This is only a problem across different compilation units.  Within the same
compilation unit construction order is defined as the order they're defined
in that unit.

Josh

On Tue, Nov 9, 2010 at 6:47 PM, Mrinal Kalakrishnan <mail@mrinal.net> wrote:

> I think that my problem could indeed be a rosconsole bug.
>
> There are two global variables in rosconsole.cpp (among others):
>
>    boost::mutex g_init_mutex;
>
> and
>
>    StaticInit g_static_init;
>
> Unfortunately the constructor of g_static_init depends on g_init_mutex
> being initialized, because it attempts to lock the mutex. But I
> believe the order of construction of global variables can never be
> guaranteed, so the mutex could get locked before it is initialized.
>
> I'm not able to think of a thread-safe way to get around this yet.
> I'll ticket this if someone can confirm that it's a bug.
>
> - Mrinal
>
> On Tue, Nov 9, 2010 at 3:43 PM, Mrinal Kalakrishnan <mail@mrinal.net>
> wrote:
> > Hello,
> >
> > I have a strange problem when linking a ROS application with Xenomai.
> > It appears that the constructor for some global objects of rosconsole
> > is waiting on a mutex (g_init_mutex). Here is the gdb backtrace when I
> > kill the hanging program:
> >
> > #0  __lll_lock_wait ()
> >    at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:136
> > #1  0x00007ffff49de295 in _L_lock_949 () from /lib/libpthread.so.0
> > #2  0x00007ffff49de0b8 in __pthread_mutex_lock (mutex=0x7ffff6304580)
> >    at pthread_mutex_lock.c:61
> > #3  0x00007ffff60f384a in boost::mutex::lock ()
> >    at /usr/include/boost/thread/pthread/mutex.hpp:50
> > #4  boost::unique_lock<boost::mutex>::lock ()
> >    at /usr/include/boost/thread/locks.hpp:338
> > #5  unique_lock () at /usr/include/boost/thread/locks.hpp:224
> > #6  ros::console::initialize ()
> >    at
> /tmp/buildd/ros-cturtle-ros-1.2.4/debian/ros-cturtle-ros/opt/ros/cturtle/ros/core/rosconsole/src/rosconsole/rosconsole.cpp:426
> > #7  0x00007ffff60fc8d6 in __do_global_ctors_aux ()
> >   from /opt/ros/cturtle/ros/core/rosconsole/lib/librosconsole.so
> > #8  0x00007ffff60ef803 in _init ()
> >   from /opt/ros/cturtle/ros/core/rosconsole/lib/librosconsole.so
> > #9  0x00007fffffffe2d8 in ?? ()
> > #10 0x00007ffff7ded6e9 in call_init (l=0x7ffff7fda510, argc=-164616432,
> >    argv=0x7fffffffe2c8, env=0x7fffffffe2d8) at dl-init.c:70
> > #11 0x00007ffff7ded86f in _dl_init (main_map=0x7ffff7ffb000, argc=1,
> >    argv=0x7fffffffe2c8, env=0x7fffffffe2d8) at dl-init.c:134
> > #12 0x00007ffff7ddfb2a in _dl_start_user () from
> /lib64/ld-linux-x86-64.so.2
> > #13 0x0000000000000001 in ?? ()
> > #14 0x00007fffffffe524 in ?? ()
> > #15 0x0000000000000000 in ?? ()
> >
> > The same program works fine when not linked with xenomai. This is
> > probably not a ROS bug, so I'm not creating a ticket, but I was
> > wondering if anyone has seen this before, or has any other ideas. This
> > problem either occurs or doesn't based on which objects I link into my
> > final binary.
> >
> > - Mrinal
> >
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