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regarded and expertly designed C++ library projects in the
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Alexandrescu, C++
Coding Standards
boost::interprocess::segment_manager
// In header: <boost/interprocess/segment_manager.hpp> template<typename CharType, typename MemoryAlgorithm, template< class IndexConfig > class IndexType> class segment_manager : public boost::interprocess::segment_manager_base< MemoryAlgorithm > { public: // types typedef MemoryAlgorithm memory_algorithm; typedef Base::void_pointer void_pointer; typedef CharType char_type; typedef segment_manager_base< MemoryAlgorithm > segment_manager_base_type; typedef Base::mutex_family mutex_family; typedef transform_iterator< typename named_index_t::const_iterator, named_transform > const_named_iterator; typedef transform_iterator< typename unique_index_t::const_iterator, unique_transform > const_unique_iterator; template<typename T> struct allocator { // types typedef boost::interprocess::allocator< T, segment_manager > type; }; template<typename T> struct deleter { // types typedef boost::interprocess::deleter< T, segment_manager > type; }; // construct/copy/destruct segment_manager(std::size_t); // public member functions template<typename T> std::pair< T *, std::size_t > find(const CharType *) ; template<typename T> std::pair< T *, std::size_t > find(unspecified) ; template<typename T> std::pair< T *, std::size_t > find_no_lock(const CharType *) ; template<typename T> std::pair< T *, std::size_t > find_no_lock(unspecified) ; template<typename T> construct_proxy< T >::type construct(char_ptr_holder_t) ; template<typename T> construct_proxy< T >::type find_or_construct(char_ptr_holder_t) ; template<typename T> construct_proxy< T >::type construct(char_ptr_holder_t, std::nothrow_t) ; template<typename T> construct_proxy< T >::type find_or_construct(char_ptr_holder_t, std::nothrow_t) ; template<typename T> construct_iter_proxy< T >::type construct_it(char_ptr_holder_t) ; template<typename T> construct_iter_proxy< T >::type find_or_construct_it(char_ptr_holder_t) ; template<typename T> construct_iter_proxy< T >::type construct_it(char_ptr_holder_t, std::nothrow_t) ; template<typename T> construct_iter_proxy< T >::type find_or_construct_it(char_ptr_holder_t, std::nothrow_t) ; template<typename Func> *void atomic_func(Func &) ; template<typename T> bool destroy(unspecified) ; template<typename T> bool destroy(const CharType *) ; template<typename T> void destroy_ptr(const T *) ; void reserve_named_objects(std::size_t) ; void reserve_unique_objects(std::size_t) ; void shrink_to_fit_indexes() ; std::size_t get_num_named_objects() ; std::size_t get_num_unique_objects() ; const_named_iterator named_begin() const; const_named_iterator named_end() const; const_unique_iterator unique_begin() const; const_unique_iterator unique_end() const; template<typename T> allocator< T >::type get_allocator() ; template<typename T> deleter< T >::type get_deleter() ; // public static functions template<typename T> static const CharType * get_instance_name(const T *) ; template<typename T> static std::size_t get_instance_length(const T *) ; template<typename T> static instance_type get_instance_type(const T *) ; static std::size_t get_min_size() ; static const std::size_t PayloadPerAllocation; };
This object is placed in the beginning of memory segment and implements the allocation (named or anonymous) of portions of the segment. This object contains two indexes that maintain an association between a name and a portion of the segment.
The first index contains the mappings for normal named objects using the char type specified in the template parameter.
The second index contains the association for unique instances. The key will be the const char * returned from type_info.name() function for the unique type to be constructed.
segment_manager<CharType, MemoryAlgorithm, IndexType> inherits publicly from segment_manager_base<MemoryAlgorithm> and inherits from it many public functions related to anonymous object and raw memory allocation. See segment_manager_base reference to know about those functions.
segment_manager
public member functionstemplate<typename T> std::pair< T *, std::size_t > find(const CharType * name) ;
Tries to find a previous named allocation. Returns the address and the object count. On failure the first member of the returned pair is 0.
template<typename T> std::pair< T *, std::size_t > find(unspecified name) ;
Tries to find a previous unique allocation. Returns the address and the object count. On failure the first member of the returned pair is 0.
