Boost C++ Libraries

boost/interprocess/sync/named_upgradable_mutex.hpp

//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2005-2008. 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.
//
//////////////////////////////////////////////////////////////////////////////

#ifndef BOOST_INTERPROCESS_named_upgradable_mutex_HPP
#define BOOST_INTERPROCESS_named_upgradable_mutex_HPP

#if (defined _MSC_VER) && (_MSC_VER >= 1200)
#  pragma once
#endif

#include <boost/interprocess/detail/config_begin.hpp>
#include <boost/interprocess/detail/workaround.hpp>
#include <boost/interprocess/creation_tags.hpp>
#include <boost/interprocess/exceptions.hpp>
#include <boost/interprocess/shared_memory_object.hpp>
#include <boost/interprocess/detail/managed_open_or_create_impl.hpp>
#include <boost/interprocess/sync/interprocess_upgradable_mutex.hpp>
#include <boost/interprocess/detail/posix_time_types_wrk.hpp>
#include <boost/interprocess/sync/emulation/named_creation_functor.hpp>

//!\file
//!Describes a named upgradable mutex class for inter-process synchronization

namespace boost {
namespace interprocess {

/// @cond
namespace detail{ class interprocess_tester; }
/// @endcond

class named_condition;

//!A upgradable mutex with a global name, so it can be found from different 
//!processes. This mutex can't be placed in shared memory, and
//!each process should have it's own named upgradable mutex.
class named_upgradable_mutex
{
   /// @cond
   //Non-copyable
   named_upgradable_mutex();
   named_upgradable_mutex(const named_upgradable_mutex &);
   named_upgradable_mutex &operator=(const named_upgradable_mutex &);
   friend class named_condition;
   /// @endcond
   public:

   //!Creates a global upgradable mutex with a name. 
   //!If the upgradable mutex can't be created throws interprocess_exception
   named_upgradable_mutex(create_only_t create_only, const char *name);

   //!Opens or creates a global upgradable mutex with a name, and an initial count. 
   //!If the upgradable mutex is created, this call is equivalent to
   //!named_upgradable_mutex(create_only_t, ...)
   //!If the upgradable mutex is already created, this call is equivalent to
   //!named_upgradable_mutex(open_only_t, ... ).
   named_upgradable_mutex(open_or_create_t open_or_create, const char *name);

   //!Opens a global upgradable mutex with a name if that upgradable mutex
   //!is previously.
   //!created. If it is not previously created this function throws
   //!interprocess_exception.
   named_upgradable_mutex(open_only_t open_only, const char *name);

   //!Destroys *this and indicates that the calling process is finished using
   //!the resource. The destructor function will deallocate
   //!any system resources allocated by the system for use by this process for
   //!this resource. The resource can still be opened again calling
   //!the open constructor overload. To erase the resource from the system
   //!use remove().
   ~named_upgradable_mutex();

   //Exclusive locking

   //!Effects: The calling thread tries to obtain exclusive ownership of the mutex,
   //!   and if another thread has exclusive, sharable or upgradable ownership of
   //!   the mutex, it waits until it can obtain the ownership.
   //!Throws: interprocess_exception on error.
   void lock();

   //!Effects: The calling thread tries to acquire exclusive ownership of the mutex
   //!   without waiting. If no other thread has exclusive, sharable or upgradable
   //!   ownership of the mutex this succeeds.
   //!Returns: If it can acquire exclusive ownership immediately returns true.
   //!   If it has to wait, returns false.
   //!Throws: interprocess_exception on error.
   bool try_lock();

   //!Effects: The calling thread tries to acquire exclusive ownership of the mutex
   //!   waiting if necessary until no other thread has has exclusive, sharable or
   //!   upgradable ownership of the mutex or abs_time is reached. 
   //!Returns: If acquires exclusive ownership, returns true. Otherwise returns false. 
   //!Throws: interprocess_exception on error.
   bool timed_lock(const boost::posix_time::ptime &abs_time);

   //!Precondition: The thread must have exclusive ownership of the mutex. 
   //!Effects: The calling thread releases the exclusive ownership of the mutex. 
   //!Throws: An exception derived from interprocess_exception on error.
   void unlock();

   //Sharable locking

   //!Effects: The calling thread tries to obtain sharable ownership of the mutex,
   //!   and if another thread has exclusive or upgradable ownership of the mutex,
   //!   waits until it can obtain the ownership.
   //!Throws: interprocess_exception on error.
   void lock_sharable();

   //!Effects: The calling thread tries to acquire sharable ownership of the mutex
   //!   without waiting. If no other thread has has exclusive or upgradable ownership
   //!   of the mutex this succeeds. 
   //!Returns: If it can acquire sharable ownership immediately returns true. If it
   //!   has to wait, returns false. 
   //!Throws: interprocess_exception on error.
   bool try_lock_sharable();

