If this is the problem, the attached patch may help -- it turns the
reinterpret_casts in the serialization of primitives into memcpys, which
shouldn't require alignment.
Josh
On Thu, Jul 8, 2010 at 8:44 AM, René Wagner <
rene.wagner@dfki.de> wrote:
> On Thu, 2010-07-08 at 19:43 +0900, Daniel Stonier wrote:
> > Got into it with a debugger, and found it hanging at
> > roslib/include/ros/serialization.h at
> >
> >
> > ROS_CREATE_SIMPLE_SERIALIZER(double);
>
> Depending on how the serializer is used, this may result in an
> unaligned write. You can check whether an alignment error is involved
> as follows:
>
> echo 5 > /proc/cpu/alignment
>
> and re-run the executable that's causing trouble. The program should
> receive a signal (so you can see where exactly things go wrong in gdb)
> and the kernel should report an "Alignment trap: ..." on the console or
> in dmesg/syslog.
>
> Cheers,
>
> Rene
>
> --
> ------------------------------------------------------------
> Dipl.-Inf. René Wagner Junior Researcher
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>
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Index: include/ros/serialization.h
===================================================================
--- include/ros/serialization.h (revision 10273)
+++ include/ros/serialization.h (working copy)
@@ -172,12 +172,12 @@
{ \
template<typename Stream> inline static void write(Stream& stream, const Type v) \
{ \
- *reinterpret_cast<Type*>(stream.advance(sizeof(v))) = v; \
+ memcpy(stream.advance(sizeof(v)), &v, sizeof(v)); \
} \
\
template<typename Stream> inline static void read(Stream& stream, Type& v) \
{ \
- v = *reinterpret_cast<Type*>(stream.advance(sizeof(v))); \
+ memcpy(&v, stream.advance(sizeof(v)), sizeof(v)); \
} \
\
inline static uint32_t serializedLength(const Type t) \
(text/plain)
