POSIX signal handling

[Joel Sherrill]

OK.. runs for me with the CVS head.

You forget to include <rtems/confdefs.h> at the bottom after CONFIGURE_INIT.
And delete the timer configuration.

Folks .. please consider support agreements. :-D

--joel

Sérgio 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.
>
> 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 naïve 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!
>
> Sérgio 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
> ----
>
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> rtems-users at rtems.com
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>   


-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill at OARcorp.com        On-Line Applications Research
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