nikolask-source/cxxshm

A C++ library to handle POSIX shared memory

CxxSHM

A C++ Library to handle POSIX shared memory

Usage

Initialize cxxshm::SharedMemory

Option A: Create Shared Memory

const std::string shm_name     = "example_shm";  // shared memory name
constexpr std::size_t shm_size = 4096;           // shared memory size
constexpr bool read_only       = false;          // allow read and write
constexpr bool exclusive       = true;           // fail if shared memory already exists
constexpr mode_t shm_mode      = 0660;           // read and write access for user and group

// create shared memory
cxxshm::SharedMemory shm(shm_name, shm_size, read_only, exclusive, shm_mode);

Option B: Connect to Existing Shared Memory

const std::string shm_name     = "example_shm";  // shared memory name
constexpr bool read_only       = false;          // allow read and write

// use shared memory
cxxshm::SharedMemory shm(shm_name, read_only);

Access Shared Memory Data

Get Pointer to Shared Memory

auto shm_data = shm.get_addr<void *>();
auto shm_data_int = shm.get_addr<int *>();

Array Access

Access element of shared memory without range check (dangerous):

const auto value = shm.operator[]<int>(1);

Access element of shared memory with range check:

const auto value = shm.at<long>(42);

Get Shared Memory Information

Get Name

const std::string& shm_name = shm.get_name();

Get Size

const std::size_t shm_size = shm.get_size();

cxxshm's Issues

Test

add test cases

add tests

• create shm
  • check size
  • already exists
  • force
• permissions