nptl/cleanup_defer_compat.c

   1 /* Copyright (C) 2002-2015 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 _pthread_cleanup_push_defer (buffer, routine, arg)
  24      struct _pthread_cleanup_buffer *buffer;
  25      void (*routine) (void *);
  26      void *arg;
  27 {
  28   struct pthread *self = THREAD_SELF;
  29
  30   buffer->__routine = routine;
  31   buffer->__arg = arg;
  32   buffer->__prev = THREAD_GETMEM (self, cleanup);
  33
  34   int cancelhandling = THREAD_GETMEM (self, cancelhandling);
  35
  36   /* Disable asynchronous cancellation for now.  */
  37   if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK))
  38     while (1)
  39       {
  40         int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
  41                                                 cancelhandling
  42                                                 & ~CANCELTYPE_BITMASK,
  43                                                 cancelhandling);
  44         if (__glibc_likely (curval == cancelhandling))
  45           /* Successfully replaced the value.  */
  46           break;
  47
  48         /* Prepare for the next round.  */
  49         cancelhandling = curval;
  50       }
  51
  52   buffer->__canceltype = (cancelhandling & CANCELTYPE_BITMASK
  53                           ? PTHREAD_CANCEL_ASYNCHRONOUS
  54                           : PTHREAD_CANCEL_DEFERRED);
  55
  56   THREAD_SETMEM (self, cleanup, buffer);
  57 }
  58 strong_alias (_pthread_cleanup_push_defer, __pthread_cleanup_push_defer)
  59
  60
  61 void
  62 _pthread_cleanup_pop_restore (buffer, execute)
  63      struct _pthread_cleanup_buffer *buffer;
  64      int execute;
  65 {
  66   struct pthread *self = THREAD_SELF;
  67
  68   THREAD_SETMEM (self, cleanup, buffer->__prev);
  69
  70   int cancelhandling;
  71   if (__builtin_expect (buffer->__canceltype != PTHREAD_CANCEL_DEFERRED, 0)
  72       && ((cancelhandling = THREAD_GETMEM (self, cancelhandling))
  73           & CANCELTYPE_BITMASK) == 0)
  74     {
  75       while (1)
  76         {
  77           int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
  78                                                   cancelhandling
  79                                                   | CANCELTYPE_BITMASK,
  80                                                   cancelhandling);
  81           if (__glibc_likely (curval == cancelhandling))
  82             /* Successfully replaced the value.  */
  83             break;
  84
  85           /* Prepare for the next round.  */
  86           cancelhandling = curval;
  87         }
  88
  89       CANCELLATION_P (self);
  90     }
  91
  92   /* If necessary call the cleanup routine after we removed the
  93      current cleanup block from the list.  */
  94   if (execute)
  95     buffer->__routine (buffer->__arg);
  96 }
  97 strong_alias (_pthread_cleanup_pop_restore, __pthread_cleanup_pop_restore)