LXR linux/include/linux/srcu.h

   1/*
   2 * Sleepable Read-Copy Update mechanism for mutual exclusion
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License as published by
   6 * the Free Software Foundation; either version 2 of the License, or
   7 * (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17 *
  18 * Copyright (C) IBM Corporation, 2006
  19 *
  20 * Author: Paul McKenney <paulmck@us.ibm.com>
  21 *
  22 * For detailed explanation of Read-Copy Update mechanism see -
  23 *              Documentation/RCU/ *.txt
  24 *
  25 */
  26
  27#ifndef _LINUX_SRCU_H
  28#define _LINUX_SRCU_H
  29
  30struct srcu_struct_array {
  31        int c[2];
  32};
  33
  34struct srcu_struct {
  35        int completed;
  36        struct srcu_struct_array *per_cpu_ref;
  37        struct mutex mutex;
  38};
  39
  40#ifndef CONFIG_PREEMPT
  41#define srcu_barrier() barrier()
  42#else /* #ifndef CONFIG_PREEMPT */
  43#define srcu_barrier()
  44#endif /* #else #ifndef CONFIG_PREEMPT */
  45
  46int init_srcu_struct(struct srcu_struct *sp);
  47void cleanup_srcu_struct(struct srcu_struct *sp);
  48int srcu_read_lock(struct srcu_struct *sp) __acquires(sp);
  49void srcu_read_unlock(struct srcu_struct *sp, int idx) __releases(sp);
  50void synchronize_srcu(struct srcu_struct *sp);
  51long srcu_batches_completed(struct srcu_struct *sp);
  52
  53#endif
  54