Date: Thu, 16 Sep 2004 18:43:26 +0000 (UTC) From: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net> To: freebsd-threads@freebsd.org Subject: assert in _lock_acquire ? Message-ID: <Pine.BSF.4.53.0409151152200.16661@e0-0.zab2.int.zabbadoz.net>
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Hi,
I am using a global mutex to serialize a longer debugging
output amongst threads. As this is only used for internal
debugging builds where I really want to see everything
I do not care about performance etc.
Recently I ran into problems with that - getting a core dump
at the same place in this debugging function. It takes some
time but I can always reproduce it.
I have seen this the last weeks with at least HEAD/ULE and since
yesterday with RELENG_5/4BSD. The first debugging log where I can
find it is dated 20040802. At that time the machine must have
been running a 5-CURRENT from around 20040625.
So I finally built libpthread with
env DEBUG_FLAGS=-g make all
and even linked with libpthread.a instead of using the shared lib.
Here's the relevant part of the backtrace:
------ cut -------
(gdb) bt full
#0 _lock_acquire (lck=0x38, lu=0x80da034, prio=56) at /u1/src/src/RELENG_5/compile-20040914-1630/lib/libpthread/sys/lock.c:168
i = 135110708
lval = 672675788
__func__ = "_lock_acquire"
#1 0x08076151 in mutex_handoff (curthread=0x80ee000, mutex=0x80d8980) at /u1/src/src/RELENG_5/compile-20040914-1630/lib/libpthread/thread/thr_mutex.c:1586
kmbx = (struct kse_mailbox *) 0x1
pthread = (struct pthread *) 0x80d7b80
#2 0x08075166 in mutex_unlock_common (m=0x8092d6c, add_reference=0) at /u1/src/src/RELENG_5/compile-20040914-1630/lib/libpthread/thread/thr_mutex.c:1026
curthread = (struct pthread *) 0x80ee000
kmbx = (struct kse_mailbox *) 0x0
ret = 0
#3 0x08074c24 in _pthread_mutex_unlock (m=0x8092d6c) at /u1/src/src/RELENG_5/compile-20040914-1630/lib/libpthread/thread/thr_mutex.c:879
No locals.
....
#9 0x0806ed84 in thread_start (curthread=0x80ee000, start_routine=0x806d62c <zzzzzz_listener_thread>, arg=0x0)
at /u1/src/src/RELENG_5/compile-20040914-1630/lib/libpthread/thread/thr_create.c:342
No locals.
#10 0x2815dcbf in _ctx_start () from /lib/libc.so.5
No symbol table info available.
------ cut -------
it seems I am running into an assert() in _lock_acquire.
does this make any sense ?
--
Bjoern A. Zeeb bzeeb at Zabbadoz dot NeT
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