sal/osl/unx/interlck.c

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20
  21 #include "system.h"
  22
  23 #include <osl/interlck.h>
  24 #include <osl/diagnose.h>
  25
  26 #if  ( defined ( SOLARIS ) || defined ( NETBSD ) ) && defined ( SPARC )
  27 #error please use asm/interlck_sparc.s
  28 #elif defined ( SOLARIS) && defined ( X86 )
  29 #error please use asm/interlck_x86.s
  30 #elif defined ( __GNUC__ ) && ( defined ( X86 ) || defined ( X86_64 ) )
  31 /* That's possible on x86-64 too since oslInterlockedCount is a sal_Int32 */
  32
  33 extern int osl_isSingleCPU;
  34
  35 oslInterlockedCount SAL_CALL osl_incrementInterlockedCount(oslInterlockedCount* pCount)
  36 {
  37     // Fast case for old, slow, single CPU Intel machines for whom
  38     // interlocking is a performance nightmare.
  39     if ( osl_isSingleCPU ) {
  40         register oslInterlockedCount nCount asm("%eax");
  41         nCount = 1;
  42         __asm__ __volatile__ (
  43             "xaddl %0, %1\n\t"
  44         :   "+r" (nCount), "+m" (*pCount)
  45         :   /* nothing */
  46         :   "memory");
  47         return ++nCount;
  48     }
  49 #if HAVE_GCC_BUILTIN_ATOMIC
  50     else
  51         return __sync_add_and_fetch (pCount, 1);
  52 #else
  53     else {
  54         register oslInterlockedCount nCount asm("%eax");
  55         nCount = 1;
  56         __asm__ __volatile__ (
  57             "lock\n\t"
  58             "xaddl %0, %1\n\t"
  59         :   "+r" (nCount), "+m" (*pCount)
  60         :   /* nothing */
  61         :   "memory");
  62         return ++nCount;
  63     }
  64 #endif
  65 }
  66
  67 oslInterlockedCount SAL_CALL osl_decrementInterlockedCount(oslInterlockedCount* pCount)
  68 {
  69     if ( osl_isSingleCPU ) {
  70         register oslInterlockedCount nCount asm("%eax");
  71         nCount = -1;
  72         __asm__ __volatile__ (
  73             "xaddl %0, %1\n\t"
  74         :   "+r" (nCount), "+m" (*pCount)
  75         :   /* nothing */
  76         :   "memory");
  77         return --nCount;
  78     }
  79 #if HAVE_GCC_BUILTIN_ATOMIC
  80     else
  81         return __sync_sub_and_fetch (pCount, 1);
  82 #else
  83     else {
  84         register oslInterlockedCount nCount asm("%eax");
  85         nCount = -1;
  86         __asm__ __volatile__ (
  87             "lock\n\t"
  88             "xaddl %0, %1\n\t"
  89         :   "+r" (nCount), "+m" (*pCount)
  90         :   /* nothing */
  91         :   "memory");
  92         return --nCount;
  93     }
  94 #endif
  95 }
  96 #elif HAVE_GCC_BUILTIN_ATOMIC
  97 oslInterlockedCount SAL_CALL osl_incrementInterlockedCount(oslInterlockedCount* pCount)
  98 {
  99     return __sync_add_and_fetch(pCount, 1);
 100 }
 101 oslInterlockedCount SAL_CALL osl_decrementInterlockedCount(oslInterlockedCount* pCount)
 102 {
 103     return __sync_sub_and_fetch(pCount, 1);
 104 }
 105 #else
 106 /* use only if nothing else works, expensive due to single mutex for all reference counts */
 107
 108 static pthread_mutex_t InterLock = PTHREAD_MUTEX_INITIALIZER;
 109
 110 oslInterlockedCount SAL_CALL osl_incrementInterlockedCount(oslInterlockedCount* pCount)
 111 {
 112     oslInterlockedCount Count;
 113
 114     pthread_mutex_lock(&InterLock);
 115     Count = ++(*pCount);
 116     pthread_mutex_unlock(&InterLock);
 117
 118     return (Count);
 119 }
 120
 121 oslInterlockedCount SAL_CALL osl_decrementInterlockedCount(oslInterlockedCount* pCount)
 122 {
 123     oslInterlockedCount Count;
 124
 125     pthread_mutex_lock(&InterLock);
 126     Count = --(*pCount);
 127     pthread_mutex_unlock(&InterLock);
 128
 129     return (Count);
 130 }
 131
 132 #endif /* default */
 133
 134 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */