Bug in pth_key_delete() ?

[Vinu V]

Hi again,

I am using the pth_key_*  APIs in my program and I came across a point where the Pth library is crashing.
Don't know whether this is a bug with Pth or with my program.

 

This is what I have done.

 

int taskVar
main ()
{

 

     int retValue;
     pth_mutex_t mutex;
     pth_mutex_t cond;

 

     pth_spawn(PTH_ATTR_DEFAULT, task1, NULL);

 

     pth_mutex_init(&mutex);
     pth_cond_init(&cond);

 

     pth_key_create(&taskVar, NULL);
     pth_key_setdata(taskVar, (int *)123);
     retValue = (int)pth_key_getdata(taskVar);
     retValue = pth_key_delete(taskVar);
  

     pth_mutex_acquire(&mutex, 0, NULL);
     pth_cond_await(&cond, &mutex, NULL);
     pth_mutex_release(&mutex);

 

} /* End of main */

 

void *task1(void *arg)
{
      pth_mutex_acquire(&mutex, 0, NULL);
      pth_cond_notify(&cond, 0);
      pth_mutex_release(&mutex);
}

 

Here the program crashes at pth_cond_await() in main.
When I comment the pth_key_delete() in main(), then this works perfectly.

 

I think this is beacause of a bug in pth_key_delete().

 

int pth_key_delete(pth_key_t key)
{
    if (key >= PTH_KEY_MAX)
        return pth_error(FALSE, EINVAL);
    if (!pth_keytab[key].used)
        return pth_error(FALSE, EINVAL);
    pth_keytab[key].used = FALSE;
    return TRUE;
}

 

This function marks the "used" field of the specified key( in this example this
is the index 0 of pth_keytab[] array) as FALSE. But it is not making the data
pointer for this key as NULL. Hence the data pointer still contains the value 123.

 

Now the pth_mutex_acquire internally uses the pth_key_getdata(), which returns the a
a value of 123 which is invalid value for the mutex event and it crashes when it
tries to manipulate this event data.

 

Possible FIX.
-------------
This problem got solved when I cleared the data_value pointer within the
pth_key_delete() function.

 

int pth_key_delete(pth_key_t key)
{
    if (key >= PTH_KEY_MAX)
        return pth_error(FALSE, EINVAL);
    if (!pth_keytab[key].used)
        return pth_error(FALSE, EINVAL);

    pth_keytab[key].used = FALSE;
    pth_current->data_value[key] =(void *)NULL;

 

    return TRUE;
}

 

Please correct me if I am doing anything wrong here ...

 

Regards
Vinu V

 

 

 

 

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