/*
 * $Id$
 */

/*
 * Harbour Project source code:
 *    header file with functions for atomic operations
 *
 * Copyright 2008 Przemyslaw Czerpak <druzus / at / priv.onet.pl>
 * www - http://www.harbour-project.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this software; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307 USA (or visit the web site http://www.gnu.org/).
 *
 * As a special exception, the Harbour Project gives permission for
 * additional uses of the text contained in its release of Harbour.
 *
 * The exception is that, if you link the Harbour libraries with other
 * files to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the Harbour library code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public License.
 *
 * This exception applies only to the code released by the Harbour
 * Project under the name Harbour.  If you copy code from other
 * Harbour Project or Free Software Foundation releases into a copy of
 * Harbour, as the General Public License permits, the exception does
 * not apply to the code that you add in this way.  To avoid misleading
 * anyone as to the status of such modified files, you must delete
 * this exception notice from them.
 *
 * If you write modifications of your own for Harbour, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.
 *
 */

#ifndef HB_ATOMIC_H_
#define HB_ATOMIC_H_

#include "hbdefs.h"

#if defined( HB_OS_WIN )
// #  define _WINSOCKAPI_   /* Prevents inclusion of Winsock.h in Windows.h */
// Don't move, must precede any #include of Windows to fix CINTERFACE support in guiddef.h and propkeydef.h!!!
#  include "cinterface.h"
#  include <windows.h>
#elif defined( HB_OS_DARWIN )
#  include <libkern/OSAtomic.h>
#endif
#if defined( __SVR4 )
#  include <thread.h>
#endif
#if defined( HB_OS_UNIX ) && !defined( __WATCOMC__ )
#  include <sched.h>
#endif


HB_EXTERN_BEGIN

/* Inline assembler version of atomic operations on memory reference counters */
#if defined( __GNUC__ )

#  if ( defined( i386 ) || defined( __i386__ ) || defined( __x86_64__ ) )

#     if HB_COUNTER_SIZE == 4

         static __inline__ void hb_atomic_inc32( volatile int * p )
         {
            __asm__ __volatile__(
               "lock; incl %0\n"
               :"=m" (*p) :"m" (*p)
            );
         }

         static __inline__ int hb_atomic_dec32( volatile int * p )
         {
            unsigned char c;
            __asm__ __volatile__(
               "lock; decl %0\n"
               "sete %1\n"
               :"=m" (*p), "=qm" (c) :"m" (*p) : "memory"
            );
            return c == 0;
         }

#        define HB_ATOM_INC( p )    ( hb_atomic_inc32( ( volatile int * ) (p) ) )
#        define HB_ATOM_DEC( p )    ( hb_atomic_dec32( ( volatile int * ) (p) ) )
#        define HB_ATOM_GET( p )    (*(int volatile *)(p))
#        define HB_ATOM_SET( p, n ) do { *((int volatile *)(p)) = (n); } while(0)

#     elif HB_COUNTER_SIZE == 8

         static __inline__ void hb_atomic_inc64( volatile long long int * p )
         {
            __asm__ __volatile__(
               "lock; incq %0\n"
               :"=m" (*p) :"m" (*p)
            );
         }

         static __inline__ int hb_atomic_dec64( volatile long long int * p )
         {
            unsigned char c;
            __asm__ __volatile__(
               "lock; decq %0\n"
               "sete %1\n"
               :"=m" (*p), "=qm" (c) :"m" (*p) : "memory"
            );
            return c == 0;
         }

#        define HB_ATOM_INC( p )    ( hb_atomic_inc64( ( volatile long long int * ) (p) ) )
#        define HB_ATOM_DEC( p )    ( hb_atomic_dec64( ( volatile long long int * ) (p) ) )
#        define HB_ATOM_GET( p )    (*(long long int volatile *)(p))
#        define HB_ATOM_SET( p, n ) do { *((long long int volatile *)(p)) = (n); } while(0)

