3rdparty/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 #include <boost/assert.hpp>
  22
  23 #ifdef BOOST_HAS_THREADS
  24
  25 #include <boost/regex/pending/static_mutex.hpp>
  26
  27 #if defined(BOOST_HAS_WINTHREADS)
  28 #ifndef NOMINMAX
  29 #  define NOMINMAX
  30 #endif
  31 #ifndef WIN32_LEAN_AND_MEAN
  32 #  define WIN32_LEAN_AND_MEAN
  33 #endif
  34 #include <windows.h>
  35 #include <boost/static_assert.hpp>
  36 #endif
  37
  38
  39 namespace boost{
  40
  41 #if defined(BOOST_HAS_PTHREADS) && defined(PTHREAD_MUTEX_INITIALIZER)
  42
  43 scoped_static_mutex_lock::scoped_static_mutex_lock(static_mutex& m, bool lk)
  44 : m_mutex(m), m_have_lock(false)
  45 {
  46    if(lk)
  47       lock();
  48 }
  49
  50 scoped_static_mutex_lock::~scoped_static_mutex_lock()
  51 {
  52    if(m_have_lock)
  53       unlock();
  54 }
  55
  56 void scoped_static_mutex_lock::lock()
  57 {
  58    if(0 == m_have_lock)
  59    {
  60       // Client code will throw if this fails:
  61       m_have_lock = (pthread_mutex_lock(&(m_mutex.m_mutex)) == 0);
  62    }
  63 }
  64
  65 void scoped_static_mutex_lock::unlock()
  66 {
  67    if(m_have_lock)
  68    {
  69       // If this fails there's nothing we can do except assert,
  70       // exceptions are out of the question as this code is called
  71       // from the lock's destructor:
  72       BOOST_VERIFY(pthread_mutex_unlock(&(m_mutex.m_mutex)) == 0);
  73       m_have_lock = false;
  74    }
  75 }
  76
  77 #elif defined(BOOST_HAS_WINTHREADS)
  78
  79 BOOST_STATIC_ASSERT(sizeof(LONG) == sizeof(boost::int32_t));
  80
  81 scoped_static_mutex_lock::scoped_static_mutex_lock(static_mutex& m, bool lk)
  82 : m_mutex(m), m_have_lock(false)
  83 {
  84    if(lk)
  85       lock();
  86 }
  87
  88 scoped_static_mutex_lock::~scoped_static_mutex_lock()
  89 {
  90    if(m_have_lock)
  91       unlock();
  92 }
  93
  94 void scoped_static_mutex_lock::lock()
  95 {
  96    if(0 == m_have_lock)
  97    {
  98 #if !defined(InterlockedCompareExchangePointer)
  99       while(0 != InterlockedCompareExchange(reinterpret_cast<void**>((boost::uint_least16_t*)&(m_mutex.m_mutex)), (void*)1, 0))
 100 #else
 101       while(0 != InterlockedCompareExchange(reinterpret_cast<LONG*>(&(m_mutex.m_mutex)), 1, 0))
 102 #endif
 103       {
 104          Sleep(0);
 105       }
 106       m_have_lock = true;
 107    }
 108 }
 109
 110 void scoped_static_mutex_lock::unlock()
 111 {
 112    if(m_have_lock)
 113    {
 114 #if !defined(InterlockedCompareExchangePointer)
 115       InterlockedExchange((LONG*)&(m_mutex.m_mutex), 0);
 116 #else
 117       InterlockedExchange(reinterpret_cast<LONG*>(&(m_mutex.m_mutex)), 0);
 118 #endif
 119       m_have_lock = false;
 120    }
 121 }
 122
 123 #else
 124 //
 125 // Portable version of a static mutex based on Boost.Thread library:
 126 //
 127 #include <stdlib.h>
 128 #include <boost/assert.hpp>
 129
 130 boost::recursive_mutex* static_mutex::m_pmutex = 0;
 131 boost::once_flag static_mutex::m_once = BOOST_ONCE_INIT;
 132
 133 extern "C" BOOST_REGEX_DECL void boost_regex_free_static_mutex()
 134 {
 135    delete static_mutex::m_pmutex;
 136    static_mutex::m_pmutex = 0;
 137 }
 138
 139 void static_mutex::init()
 140 {
 141    m_pmutex = new boost::recursive_mutex();
 142    int r = atexit(boost_regex_free_static_mutex);
 143    BOOST_ASSERT(0 == r);
 144 }
 145
 146 scoped_static_mutex_lock::scoped_static_mutex_lock(static_mutex& , bool lk)
 147 : m_plock(0), m_have_lock(false)
 148 {
 149    if(lk)
 150       lock();
 151 }
 152
 153 scoped_static_mutex_lock::~scoped_static_mutex_lock()
 154 {
 155    if(m_have_lock)
 156       unlock();
 157    delete m_plock;
 158 }
 159
 160 void scoped_static_mutex_lock::lock()
 161 {
 162    if(0 == m_have_lock)
 163    {
 164        boost::call_once(static_mutex::m_once,&static_mutex::init);
 165       if(0 == m_plock)
 166          m_plock = new boost::unique_lock<boost::recursive_mutex>(*static_mutex::m_pmutex, boost::defer_lock);
 167       m_plock->lock();
 168       m_have_lock = true;
 169    }
 170 }
 171
 172 void scoped_static_mutex_lock::unlock()
 173 {
 174    if(m_have_lock)
 175    {
 176       m_plock->unlock();
 177       m_have_lock = false;
 178    }
 179 }
 180
 181 #endif
 182
 183 }
 184
 185 #endif // BOOST_HAS_THREADS