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POSIX signal handling



> -----Original Message-----
> From: Joel Sherrill [mailto:joel.sherrill at OARcorp.com]
> Sent: segunda-feira, 30 de Mar?o de 2009 18:10
> To: S?rgio Santos
> Cc: rtems-users at rtems.com
> Subject: Re: POSIX signal handling
> 
> S?rgio Santos wrote:
> > Hello all,
> >
> > I'm using rtems 4.8.1, target is i386 (single core, with FC9), using
> bsp's between pc386 and pc686 and the RTEMS makefile templates.
> >
> >
> >
> You have configured the Timer and Clock drivers.  The Timer driver is
> very likely
> conflicting with the Clock driver.  In 4.9, you should have gotten an
> error from
> confdefs.h for defining them both.
> 
> Before I take time to try this myself, can you delete the configure
> timer driver
> and try it again.
> 
> --joel

Hi Joel,

Thank you for the quick answer.
I've just tried commenting the timer driver out but the test is still not running the handler, so this appears to have had no effect. 


> > I have been trying to port a Linux based application to RTEMS and found
> at some point I couldn't get POSIX signal handlers (set with sigaction) to
> ever execute. From what I've read in rtems-users and user docs, no
> problems should arise from using POSIX asynchronous signal handling in
> RTEMS, so my guess is I'm making some na?ve mistake on code or
> configuration...
> >
> > Also, searching on the list, came across a similar problem, but this was
> a unique case and a long while ago:
> > http://www.rtems.com/ml/rtems-users/2002/september/msg00015.html
> > Unfortunately that thread was not conclusive.
> >
> > After a few other tests I've got down to a simple test application (see
> below), similar to the code in the post I mentioned above: a thread sets
> sigaction and just does alarm(1), sleep(3) in a cycle. Alike the other
> tests, in RTEMS the handler never gets to run (although the signal
> (SIGALRM) is seen pending); in Linux all tests will work.
> >
> > POSIX was enabled in the build configuration:
> > ../../../rtems-4.8.1/c/configure --prefix=/opt/rtems-4.8 --host=i386-
> rtems4.8 --build=i686-pc-linux-gnu --target=i386-rtems4.8 --enable-posix -
> -disable-itron --enable-networking --enable-cxx --enable-rtems-debug --
> enable-rdbg --enable-rtemsbsp=pc386 --with-target-subdir=i386-rtems4.8 --
> exec-prefix=/opt/rtems-4.8/i386-rtems4.8 --includedir=/opt/rtems-4.8/i386-
> rtems4.8/include --cache-file=/dev/null --srcdir=../../../rtems-4.8.1/c
> >
> > I post below the src for the simple test, having the RTEMS definitions
> in the end.
> >
> >
> > Thanks in advance for your help!
> >
> > S?rgio Santos
> >
> >
> > --------------
> >
> >
> > #include <signal.h>
> > #include <stdio.h>
> > #include <unistd.h>
> > #include <stdlib.h>
> >
> > #include <bsp.h>
> >
> > void sig_handler(int sig){
> > 	switch(sig){
> > 	case SIGALRM:
> > 		printf("HANDLER: caught SIGALRM\n");
> > 		break;
> > 	default:
> > 		printf("Received unexpected signal (%d)\nBye!", sig);
> > 		exit(1);
> > 	}
> > }
> >
> > void sig_init(){
> >
> > 	int rc;
> > 	sigset_t 			sigset;
> > 	struct sigaction 	sigact;
> >
> > 	rc = sigemptyset(&sigset);
> > 	if (rc != 0) {
> > 		printf("Can't empty set\n");exit(1);
> > 	}
> >
> > 	sigact.sa_mask 		= sigset;
> > 	sigact.sa_flags 	= 0;
> > 	sigact.sa_handler 	= &sig_handler;
> >
> > 	rc = sigaction(SIGALRM, &sigact, NULL);
> > 	if (rc != 0) {
> > 		printf("Can't install handler\n"); exit(1);
> > 	}
> > }
> >
> > void *POSIX_Init(void *arg){
> >
> > 	int rc = 0;
> > 	sigset_t pendingset;
> >
> > 	sig_init();
> >
> > 	rc = sigemptyset(&pendingset);
> > 	if (rc != 0) {
> > 		printf("Can't empty set\n");exit(1);
> > 	}
> >
> > 	while(1){
> > 		alarm(1);
> > 		sleep(3);
> > 		sigpending(&pendingset);
> > 		printf("%s\n\n", ( sigismember(&pendingset, SIGALRM) ?
> > 				"SIGALRM is pending" : "SIGALRM not pending" ));
> > 	}
> > 	return 0;
> > }
> >
> > #define CONFIGURE_MAXIMUM_POSIX_THREADS 10
> > #define CONFIGURE_MAXIMUM_POSIX_MUTEXES 10
> > #define CONFIGURE_MAXIMUM_POSIX_TIMERS  10
> > #define CONFIGURE_MAXIMUM_POSIX_QUEUED_SIGNALS 40
> >
> > #define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
> > #define CONFIGURE_APPLICATION_NEEDS_TIMER_DRIVER
> > #define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER
> > #define CONFIGURE_POSIX_INIT_THREAD_TABLE
> > #define CONFIGURE_INIT
> >
> > // EOF
> > ----
> >
> > _______________________________________________
> > rtems-users mailing list
> > rtems-users at rtems.com
> > http://rtems.rtems.org/mailman/listinfo/rtems-users
> >
> 
> 
> --
> Joel Sherrill, Ph.D.             Director of Research & Development
> joel.sherrill at OARcorp.com        On-Line Applications Research
> Ask me about RTEMS: a free RTOS  Huntsville AL 35805
>    Support Available             (256) 722-9985
>