lib/util/talloc_stack.h

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Implement a stack of talloc contexts
   4    Copyright (C) Volker Lendecke 2007
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 /*
  21  * Implement a stack of talloc frames.
  22  *
  23  * When a new talloc stackframe is allocated with talloc_stackframe(), then
  24  * the TALLOC_CTX returned with talloc_tos() is reset to that new
  25  * frame. Whenever that stack frame is TALLOC_FREE()'ed, then the reverse
  26  * happens: The previous talloc_tos() is restored.
  27  *
  28  * This API is designed to be robust in the sense that if someone forgets to
  29  * TALLOC_FREE() a stackframe, then the next outer one correctly cleans up and
  30  * resets the talloc_tos().
  31  *
  32  */
  33
  34 #ifndef _TALLOC_STACK_H
  35 #define _TALLOC_STACK_H
  36
  37 #include <talloc.h>
  38
  39 /*
  40  * Create a new talloc stack frame.
  41  *
  42  * When free'd, it frees all stack frames that were created after this one and
  43  * not explicitly freed.
  44  */
  45
  46 #define talloc_stackframe() _talloc_stackframe(__location__)
  47 #define talloc_stackframe_pool(sz) _talloc_stackframe_pool(__location__, (sz))
  48 TALLOC_CTX *_talloc_stackframe(const char *location);
  49 TALLOC_CTX *_talloc_stackframe_pool(const char *location, size_t poolsize);
  50
  51 /*
  52  * Get us the current top of the talloc stack.
  53  */
  54
  55 #define talloc_tos() _talloc_tos(__location__)
  56 TALLOC_CTX *_talloc_tos(const char *location);
  57
  58 /*
  59  * return true if a talloc stackframe exists
  60  * this can be used to prevent memory leaks for code that can
  61  * optionally use a talloc stackframe (eg. nt_errstr())
  62  */
  63
  64 bool talloc_stackframe_exists(void);
  65
  66 #endif