glibc/nptl/cleanup_defer.c

/* Copyright (C) 2002 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include "pthreadP.h"
#include <atomic.h>


void
_pthread_cleanup_push_defer (buffer, routine, arg)
     struct _pthread_cleanup_buffer *buffer;
     void (*routine) (void *);
     void *arg;
{
  struct pthread *self = THREAD_SELF;

  buffer->__routine = routine;
  buffer->__arg = arg;
  buffer->__prev = THREAD_GETMEM (self, cleanup);

  if (buffer->__prev != NULL && FRAME_LEFT (buffer, buffer->__prev))
    buffer->__prev = NULL;

  int cancelhandling = THREAD_GETMEM (self, cancelhandling);

  /* Disable asynchronous cancellation for now.  */
  if (__builtin_expect (cancelhandling & CANCELTYPE_BITMASK, 0))
    {
      while (atomic_compare_and_exchange_acq (&self->cancelhandling,
					      cancelhandling
					      & ~CANCELTYPE_BITMASK,
					      cancelhandling) != 0)
	cancelhandling = self->cancelhandling;
    }

  buffer->__canceltype = (cancelhandling & CANCELTYPE_BITMASK
			  ? PTHREAD_CANCEL_ASYNCHRONOUS
			  : PTHREAD_CANCEL_DEFERRED);

  THREAD_SETMEM (self, cleanup, buffer);
}


void
_pthread_cleanup_pop_restore (buffer, execute)
     struct _pthread_cleanup_buffer *buffer;
     int execute;
{
  struct pthread *self = THREAD_SELF;

  THREAD_SETMEM (self, cleanup, buffer->__prev);

  int cancelhandling;
  if (__builtin_expect (buffer->__canceltype != PTHREAD_CANCEL_DEFERRED, 0)
      && ((cancelhandling = THREAD_GETMEM (self, cancelhandling))
	  & CANCELTYPE_BITMASK) == 0)
    {
      while (atomic_compare_and_exchange_acq (&self->cancelhandling,
					      cancelhandling
					      | CANCELTYPE_BITMASK,
					      cancelhandling) != 0)
	cancelhandling = self->cancelhandling;

      CANCELLATION_P (self);
    }

  /* If necessary call the cleanup routine after we removed the
     current cleanup block from the list.  */
  if (execute)
    buffer->__routine (buffer->__arg);
}