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Many people have contributed with ideas and revisions, so this is the place to thank them:
#define
BOOST_INTERPROCESS_HAS_KERNEL_BOOTTIME
in the windows configuration part to get Boost 1.48 & Boost 1.49
behaviour.
mapped_region::flush initiates disk flushing but
does not guarantee it's completed when returns, since it is not portable.
semaphore and named_semaphore
now implemented more efficiently with atomic operations.
stable_vector
container.
shared_memory_object::remove
has now POSIX unlink
semantics and file_mapping::remove
was added to obtain POSIX unlink
semantics with mapped files.
BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION
macro option to force the use of generic emulation code for process-shared
synchronization primitives instead of native POSIX functions.
boost::posix_time::pos_inf value is now handled portably
for timed functions.
iterator
to const_iterator in
containers to keep up with the draft of the next standard.
void return
types from flat_map::erase() functions.
mapped_region the mode used to create
it.
shared_ptr is movable
and supports aliasing.
shared_ptr,
weak_ptr
and unique_ptr.
Added explanations and examples of these smart pointers in the documentation.
pointer
as an smart pointer. This increases performance and improves
compilation times.
named_mutex
and named_semaphore
with POSIX named semaphores in systems supporting that option. named_condition
has been accordingly changed to support interoperability with named_mutex.
mapped_region
in UNIX when mapping address was provided but the region was mapped
in another address.
aligned_allocate
and allocate_many functions
to managed memory segments.
get_instance_name,
get_instance_length
and get_instance_type
functions to managed memory segments.
rbtree_best_fit.
vector.
segment_manager
to avoid code bloat associated with templated instantiations.
deque::clear() and deque::erase(), they were declared private.
deque::erase(). Thanks to Steve LoBasso.
atomic_dec32(). Thanks to Glenn Schrader.
offset_ptr
pointers.
managed_mapped_file.
boost::has_trivial_destructor.
This optimization avoids calling destructors of elements that have
a trivial destructor.
has_trivial_destructor_after_move
trait. This optimization avoids calling destructors of elements that
have a trivial destructor if the element has been moved (which is the
case of many movable types). This trick was provided by Howard Hinnant.
deallocate_free_chunks()) to manually deallocate completely
free chunks from node allocators.
multiset
and multimap
classes.
shared_memory_object.hpp
header instead of shared
memory.hpp.
mode_t type.
mapped_region
constructor no longer requires classes derived from memory_mappable,
but classes must fulfill the MemoryMappable concept.
Some useful references about the C++ programming language, C++ internals, shared memory, allocators and containers used to design Boost.Interprocess.
There are some Interprocess features that I would like to implement and some Boost.Interprocess code that can be much better. Let's see some ideas:
Win32 version of shared mutexes and shared conditions are based on "spin and wait" atomic instructions. This leads to poor performance and does not manage any issues like priority inversions. We would need very serious help from threading experts on this. And I'm not sure that this can be achieved in user-level software. Posix based implementations use PTHREAD_PROCESS_SHARED attribute to place mutexes in shared memory, so there are no such problems. I'm not aware of any implementation that simulates PTHREAD_PROCESS_SHARED attribute for Win32. We should be able to construct these primitives in memory mapped files, so that we can get filesystem persistence just like with POSIX primitives.
Currently Interprocess only allows char based names for basic named objects. However, several operating systems use wchar_t names for resources (mapped files, for example). In the future Interprocess should try to present a portable narrow/wide char interface. To do this, it would be useful to have a boost wstring <-> string conversion utilities to translate resource names (escaping needed characters that can conflict with OS names) in a portable way. It would be interesting also the use of boost::filesystem paths to avoid operating system specific issues.
Boost.Interprocess does not define security attributes for shared memory and synchronization objects. Standard C++ also ignores security attributes with files so adding security attributes would require some serious work.
Boost.Interprocess offers a process-shared message queue based on Boost.Interprocess primitives like mutexes and conditions. I would want to develop more mechanisms, like stream-oriented named fifo so that we can use it with a iostream-interface wrapper (we can imitate Unix pipes).
C++ needs more complex mechanisms and it would be nice to have a stream and datagram oriented PF_UNIX-like mechanism in C++. And for very fast inter-process remote calls Solaris doors is an interesting alternative to implement for C++. But the work to implement PF_UNIX-like sockets and doors would be huge (and it might be difficult in a user-level library). Any network expert volunteer?