ceph/src/boost/libs/interprocess/include/boost/interprocess/sync/interprocess_mutex.hpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2005-2012. Distributed under the Boost
   4 // Software License, Version 1.0. (See accompanying file
   5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/interprocess for documentation.
   8 //
   9 //////////////////////////////////////////////////////////////////////////////
  10 //
  11 // Parts of the pthread code come from Boost Threads code.
  12 //
  13 //////////////////////////////////////////////////////////////////////////////
  14
  15 #ifndef BOOST_INTERPROCESS_MUTEX_HPP
  16 #define BOOST_INTERPROCESS_MUTEX_HPP
  17
  18 #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
  19
  20 #ifndef BOOST_CONFIG_HPP
  21 #  include <boost/config.hpp>
  22 #endif
  23 #
  24 #if defined(BOOST_HAS_PRAGMA_ONCE)
  25 #  pragma once
  26 #endif
  27
  28 #include <boost/interprocess/detail/config_begin.hpp>
  29 #include <boost/interprocess/exceptions.hpp>
  30 #include <boost/interprocess/detail/workaround.hpp>
  31 #include <boost/interprocess/detail/posix_time_types_wrk.hpp>
  32 #include <boost/assert.hpp>
  33
  34 #if !defined(BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION) && defined (BOOST_INTERPROCESS_POSIX_PROCESS_SHARED)
  35    #include <boost/interprocess/sync/posix/mutex.hpp>
  36    #define BOOST_INTERPROCESS_USE_POSIX
  37 //Experimental...
  38 #elif !defined(BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION) && defined (BOOST_INTERPROCESS_WINDOWS)
  39    #include <boost/interprocess/sync/windows/mutex.hpp>
  40    #define BOOST_INTERPROCESS_USE_WINDOWS
  41 #elif !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
  42    #include <boost/interprocess/sync/spin/mutex.hpp>
  43    #define BOOST_INTERPROCESS_USE_GENERIC_EMULATION
  44
  45 namespace boost {
  46 namespace interprocess {
  47 namespace ipcdetail{
  48 namespace robust_emulation_helpers {
  49
  50 template<class T>
  51 class mutex_traits;
  52
  53 }}}}
  54
  55 #endif
  56
  57 #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
  58
  59 //!\file
  60 //!Describes a mutex class that can be placed in memory shared by
  61 //!several processes.
  62
  63 namespace boost {
  64 namespace interprocess {
  65
  66 class interprocess_condition;
  67
  68 //!Wraps a interprocess_mutex that can be placed in shared memory and can be
  69 //!shared between processes. Allows timed lock tries
  70 class interprocess_mutex
  71 {
  72    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
  73    //Non-copyable
  74    interprocess_mutex(const interprocess_mutex &);
  75    interprocess_mutex &operator=(const interprocess_mutex &);
  76    friend class interprocess_condition;
  77
  78    public:
  79    #if defined(BOOST_INTERPROCESS_USE_GENERIC_EMULATION)
  80       #undef BOOST_INTERPROCESS_USE_GENERIC_EMULATION
  81       typedef ipcdetail::spin_mutex internal_mutex_type;
  82       private:
  83       friend class ipcdetail::robust_emulation_helpers::mutex_traits<interprocess_mutex>;
  84       void take_ownership(){ m_mutex.take_ownership(); }
  85       public:
  86    #elif defined(BOOST_INTERPROCESS_USE_POSIX)
  87       #undef BOOST_INTERPROCESS_USE_POSIX
  88       typedef ipcdetail::posix_mutex internal_mutex_type;
  89    #elif defined(BOOST_INTERPROCESS_USE_WINDOWS)
  90       #undef BOOST_INTERPROCESS_USE_WINDOWS
  91       typedef ipcdetail::windows_mutex internal_mutex_type;
  92    #else
  93       #error "Unknown platform for interprocess_mutex"
  94    #endif
  95
  96    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
  97    public:
  98
  99    //!Constructor.
 100    //!Throws interprocess_exception on error.
 101    interprocess_mutex();
 102
 103    //!Destructor. If any process uses the mutex after the destructor is called
 104    //!the result is undefined. Does not throw.
 105    ~interprocess_mutex();
 106
 107    //!Effects: The calling thread tries to obtain ownership of the mutex, and
 108    //!   if another thread has ownership of the mutex, it waits until it can
 109    //!   obtain the ownership. If a thread takes ownership of the mutex the
 110    //!   mutex must be unlocked by the same mutex.
 111    //!Throws: interprocess_exception on error.
 112    void lock();
 113
 114    //!Effects: The calling thread tries to obtain ownership of the mutex, and
 115    //!   if another thread has ownership of the mutex returns immediately.
 116    //!Returns: If the thread acquires ownership of the mutex, returns true, if
 117    //!   the another thread has ownership of the mutex, returns false.
 118    //!Throws: interprocess_exception on error.
 119    bool try_lock();
 120
 121    //!Effects: The calling thread will try to obtain exclusive ownership of the
 122    //!   mutex if it can do so in until the specified time is reached. If the
 123    //!   mutex supports recursive locking, the mutex must be unlocked the same
 124    //!   number of times it is locked.
 125    //!Returns: If the thread acquires ownership of the mutex, returns true, if
 126    //!   the timeout expires returns false.
 127    //!Throws: interprocess_exception on error.
 128    bool timed_lock(const boost::posix_time::ptime &abs_time);
 129
 130    //!Effects: The calling thread releases the exclusive ownership of the mutex.
 131    //!Throws: interprocess_exception on error.
 132    void unlock();
 133
 134    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
 135    internal_mutex_type &internal_mutex()
 136    {  return m_mutex;   }
 137
 138    const internal_mutex_type &internal_mutex() const
 139    {  return m_mutex;   }
 140
 141    private:
 142    internal_mutex_type m_mutex;
 143    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
 144 };
 145
 146 }  //namespace interprocess {
 147 }  //namespace boost {
 148
 149
 150 namespace boost {
 151 namespace interprocess {
 152
 153 inline interprocess_mutex::interprocess_mutex(){}
 154
 155 inline interprocess_mutex::~interprocess_mutex(){}
 156
 157 inline void interprocess_mutex::lock()
 158 {
 159    #ifdef BOOST_INTERPROCESS_ENABLE_TIMEOUT_WHEN_LOCKING
 160       boost::posix_time::ptime wait_time
 161          = microsec_clock::universal_time()
 162          + boost::posix_time::milliseconds(BOOST_INTERPROCESS_TIMEOUT_WHEN_LOCKING_DURATION_MS);
 163       if (!m_mutex.timed_lock(wait_time))
 164       {
 165          throw interprocess_exception(timeout_when_locking_error
 166                                      , "Interprocess mutex timeout when locking. Possible deadlock: "
 167                                        "owner died without unlocking?");
 168       }
 169    #else
 170       m_mutex.lock();
 171    #endif
 172 }
 173
 174 inline bool interprocess_mutex::try_lock()
 175 { return m_mutex.try_lock(); }
 176
 177 inline bool interprocess_mutex::timed_lock(const boost::posix_time::ptime &abs_time)
 178 { return m_mutex.timed_lock(abs_time); }
 179
 180 inline void interprocess_mutex::unlock()
 181 { m_mutex.unlock(); }
 182
 183 }  //namespace interprocess {
 184 }  //namespace boost {
 185
 186 #include <boost/interprocess/detail/config_end.hpp>
 187
 188 #endif   //BOOST_INTERPROCESS_MUTEX_HPP