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 /*
  *                Copyright Lingxi Li 2015.
  *             Copyright Andrey Semashev 2016.
  * 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)
  */
 /*!
  * \file   utility/ipc/reliable_message_queue.hpp
  * \author Lingxi Li
  * \author Andrey Semashev
  * \date   01.01.2016
  *
  * The header contains declaration of a reliable interprocess message queue.
  */
 
 #ifndef BOOST_LOG_UTILITY_IPC_RELIABLE_MESSAGE_QUEUE_HPP_INCLUDED_
 #define BOOST_LOG_UTILITY_IPC_RELIABLE_MESSAGE_QUEUE_HPP_INCLUDED_
 
 #include <boost/log/detail/config.hpp>
 #include <cstddef>
 #include <boost/cstdint.hpp>
 #include <boost/move/core.hpp>
 #include <boost/log/keywords/open_mode.hpp>
 #include <boost/log/keywords/name.hpp>
 #include <boost/log/keywords/capacity.hpp>
 #include <boost/log/keywords/block_size.hpp>
 #include <boost/log/keywords/overflow_policy.hpp>
 #include <boost/log/keywords/permissions.hpp>
 #include <boost/log/utility/open_mode.hpp>
 #include <boost/log/utility/permissions.hpp>
 #include <boost/log/utility/ipc/object_name.hpp>
 #include <boost/log/detail/parameter_tools.hpp>
 #include <boost/log/detail/header.hpp>
 
 #ifdef BOOST_HAS_PRAGMA_ONCE
 #pragma once
 #endif
 
 namespace boost {
 
 BOOST_LOG_OPEN_NAMESPACE
 
 namespace ipc {
 
 namespace aux {
 
 template< typename T, typename R >
 struct enable_if_byte {};
 template< typename R >
 struct enable_if_byte< char, R > { typedef R type; };
 template< typename R >
 struct enable_if_byte< signed char, R > { typedef R type; };
 template< typename R >
 struct enable_if_byte< unsigned char, R > { typedef R type; };
 #if defined(__cpp_lib_byte) && __cpp_lib_byte >= 201603
 template< typename R >
 struct enable_if_byte< std::byte, R > { typedef R type; };
 #endif
 
 } // namespace aux
 
 /*!
  * \brief A reliable interprocess message queue
  *
  * The queue implements a reliable one-way channel of passing messages from one or multiple writers to a single reader.
  * The format of the messages is user-defined and must be consistent across all writers and the reader. The queue does
  * not enforce any specific format of the messages, other than they should be supplied as a contiguous array of bytes.
  *
  * The queue internally uses a process-shared storage identified by an \c object_name (the queue name). Refer to \c object_name
  * documentation for details on restrictions imposed on object names.
  *
  * The queue storage is organized as a fixed number of blocks of a fixed size. The block size must be an integer power of 2 and
  * is expressed in bytes. Each written message, together with some metadata added by the queue, consumes an integer number
  * of blocks. Each read message received by the reader releases the blocks allocated for that message. As such the maximum size
  * of a message is slightly less than block size times capacity of the queue. For efficiency, it is recommended to choose
  * block size large enough to accommodate most of the messages to be passed through the queue.
  *
  * The queue is considered empty when no messages are enqueued (all blocks are free). The queue is considered full at the point
  * of enqueueing a message when there is not enough free blocks to accommodate the message.
  *
  * The queue is reliable in that it will not drop successfully sent messages that are not received by the reader, other than the
  * case when a non-empty queue is destroyed by the last user. If a message cannot be enqueued by the writer because the queue is
  * full, the queue can either block the writer or return an error or throw an exception, depending on the policy specified at
  * the queue creation. The policy is object local, i.e. different writers and the reader can have different overflow policies.
  *
  * If the queue is empty and the reader attempts to dequeue a message, it will block until a message is enqueued by a writer.
  *
  * A blocked reader or writer can be unblocked by calling \c stop_local. After this method is called, all threads blocked on
  * this particular object are released and return \c operation_result::aborted. The other instances of the queue (in the current
  * or other processes) are unaffected. In order to restore the normal functioning of the queue instance after the \c stop_local
  * call the user has to invoke \c reset_local.
  *
  * The queue does not guarantee any particular order of received messages from different writer threads. Messages sent by a
  * particular writer thread will be received in the order of sending.
  *
  * Methods of this class are not thread-safe, unless otherwise specified.
  */
 class reliable_message_queue
 {
 public:
     //! Result codes for various operations on the queue
     enum operation_result
     {
         succeeded,    //!< The operation has completed successfully
         no_space,     //!< The message could not be sent because the queue is full
         aborted       //!< The operation has been aborted because the queue method <tt>stop_local()</tt> has been called
     };
 
