Re: [Xenomai-help] rt_task_spawn how to

[Jan Kiszka <jan.kiszka@domain.hid>]

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Hi Patrice,

Patrice Congo wrote:
> Hi all,
> 
> is it posible to spawn a  task from another rt task?
> The following code tries to, but does not succeed:
> <code>
> #include <string.h>
> #include <stdio.h>
> 
> #include <native/task.h>
> //#include <general_macros.h>
> 
> #define STACK_SIZE 8192
> 
> RT_TASK spawner;
> RT_TASK spawnee;
> void spawner_work(void* c);
> void spawnee_work(void* c);
> 
> void spawner_work(void* c)
> {
> 	printf("\nspawner\n");
> 	//SWITCH_TASK_TO_SECONDARY_MODE();
> 	int
> ret=rt_task_spawn(&spawnee,"spawnee",STACK_SIZE,50,0,spawnee_work,NULL);
> 	printf("IN SPAWNER WORK: ret=%d
> %s\n",ret,strerror(ret));
> }
> 
> void spawnee_work(void* c)
> {
> 	printf("I am spawnee");	
> }
> 
> int main(int argc, char *argv[])
> {
> 	int ret=
> 	
> rt_task_spawn(&spawner,"spawner",STACK_SIZE,50,0,spawner_work,NULL);
> 	printf("\nIN MAIN:ret=%d %s\n",ret,strerror(-ret));
> 	getchar();
> 	return 0;
> }
> 
> 
> </code>
> 
> the resulting output is:
> <output>
> spawner
> 
> IN MAIN:ret=0 Success
> 
> </output>
> This means that the task "spawner" starts but get
> blocked at rt_task_spwan call.

Hmm, strange. This is what I see with latest SVN checkout of Xenomai:

spawner
IN SPAWNER WORK: ret=0 Success
I am spawnee
IN MAIN:ret=0 Success

Looks fine.

But you are lacking mlockall() in your demo. Maybe some page fault is
hitting your spawnee during creation.

> 
> Switching context explicitely to secondary or to
> primary does not help too.
> 
> can you help?
> 
> best, patrice
> 

Jan

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