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
Is there any way to let compositor set the data in client space and then return back to client?
Hi, All I want to allocate some space in client, and let compositor set some data in this space and then return back to client. It seems like user data mechanism. Any way to implement that? Thanks Regards Quanxian Wang ___ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
Re: Is there any way to let compositor set the data in client space and then return back to client?
On Sat, 8 Feb 2014 08:19:06 + Wang, Quanxian quanxian.w...@intel.com wrote: Hi, All I want to allocate some space in client, and let compositor set some data in this space and then return back to client. It seems like user data mechanism. Any way to implement that? Not really, it's nothing like user data. You have to make the client bind to a new protocol interface you designed, and then use events to pass the data to the client. If you need to pass significant amounts of data, you can use a mechanism similar to passing XKB keymaps, see wl_keyboard.keymap event. There the compositor creates the shm file. If you want the shm file created by the client, you pass the file descriptor in the other direction, similar to wl_shm.create_pool, have the server fill out the memory, and then send an event to say it's done or rely on a wl_display.sync roundtrip. Thanks, pq ___ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
Re: Is there any way to let compositor set the data in client space and then return back to client?
Well, there's not really anything that allows process A to arbitrarily modify process B's memory. The only thing that's close is memory-mapped files, and that's already what we use to share image data between the client and the compositor. There's also memfd, which is more secure than a memory-mapped tmpfile, simply because it allows sealing the fd, so you can be sure it will never change as you try to read from it. But memfd isn't a public API yet. What exactly are you trying to do here? On Sat, Feb 8, 2014 at 3:19 AM, Wang, Quanxian quanxian.w...@intel.comwrote: Hi, All I want to allocate some space in client, and let compositor set some data in this space and then return back to client. It seems like user data mechanism. Any way to implement that? Thanks Regards Quanxian Wang ___ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel -- Jasper ___ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
