boost/libs/regex/src/static_mutex.cpp

   1 /*
   2  *
   3  * Copyright (c) 2004
   4  * John Maddock
   5  *
   6  * Use, modification and distribution are subject to the
   7  * Boost Software License, Version 1.0. (See accompanying file
   8  * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9  *
  10  */
  11
  12  /*
  13   *   LOCATION:    see http://www.boost.org for most recent version.
  14   *   FILE         static_mutex.cpp
  15   *   VERSION      see <boost/version.hpp>
  16   *   DESCRIPTION: Declares static_mutex lock type.
  17   */
  18
  19 #define BOOST_REGEX_SOURCE
  20 #include <boost/config.hpp>
  21
  22 #ifdef BOOST_HAS_THREADS
  23
  24 #include <boost/regex/pending/static_mutex.hpp>
  25
  26 #if defined(BOOST_HAS_WINTHREADS)
  27 #ifndef NOMINMAX
  28 #  define NOMINMAX
  29 #endif
  30 #define WIN32_LEAN_AND_MEAN
  31 #include <windows.h>
  32 #include <boost/static_assert.hpp>
  33 #endif
  34
  35
  36 namespace boost{
  37
  38 #if defined(BOOST_HAS_PTHREADS) && defined(PTHREAD_MUTEX_INITIALIZER)
  39
  40 scoped_static_mutex_lock::scoped_static_mutex_lock(static_mutex& m, bool lk)
  41 : m_mutex(m), m_have_lock(false)
  42 {
  43    if(lk)
  44       lock();
  45 }
  46
  47 scoped_static_mutex_lock::~scoped_static_mutex_lock()
  48 {
  49    if(m_have_lock)
  50       unlock();
  51 }
  52
  53 void scoped_static_mutex_lock::lock()
  54 {
  55    if(0 == m_have_lock)
  56    {
  57       pthread_mutex_lock(&(m_mutex.m_mutex));
  58       m_have_lock = true;
  59    }
  60 }
  61
  62 void scoped_static_mutex_lock::unlock()
  63 {
  64    if(m_have_lock)
  65    {
  66       pthread_mutex_unlock(&(m_mutex.m_mutex));
  67       m_have_lock = false;
  68    }
  69 }
  70
  71 #elif defined(BOOST_HAS_WINTHREADS)
  72
  73 BOOST_STATIC_ASSERT(sizeof(LONG) == sizeof(boost::int32_t));
  74
  75 scoped_static_mutex_lock::scoped_static_mutex_lock(static_mutex& m, bool lk)
  76 : m_mutex(m), m_have_lock(false)
  77 {
  78    if(lk)
  79       lock();
  80 }
  81
  82 scoped_static_mutex_lock::~scoped_static_mutex_lock()
  83 {
  84    if(m_have_lock)
  85       unlock();
  86 }
  87
  88 void scoped_static_mutex_lock::lock()
  89 {
  90    if(0 == m_have_lock)
  91    {
  92 #if !defined(InterlockedCompareExchangePointer)
  93       while(0 != InterlockedCompareExchange(reinterpret_cast<void**>((boost::uint_least16_t*)&(m_mutex.m_mutex)), (void*)1, 0))
  94 #else
  95       while(0 != InterlockedCompareExchange(reinterpret_cast<LONG*>(&(m_mutex.m_mutex)), 1, 0))
  96 #endif
  97       {
  98          Sleep(0);
  99       }
 100       m_have_lock = true;
 101    }
 102 }
 103
 104 void scoped_static_mutex_lock::unlock()
 105 {
 106    if(m_have_lock)
 107    {
 108 #if !defined(InterlockedCompareExchangePointer)
 109       InterlockedExchange((LONG*)&(m_mutex.m_mutex), 0);
 110 #else
 111       InterlockedExchange(reinterpret_cast<LONG*>(&(m_mutex.m_mutex)), 0);
 112 #endif
 113       m_have_lock = false;
 114    }
 115 }
 116
 117 #else
 118 //
 119 // Portable version of a static mutex based on Boost.Thread library:
 120 //
 121 #include <stdlib.h>
 122 #include <boost/assert.hpp>
 123
 124 boost::recursive_mutex* static_mutex::m_pmutex = 0;
 125 boost::once_flag static_mutex::m_once = BOOST_ONCE_INIT;
 126
 127 extern "C" BOOST_REGEX_DECL void free_static_mutex()
 128 {
 129    delete static_mutex::m_pmutex;
 130    static_mutex::m_pmutex = 0;
 131 }
 132
 133 void static_mutex::init()
 134 {
 135    m_pmutex = new boost::recursive_mutex();
 136    int r = atexit(free_static_mutex);
 137    BOOST_ASSERT(0 == r);
 138 }
 139
 140 scoped_static_mutex_lock::scoped_static_mutex_lock(static_mutex& , bool lk)
 141 : m_plock(0), m_have_lock(false)
 142 {
 143    if(lk)
 144       lock();
 145 }
 146
 147 scoped_static_mutex_lock::~scoped_static_mutex_lock()
 148 {
 149    if(m_have_lock)
 150       unlock();
 151    delete m_plock;
 152 }
 153
 154 void scoped_static_mutex_lock::lock()
 155 {
 156    if(0 == m_have_lock)
 157    {
 158        boost::call_once(static_mutex::m_once,&static_mutex::init);
 159       if(0 == m_plock)
 160          m_plock = new boost::recursive_mutex::scoped_lock(*static_mutex::m_pmutex, false);
 161       m_plock->lock();
 162       m_have_lock = true;
 163    }
 164 }
 165
 166 void scoped_static_mutex_lock::unlock()
 167 {
 168    if(m_have_lock)
 169    {
 170       m_plock->unlock();
 171       m_have_lock = false;
 172    }
 173 }
 174
 175 #endif
 176
 177 }
 178
 179 #endif // BOOST_HAS_THREADS