Re: LuaLanes on Ubuntu 11.10, kernel 3.0

[Philipp Janda <siffiejoe@...>]

Hi!

On 09.11.2011 09:51, Benoit Germain wrote:
> 2011/11/7 Taj Khattra<taj.khattra@gmail.com>:
> > try moving -lpthread to the end of the command line
> >     cc -shared lanes.o threading.o tools.o keeper.o -lpthread -o lua51-lanes.so
> >
> > (re: https://wiki.ubuntu.com/OneiricOcelot/ReleaseNotes#GCC_4.6_Toolchain)
>
> MinGW compilation remains happy if I change the makefile as follows:
>
> lua51-$(MODULE)$(_SO): $(OBJ)
> -	$(CC) $(LIBFLAG) $(LIBS) $^ $(LUA_LIBS) -o $@
> +	$(CC) $(LIBFLAG) $^ $(LIBS) $(LUA_LIBS) -o $@
>
> Tell me if Ubuntu 11.10 is happy with this change too, so that I can commit it.

LuaLanes builds on Ubuntu 11.10 with this fix. But note that in general 
linking with libpthread is not enough to compile multithreaded programs, 
and it is not equivalent to the -pthread compiler flag[1], which on 
Linux also sets -D_REENTRANT (which is required by POSIX for all 
multithreaded code). But I guess it only makes a difference if you 
compile Lua and all your C extensions yourself, since I doubt that this 
flag is used in most makefiles by default. Lanes itself currently does 
not use any feature that depends on _REENTRANT in Ubuntu 11.10. So let's 
hope for the best.
Btw, there is also a -mthread gcc option for MinGW ...

  [1]: 
http://stackoverflow.com/questions/875789/gcc-do-i-need-d-reentrant-with-pthreads

While you are at it, there are still two warnings which break the build 
if -Werror is set:
lanes.c: In function ‘LG_set_debug_threadname’:
lanes.c:1361:14: warning: variable ‘threadName’ set but not used 
[-Wunused-but-set-variable]
tools.c: In function ‘populate_func_lookup_table_recur’:
tools.c:291:17: warning: variable ‘fqnString’ set but not used 
[-Wunused-but-set-variable]

... and two more if using -Wextra:lanes.c:
In function ‘LG_wakeup_conv’:
lanes.c:2206:12: warning: missing initializer [-Wmissing-field-initializers]
lanes.c:2206:12: warning: (near initialization for ‘t.tm_gmtoff’) 
[-Wmissing-field-initializers]
threading.c: In function ‘THREAD_WAIT’:
threading.c:666:33: warning: unused parameter ‘ref’ [-Wunused-parameter]

The glibc memory corruption is gone, but now I get an assertion failure 
on 'make test' (not always on the first test, but I don't get far):
lua5.1: lanes.c:1018: selfdestruct_remove: Assertion `found' failed.
Aborted (core dumped)

Philipp