     //! Interprocess queue overflow policies
     enum overflow_policy
     {
         //! Block the send operation when the queue is full
         block_on_overflow,
         //! Return \c operation_result::no_space when the queue is full
         fail_on_overflow,
         //! Throw \c capacity_limit_reached exception when the queue is full
         throw_on_overflow
     };
 
     //! Queue message size type
     typedef uint32_t size_type;
 
 #if !defined(BOOST_LOG_DOXYGEN_PASS)
 
     BOOST_MOVABLE_BUT_NOT_COPYABLE(reliable_message_queue)
 
 private:
     typedef void (*receive_handler)(void* state, const void* data, size_type size);
 
     struct fixed_buffer_state
     {
         uint8_t* data;
         size_type size;
     };
 
     struct implementation;
     implementation* m_impl;
 
 #endif // !defined(BOOST_LOG_DOXYGEN_PASS)
 
 public:
     /*!
      * Default constructor. The method constructs an object that is not associated with any
      * message queue.
      *
      * \post <tt>is_open() == false</tt>
      */
     BOOST_CONSTEXPR reliable_message_queue() BOOST_NOEXCEPT : m_impl(NULL)
     {
     }
 
     /*!
      * Constructor. The method is used to construct an object and create the associated
      * message queue. The constructed object will be in running state if the message queue is
      * successfully created.
      *
      * \post <tt>is_open() == true</tt>
      *
      * \param name Name of the message queue to be associated with.
      * \param capacity Maximum number of allocation blocks the queue can hold.
      * \param block_size Size in bytes of allocation block. Must be a power of 2.
      * \param oflow_policy Queue behavior policy in case of overflow.
      * \param perms Access permissions for the associated message queue.
      */
     reliable_message_queue
     (
         open_mode::create_only_tag,
         object_name const& name,
         uint32_t capacity,
         size_type block_size,
         overflow_policy oflow_policy = block_on_overflow,
         permissions const& perms = permissions()
     ) :
         m_impl(NULL)
     {
         this->create(name, capacity, block_size, oflow_policy, perms);
     }
 
     /*!
      * Constructor. The method is used to construct an object and create or open the associated
      * message queue. The constructed object will be in running state if the message queue is
      * successfully created or opened. If the message queue that is identified by the name already
      * exists then the other queue parameters are ignored. The actual queue parameters can be obtained
      * with accessors from the constructed object.
      *
      * \post <tt>is_open() == true</tt>
      *
      * \param name Name of the message queue to be associated with.
      * \param capacity Maximum number of allocation blocks the queue can hold.
      * \param block_size Size in bytes of allocation block. Must be a power of 2.
      * \param oflow_policy Queue behavior policy in case of overflow.
      * \param perms Access permissions for the associated message queue.
      */
     reliable_message_queue
     (
         open_mode::open_or_create_tag,
         object_name const& name,
         uint32_t capacity,
         size_type block_size,
         overflow_policy oflow_policy = block_on_overflow,
         permissions const& perms = permissions()
     ) :
         m_impl(NULL)
     {
         this->open_or_create(name, capacity, block_size, oflow_policy, perms);
     }
 
     /*!
      * Constructor. The method is used to construct an object and open the existing
      * message queue. The constructed object will be in running state if the message queue is
      * successfully opened.
      *
      * \post <tt>is_open() == true</tt>
      *
      * \param name Name of the message queue to be associated with.
      * \param oflow_policy Queue behavior policy in case of overflow.
      * \param perms Access permissions for the associated message queue. The permissions will only be used
      *              if the queue implementation has to create system objects while operating.
      *              This parameter is currently not used on POSIX systems.
      */
     reliable_message_queue
     (
         open_mode::open_only_tag,
         object_name const& name,
         overflow_policy oflow_policy = block_on_overflow,
         permissions const& perms = permissions()
     ) :
         m_impl(NULL)
     {
         this->open(name, oflow_policy, perms);
     }
 