#     endif

      static __inline__ int hb_spinlock_trylock( volatile int * p )
      {
         int i = 1;
         __asm__ __volatile__(
            "xchgl %0, %1\n\t"
            : "=r" (i)
            : "m" (*p), "0" (i)
            : "memory"
         );
         return i;
      }

      static __inline__ void hb_spinlock_acquire( volatile int * l )
      {
         for( ;; )
         {
            if( !hb_spinlock_trylock( l ) )
               return;

            #ifdef HB_SPINLOCK_SLEEP
               if( !hb_spinlock_trylock( l ) )
                  return;
               #if defined( HB_OS_WIN )
                  Sleep( 0 );
               #elif defined( HB_OS_OS2 )
                  DosSleep( 0 );
               #elif defined( __SVR4 )
                  thr_yield();
               #elif defined( HB_OS_UNIX )
                  sched_yield();
               #else
                  sleep( 0 );
               #endif
            #endif
         }
      }

      static __inline__ void hb_spinlock_release( volatile int * l )
      {
         *l = 0;
      }

#     define HB_SPINLOCK_T          volatile int
#     define HB_SPINLOCK_INIT       0
#     define HB_SPINLOCK_ACQUIRE(l) hb_spinlock_acquire(l)
#     define HB_SPINLOCK_RELEASE(l) hb_spinlock_release(l)

#  elif ( ( __GNUC__ > 4 ) || ( __GNUC__ == 4 && __GNUC_MINOR__ >= 1) )

#     define HB_ATOM_INC( p )       __sync_add_and_fetch( (p), 1 )
#     define HB_ATOM_DEC( p )       __sync_sub_and_fetch( (p), 1 )
#     define HB_ATOM_GET( p )       ( *(p) )
#     define HB_ATOM_SET( p, n )    do { *(p) = (n); } while(0)

      static __inline__ void hb_spinlock_acquire( int * l )
      {
         for( ;; )
         {
            if( !__sync_lock_test_and_set( l, 1 ) )
               return;

            #ifdef HB_SPINLOCK_SLEEP
               if( !__sync_lock_test_and_set( l, 1 ) )
                  return;
               #if defined( HB_OS_WIN )
                  Sleep( 0 );
               #elif defined( HB_OS_OS2 )
                  DosSleep( 0 );
               #elif defined( __SVR4 )
                  thr_yield();
               #elif defined( HB_OS_UNIX )
                  sched_yield();
               #else
                  sleep( 0 );
               #endif
            #endif
         }
      }

#     define HB_SPINLOCK_T          int
#     define HB_SPINLOCK_INIT       0
#     define HB_SPINLOCK_ACQUIRE(l) hb_spinlock_acquire(l)
#     define HB_SPINLOCK_RELEASE(l) __sync_lock_release(l)

#  elif defined( __powerpc__ ) || defined( __ppc )

#     if HB_COUNTER_SIZE == 4

         static __inline__ void hb_atomic_inc32( volatile int * p )
         {
            int i;

            __asm__ __volatile__(
               "1:   lwarx    %0,0,%2\n\t"
               "     addic    %0,%0,1\n\t"
               "     stwcx.   %0,0,%2\n\t"
               "     bne-     1b\n\t"
               : "=&r" (i), "=m" (*p) : "r" (p), "m" (*p) : "cc"
            );
         }

         static __inline__ int hb_atomic_dec32( volatile int * p )
         {
            int i;

            __asm__ __volatile__(
               "1:   lwarx    %0,0,%1\n\t"
               "     addic    %0,%0,-1\n\t"
               "     stwcx.   %0,0,%1\n\t"
               "     bne-     1b\n\t"
               "     isync\n\t"
               : "=&r" (i) : "r" (p) : "cc", "memory"
            );
            return i;
         }

#        define HB_ATOM_INC( p )    ( hb_atomic_inc32( ( volatile int * ) (p) ) )
#        define HB_ATOM_DEC( p )    ( hb_atomic_dec32( ( volatile int * ) (p) ) )
#        define HB_ATOM_GET( p )    (*(int volatile *)(p))
#        define HB_ATOM_SET( p, n ) do { *((int volatile *)(p)) = (n); } while(0)

