libobjc/objc/objc-sync.h

   1 /* GNU Objective C Runtime @synchronized implementation
   2    Copyright (C) 2010-2020 Free Software Foundation, Inc.
   3    Contributed by Nicola Pero <nicola.pero@meta-innovation.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #ifndef __objc_sync_INCLUDE_GNU
  27 #define __objc_sync_INCLUDE_GNU
  28
  29 #include "objc.h"
  30 #include "objc-decls.h"
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 /* These functions are automatically called by @synchronized().  */
  37
  38 /* 'objc_sync_enter' is automatically called when entering a
  39    @synchronized() block.  It locks the recursive lock associated with
  40    'object'.  If 'object' is nil, it does nothing.  It returns
  41    OBJC_SYNC_SUCCESS on success; see the enumeration below for error
  42    values.
  43
  44    Note that you should not rely on the behaviour when 'object' is nil
  45    because it could change.  */
  46 objc_EXPORT int objc_sync_enter (id object);
  47
  48 /* 'objc_sync_exit' is automatically called when exiting from a
  49    @synchronized() block.  It unlocks the recursive lock associated
  50    with 'object'.  If 'object' is nil, it does nothing.  It returns
  51    OBJC_SYNC_SUCCESS on success; see the enumeration below for error
  52    values.  */
  53 objc_EXPORT int objc_sync_exit (id object);
  54
  55 /* All the possible return values for objc_sync_enter() and
  56    objc_sync_exit().
  57  */
  58 enum {
  59   OBJC_SYNC_SUCCESS = 0,
  60   OBJC_SYNC_NOT_OWNING_THREAD_ERROR = -1,
  61   OBJC_SYNC_TIMED_OUT = -2,
  62   OBJC_SYNC_NOT_INITIALIZED = -3
  63 };
  64
  65 #ifdef __cplusplus
  66 }
  67 #endif
  68
  69 #endif /* not __objc_sync_INCLUDE_GNU */