     /*!
      * Constructor with named parameters. The method is used to construct an object and create or open
      * the associated message queue. The constructed object will be in running state if the message queue is
      * successfully created.
      *
      * The following named parameters are accepted:
      *
      * * open_mode - One of the open mode tags: \c open_mode::create_only, \c open_mode::open_only or
      *               \c open_mode::open_or_create.
      * * name - Name of the message queue to be associated with.
      * * capacity - Maximum number of allocation blocks the queue can hold. Used only if the queue is created.
      * * block_size - Size in bytes of allocation block. Must be a power of 2. Used only if the queue is created.
      * * overflow_policy - Queue behavior policy in case of overflow, see \c overflow_policy.
      * * permissions - Access permissions for the associated message queue.
      *
      * \post <tt>is_open() == true</tt>
      */
 #if !defined(BOOST_LOG_DOXYGEN_PASS)
     BOOST_LOG_PARAMETRIZED_CONSTRUCTORS_CALL(reliable_message_queue, construct)
 #else
     template< typename... Args >
     explicit reliable_message_queue(Args const&... args);
 #endif
 
     /*!
      * Destructor. Calls <tt>close()</tt>.
      */
     ~reliable_message_queue() BOOST_NOEXCEPT
     {
         this->close();
     }
 
     /*!
      * Move constructor. The method move-constructs an object from \c other. After
      * the call, the constructed object becomes \c other, while \c other is left in
      * default constructed state.
      *
      * \param that The object to be moved.
      */
     reliable_message_queue(BOOST_RV_REF(reliable_message_queue) that) BOOST_NOEXCEPT :
         m_impl(that.m_impl)
     {
         that.m_impl = NULL;
     }
 
     /*!
      * Move assignment operator. If the object is associated with a message queue,
      * <tt>close()</tt> is first called and the precondition to calling <tt>close()</tt>
      * applies. After the call, the object becomes \a that while \a that is left
      * in default constructed state.
      *
      * \param that The object to be moved.
      *
      * \return A reference to the assigned object.
      */
     reliable_message_queue& operator= (BOOST_RV_REF(reliable_message_queue) that) BOOST_NOEXCEPT
     {
         reliable_message_queue other(static_cast< BOOST_RV_REF(reliable_message_queue) >(that));
         this->swap(other);
         return *this;
     }
 
     /*!
      * The method swaps the object with \a that.
      *
      * \param that The other object to swap with.
      */
     void swap(reliable_message_queue& that) BOOST_NOEXCEPT
     {
         implementation* p = m_impl;
         m_impl = that.m_impl;
         that.m_impl = p;
     }
 
     //! Swaps the two \c reliable_message_queue objects.
     friend void swap(reliable_message_queue& a, reliable_message_queue& b) BOOST_NOEXCEPT
     {
         a.swap(b);
     }
 
     /*!
      * The method creates the message queue to be associated with the object. After the call,
      * the object will be in running state if a message queue is successfully created.
      *
      * \pre <tt>is_open() == false</tt>
      * \post <tt>is_open() == true</tt>
      *
      * \param name Name of the message queue to be associated with.
      * \param capacity Maximum number of allocation blocks the queue can hold.
      * \param block_size Size in bytes of allocation block. Must be a power of 2.
      * \param oflow_policy Queue behavior policy in case of overflow.
      * \param perms Access permissions for the associated message queue.
      */
     BOOST_LOG_API void create
     (
         object_name const& name,
         uint32_t capacity,
         size_type block_size,
         overflow_policy oflow_policy = block_on_overflow,
         permissions const& perms = permissions()
     );
 
     /*!
      * The method creates or opens the message queue to be associated with the object.
      * After the call, the object will be in running state if a message queue is successfully
      * created or opened. If the message queue that is identified by the name already exists then
      * the other queue parameters are ignored. The actual queue parameters can be obtained
      * with accessors from this object after this method returns.
      *
      * \pre <tt>is_open() == false</tt>
      * \post <tt>is_open() == true</tt>
      *
      * \param name Name of the message queue to be associated with.
      * \param capacity Maximum number of allocation blocks the queue can hold.
      * \param block_size Size in bytes of allocation block. Must be a power of 2.
      * \param oflow_policy Queue behavior policy in case of overflow.
      * \param perms Access permissions for the associated message queue.
      */
     BOOST_LOG_API void open_or_create
     (
         object_name const& name,
         uint32_t capacity,
         size_type block_size,
         overflow_policy oflow_policy = block_on_overflow,
         permissions const& perms = permissions()
     );
 
