POSIX signal handling

[Joel Sherrill]

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