/* Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved.

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License, version 2.0,
  as published by the Free Software Foundation.

  This program is also distributed with certain software (including
  but not limited to OpenSSL) that is licensed under separate terms,
  as designated in a particular file or component or in included license
  documentation.  The authors of MySQL hereby grant you an additional
  permission to link the program and your derivative works with the
  separately licensed software that they have included with MySQL.

  This program 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 General Public License, version 2.0, for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software Foundation,
  51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */

#ifndef PFS_ATOMIC_H
#define PFS_ATOMIC_H

/**
  @file storage/perfschema/pfs_atomic.h
  Atomic operations (declarations).
*/

#include <my_atomic.h>

/** Helper for atomic operations. */
class PFS_atomic
{
public:
  /** Initialise the PFS_atomic component. */
  static void init();
  /** Cleanup the PFS_atomic component. */
  static void cleanup();

  /** Atomic load. */
  static inline int32 load_32(volatile int32 *ptr)
  {
    int32 result;
    rdlock(ptr);
    result= my_atomic_load32(ptr);
    rdunlock(ptr);
    return result;
  }

  /** Atomic load. */
  static inline int64 load_64(volatile int64 *ptr)
  {
    int64 result;
    rdlock(ptr);
    result= my_atomic_load64(ptr);
    rdunlock(ptr);
    return result;
  }

  /** Atomic load. */
  static inline uint32 load_u32(volatile uint32 *ptr)
  {
    uint32 result;
    rdlock(ptr);
    result= (uint32) my_atomic_load32((int32*) ptr);
    rdunlock(ptr);
    return result;
  }

  /** Atomic load. */
  static inline uint64 load_u64(volatile uint64 *ptr)
  {
    uint64 result;
    rdlock(ptr);
    result= (uint64) my_atomic_load64((int64*) ptr);
    rdunlock(ptr);
    return result;
  }

  /** Atomic store. */
  static inline void store_32(volatile int32 *ptr, int32 value)
  {
    wrlock(ptr);
    my_atomic_store32(ptr, value);
    wrunlock(ptr);
  }

  /** Atomic store. */
  static inline void store_64(volatile int64 *ptr, int64 value)
  {
    wrlock(ptr);
    my_atomic_store64(ptr, value);
    wrunlock(ptr);
  }

  /** Atomic store. */
  static inline void store_u32(volatile uint32 *ptr, uint32 value)
  {
    wrlock(ptr);
    my_atomic_store32((int32*) ptr, (int32) value);
    wrunlock(ptr);
  }

  /** Atomic store. */
  static inline void store_u64(volatile uint64 *ptr, uint64 value)
  {
    wrlock(ptr);
    my_atomic_store64((int64*) ptr, (int64) value);
    wrunlock(ptr);
  }

  /** Atomic add. */
  static inline int32 add_32(volatile int32 *ptr, int32 value)
  {
    int32 result;
    wrlock(ptr);
    result= my_atomic_add32(ptr, value);
    wrunlock(ptr);
    return result;
  }

  /** Atomic add. */
  static inline int64 add_64(volatile int64 *ptr, int64 value)
  {
    int64 result;
    wrlock(ptr);
    result= my_atomic_add64(ptr, value);
    wrunlock(ptr);
    return result;
  }

  /** Atomic add. */
  static inline uint32 add_u32(volatile uint32 *ptr, uint32 value)
  {
    uint32 result;
    wrlock(ptr);
    result= (uint32) my_atomic_add32((int32*) ptr, (int32) value);
    wrunlock(ptr);
    return result;
  }

  /** Atomic add. */
  static inline uint64 add_u64(volatile uint64 *ptr, uint64 value)
  {
    uint64 result;
    wrlock(ptr);
    result= (uint64) my_atomic_add64((int64*) ptr, (int64) value);
    wrunlock(ptr);
    return result;
  }

  /** Atomic compare and swap. */
  static inline bool cas_32(volatile int32 *ptr, int32 *old_value,
                            int32 new_value)
  {
    bool result;
    wrlock(ptr);
    result= my_atomic_cas32(ptr, old_value, new_value);
    wrunlock(ptr);
    return result;
  }

  /** Atomic compare and swap. */
  static inline bool cas_64(volatile int64 *ptr, int64 *old_value,
                            int64 new_value)
  {
    bool result;
    wrlock(ptr);
    result= my_atomic_cas64(ptr, old_value, new_value);
    wrunlock(ptr);
    return result;
  }

  /** Atomic compare and swap. */
  static inline bool cas_u32(volatile uint32 *ptr, uint32 *old_value,
                             uint32 new_value)
  {
    bool result;
    wrlock(ptr);
    result= my_atomic_cas32((int32*) ptr, (int32*) old_value,
                            (uint32) new_value);
    wrunlock(ptr);
    return result;
  }

  /** Atomic compare and swap. */
  static inline bool cas_u64(volatile uint64 *ptr, uint64 *old_value,
                             uint64 new_value)
  {
    bool result;
    wrlock(ptr);
    result= my_atomic_cas64((int64*) ptr, (int64*) old_value,
                            (uint64) new_value);
    wrunlock(ptr);
    return result;
  }

private:
  static my_atomic_rwlock_t m_rwlock_array[256];

  /**
    Helper used only with non native atomic implementations.
    @sa MY_ATOMIC_MODE_RWLOCKS
  */
  static inline my_atomic_rwlock_t *get_rwlock(volatile void *ptr)
  {
    /*
      Divide an address by 8 to remove alignment,
      modulo 256 to fall in the array.
    */
    uint index= (((intptr) ptr) >> 3) & 0xFF;
    my_atomic_rwlock_t *result= &m_rwlock_array[index];
    return result;
  }

  /**
    Helper used only with non native atomic implementations.
    @sa MY_ATOMIC_MODE_RWLOCKS
  */
  static inline void rdlock(volatile void *ptr)
  {
    my_atomic_rwlock_rdlock(get_rwlock(ptr));
  }

  /**
    Helper used only with non native atomic implementations.
    @sa MY_ATOMIC_MODE_RWLOCKS
  */
  static inline void wrlock(volatile void *ptr)
  {
    my_atomic_rwlock_wrlock(get_rwlock(ptr));
  }

  /**
    Helper used only with non native atomic implementations.
    @sa MY_ATOMIC_MODE_RWLOCKS
  */
  static inline void rdunlock(volatile void *ptr)
  {
    my_atomic_rwlock_rdunlock(get_rwlock(ptr));
  }

  /**
    Helper used only with non native atomic implementations.
    @sa MY_ATOMIC_MODE_RWLOCKS
  */
  static inline void wrunlock(volatile void *ptr)
  {
    my_atomic_rwlock_wrunlock(get_rwlock(ptr));
  }
};

#endif