#     elif HB_COUNTER_SIZE == 8

         /* TODO: */

#     endif

#  endif  /* ???CPU?? */

#endif  /* __GNUC__ */


#if defined( HB_OS_WIN )

   /* Atomic operations on memory reference counters */
#  if !defined( HB_ATOM_INC ) || !defined( HB_ATOM_DEC )
#     undef HB_ATOM_DEC
#     undef HB_ATOM_INC
#     undef HB_ATOM_GET
#     undef HB_ATOM_SET
#     if HB_COUNTER_SIZE == 8
#        define HB_ATOM_INC( p )    (InterlockedIncrement64((LONGLONG *)(p)))
#        define HB_ATOM_DEC( p )    (InterlockedDecrement64((LONGLONG *)(p)))
#        define HB_ATOM_GET( p )    (*(LONGLONG volatile *)(p))
#        define HB_ATOM_SET( p, n ) do { (*(LONGLONG volatile *)(p)) = (n); } while(0)
#     else
#        define HB_ATOM_INC( p )    (InterlockedIncrement((LONG *)(p)))
#        define HB_ATOM_DEC( p )    (InterlockedDecrement((LONG *)(p)))
#        define HB_ATOM_GET( p )    (*(LONG volatile *)(p))
#        define HB_ATOM_SET( p, n ) do { (*(LONG volatile *)(p)) = (n); } while(0)
#     endif
#  endif

   /* Spin locks */
#  if !defined( HB_SPINLOCK_T )
#     define HB_SPINLOCK_T          volatile LONG
#     define HB_SPINLOCK_INIT       0
#     define HB_SPINLOCK_ACQUIRE(l) do { \
                                       for( ;; ) \
                                       { \
                                          if( !InterlockedExchange( (LONG *)(l), 1 ) ) \
                                             break; \
                                          if( !InterlockedExchange( (LONG *)(l), 1 ) ) \
                                             break; \
                                          Sleep( 0 ); \
                                       } \
                                    } while(0)
#     define HB_SPINLOCK_RELEASE(l) do { *(l) = 0; } while(0)
#  endif

#elif defined( HB_OS_DARWIN )

   /* Atomic operations on memory reference counters */
#  if !defined( HB_ATOM_INC ) || !defined( HB_ATOM_DEC )
#     undef HB_ATOM_DEC
#     undef HB_ATOM_INC
#     undef HB_ATOM_GET
#     undef HB_ATOM_SET
#     if HB_COUNTER_SIZE == 8
#        define HB_ATOM_INC( p )    (OSAtomicIncrement64((int64_t *)(p)))
#        define HB_ATOM_DEC( p )    (OSAtomicDecrement64((int64_t *)(p)))
#        define HB_ATOM_GET( p )    (*(int64_t volatile *)(p))
#        define HB_ATOM_SET( p, n ) do { *((int64_t volatile *)(p)) = (n); } while(0)
#     else
#        define HB_ATOM_INC( p )    (OSAtomicIncrement32((int32_t *)(p)))
#        define HB_ATOM_DEC( p )    (OSAtomicDecrement32((int32_t *)(p)))
#        define HB_ATOM_GET( p )    (*(volatile int32_t *)(p))
#        define HB_ATOM_SET( p, n ) do { *((volatile int32_t *)(p)) = (n); } while(0)
#     endif
#  endif

   /* Spin locks */
#  if !defined( HB_SPINLOCK_T ) || 1 /* <= force using OSSpinLock */
#     undef HB_SPINLOCK_T
#     undef HB_SPINLOCK_INIT
#     undef HB_SPINLOCK_ACQUIRE
#     undef HB_SPINLOCK_RELEASE
#     define HB_SPINLOCK_T          OSSpinLock
#     define HB_SPINLOCK_INIT       OS_SPINLOCK_INIT
#     define HB_SPINLOCK_ACQUIRE(l) OSSpinLockLock(l)
#     define HB_SPINLOCK_RELEASE(l) OSSpinLockUnlock(l)
#  endif

#endif  /* HB_OS_??? */

HB_EXTERN_END

#endif /* HB_ATOMIC_H_ */
