Package: emacs;
Reported by: Konrad Podczeck <konrad.podczeck <at> univie.ac.at>
Date: Fri, 17 Jul 2020 15:37:02 UTC
Severity: normal
Message #51 received at 42406 <at> debbugs.gnu.org (full text, mbox):
From: Konrad Podczeck <konrad.podczeck <at> univie.ac.at> To: Alan Third <alan <at> idiocy.org> Cc: Eli Zaretskii <eliz <at> gnu.org>, 42406 <at> debbugs.gnu.org Subject: Re: bug#42406: Mouse-wheel scrolling can be flickering Date: Mon, 14 Dec 2020 01:20:39 +0100
In view of the comments made by Eli, I made a shoot in the dark, and, in window.c, commented out the occurrences of wset_update_mode_line on lines 1850, 4011, 5630, 5819, 6079, as well as the respective line after the three statements lines where "Bug#15957" is written. With these (actually I have not testes which of these (out-commentings are relevant) the problem has completely gone. I am aware that this is not a real solution, but it shows that there is some room. Which are the risks caused by these changes of the code? > Am 13.12.2020 um 20:46 schrieb Alan Third <alan <at> idiocy.org>: > > On Sun, Dec 13, 2020 at 09:05:29PM +0200, Eli Zaretskii wrote: >>> Date: Fri, 11 Dec 2020 20:37:56 +0000 >>> From: Alan Third <alan <at> idiocy.org> >>> Cc: konrad.podczeck <at> univie.ac.at, 42406 <at> debbugs.gnu.org >>> >>>> Any pointers to the code which causes all the frames to be updated in >>>> C-v/M-v case? >>> >>> I don't know. I'm looking at redisplay_internal in a debugger and I >>> can see that consider_all_windows_p is true, which will be because >>> windows_or_buffers_changed == 2 == REDISPLAY_SOME or because >>> update_mode_lines == 42. >>> >>> I can't find anywhere that sets update_mode_lines to 42... >> >> wset_update_mode_line does it, so any caller of that function would. >> >> But where do you see the value of 42 being tested? > > I've got two frames open, I set up a breakpoint in > ns_clear_under_internal_border and scroll. When I hit the breakpoint > for the frame I don't expect to be updated I get this backtrace: > > * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1 > * frame #0: 0x00000001001eb35f temacs`ns_clear_under_internal_border(f=0x000000010711cea0) at nsterm.m:3036:7 [opt] > frame #1: 0x0000000100029cd5 temacs`redisplay_internal at xdisp.c:16030:21 [opt] > frame #2: 0x00000001000cb1d5 temacs`read_char(commandflag=1, map=0x0000000107d635c3, prev_event=0x0000000000000000, used_mouse_menu=0x00007ffeefbff36b, end_time=0x0000000000000000) at keyboard.c:2496:6 [opt] > frame #3: 0x00000001000c8e72 temacs`read_key_sequence(keybuf=<unavailable>, prompt=0x0000000000000000, dont_downcase_last=<unavailable>, can_return_switch_frame=<unavailable>, fix_current_buffer=<unavailable>, prevent_redisplay=<unavailable>) at keyboard.c:9483:12 [opt] > frame #4: 0x00000001000c756c temacs`command_loop_1 at keyboard.c:1353:15 [opt] > frame #5: 0x000000010014dd17 temacs`internal_condition_case(bfun=(temacs`command_loop_1 at keyboard.c:1239), handlers=0x0000000000000090, hfun=(temacs`cmd_error at keyboard.c:922)) at eval.c:1415:25 [opt] > frame #6: 0x00000001000d7670 temacs`command_loop_2(ignore=<unavailable>) at keyboard.c:1094:11 [opt] > frame #7: 0x000000010014d53b temacs`internal_catch(tag=0x000000000000c9f0, func=(temacs`command_loop_2 at keyboard.c:1090), arg=0x0000000000000000) at eval.c:1176:25 [opt] > frame #8: 0x0000000100212935 temacs`command_loop.cold.1 + 69 > frame #9: 0x00000001000c6633 temacs`command_loop at keyboard.c:1072:2 [opt] > frame #10: 0x00000001000c6563 temacs`recursive_edit_1 at keyboard.c:720:9 [opt] > frame #11: 0x00000001000c67bb temacs`Frecursive_edit at keyboard.c:789:3 [opt] > frame #12: 0x00000001000c5343 temacs`main(argc=<unavailable>, argv=0x00007ffeefbff810) at emacs.c:2054:3 [opt] > frame #13: 0x00007fff712cd3d5 libdyld.dylib`start + 1* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1 > * frame #0: 0x00000001001eb35f temacs`ns_clear_under_internal_border(f=0x000000010711cea0) at nsterm.m:3036:7 [opt] > frame #1: 0x0000000100029cd5 temacs`redisplay_internal at xdisp.c:16030:21 [opt] > frame #2: 0x00000001000cb1d5 temacs`read_char(commandflag=1, map=0x0000000107d635c3, prev_event=0x0000000000000000, used_mouse_menu=0x00007ffeefbff36b, end_time=0x0000000000000000) at keyboard.c:2496:6 [opt] > frame #3: 0x00000001000c8e72 temacs`read_key_sequence(keybuf=<unavailable>, prompt=0x0000000000000000, dont_downcase_last=<unavailable>, can_return_switch_frame=<unavailable>, fix_current_buffer=<unavailable>, prevent_redisplay=<unavailable>) at keyboard.c:9483:12 [opt] > frame #4: 0x00000001000c756c temacs`command_loop_1 at keyboard.c:1353:15 [opt] > frame #5: 0x000000010014dd17 temacs`internal_condition_case(bfun=(temacs`command_loop_1 at keyboard.c:1239), handlers=0x0000000000000090, hfun=(temacs`cmd_error at keyboard.c:922)) at eval.c:1415:25 [opt] > frame #6: 0x00000001000d7670 temacs`command_loop_2(ignore=<unavailable>) at keyboard.c:1094:11 [opt] > frame #7: 0x000000010014d53b temacs`internal_catch(tag=0x000000000000c9f0, func=(temacs`command_loop_2 at keyboard.c:1090), arg=0x0000000000000000) at eval.c:1176:25 [opt] > frame #8: 0x0000000100212935 temacs`command_loop.cold.1 + 69 > frame #9: 0x00000001000c6633 temacs`command_loop at keyboard.c:1072:2 [opt] > frame #10: 0x00000001000c6563 temacs`recursive_edit_1 at keyboard.c:720:9 [opt] > frame #11: 0x00000001000c67bb temacs`Frecursive_edit at keyboard.c:789:3 [opt] > frame #12: 0x00000001000c5343 temacs`main(argc=<unavailable>, argv=0x00007ffeefbff810) at emacs.c:2054:3 [opt] > frame #13: 0x00007fff712cd3d5 libdyld.dylib`start + 1 > > Which I've not found very useful. I had a look at redisplay_internal > to see if I could work out why the frame is being updated, but I > can't. > > I looked at some of the variables in redisplay_internal that are > involved in making the decision whether to check all frames: > > (lldb) p update_mode_lines; > (int) $0 = 42 > (lldb) p windows_or_buffers_changed > (int) $1 = 2 > > but I have no idea if this is useful at all. > > Is there anything specific you'd like me to check? > -- > Alan Third
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