blocxx

AtomicOps.cpp

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00001 /*******************************************************************************
00002 * Copyright (C) 2005, Vintela, Inc. All rights reserved.
00003 * Copyright (C) 2006, Novell, Inc. All rights reserved.
00004 * 
00005 * Redistribution and use in source and binary forms, with or without
00006 * modification, are permitted provided that the following conditions are met:
00007 * 
00008 *     * Redistributions of source code must retain the above copyright notice,
00009 *       this list of conditions and the following disclaimer.
00010 *     * Redistributions in binary form must reproduce the above copyright
00011 *       notice, this list of conditions and the following disclaimer in the
00012 *       documentation and/or other materials provided with the distribution.
00013 *     * Neither the name of 
00014 *       Vintela, Inc., 
00015 *       nor Novell, Inc., 
00016 *       nor the names of its contributors or employees may be used to 
00017 *       endorse or promote products derived from this software without 
00018 *       specific prior written permission.
00019 * 
00020 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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00022 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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00032 
00033 
00038 #include "blocxx/BLOCXX_config.h"
00039 #include "blocxx/AtomicOps.hpp"
00040 
00041 #if defined(BLOCXX_USE_PTHREAD_SPIN_LOCK_ATOMIC_OPS)
00042 
00043 namespace BLOCXX_NAMESPACE
00044 {
00045 
00046 Atomic_t::Atomic_t()
00047    : val(0)
00048 {
00049    pthread_spin_init(&spinlock, 0);
00050 }
00051 Atomic_t::Atomic_t(int i)
00052    : val(i)
00053 {
00054    pthread_spin_init(&spinlock, 0);
00055 }
00056 void AtomicInc(Atomic_t &v)
00057 {
00058    pthread_spin_lock(&v.spinlock);
00059    ++v.val;
00060    pthread_spin_unlock(&v.spinlock);
00061 }
00062 bool AtomicDecAndTest(Atomic_t &v)
00063 {
00064    pthread_spin_lock(&v.spinlock);
00065    --v.val;
00066    bool b = ((v.val == 0) ? true : false) ;
00067    pthread_spin_unlock(&v.spinlock);
00068    return b;
00069 }
00070 int AtomicGet(Atomic_t const &v)
00071 {
00072    return v.val;
00073 }
00074 void AtomicDec(Atomic_t &v)
00075 {
00076    pthread_spin_lock(&v.spinlock);
00077    --v.val;
00078    pthread_spin_unlock(&v.spinlock);
00079 }
00080 
00081 } // end namespace BLOCXX_NAMESPACE
00082 
00083 #elif defined(BLOCXX_USE_BLOCXX_DEFAULT_ATOMIC_OPS)
00084 #include "blocxx/Mutex.hpp"
00085 #include "blocxx/MutexLock.hpp"
00086 #include "blocxx/ThreadOnce.hpp"
00087 
00088 namespace BLOCXX_NAMESPACE
00089 {
00090 
00091 // this needs to be a pointer because of static initialization order conflicts.  
00092 // It shouldn't ever be deleted b/c it may be referenced by a destructor of a 
00093 // static variable that is being deleted.
00094 static Mutex* guard = 0;
00095 static OnceFlag g_once = BLOCXX_ONCE_INIT;
00096 static void initGuard()
00097 {
00098    guard = new Mutex();
00099 }
00100 void AtomicInc(Atomic_t &v)
00101 {
00102    callOnce(g_once, initGuard);
00103    MutexLock lock(*guard);
00104    ++v.val;
00105 }
00106 bool AtomicDecAndTest(Atomic_t &v)
00107 {
00108    callOnce(g_once, initGuard);
00109    MutexLock lock(*guard);
00110    return --v.val == 0;
00111 }
00112 int AtomicGet(Atomic_t const &v)
00113 {
00114    callOnce(g_once, initGuard);
00115    MutexLock lock(*guard);
00116    return v.val;
00117 }
00118 void AtomicDec(Atomic_t &v)
00119 {
00120    callOnce(g_once, initGuard);
00121    MutexLock lock(*guard);
00122    --v.val;
00123 }
00124 
00125 } // end namespace BLOCXX_NAMESPACE
00126 
00127 #endif
00128 
00129