[wmii] blocking on 'wmiir read /event'

From: Chris Foster <foster_AT_physics.uq.edu.au>
Date: Tue, 20 Jun 2006 18:57:46 +1000

Hi everyone,

I'm having a very strange problem with wmiir which has got me totally
stumped.

When I start wmii, the wmiirc script sometimes fails to read any events.
For a long while I thought this was just that my changes had broken the
script (I've never had this problem with the default script), but I've
found that something as simple as replacing xterm with aterm and Mod1
with Mod4 produces the effect. Unfortunately the bug is intermittent,
and I have the feeling that the only reason I haven't seen it with the
default wmiirc is that I haven't tried running it this way enough times.

In any case, at the moment I have the system running with the problem in
evidence.

ps confirms that wmiir and wmiirc are indeed running, so I haven't done
something extremely stupid and crashed wmiirc:
$ ps -U foster | grep wmii
23659 tty2 00:00:00 wmii
23685 tty2 00:00:00 wmiiwm
23714 tty2 00:00:00 wmiirc
23713 tty2 00:00:00 wmiir

Putting some logging into wmiirc indicates that the wmiir instance in
question is the one which sends events to the event loop.

I loaded wmiir into gdb and noticed that it has blocked on the read
request at transport.c:46

(gdb) bt
#0 0x00533402 in __kernel_vsyscall ()
#1 0x001bafa3 in __read_nocancel () from /lib/libc.so.6
#2 0x0804c169 in ixp_recv_data (fd=3, msg=0x80549c0, msize=4,
    errstr=0x805086c) at transport.c:46
#3 0x0804c1d6 in ixp_recv_message (fd=3, msg=0x80549c0, msglen=8192,
    errstr=0x805086c) at transport.c:64
#4 0x08049af8 in ixp_client_do_fcall (c=0x804dbe0) at client.c:23
#5 0x0804a09e in ixp_client_read (c=0x804dbe0, fid=94852, offset=0,
    result=0x80529c0, res_len=8192) at client.c:159
#6 0x08049565 in xread (file=0xbf85c83c "/event") at wmiir.c:229
#7 0x08049940 in main (argc=3, argv=0xbf85bf64) at wmiir.c:305

Putting a breakpoint at transport.c:47 and continuing seems to indicate
that the read request really has blocked, since the breakpoint is never
reached. This is after going back to the frozen X and pounding on the
keys for a while in the hope of generating some events. On the other
hand, wmiiwm is still running fine, since I can see the status bar being
updated.

I'm running the latest snapshot at the moment:
$ wmiiwm -v
wmiiwm - 20060607, (C)opyright MMIV-MMVI Anselm R. Garbe

However, I first noticed this issue after wmii-3-rc4; I certinally had
similar symptoms when I tried using wmii-3.

Any ideas? I love wmii but this is driving me a little bit nuts.

Thanks,
~Chris.
Received on Tue Jun 20 2006 - 10:57:53 UTC

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