   //!Effects: The calling thread tries to acquire sharable ownership of the mutex
   //!   waiting if necessary until no other thread has has exclusive or upgradable
   //!   ownership of the mutex or abs_time is reached. 
   //!Returns: If acquires sharable ownership, returns true. Otherwise returns false. 
   //!Throws: interprocess_exception on error.
   bool timed_lock_sharable(const boost::posix_time::ptime &abs_time);

   //!Precondition: The thread must have sharable ownership of the mutex. 
   //!Effects: The calling thread releases the sharable ownership of the mutex. 
   //!Throws: An exception derived from interprocess_exception on error.
   void unlock_sharable();

   //Upgradable locking

   //!Effects: The calling thread tries to obtain upgradable ownership of the mutex,
   //!   and if another thread has exclusive or upgradable ownership of the mutex,
   //!   waits until it can obtain the ownership.
   //!Throws: interprocess_exception on error.
   void lock_upgradable();

   //!Effects: The calling thread tries to acquire upgradable ownership of the mutex
   //!   without waiting. If no other thread has has exclusive or upgradable ownership
   //!   of the mutex this succeeds. 
   //!Returns: If it can acquire upgradable ownership immediately returns true.
   //!   If it has to wait, returns false.
   //!Throws: interprocess_exception on error.
   bool try_lock_upgradable();

   //!Effects: The calling thread tries to acquire upgradable ownership of the mutex
   //!   waiting if necessary until no other thread has has exclusive or upgradable
   //!   ownership of the mutex or abs_time is reached.
   //!Returns: If acquires upgradable ownership, returns true. Otherwise returns false. 
   //!Throws: interprocess_exception on error.
   bool timed_lock_upgradable(const boost::posix_time::ptime &abs_time);

   //!Precondition: The thread must have upgradable ownership of the mutex. 
   //!Effects: The calling thread releases the upgradable ownership of the mutex. 
   //!Throws: An exception derived from interprocess_exception on error.
   void unlock_upgradable();

   //Demotions

   //!Precondition: The thread must have exclusive ownership of the mutex. 
   //!Effects: The thread atomically releases exclusive ownership and acquires
   //!   upgradable ownership. This operation is non-blocking. 
   //!Throws: An exception derived from interprocess_exception on error.
   void unlock_and_lock_upgradable();

   //!Precondition: The thread must have exclusive ownership of the mutex. 
   //!Effects: The thread atomically releases exclusive ownership and acquires
   //!   sharable ownership. This operation is non-blocking. 
   //!Throws: An exception derived from interprocess_exception on error.
   void unlock_and_lock_sharable();

   //!Precondition: The thread must have upgradable ownership of the mutex. 
   //!Effects: The thread atomically releases upgradable ownership and acquires
   //!   sharable ownership. This operation is non-blocking. 
   //!Throws: An exception derived from interprocess_exception on error.
   void unlock_upgradable_and_lock_sharable();

   //Promotions

   //!Precondition: The thread must have upgradable ownership of the mutex. 
   //!Effects: The thread atomically releases upgradable ownership and acquires
   //!   exclusive ownership. This operation will block until all threads with
   //!   sharable ownership release it. 
   //!Throws: An exception derived from interprocess_exception on error.
   void unlock_upgradable_and_lock();

   //!Precondition: The thread must have upgradable ownership of the mutex. 
   //!Effects: The thread atomically releases upgradable ownership and tries to
   //!   acquire exclusive ownership. This operation will fail if there are threads
   //!   with sharable ownership, but it will maintain upgradable ownership. 
   //!Returns: If acquires exclusive ownership, returns true. Otherwise returns false.
   //!Throws: An exception derived from interprocess_exception on error.
   bool try_unlock_upgradable_and_lock();

   //!Precondition: The thread must have upgradable ownership of the mutex. 
   //!Effects: The thread atomically releases upgradable ownership and tries to acquire
   //!   exclusive ownership, waiting if necessary until abs_time. This operation will
   //!   fail if there are threads with sharable ownership or timeout reaches, but it
   //!   will maintain upgradable ownership. 
   //!Returns: If acquires exclusive ownership, returns true. Otherwise returns false. 
   //!Throws: An exception derived from interprocess_exception on error.
   bool timed_unlock_upgradable_and_lock(const boost::posix_time::ptime &abs_time);

   //!Precondition: The thread must have sharable ownership of the mutex. 
   //!Effects: The thread atomically releases sharable ownership and tries to acquire
   //!   exclusive ownership. This operation will fail if there are threads with sharable
   //!   or upgradable ownership, but it will maintain sharable ownership.
   //!Returns: If acquires exclusive ownership, returns true. Otherwise returns false. 
   //!Throws: An exception derived from interprocess_exception on error.
   bool try_unlock_sharable_and_lock();

   bool try_unlock_sharable_and_lock_upgradable();

   //!Erases a named upgradable mutex from the system.
   //!Returns false on error. Never throws.
   static bool remove(const char *name);

