boost/interprocess/sync/named_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_MUTEX_HPP #define BOOST_INTERPROCESS_NAMED_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/sync/emulation/named_creation_functor.hpp> #include <boost/interprocess/detail/interprocess_tester.hpp> #if defined(BOOST_INTERPROCESS_NAMED_MUTEX_USES_POSIX_SEMAPHORES) #include <boost/interprocess/sync/posix/semaphore_wrapper.hpp> #else #include <boost/interprocess/shared_memory_object.hpp> #include <boost/interprocess/sync/interprocess_mutex.hpp> #include <boost/interprocess/detail/managed_open_or_create_impl.hpp> #include <boost/interprocess/detail/posix_time_types_wrk.hpp> #endif //!\file //!Describes a named mutex class for inter-process synchronization namespace boost { namespace interprocess { class named_condition; //!A 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_mutex. class named_mutex { /// @cond //Non-copyable named_mutex(); named_mutex(const named_mutex &); named_mutex &operator=(const named_mutex &); friend class named_condition; /// @endcond public: //!Creates a global interprocess_mutex with a name. //!Throws interprocess_exception on error. named_mutex(create_only_t create_only, const char *name); //!Opens or creates a global mutex with a name. //!If the mutex is created, this call is equivalent to //!named_mutex(create_only_t, ... ) //!If the mutex is already created, this call is equivalent //!named_mutex(open_only_t, ... ) //!Does not throw named_mutex(open_or_create_t open_or_create, const char *name); //!Opens a global mutex with a name if that mutex is previously //!created. If it is not previously created this function throws //!interprocess_exception. named_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_mutex(); //!Unlocks a previously locked //!interprocess_mutex. void unlock(); //!Locks interprocess_mutex, sleeps when interprocess_mutex is already locked. //!Throws interprocess_exception if a severe error is found void lock(); //!Tries to lock the interprocess_mutex, returns false when interprocess_mutex //!is already locked, returns true when success. //!Throws interprocess_exception if a severe error is found bool try_lock(); //!Tries to lock the interprocess_mutex until time abs_time, //!Returns false when timeout expires, returns true when locks. //!Throws interprocess_exception if a severe error is found bool timed_lock(const boost::posix_time::ptime &abs_time); //!Erases a named 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(); #if defined(BOOST_INTERPROCESS_NAMED_MUTEX_USES_POSIX_SEMAPHORES) detail::named_semaphore_wrapper m_sem; #else interprocess_mutex *mutex() const { return static_cast<interprocess_mutex*>(m_shmem.get_user_address()); } detail::managed_open_or_create_impl<shared_memory_object> m_shmem; typedef detail::named_creation_functor<interprocess_mutex> construct_func_t; #endif /// @endcond }; /// @cond #if defined(BOOST_INTERPROCESS_NAMED_MUTEX_USES_POSIX_SEMAPHORES) inline named_mutex::named_mutex(create_only_t, const char *name) : m_sem(detail::DoCreate, name, read_write, 1) {} inline named_mutex::named_mutex(open_or_create_t, const char *name) : m_sem(detail::DoOpenOrCreate, name, read_write, 1) {} inline named_mutex::named_mutex(open_only_t, const char *name) : m_sem(detail::DoOpen, name, read_write, 1) {} inline void named_mutex::dont_close_on_destruction() { detail::interprocess_tester::dont_close_on_destruction(m_sem); } inline named_mutex::~named_mutex() {} inline void named_mutex::lock() { m_sem.wait(); } inline void named_mutex::unlock() { m_sem.post(); } inline bool named_mutex::try_lock() { return m_sem.try_wait(); } inline bool named_mutex::timed_lock(const boost::posix_time::ptime &abs_time) { if(abs_time == boost::posix_time::pos_infin){ this->lock(); return true; } return m_sem.timed_wait(abs_time); } inline bool named_mutex::remove(const char *name) { return detail::named_semaphore_wrapper::remove(name); } #else inline void named_mutex::dont_close_on_destruction() { detail::interprocess_tester::dont_close_on_destruction(m_shmem); } inline named_mutex::~named_mutex() {} inline named_mutex::named_mutex(create_only_t, const char *name) : m_shmem (create_only ,name ,sizeof(interprocess_mutex) + detail::managed_open_or_create_impl<shared_memory_object>:: ManagedOpenOrCreateUserOffset ,read_write ,0 ,construct_func_t(detail::DoCreate)) {} inline named_mutex::named_mutex(open_or_create_t, const char *name) : m_shmem (open_or_create ,name ,sizeof(interprocess_mutex) + detail::managed_open_or_create_impl<shared_memory_object>:: ManagedOpenOrCreateUserOffset ,read_write ,0 ,construct_func_t(detail::DoOpenOrCreate)) {} inline named_mutex::named_mutex(open_only_t, const char *name) : m_shmem (open_only ,name ,read_write ,0 ,construct_func_t(detail::DoOpen)) {} inline void named_mutex::lock() { this->mutex()->lock(); } inline void named_mutex::unlock() { this->mutex()->unlock(); } inline bool named_mutex::try_lock() { return this->mutex()->try_lock(); } inline bool named_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 bool named_mutex::remove(const char *name) { return shared_memory_object::remove(name); } #endif /// @endcond } //namespace interprocess { } //namespace boost { #include <boost/interprocess/detail/config_end.hpp> #endif //BOOST_INTERPROCESS_NAMED_MUTEX_HPP