2001-04-20 Correo Fernando-ruiz <correo@fernando-ruiz.com>

	* include/rtems/libio_.h, libc/chroot.c, libc/privateenv.c:
	Private environment and chroot() enhancements and fixes.  Comments:
	  + privateenv has been modified to let at chroot() to be more
	    POSIX like Sergei Organov recommended.
	  + A task owner lets that rtems_set_private_env() will be
	    called twice or more times.
	  + chroot() can be called without a previous
	    rtems_set_private_env(); (transpanrently)
	  + The second call of rtems_set_private_env() makes a internal
	    chroot("/") into global imfs_root.
	  + chroot() runs like chdir() without a previous chdir("/") with
	    the global root.
	  + The current directory can be in a wrong place like Linux and
	    many other Unices.

1 files changed, 49 insertions, 7 deletions

diff --git a/c/src/lib/libc/privateenv.c b/c/src/lib/libc/privateenv.c
index 4dc0144acc..7b1e5d1e8e 100644
--- a/c/src/lib/libc/privateenv.c
+++ b/c/src/lib/libc/privateenv.c
@@ -23,15 +23,57 @@
 
 rtems_status_code rtems_libio_set_private_env(void) {
   rtems_status_code sc;
+  rtems_id          task_id;
 
-  sc = rtems_task_variable_add(RTEMS_SELF,(void*)&rtems_current_user_env,free);
-  if (sc != RTEMS_SUCCESSFUL)
-    return sc;
+  sc=rtems_task_ident(RTEMS_SELF,0,&task_id);
+  if (sc != RTEMS_SUCCESSFUL) return sc;
 
-  rtems_current_user_env = malloc(sizeof(rtems_user_env_t));
-  if (!rtems_current_user_env)
-    return RTEMS_NO_MEMORY;
+  /* Only for the first time a malloc is necesary */
+  if (rtems_current_user_env==&rtems_global_user_env) { 
+   sc = rtems_task_variable_add(RTEMS_SELF,(void*)&rtems_current_user_env,free);
+   if (sc != RTEMS_SUCCESSFUL) return sc;
+   rtems_current_user_env = malloc(sizeof(rtems_user_env_t));
+   if (!rtems_current_user_env)
+     return RTEMS_NO_MEMORY;
+  }; 
+
+  /* the side effect desired . chroot("/") */
+  *rtems_current_user_env = rtems_global_user_env; /* get the global values*/
+  rtems_current_user_env->task_id=task_id;         /* mark the local values*/
+
+  return RTEMS_SUCCESSFUL;
+}
+
+/*
+ *  Share a same private environment beetween two task:
+ *   Task_id (remote) and RTEMS_SELF(current).
+ */
+
+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,&current_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*/	  
+   free(rtems_current_user_env);	  
+   sc = rtems_task_variable_delete(RTEMS_SELF,(void*)&rtems_current_user_env);
+   if (sc != RTEMS_SUCCESSFUL) return sc;
+  };
+
+  sc = rtems_task_variable_get(task_id,(void*)&rtems_current_user_env,
+		                       (void*)&shared_user_env       );
+  if (sc != RTEMS_SUCCESSFUL) return sc;
+
+  /* don't free(NULL'ed) at the task_delete. It is a shared var... */	   
+  sc = rtems_task_variable_add(RTEMS_SELF,(void*)&rtems_current_user_env,NULL);
+  if (sc != RTEMS_SUCCESSFUL) return sc;
+  
+  /* the current_user_env is the same pointer that remote env */
+  rtems_current_user_env = shared_user_env;
 
-  *rtems_current_user_env = rtems_global_user_env;
   return RTEMS_SUCCESSFUL;
 }