[ECOS] Timeslicing on arm

["Martin Hansen" <farhansen at gmail dot com>]

Hi

I am havinf trouble getting my litle program to work.
I make two threads each writting to the seriel port, I exspected them
to both get some output on the port, probably mixed in strange ways.
(It should be a demo of when to use syncronisation objects.)

But all runtime is given to just the one thread.

They have the same priority, mlque is used as scheduler, and
CYGSEM_KERNEL_SCHED_TIMESLICE is true


It does not apear the that it is the serial port that somehows just
belongs to one thread or other error, setting a breakpoint in the
other thread will newer trigger

Below is my small program, it gives just BBBB... on seriel console

#include <cyg/kernel/kapi.h>	// Kernel API.
#include <cyg/hal/hal_arch.h>	// hal specific defines.
#include <cyg/io/io.h>
#include <cyg/io/serialio.h>
#include <cyg/error/strerror.h>
#include <stdio.h>

#define THREAD_STACK_SIZE	(CYGNUM_HAL_STACK_SIZE_TYPICAL )
#define THREAD_PRIORITY		12


int thread_b_stack[ THREAD_STACK_SIZE ];
int thread_c_stack[ THREAD_STACK_SIZE ];

cyg_thread thread_b_obj;
cyg_thread thread_c_obj;
cyg_handle_t thread_b_hdl;
cyg_handle_t thread_c_hdl;

cyg_io_handle_t serhand;

// Thread B
void thread_b( cyg_addrword_t data )
{
	char * strW = "BBBBBBBBBBBBBBBBBBBBBB\n";
	cyg_uint32  len;
	len  = strlen(strW);

	while( 1 )
	{
			cyg_io_write(serhand, strW , &len);
	}
}

// Thread C
void thread_c( cyg_addrword_t data )
{
	char * strW = "CCCCCCCCCCCCCCC\n";
	cyg_uint32  len;
	len  = strlen(strW);

	while( 1 )
	{
			cyg_io_write(serhand, strW , &len);   /*breakpoint here wil only
trigger once, then never again.*/
	}
}


int main( void )
{
  cyg_io_lookup("/dev/ser0", serhand);
  Cyg_ErrNo error;
		
  error = cyg_io_lookup("/dev/ser0", &serhand );
  if (error < 0) {
	  printf("Error %d = %s opening serial port.\n",
			  errno, strerror(error));
	  return -1;
  }

  //
  // Create our two threads.
  //
  cyg_thread_create(
		    THREAD_PRIORITY,
		    thread_b,
		    (cyg_addrword_t) 68,
		    "Thread B",
		    (void *)thread_b_stack,
		    THREAD_STACK_SIZE,
		    &thread_b_hdl,
		    &thread_b_obj );

  cyg_thread_create(
		    THREAD_PRIORITY ,
		    thread_c,
		    (cyg_addrword_t) 68,
		    "Thread C",
		    (void *)thread_c_stack,
		    THREAD_STACK_SIZE,
		    &thread_c_hdl,
		    &thread_c_obj );

  // Resume the threads so they start when the scheduler begins.
  cyg_thread_resume( thread_b_hdl );
  cyg_thread_resume( thread_c_hdl );
  return 0;
}

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