     /*!
      * The method opens the existing message queue to be associated with the object.
      * After the call, the object will be in running state if a message queue is successfully
      * opened.
      *
      * \pre <tt>is_open() == false</tt>
      * \post <tt>is_open() == true</tt>
      *
      * \param name Name of the message queue to be associated with.
      * \param oflow_policy Queue behavior policy in case of overflow.
      * \param perms Access permissions for the associated message queue. The permissions will only be used
      *              if the queue implementation has to create system objects while operating.
      *              This parameter is currently not used on POSIX systems.
      */
     BOOST_LOG_API void open
     (
         object_name const& name,
         overflow_policy oflow_policy = block_on_overflow,
         permissions const& perms = permissions()
     );
 
     /*!
      * Tests whether the object is associated with any message queue.
      *
      * \return \c true if the object is associated with a message queue, and \c false otherwise.
      */
     bool is_open() const BOOST_NOEXCEPT
     {
         return m_impl != NULL;
     }
 
     /*!
      * This method empties the associated message queue. Concurrent calls to this method, <tt>send()</tt>,
      * <tt>try_send()</tt>, <tt>receive()</tt>, <tt>try_receive()</tt>, and <tt>stop_local()</tt> are allowed.
      *
      * \pre <tt>is_open() == true</tt>
      */
     BOOST_LOG_API void clear();
 
     /*!
      * The method returns the name of the associated message queue.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \return Name of the associated message queue
      */
     BOOST_LOG_API object_name const& name() const;
 
     /*!
      * The method returns the maximum number of allocation blocks the associated message queue
      * can hold. Note that the returned value may be different from the corresponding
      * value passed to the constructor or <tt>open_or_create()</tt>, for the message queue may
      * not have been created by this object.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \return Maximum number of allocation blocks the associated message queue can hold.
      */
     BOOST_LOG_API uint32_t capacity() const;
 
     /*!
      * The method returns the allocation block size, in bytes. Each message in the
      * associated message queue consumes an integer number of allocation blocks.
      * Note that the returned value may be different from the corresponding value passed
      * to the constructor or <tt>open_or_create()</tt>, for the message queue may not
      * have been created by this object.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \return Allocation block size, in bytes.
      */
     BOOST_LOG_API size_type block_size() const;
 
     /*!
      * The method wakes up all threads that are blocked in calls to <tt>send()</tt> or
      * <tt>receive()</tt>. Those calls would then return <tt>operation_result::aborted</tt>.
      * Note that, the method does not block until the woken-up threads have actually
      * returned from <tt>send()</tt> or <tt>receive()</tt>. Other means is needed to ensure
      * that calls to <tt>send()</tt> or <tt>receive()</tt> have returned, e.g., joining the
      * threads that might be blocking on the calls.
      *
      * The method also puts the object in stopped state. When in stopped state, calls to
      * <tt>send()</tt> or <tt>receive()</tt> will return immediately with return value
      * <tt>operation_result::aborted</tt> when they would otherwise block in running state.
      *
      * Concurrent calls to this method, <tt>send()</tt>, <tt>try_send()</tt>, <tt>receive()</tt>,
      * <tt>try_receive()</tt>, and <tt>clear()</tt> are allowed.
      *
      * \pre <tt>is_open() == true</tt>
      */
     BOOST_LOG_API void stop_local();
 
     /*!
      * The method puts the object in running state where calls to <tt>send()</tt> or
      * <tt>receive()</tt> may block. This method is not thread-safe.
      *
      * \pre <tt>is_open() == true</tt>
      */
     BOOST_LOG_API void reset_local();
 
     /*!
      * The method disassociates the associated message queue, if any. No other threads
      * should be using this object before calling this method. The <tt>stop_local()</tt> method
      * can be used to have any threads currently blocked in <tt>send()</tt> or
      * <tt>receive()</tt> return, and prevent further calls to them from blocking. Typically,
      * before calling this method, one would first call <tt>stop_local()</tt> and then join all
      * threads that might be blocking on <tt>send()</tt> or <tt>receive()</tt> to ensure that
      * they have returned from the calls. The associated message queue is destroyed if the
      * object represents the last outstanding reference to it.
      *
      * \post <tt>is_open() == false</tt>
      */
     void close() BOOST_NOEXCEPT
     {
         if (is_open())
             do_close();
     }
 
