CPU leak in ringboard-egui

[vi]

Idling ringboard-egui consumes considerable CPU time.

strace shows significant syscall activity:

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 23.78    0.014925           4      3704      1589 recvmsg
 22.49    0.014117           3      4161           poll
 21.02    0.013197           4      2706        10 ioctl
 17.38    0.010912           5      2142           writev
  3.35    0.002101           2       918           getpid
  2.95    0.001854           7       258           epoll_wait
  2.94    0.001848           3       516           epoll_ctl
  2.69    0.001691           4       411       258 read
  1.85    0.001159           3       307           write
  1.49    0.000935           3       258           timerfd_settime
  0.06    0.000036          18         2           mmap
  0.00    0.000000           0         2           munmap
------ ----------- ----------- --------- --------- ----------------
100.00    0.062775           4     15385      1857 total

When inactive, I expected it to just wait on read from inotify for the trigger file, not poll something again and again.

[SUPERCILEX]

Ah yeah that's a known bug somewhere in winit/x11 I think. What's your DE echo $XDG_CURRENT_DESKTOP? You can avoid the bug by running XDG_CURRENT_DESKTOP=i3 cargo +nightly install clipboard-history-egui --no-default-features --features $XDG_SESSION_TYPE --force which compiles out the problematic code:

clipboard-history/egui/src/main.rs

Line 412 in e5db6e8

ctx.send_viewport_cmd(ViewportCommand::Visible(false));

[vi]

Desktop is i3, but XDG_CURRENT_DESKTOP is typically empty.

Setting it to i3 for ringboard-egui does not seem to change things - still constant 1% cpu and the same syscalls.

[SUPERCILEX]

Did you killall ringboard-egui? Won't have picked up the change otherwise.

[SUPERCILEX]

See 1b3cdd8

[vi]

Built from commit 1b3cdd8.

With RINGBOARD_NO_DAEMON, the process exits when I close the window.

But without RINGBOARD_NO_DAEMON (i.e. the default mode), it still consumes CPU. Activity displayed by strace surge when I move mouse.

$ pgrep ringboard-egui
5640

(without mouse moving):
$ timelimit -t 5 strace -cfp 5640
...
(15 threads attached. Why so many?)
...
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 23.59    0.003482           3      1020       440 recvmsg
 21.89    0.003231           4       674         1 ioctl
 19.97    0.002948           2      1139           poll
 16.35    0.002413           4       588           writev
  3.81    0.000563           2       252           getpid
  3.74    0.000552           3       147           epoll_ctl
  3.51    0.000518           7        73           epoll_wait
  3.14    0.000464           4       115        73 read
  1.97    0.000291           3        74           timerfd_settime
  1.92    0.000283           3        84           write
  0.10    0.000015          15         1           munmap
------ ----------- ----------- --------- --------- ----------------
100.00    0.014760           3      4167       514 total

(now with moving mouse:)
$ timelimit -t 5 strace -cfp 5640
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 26.50    0.032734           3      9336           poll
 25.82    0.031889           4      7719      2350 recvmsg
 20.89    0.025802           5      4884         2 ioctl
 15.43    0.019059           4      4222           writev
  4.07    0.005029           2      1852           write
  3.38    0.004170           2      1808           getpid
  1.24    0.001530           2       602       301 read
  1.21    0.001500           2       602           epoll_ctl
  0.73    0.000899           2       301           timerfd_settime
  0.69    0.000847           2       301           epoll_wait
  0.03    0.000038          38         1           mmap
  0.01    0.000012          12         1           munmap
------ ----------- ----------- --------- --------- ----------------
100.00    0.123509           3     31629      2653 total

$ tr '\0' '\n' < /proc/5640/environ | rg XDG
XDG_CURRENT_DESKTOP=i3

Note that XDG_CURRENT_DESKTOP is only set specifically for ringboard-egui, not e.g. for rustc that was compiling ringboard-egui, so option_env!("XDG_CURRENT_DESKTOP") is likely None.

[SUPERCILEX]

Ah well yeah you need actually have XDG_CURRENT_DESKTOP set by the time you compile.