libpthread/nptl/cleanup_defer_compat.c

   1 /* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include "pthreadP.h"
  20
  21
  22 void
  23 attribute_protected
  24 __pthread_cleanup_push_defer (
  25      struct _pthread_cleanup_buffer *buffer,
  26      void (*routine) (void *),
  27      void *arg)
  28 {
  29   struct pthread *self = THREAD_SELF;
  30
  31   buffer->__routine = routine;
  32   buffer->__arg = arg;
  33   buffer->__prev = THREAD_GETMEM (self, cleanup);
  34
  35   int cancelhandling = THREAD_GETMEM (self, cancelhandling);
  36
  37   /* Disable asynchronous cancellation for now.  */
  38   if (__builtin_expect (cancelhandling & CANCELTYPE_BITMASK, 0))
  39     while (1)
  40       {
  41         int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
  42                                                 cancelhandling
  43                                                 & ~CANCELTYPE_BITMASK,
  44                                                 cancelhandling);
  45         if (__builtin_expect (curval == cancelhandling, 1))
  46           /* Successfully replaced the value.  */
  47           break;
  48
  49         /* Prepare for the next round.  */
  50         cancelhandling = curval;
  51       }
  52
  53   buffer->__canceltype = (cancelhandling & CANCELTYPE_BITMASK
  54                           ? PTHREAD_CANCEL_ASYNCHRONOUS
  55                           : PTHREAD_CANCEL_DEFERRED);
  56
  57   THREAD_SETMEM (self, cleanup, buffer);
  58 }
  59 strong_alias (__pthread_cleanup_push_defer, _pthread_cleanup_push_defer)
  60
  61
  62 void
  63 attribute_protected
  64 __pthread_cleanup_pop_restore (
  65      struct _pthread_cleanup_buffer *buffer,
  66      int execute)
  67 {
  68   struct pthread *self = THREAD_SELF;
  69
  70   THREAD_SETMEM (self, cleanup, buffer->__prev);
  71
  72   int cancelhandling;
  73   if (__builtin_expect (buffer->__canceltype != PTHREAD_CANCEL_DEFERRED, 0)
  74       && ((cancelhandling = THREAD_GETMEM (self, cancelhandling))
  75           & CANCELTYPE_BITMASK) == 0)
  76     {
  77       while (1)
  78         {
  79           int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
  80                                                   cancelhandling
  81                                                   | CANCELTYPE_BITMASK,
  82                                                   cancelhandling);
  83           if (__builtin_expect (curval == cancelhandling, 1))
  84             /* Successfully replaced the value.  */
  85             break;
  86
  87           /* Prepare for the next round.  */
  88           cancelhandling = curval;
  89         }
  90
  91       CANCELLATION_P (self);
  92     }
  93
  94   /* If necessary call the cleanup routine after we removed the
  95      current cleanup block from the list.  */
  96   if (execute)
  97     buffer->__routine (buffer->__arg);
  98 }
  99 strong_alias (__pthread_cleanup_pop_restore, _pthread_cleanup_pop_restore)