     /*!
      * The method sends a message to the associated message queue. When the object is in
      * running state and the queue has no free space for the message, the method either blocks
      * or throws an exception, depending on the overflow policy that was specified on the queue
      * opening/creation. If blocking policy is in effect, the blocking can be interrupted by
      * calling <tt>stop_local()</tt>, in which case the method returns \c operation_result::aborted.
      * When the object is already in the stopped state, the method does not block but returns
      * immediately with return value \c operation_result::aborted.
      *
      * It is possible to send an empty message by passing \c 0 to the parameter \c message_size.
      *
      * Concurrent calls to <tt>send()</tt>, <tt>try_send()</tt>, <tt>receive()</tt>, <tt>try_receive()</tt>,
      * <tt>stop_local()</tt>, and <tt>clear()</tt> are allowed.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \param message_data The message data to send. Ignored when \c message_size is \c 0.
      * \param message_size Size of the message data in bytes. If the size is larger than
      *                     the associated message queue capacity, an <tt>std::logic_error</tt> exception is thrown.
      *
      * \retval operation_result::succeeded if the operation is successful
      * \retval operation_result::no_space if \c overflow_policy::fail_on_overflow is in effect and the queue is full
      * \retval operation_result::aborted if the call was interrupted by <tt>stop_local()</tt>
      *
      * <b>Throws:</b> <tt>std::logic_error</tt> in case if the message size exceeds the queue
      *                capacity, <tt>system_error</tt> in case if a native OS method fails.
      */
     BOOST_LOG_API operation_result send(void const* message_data, size_type message_size);
 
     /*!
      * The method performs an attempt to send a message to the associated message queue.
      * The method is non-blocking, and always returns immediately.
      * <tt>boost::system::system_error</tt> is thrown for errors resulting from native
      * operating system calls. Note that it is possible to send an empty message by passing
      * \c 0 to the parameter \c message_size. Concurrent calls to <tt>send()</tt>,
      * <tt>try_send()</tt>, <tt>receive()</tt>, <tt>try_receive()</tt>, <tt>stop_local()</tt>,
      * and <tt>clear()</tt> are allowed.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \param message_data The message data to send. Ignored when \c message_size is \c 0.
      * \param message_size Size of the message data in bytes. If the size is larger than the
      *                     maximum size allowed by the associated message queue, an
      *                     <tt>std::logic_error</tt> exception is thrown.
      *
      * \return \c true if the message is successfully sent, and \c false otherwise (e.g.,
      *         when the queue is full).
      *
      * <b>Throws:</b> <tt>std::logic_error</tt> in case if the message size exceeds the queue
      *                capacity, <tt>system_error</tt> in case if a native OS method fails.
      */
     BOOST_LOG_API bool try_send(void const* message_data, size_type message_size);
 
     /*!
      * The method takes a message from the associated message queue. When the object is in
      * running state and the queue is empty, the method blocks. The blocking is interrupted
      * when <tt>stop_local()</tt> is called, in which case the method returns \c operation_result::aborted.
      * When the object is already in the stopped state and the queue is empty, the method
      * does not block but returns immediately with return value \c operation_result::aborted.
      *
      * Concurrent calls to <tt>send()</tt>, <tt>try_send()</tt>, <tt>receive()</tt>,
      * <tt>try_receive()</tt>, <tt>stop_local()</tt>, and <tt>clear()</tt> are allowed.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \param buffer The memory buffer to store the received message in.
      * \param buffer_size The size of the buffer, in bytes.
      * \param message_size Receives the size of the received message, in bytes.
      *
      * \retval operation_result::succeeded if the operation is successful
      * \retval operation_result::aborted if the call was interrupted by <tt>stop_local()</tt>
      */
     operation_result receive(void* buffer, size_type buffer_size, size_type& message_size)
     {
         fixed_buffer_state state = { static_cast< uint8_t* >(buffer), buffer_size };
         operation_result result = do_receive(&reliable_message_queue::fixed_buffer_receive_handler, &state);
         message_size = buffer_size - state.size;
         return result;
     }
 