   /// @cond
   private:
   friend class detail::interprocess_tester;
   void dont_close_on_destruction();

   interprocess_upgradable_mutex *mutex() const
   {  return static_cast<interprocess_upgradable_mutex*>(m_shmem.get_user_address()); }

   detail::managed_open_or_create_impl<shared_memory_object> m_shmem;
   typedef detail::named_creation_functor<interprocess_upgradable_mutex> construct_func_t;
   /// @endcond
};

/// @cond

inline named_upgradable_mutex::~named_upgradable_mutex()
{}

inline named_upgradable_mutex::named_upgradable_mutex
   (create_only_t, const char *name)
   :  m_shmem  (create_only
               ,name
               ,sizeof(interprocess_upgradable_mutex) +
                  detail::managed_open_or_create_impl<shared_memory_object>::
                     ManagedOpenOrCreateUserOffset
               ,read_write
               ,0
               ,construct_func_t(detail::DoCreate))
{}

inline named_upgradable_mutex::named_upgradable_mutex
   (open_or_create_t, const char *name)
   :  m_shmem  (open_or_create
               ,name
               ,sizeof(interprocess_upgradable_mutex) +
                  detail::managed_open_or_create_impl<shared_memory_object>::
                     ManagedOpenOrCreateUserOffset
               ,read_write
               ,0
               ,construct_func_t(detail::DoOpenOrCreate))
{}

inline named_upgradable_mutex::named_upgradable_mutex
   (open_only_t, const char *name)
   :  m_shmem  (open_only
               ,name
               ,read_write
               ,0
               ,construct_func_t(detail::DoOpen))
{}

inline void named_upgradable_mutex::dont_close_on_destruction()
{  detail::interprocess_tester::dont_close_on_destruction(m_shmem);  }

inline void named_upgradable_mutex::lock()
{  this->mutex()->lock();  }

inline void named_upgradable_mutex::unlock()
{  this->mutex()->unlock();  }

inline bool named_upgradable_mutex::try_lock()
{  return this->mutex()->try_lock();  }

inline bool named_upgradable_mutex::timed_lock
   (const boost::posix_time::ptime &abs_time)
{
   if(abs_time == boost::posix_time::pos_infin){
      this->lock();
      return true;
   }
   return this->mutex()->timed_lock(abs_time);
}

inline void named_upgradable_mutex::lock_upgradable()
{  this->mutex()->lock_upgradable();  }

inline void named_upgradable_mutex::unlock_upgradable()
{  this->mutex()->unlock_upgradable();  }

inline bool named_upgradable_mutex::try_lock_upgradable()
{  return this->mutex()->try_lock_upgradable();  }

inline bool named_upgradable_mutex::timed_lock_upgradable
   (const boost::posix_time::ptime &abs_time)
{
   if(abs_time == boost::posix_time::pos_infin){
      this->lock_upgradable();
      return true;
   }
   return this->mutex()->timed_lock_upgradable(abs_time);
}

inline void named_upgradable_mutex::lock_sharable()
{  this->mutex()->lock_sharable();  }

inline void named_upgradable_mutex::unlock_sharable()
{  this->mutex()->unlock_sharable();  }

inline bool named_upgradable_mutex::try_lock_sharable()
{  return this->mutex()->try_lock_sharable();  }

inline bool named_upgradable_mutex::timed_lock_sharable
   (const boost::posix_time::ptime &abs_time)
{
   if(abs_time == boost::posix_time::pos_infin){
      this->lock_sharable();
      return true;
   }
   return this->mutex()->timed_lock_sharable(abs_time);
}

inline void named_upgradable_mutex::unlock_and_lock_upgradable()
{  this->mutex()->unlock_and_lock_upgradable();  }

inline void named_upgradable_mutex::unlock_and_lock_sharable()
{  this->mutex()->unlock_and_lock_sharable();  }

inline void named_upgradable_mutex::unlock_upgradable_and_lock_sharable()
{  this->mutex()->unlock_upgradable_and_lock_sharable();  }

inline void named_upgradable_mutex::unlock_upgradable_and_lock()
{  this->mutex()->unlock_upgradable_and_lock();  }

inline bool named_upgradable_mutex::try_unlock_upgradable_and_lock()
{  return this->mutex()->try_unlock_upgradable_and_lock();  }

inline bool named_upgradable_mutex::timed_unlock_upgradable_and_lock
   (const boost::posix_time::ptime &abs_time)
{  return this->mutex()->timed_unlock_upgradable_and_lock(abs_time);  }

inline bool named_upgradable_mutex::try_unlock_sharable_and_lock()
{  return this->mutex()->try_unlock_sharable_and_lock();  }

inline bool named_upgradable_mutex::try_unlock_sharable_and_lock_upgradable()
{  return this->mutex()->try_unlock_sharable_and_lock_upgradable();  }

inline bool named_upgradable_mutex::remove(const char *name)
{  return shared_memory_object::remove(name); }

/// @endcond

}  //namespace interprocess {
}  //namespace boost {

#include <boost/interprocess/detail/config_end.hpp>

#endif   //BOOST_INTERPROCESS_named_upgradable_mutex_HPP