Many people have contributed with ideas and revisions, so this is the place to thank them:
Boost.Interprocess STL containers are based on the SGI STL library implementation:
Copyright (c) 1996,1997 Silicon Graphics Computer Systems, Inc. Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation. Silicon Graphics makes no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.
Copyright (c) 1994 Hewlett-Packard Company Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation. Hewlett-Packard Company makes no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.
unique_ptr. Added explanations and examples of these smart pointers in the documenation.
pointeras an smart pointer. This increases performance and improves compilation times.
named_semaphorewith POSIX named semaphores in systems supporting that option.
named_conditionhas been accordingly changed to support interoperability with
mapped_regionin UNIX when mapping address was provided but the region was mapped in another address.
allocate_manyfunctions to managed memory segments.
get_instance_typefunctions to managed memory segments.
segment_managerto avoid code bloat associated with templated instantiations.
deque::erase(), they were declared private.
deque::erase(). Thanks to Steve LoBasso.
atomic_dec32(). Thanks to Glenn Schrader.
boost::has_trivial_destructor. This optimization avoids calling destructors of elements that have a trivial destructor.
has_trivial_destructor_after_movetrait. 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.
shared_memory_object.hppheader instead of
mapped_regionconstructor 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?
We should be able to construct boost::unordered_xxx family in managed memory segments, so that there is no code duplication in boost. So Boost.Interprocess should cooperate with boost container developers instead of duplicating effort writing it's own containers.
A very interesting project is making boost::multi_index compatible with Boost.Interprocess ready for shared memory. This could be a good basis for memory mapped data-bases. The work to achieve this, however, can be huge. It would be interesting a collaboration with Intrusive library to achieve shared memory intrusive containers.