template<typename T> std::pair< T *, std::size_t > find_no_lock(const CharType * name) ;
Tries to find a previous named allocation. Returns the address and the object count. On failure the first member of the returned pair is 0. This search is not mutex-protected!
template<typename T> std::pair< T *, std::size_t > find_no_lock(unspecified name) ;
Tries to find a previous unique allocation. Returns the address and the object count. On failure the first member of the returned pair is 0. This search is not mutex-protected!
template<typename T> construct_proxy< T >::type construct(char_ptr_holder_t name) ;
Returns throwing "construct" proxy object
template<typename T> construct_proxy< T >::type find_or_construct(char_ptr_holder_t name) ;
Returns throwing "search or construct" proxy object
template<typename T> construct_proxy< T >::type construct(char_ptr_holder_t name, std::nothrow_t) ;
Returns no throwing "construct" proxy object
template<typename T> construct_proxy< T >::type find_or_construct(char_ptr_holder_t name, std::nothrow_t) ;
Returns no throwing "search or construct" proxy object
template<typename T> construct_iter_proxy< T >::type construct_it(char_ptr_holder_t name) ;Returns throwing "construct from iterators" proxy object.
template<typename T> construct_iter_proxy< T >::type find_or_construct_it(char_ptr_holder_t name) ;
Returns throwing "search or construct from iterators" proxy object
template<typename T> construct_iter_proxy< T >::type construct_it(char_ptr_holder_t name, std::nothrow_t) ;
Returns no throwing "construct from iterators" proxy object
template<typename T> construct_iter_proxy< T >::type find_or_construct_it(char_ptr_holder_t name, std::nothrow_t) ;
Returns no throwing "search or construct from iterators" proxy object
template<typename Func> *void atomic_func(Func & f) ;
Calls object function blocking recursive interprocess_mutex and guarantees that no new named_alloc or destroy will be executed by any process while executing the object function call
template<typename T> bool destroy(unspecified) ;
Destroys a previously created unique instance. Returns false if the object was not present.
template<typename T> bool destroy(const CharType * name) ;
Destroys the named object with the given name. Returns false if that object can't be found.
template<typename T> void destroy_ptr(const T * p) ;
Destroys an anonymous, unique or named object using it's address
void reserve_named_objects(std::size_t num) ;
Preallocates needed index resources to optimize the creation of "num" named objects in the managed memory segment. Can throw boost::interprocess::bad_alloc if there is no enough memory.
void reserve_unique_objects(std::size_t num) ;
Preallocates needed index resources to optimize the creation of "num" unique objects in the managed memory segment. Can throw boost::interprocess::bad_alloc if there is no enough memory.
void shrink_to_fit_indexes() ;
Calls shrink_to_fit in both named and unique object indexes to try to free unused memory from those indexes.
std::size_t get_num_named_objects() ;
Returns the number of named objects stored in the segment.
std::size_t get_num_unique_objects() ;
Returns the number of unique objects stored in the segment.
const_named_iterator named_begin() const;
Returns a constant iterator to the beginning of the information about the named allocations performed in this segment manager
const_named_iterator named_end() const;
Returns a constant iterator to the end of the information about the named allocations performed in this segment manager
const_unique_iterator unique_begin() const;
Returns a constant iterator to the beginning of the information about the unique allocations performed in this segment manager
const_unique_iterator unique_end() const;
Returns a constant iterator to the end of the information about the unique allocations performed in this segment manager
template<typename T> allocator< T >::type get_allocator() ;
Returns an instance of the default allocator for type T initialized that allocates memory from this segment manager.
template<typename T> deleter< T >::type get_deleter() ;
Returns an instance of the default allocator for type T initialized that allocates memory from this segment manager.
segment_manager
public static functionstemplate<typename T> static const CharType * get_instance_name(const T * ptr) ;
Returns the name of an object created with construct/find_or_construct functions. Does not throw
template<typename T> static std::size_t get_instance_length(const T * ptr) ;
Returns the length of an object created with construct/find_or_construct functions. Does not throw.
template<typename T> static instance_type get_instance_type(const T * ptr) ;
Returns is the the name of an object created with construct/find_or_construct functions. Does not throw
static std::size_t get_min_size() ;
Obtains the minimum size needed by the segment manager