__lll_mutex_lock_wait ()

[Mani]

Hi,
I am having an issue with a C++ application pegging CPU on a RedHat AS3.0
box. I did a gdb on the process and the trace is given below.

#0 0xb6f2c241 in __lll_mutex_lock_wait () from /lib/tls/libc.so.6
#1 0xb6eb7e64 in _L_mutex_lock_2507 () from /lib/tls/libc.so.6
#2 0x0820f5b0 in ?? ()
#3 0xafdcd538 in ?? ()
#4 0xb6e3c7fc in ?? () from /usr/lib/libstdc++.so.5
#5 0x0820f520 in ?? ()
#6 0x0820f5b0 in ?? ()
#7 0xafdcd538 in ?? ()
#8 0xb6e1a263 in operator delete () from /usr/lib/libstdc++.so.5

In the code I am doing a delete on a pointer. Don't know why should it hang
on some mutex? Also why should hang result in CPU being pegged.

Will be gateful to any help.

Thanks,
Mani.

[Thomas Maier-Komor]

Mani wrote:

Hi,
I am having an issue with a C++ application pegging CPU on a RedHat AS3.0
box. I did a gdb on the process and the trace is given below.

#0 0xb6f2c241 in __lll_mutex_lock_wait () from /lib/tls/libc.so.6
#1 0xb6eb7e64 in _L_mutex_lock_2507 () from /lib/tls/libc.so.6
#2 0x0820f5b0 in ?? ()
#3 0xafdcd538 in ?? ()
#4 0xb6e3c7fc in ?? () from /usr/lib/libstdc++.so.5
#5 0x0820f520 in ?? ()
#6 0x0820f5b0 in ?? ()
#7 0xafdcd538 in ?? ()
#8 0xb6e1a263 in operator delete () from /usr/lib/libstdc++.so.5

In the code I am doing a delete on a pointer. Don't know why should it hang
on some mutex? Also why should hang result in CPU being pegged.

Will be gateful to any help.

Thanks,
Mani.

looks like a corrupted heap as a result of a memory management
error. This is usually caused by calling delete on a single object
multiple times or by writing past the end of an allocated memory
block... I suggest using valgrind to find the offending lines of
code.

Tom

[Paul Pluzhnikov]

Thomas Maier-Komor <ma******@lpr.e-technik.no-spam.tu-muenchen.de> writes:

Mani wrote:

I am having an issue with a C++ application pegging CPU on a RedHat AS3.0
box. I did a gdb on the process and the trace is given below.
#0 0xb6f2c241 in __lll_mutex_lock_wait () from /lib/tls/libc.so.6
#1 0xb6eb7e64 in _L_mutex_lock_2507 () from /lib/tls/libc.so.6 .... In the code I am doing a delete on a pointer. Don't know why should
it hang on some mutex? Also why should hang result in CPU being pegged.

The most likely reason is that the heap mutex that free() is trying
to lock is corrupt.

The most likely reason for that is calling async-signal-unsafe
functions (such as malloc or printf) from a signal handler.

Does your app handle any signals?
looks like a corrupted heap as a result of a memory management
error.
No, it doesn't look anything like that.
I suggest using valgrind to find the offending lines of code.

This suggestion is still good though.

[This has nothing to do with comp.lang.c++. Follow-to set]

Cheers,
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