     /*!
      * The method takes a message from the associated message queue. When the object is in
      * running state and the queue is empty, the method blocks. The blocking is interrupted
      * when <tt>stop_local()</tt> is called, in which case the method returns \c operation_result::aborted.
      * When the object is already in the stopped state and the queue is empty, the method
      * does not block but returns immediately with return value \c operation_result::aborted.
      *
      * Concurrent calls to <tt>send()</tt>, <tt>try_send()</tt>, <tt>receive()</tt>,
      * <tt>try_receive()</tt>, <tt>stop_local()</tt>, and <tt>clear()</tt> are allowed.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \param buffer The memory buffer to store the received message in.
      * \param message_size Receives the size of the received message, in bytes.
      *
      * \retval operation_result::succeeded if the operation is successful
      * \retval operation_result::aborted if the call was interrupted by <tt>stop_local()</tt>
      */
     template< typename ElementT, size_type SizeV >
 #if !defined(BOOST_LOG_DOXYGEN_PASS)
     typename aux::enable_if_byte< ElementT, operation_result >::type
 #else
     operation_result
 #endif
     receive(ElementT (&buffer)[SizeV], size_type& message_size)
     {
         return receive(buffer, SizeV, message_size);
     }
 
     /*!
      * The method takes a message from the associated message queue. When the object is in
      * running state and the queue is empty, the method blocks. The blocking is interrupted
      * when <tt>stop_local()</tt> is called, in which case the method returns \c operation_result::aborted.
      * When the object is already in the stopped state and the queue is empty, the method
      * does not block but returns immediately with return value \c operation_result::aborted.
      *
      * Concurrent calls to <tt>send()</tt>, <tt>try_send()</tt>, <tt>receive()</tt>,
      * <tt>try_receive()</tt>, <tt>stop_local()</tt>, and <tt>clear()</tt> are allowed.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \param container The container to store the received message in. The container should have
      *                  value type of <tt>char</tt>, <tt>signed char</tt> or <tt>unsigned char</tt>
      *                  and support inserting elements at the end.
      *
      * \retval operation_result::succeeded if the operation is successful
      * \retval operation_result::aborted if the call was interrupted by <tt>stop_local()</tt>
      */
     template< typename ContainerT >
 #if !defined(BOOST_LOG_DOXYGEN_PASS)
     typename aux::enable_if_byte< typename ContainerT::value_type, operation_result >::type
 #else
     operation_result
 #endif
     receive(ContainerT& container)
     {
         return do_receive(&reliable_message_queue::container_receive_handler< ContainerT >, &container);
     }
 
     /*!
      * The method performs an attempt to take a message from the associated message queue. The
      * method is non-blocking, and always returns immediately.
      *
      * Concurrent calls to <tt>send()</tt>, <tt>try_send()</tt>, <tt>receive()</tt>,
      * <tt>try_receive()</tt>, <tt>stop_local()</tt>, and <tt>clear()</tt> are allowed.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \param buffer The memory buffer to store the received message in.
      * \param buffer_size The size of the buffer, in bytes.
      * \param message_size Receives the size of the received message, in bytes.
      *
      * \return \c true if a message is successfully received, and \c false otherwise (e.g.,
      *         when the queue is empty).
      */
     bool try_receive(void* buffer, size_type buffer_size, size_type& message_size)
     {
         fixed_buffer_state state = { static_cast< uint8_t* >(buffer), buffer_size };
         bool result = do_try_receive(&reliable_message_queue::fixed_buffer_receive_handler, &state);
         message_size = buffer_size - state.size;
         return result;
     }
 
     /*!
      * The method performs an attempt to take a message from the associated message queue. The
      * method is non-blocking, and always returns immediately.
      *
      * Concurrent calls to <tt>send()</tt>, <tt>try_send()</tt>, <tt>receive()</tt>,
      * <tt>try_receive()</tt>, <tt>stop_local()</tt>, and <tt>clear()</tt> are allowed.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \param buffer The memory buffer to store the received message in.
      * \param message_size Receives the size of the received message, in bytes.
      *
      * \return \c true if a message is successfully received, and \c false otherwise (e.g.,
      *         when the queue is empty).
      */
     template< typename ElementT, size_type SizeV >
 #if !defined(BOOST_LOG_DOXYGEN_PASS)
     typename aux::enable_if_byte< ElementT, bool >::type
 #else
     bool
 #endif
     try_receive(ElementT (&buffer)[SizeV], size_type& message_size)
     {
         return try_receive(buffer, SizeV, message_size);
     }
 
