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Date: Tue, 04 Mar 2008 20:42:30 +0100
From: Anders Blomdell <anders.blomdell@domain.hid>
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Subject: [Xenomai-help] How should rt_task_delete(NULL)  be used?
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Why does the following program grow it's VMSIZE? This is the output I get:

[child =  0,  0] VmSize:            1912 kB
[child =  1,  1] VmSize:            1980 kB
[child =  2,  2] VmSize:            2048 kB
[child =  3,  3] VmSize:            2116 kB
[child =  4,  4] VmSize:            2184 kB
[child =  5,  5] VmSize:            2252 kB
[child =  6,  6] VmSize:            2320 kB
[child =  7,  7] VmSize:            2388 kB
[child =  8,  8] VmSize:            2456 kB
[child =  9,  9] VmSize:            2524 kB
[child = 10, 10] VmSize:            2592 kB
[child = 11, 11] VmSize:            2660 kB
[child = 12, 12] VmSize:            2728 kB
[child = 13, 13] VmSize:            2796 kB
[child = 14, 14] VmSize:            2864 kB
[child = 15, 15] VmSize:            2932 kB
[child = 16, 16] VmSize:            3000 kB
[child = 17, 17] VmSize:            3068 kB
[child = 18, 18] VmSize:            3136 kB
[child = 19, 19] VmSize:            3204 kB

But I would have expecte dthe size to remain constant (API docs says: "Terminate
a task and release all the real-time kernel resources it currently holds." ...
"If task is NULL, the current task is deleted.")

Versions used are:

# uname -r ; cat /proc/xenomai/version
2.6.24.3-ipipe
2.4.2

#include <sys/mman.h>
#include <native/cond.h>
#include <native/mutex.h>
#include <native/task.h>
#include <native/timer.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>



static void child(void *arg)
{
  int n = (int)arg;

  printf("[child = %2d", n);
  fflush(stdout);
  rt_task_delete(NULL);
}

int main(int argc, char *argv[])
{
  int i;
  RT_TASK task_main;
  RT_TASK task;

  mlockall(MCL_CURRENT|MCL_FUTURE);

  rt_task_shadow(&task_main, "main", 1, T_FPU);

  for  (i = 0 ; i < 20 ; i++) {
    if (rt_task_create(&task, NULL, 0, 1, 0)) {
      fprintf(stderr, "Failed to create  task\n");
      exit(1);
    }
    if (rt_task_start(&task, &child, (void*)i)) {
      fprintf(stderr, "Failed to start task\n");
      exit(1);
    }
    rt_task_sleep(1000000000L);
    {
      int fd;
      char *p1 = NULL, *p2 = NULL;
      char buf[4000];

      fd = open("/proc/self/status", O_RDONLY);
      if (read(fd, buf, 4000) > 0) {
	p1 = strstr(buf, "VmSize");
	if (p1) { p2 = strstr(p1, "\n"); }
	if (p1 && p2) {	printf(", %2d] %1.*s\n", i, p2 - p1, p1); }
      }
      close(fd);
    }
  }
  exit(0);
}

Regards

Anders

-- 
Anders Blomdell                  Email: anders.blomdell@domain.hid
Department of Automatic Control
Lund University                  Phone:    +46 46 222 4625
P.O. Box 118                     Fax:      +46 46 138118
SE-221 00 Lund, Sweden