shared_allocator

SharedAllocator is simple allocator that allocates memory inside one shared library and can be used to make it safe to share STL containers between several shared libraries. SharedAllocator interface is similar to std::allocator interface so std::allocator can be easily replaced by salloc::shared_allocator (or by other salloc:: allocators).

compiling

SharedAllocator is using features of C++11 standard, so you have to use C++11 compatible compiler.

adding shared_allocator to your project with CMake

1. Copy files include/shared_allocator/*.* to your include directory (for example, include/third_party/shared_allocator or just include/shared_allocator).
2. Copy files source/*.* to your sources directory (for example, source/shared_allocator).
3. Include source/shared_allocator/CMakeLists.txt (from step 2) into your main CMakeLists.txt: add_subdirectory(source/shared_allocator)
4. Add path to shared_allocator header files into additional include directories: include_directories(include/third_party) to make it possible for your compiler to find includes like #include "shared_allocator/shared_allocator.hpp".
5. Add link to shared_allocator library into every project's CMakeLists.txt that would be using salloc::shared_allocator<T> (or shared_allocate function and so on): target_link_libraries(${PROJECT_NAME} shared_allocator)

example code

#include "shared_allocator/shared_allocator.hpp"
#include <vector>

int main()
{
    // This vector can be safely shared among several shared libraries.
    std::vector<int, salloc::shared_allocator<int> > shared_vector;
    
    shared_vector.reserve(100);
    for (int i = 0; i < 100; ++i)
    {
        shared_vector.push_back(i);
    }
    
    return 0;
}

allocators

• salloc::shared_allocator is simple allocator that allocates and deallocates memory using imported functions shared_allocate and shared_deallocate. All instances of this allocator will allocate and deallocate memory inside one heap.
• salloc::cached_allocator is allocator that caches deallocated memory (stores pointers to previously allocated memory for further usage). So if you allocating and deallocating memory buffers of the same size rapidly you will have a very small number of real memory allocations, because once allocated, this memory buffer will be reused for many times. It is best suited for containers that allocating and deallocating memory buffers of the same size (for example, std::list, std::set, std::map). It is not so good for std::vector because it needs memory allocations of different size, but it should not impact performance if you will use salloc::cached_allocator instead of salloc::shared_allocator for std::vector.
• salloc::size_cached_allocator works like salloc::cached_allocator but it have an individual cache for each size of memory buffer (pointers for deallocated memory buffers of each size are stored in individual lists. For example, 3 pointers of size 100 will be stored in one list and 5 pointers of size 60 will be stored in another list). It is not recommended to use this allocator with individual containers, it is better to share this allocator between several containers at once.

LICENSE

SharedAllocator is licensed under terms of MIT license.