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/*
* Instantatiate a private user environment for the calling thread.
*
* Submitted by: fernando.ruiz@ctv.es (correo@fernando-ruiz.com)
*
* COPYRIGHT (c) 1989-2000.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.OARcorp.com/rtems/license.html.
*
* $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h> /* free */
#include <rtems.h>
#include <rtems/libio.h>
#include <rtems/libio_.h>
extern Chain_Control rtems_filesystem_mount_table_control;
#define THE_ROOT_FS_LOC \
(((rtems_filesystem_mount_table_entry_t*)\
rtems_filesystem_mount_table_control.first)->mt_fs_root)
/* cleanup a user environment
* NOTE: this must be called with
* thread dispatching disabled!
*/
static void
free_user_env(rtems_user_env_t *env)
{
if (env != &rtems_global_user_env
#ifdef HAVE_USERENV_REFCNT
&& --env->refcnt <= 0
#endif
) {
rtems_filesystem_freenode( &env->current_directory);
rtems_filesystem_freenode( &env->root_directory);
free(env);
}
}
rtems_status_code rtems_libio_set_private_env(void) {
rtems_status_code sc;
rtems_id task_id;
rtems_filesystem_location_info_t loc;
sc=rtems_task_ident(RTEMS_SELF,0,&task_id);
if (sc != RTEMS_SUCCESSFUL) return sc;
/* Only for the first time a malloc is necesary */
if (rtems_current_user_env==&rtems_global_user_env) {
rtems_user_env_t *tmp = malloc(sizeof(rtems_user_env_t));
if (!tmp)
return RTEMS_NO_MEMORY;
#ifdef HAVE_USERENV_REFCNT
tmp->refcnt = 1;
#endif
sc = rtems_task_variable_add(RTEMS_SELF,(void*)&rtems_current_user_env,(void(*)(void *))free_user_env);
if (sc != RTEMS_SUCCESSFUL) {
/* don't use free_user_env because the pathlocs are
* not initialized yet
*/
free(tmp);
return sc;
}
rtems_current_user_env = tmp;
};
*rtems_current_user_env = rtems_global_user_env; /* get the global values*/
rtems_current_user_env->task_id=task_id; /* mark the local values*/
/* get a clean root */
rtems_filesystem_root = THE_ROOT_FS_LOC;
/* Clone the pathlocs. In contrast to most other
* code we must _not_ free the original locs because
* what we are trying to do here is forking off
* clones.
*/
rtems_filesystem_evaluate_path("/", 0, &loc, 0);
rtems_filesystem_root = loc;
rtems_filesystem_evaluate_path("/", 0, &loc, 0);
rtems_filesystem_current = loc;
return RTEMS_SUCCESSFUL;
}
/*
* Share a same private environment beetween two task:
* Task_id (remote) and RTEMS_SELF(current).
*/
/* NOTE:
*
* THIS CODE HAS NO PROTECTION IMPLEMENTED
*
* Tasks who wish to share their environments must
*
* a) assert that no participants are concurrently
* executing
* libio_share_private_env() and/or libio_set_private_env()
*
* b) mutex access to rtems_filesystem_current, rtems_filesytem_root
* while changing any of those (chdir(), chroot()).
*/
#ifndef HAVE_USERENV_REFCNT
rtems_status_code rtems_libio_share_private_env(rtems_id task_id) {
rtems_status_code sc;
rtems_user_env_t * shared_user_env;
rtems_id current_task_id;
sc=rtems_task_ident(RTEMS_SELF,0,¤t_task_id);
if (sc != RTEMS_SUCCESSFUL) return sc;
if (rtems_current_user_env->task_id==current_task_id) {
/* kill the current user env & task_var*/
rtems_user_env_t *tmp = rtems_current_user_env;
sc = rtems_task_variable_delete(RTEMS_SELF,(void*)&rtems_current_user_env);
if (sc != RTEMS_SUCCESSFUL) return sc;
free_user_env(tmp);
};
/* AT THIS POINT, rtems_current_user_env is DANGLING */
sc = rtems_task_variable_get(task_id,(void*)&rtems_current_user_env,
(void*)&shared_user_env );
if (sc != RTEMS_SUCCESSFUL)
goto bailout;
sc = rtems_task_variable_add(RTEMS_SELF,(void*)&rtems_current_user_env,free_user_env);
if (sc != RTEMS_SUCCESSFUL)
goto bailout;
/* the current_user_env is the same pointer that remote env */
rtems_current_user_env = shared_user_env;
/* increase the reference count */
#ifdef HAVE_USERENV_REFCNT
rtems_current_user_env->refcnt++;
#endif
return RTEMS_SUCCESSFUL;
bailout:
/* fallback to the global env */
rtems_current_user_env = &rtems_global_user_env;
return sc;
}
#endif
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