Re: [rtl] Cannot Use Semaphore fuction!! (Help)

[Michael Barabanov <baraban@fsmlabs.com>]

Please look at examples/mutex/sema_test.c.
Also, you probably need to use relative linking (ld -r) like
in examples/fp/Makefile.

Michael.

paladin@kist.re.kr (paladin@kist.re.kr) wrote:
> I want to use Semaphore function  and to Sync thread.
> As man page mentioned sem_init and etc can use with rtl_fuction .
> 
> there is no compiling error on it. 
> includeing  and Loading  Object file to RT-kernel.
> but the Failure Look like here.
> ----------------------------------------------------------------------- 
> gcc -D_REENTRANT -I/usr/src/rtlinux-2.2/include -I/usr/src/rtlinux-2.2/linux/include -Wall -Wstrict-prototypes -O2 -fno-strength-reduce -D__SMP__ -D__RTL__ -D__KERNEL__ -DMODULE -c   -DMODVERSIONS -include /usr/src/rtlinux-2.2/linux/include/linux/modversions.h can_drv.c -lpthread
> 
> gcc: -lpthread: linker input file unused since linking not done
> gcc -I/usr/src/rtlinux-2.2/include -I/usr/src/rtlinux-2.2/linux/include -O2 -Wall -o monitor can_m.c -lcanlib -L. 
> 
> can_drv.o: unresolved symbol sem_init
> can_drv.o: unresolved symbol sem_post
> can_drv.o: unresolved symbol sem_destroy
> can_drv.o: unresolved symbol sem_wait
> Error opening /dev/rtf0
> -------------------------------------------------------------------------------
> 
> what is that means... some time i used "exit" fuction at that RT-kernel the  unresolved
> symbol error happen like this way.
> Semaphore Can't use RT-Kernel? Please help 
>   
> 
> 
> 
> 
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