boost/interprocess/sync/interprocess_mutex.hpp
//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2005-2012. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/interprocess for documentation.
//
//////////////////////////////////////////////////////////////////////////////
//
// Parts of the pthread code come from Boost Threads code.
//
//////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_INTERPROCESS_MUTEX_HPP
#define BOOST_INTERPROCESS_MUTEX_HPP
/// @cond
#if (defined _MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif
#include <boost/interprocess/detail/config_begin.hpp>
#include <boost/interprocess/exceptions.hpp>
#include <boost/interprocess/detail/workaround.hpp>
#include <boost/interprocess/detail/posix_time_types_wrk.hpp>
#include <boost/assert.hpp>
#if !defined(BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION) && defined (BOOST_INTERPROCESS_POSIX_PROCESS_SHARED)
#include <boost/interprocess/sync/posix/mutex.hpp>
#define BOOST_INTERPROCESS_USE_POSIX
//Experimental...
#elif !defined(BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION) && defined (BOOST_INTERPROCESS_WINDOWS)
#include <boost/interprocess/sync/windows/mutex.hpp>
#define BOOST_INTERPROCESS_USE_WINDOWS
#elif !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
#include <boost/interprocess/sync/spin/mutex.hpp>
#define BOOST_INTERPROCESS_USE_GENERIC_EMULATION
namespace boost {
namespace interprocess {
namespace ipcdetail{
namespace robust_emulation_helpers {
template<class T>
class mutex_traits;
}}}}
#endif
/// @endcond
//!\file
//!Describes a mutex class that can be placed in memory shared by
//!several processes.
namespace boost {
namespace interprocess {
class interprocess_condition;
//!Wraps a interprocess_mutex that can be placed in shared memory and can be
//!shared between processes. Allows timed lock tries
class interprocess_mutex
{
/// @cond
//Non-copyable
interprocess_mutex(const interprocess_mutex &);
interprocess_mutex &operator=(const interprocess_mutex &);
friend class interprocess_condition;
public:
#if defined(BOOST_INTERPROCESS_USE_GENERIC_EMULATION)
#undef BOOST_INTERPROCESS_USE_GENERIC_EMULATION
typedef ipcdetail::spin_mutex internal_mutex_type;
private:
friend class ipcdetail::robust_emulation_helpers::mutex_traits<interprocess_mutex>;
void take_ownership(){ m_mutex.take_ownership(); }
public:
#elif defined(BOOST_INTERPROCESS_USE_POSIX)
#undef BOOST_INTERPROCESS_USE_POSIX
typedef ipcdetail::posix_mutex internal_mutex_type;
#elif defined(BOOST_INTERPROCESS_USE_WINDOWS)
#undef BOOST_INTERPROCESS_USE_WINDOWS
typedef ipcdetail::windows_mutex internal_mutex_type;
#else
#error "Unknown platform for interprocess_mutex"
#endif
/// @endcond
public:
//!Constructor.
//!Throws interprocess_exception on error.
interprocess_mutex();
//!Destructor. If any process uses the mutex after the destructor is called
//!the result is undefined. Does not throw.
~interprocess_mutex();
//!Effects: The calling thread tries to obtain ownership of the mutex, and
//! if another thread has ownership of the mutex, it waits until it can
//! obtain the ownership. If a thread takes ownership of the mutex the
//! mutex must be unlocked by the same mutex.
//!Throws: interprocess_exception on error.
void lock();
//!Effects: The calling thread tries to obtain ownership of the mutex, and
//! if another thread has ownership of the mutex returns immediately.
//!Returns: If the thread acquires ownership of the mutex, returns true, if
//! the another thread has ownership of the mutex, returns false.
//!Throws: interprocess_exception on error.
bool try_lock();
//!Effects: The calling thread will try to obtain exclusive ownership of the
//! mutex if it can do so in until the specified time is reached. If the
//! mutex supports recursive locking, the mutex must be unlocked the same
//! number of times it is locked.
//!Returns: If the thread acquires ownership of the mutex, returns true, if
//! the timeout expires returns false.
//!Throws: interprocess_exception on error.
bool timed_lock(const boost::posix_time::ptime &abs_time);
//!Effects: The calling thread releases the exclusive ownership of the mutex.
//!Throws: interprocess_exception on error.
void unlock();
/// @cond
internal_mutex_type &internal_mutex()
{ return m_mutex; }
const internal_mutex_type &internal_mutex() const
{ return m_mutex; }
private:
internal_mutex_type m_mutex;
/// @endcond
};
} //namespace interprocess {
} //namespace boost {
namespace boost {
namespace interprocess {
inline interprocess_mutex::interprocess_mutex(){}
inline interprocess_mutex::~interprocess_mutex(){}
inline void interprocess_mutex::lock()
{
#ifdef BOOST_INTERPROCESS_ENABLE_TIMEOUT_WHEN_LOCKING
boost::posix_time::ptime wait_time
= boost::posix_time::microsec_clock::universal_time()
+ boost::posix_time::milliseconds(BOOST_INTERPROCESS_TIMEOUT_WHEN_LOCKING_DURATION_MS);
if (!m_mutex.timed_lock(wait_time))
{
throw interprocess_exception(timeout_when_locking_error
, "Interprocess mutex timeout when locking. Possible deadlock: "
"owner died without unlocking?");
}
#else
m_mutex.lock();
#endif
}
inline bool interprocess_mutex::try_lock()
{ return m_mutex.try_lock(); }
inline bool interprocess_mutex::timed_lock(const boost::posix_time::ptime &abs_time)
{ return m_mutex.timed_lock(abs_time); }
inline void interprocess_mutex::unlock()
{ m_mutex.unlock(); }
} //namespace interprocess {
} //namespace boost {
#include <boost/interprocess/detail/config_end.hpp>
#endif //BOOST_INTERPROCESS_MUTEX_HPP