     /*!
      * The method performs an attempt to take a message from the associated message queue. The
      * method is non-blocking, and always returns immediately.
      *
      * Concurrent calls to <tt>send()</tt>, <tt>try_send()</tt>, <tt>receive()</tt>,
      * <tt>try_receive()</tt>, <tt>stop_local()</tt>, and <tt>clear()</tt> are allowed.
      *
      * \pre <tt>is_open() == true</tt>
      *
      * \param container The container to store the received message in. The container should have
      *                  value type of <tt>char</tt>, <tt>signed char</tt> or <tt>unsigned char</tt>
      *                  and support inserting elements at the end.
      *
      * \return \c true if a message is successfully received, and \c false otherwise (e.g.,
      *         when the queue is empty).
      */
     template< typename ContainerT >
 #if !defined(BOOST_LOG_DOXYGEN_PASS)
     typename aux::enable_if_byte< typename ContainerT::value_type, bool >::type
 #else
     bool
 #endif
     try_receive(ContainerT& container)
     {
         return do_try_receive(&reliable_message_queue::container_receive_handler< ContainerT >, &container);
     }
 
     /*!
      * The method frees system-wide resources, associated with the interprocess queue with the supplied name.
      * The queue referred to by the specified name must not be opened in any process at the point of this call.
      * After this call succeeds a new queue with the specified name can be created.
      *
      * This call can be useful to recover from an earlier process misbehavior (e.g. a crash without properly
      * closing the message queue). In this case resources allocated for the interprocess queue may remain
      * allocated after the last process closed the queue, which in turn may prevent creating a new queue with
      * the same name. By calling this method before creating a queue the application can attempt to ensure
      * it starts with a clean slate.
      *
      * On some platforms resources associated with the queue are automatically reclaimed by the operating system
      * when the last process using those resources terminates (even if it terminates abnormally). On these
      * platforms this call may be a no-op. However, portable code should still call this method at appropriate
      * places to ensure compatibility with other platforms and future library versions, which may change implementation
      * of the queue.
      *
      * \param name Name of the message queue to be removed.
      */
     static BOOST_LOG_API void remove(object_name const& name);
 
 #if !defined(BOOST_LOG_DOXYGEN_PASS)
 private:
     //! Implementation of the constructor with named arguments
     template< typename ArgsT >
     void construct(ArgsT const& args)
     {
         m_impl = NULL;
         construct_dispatch(args[keywords::open_mode], args);
     }
 
     //! Implementation of the constructor with named arguments
     template< typename ArgsT >
     void construct_dispatch(open_mode::create_only_tag, ArgsT const& args)
     {
         this->create(args[keywords::name], args[keywords::capacity], args[keywords::block_size], args[keywords::overflow_policy | block_on_overflow], args[keywords::permissions | permissions()]);
     }
 
     //! Implementation of the constructor with named arguments
     template< typename ArgsT >
     void construct_dispatch(open_mode::open_or_create_tag, ArgsT const& args)
     {
         this->open_or_create(args[keywords::name], args[keywords::capacity], args[keywords::block_size], args[keywords::overflow_policy | block_on_overflow], args[keywords::permissions | permissions()]);
     }
 
     //! Implementation of the constructor with named arguments
     template< typename ArgsT >
     void construct_dispatch(open_mode::open_only_tag, ArgsT const& args)
     {
         this->open(args[keywords::name], args[keywords::overflow_policy | block_on_overflow], args[keywords::permissions | permissions()]);
     }
 
     //! Closes the message queue, if it's open
     BOOST_LOG_API void do_close() BOOST_NOEXCEPT;
 
     //! Receives the message from the queue and calls the handler to place the data in the user's storage
     BOOST_LOG_API operation_result do_receive(receive_handler handler, void* state);
     //! Attempts to receives the message from the queue and calls the handler to place the data in the user's storage
     BOOST_LOG_API bool do_try_receive(receive_handler handler, void* state);
 
     //! Fixed buffer receive handler
     static BOOST_LOG_API void fixed_buffer_receive_handler(void* state, const void* data, size_type size);
     //! Receive handler for a container
     template< typename ContainerT >
     static void container_receive_handler(void* state, const void* data, size_type size)
     {
         ContainerT* const container = static_cast< ContainerT* >(state);
         container->insert
         (
             container->end(),
             static_cast< typename ContainerT::value_type const* >(data),
             static_cast< typename ContainerT::value_type const* >(data) + size
         );
     }
 #endif
 };
 
 } // namespace ipc
 
 BOOST_LOG_CLOSE_NAMESPACE // namespace log
 
 } // namespace boost
 
 #include <boost/log/detail/footer.hpp>
 
 #endif // BOOST_LOG_UTILITY_IPC_RELIABLE_MESSAGE_QUEUE_HPP_INCLUDED_

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