POSIX signal handling
Sérgio Santos
Sergio.santos at skysoft.pt
Tue Mar 31 12:18:35 UTC 2009
Hi, Joel
I'm using qemu (mostly) but have tried running directly on the target too.
Our current guess is some build configuration conflict or mistake, but we're still to find what exactly. Still, we haven't debugged much for some clues or looked at the rtems code.
Our option is now getting closer to drop POSIX and go for the RTEMS classic API on the async signals matter in particular, and for the port of our Linux app overall. Still we'll report any findings.
Thank you much
Sérgio
> -----Original Message-----
> From: Joel Sherrill [mailto:joel.sherrill at OARcorp.com]
> Sent: segunda-feira, 30 de Março de 2009 20:30
> To: Sérgio Santos
> Cc: rtems-users at rtems.com
> Subject: Re: POSIX signal handling
>
> Sérgio Santos wrote:
> >
> >> -----Original Message-----
> >> From: Joel Sherrill [mailto:joel.sherrill at OARcorp.com]
> >> Sent: segunda-feira, 30 de Março de 2009 19:11
> >> To: Sérgio Santos
> >> Cc: rtems-users at rtems.com
> >> Subject: Re: POSIX signal handling
> >>
> >> Sergios,
> >>
> >> I meant to ask.. Is it ok to include this in the RTEMS examples
> >> as a simple example of alarm and signals?
> >>
> >
> > Joel,
> >
> > Sure! Can't help feeling it's a privilege, despite the simplicity of the
> code :) Nevertheless I must say I'd be happier if it would work at all in
> my system! (please see below)
> >
> >
> >
> >> Joel Sherrill wrote:
> >>
> >>> OK.. runs for me with the CVS head.
> >>>
> >>> You forget to include <rtems/confdefs.h> at the bottom after
> >>>
> >> CONFIGURE_INIT.
> >>
> > You're right in pointing this, it was actually an unfortunate typo...
> >
> >
> :) I expected as much. :)
> >>> And delete the timer configuration.
> >>>
> > Done already! So a conclusion is still open for me, the code is ok,
> configuration is (now) ok, but instead of the current 4.8.1, I should try
> it with the CVS head (4.9.99?)
> >
> >
> How are you running it?
> > Thanks again for your help,
> >
> > Sérgio
> >
> >
> >
> >>> 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
> >>>> ----
> >>>>
> >>>> _______________________________________________
> >>>> 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
> >>
> >>
> >
> >
>
>
> --
> 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
>
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