C++ multiple processes?

Question

I've got a project that consists of two processes and I need to pass some data between them in a fast and efficent manner.

I'm aware that I could use sockets to do this using TCP, even though both processes will always exist on the same computer, however this does not seem to be a very efficient solution.

I see lots of information about using "pipes" on Linux. However I primarily want this for Windows and Linux (preferably via a cross platform library), ideally in a type safe, non-blocking manner.

Another important thing is I need to support multiple instances of the whole application (i.e. both processes), each with their own independent copy of the communication objects.

Also is there a cross platform way to spawn a new process?

Answer 1

Take a look at Boost.Interprocess

Boost.Interprocess simplifies the use of common interprocess communication and synchronization mechanisms and offers a wide range of them:

• Shared memory.
• Memory-mapped files.
• Semaphores, mutexes, condition variables and upgradable mutex types to place them in shared memory and memory mapped files.
• Named versions of those synchronization objects, similar to UNIX/Windows sem_open/CreateSemaphore API.
• File locking.
• Relative pointers.
• Message queues.

Boost.Interprocess also offers higher-level interprocess mechanisms to allocate dynamically portions of a shared memory or a memory mapped file (in general, to allocate portions of a fixed size memory segment). Using these mechanisms, Boost.Interprocess offers useful tools to construct C++ objects, including STL-like containers, in shared memory and memory mapped files:

• Dynamic creation of anonymous and named objects in a shared memory or memory mapped file.
• STL-like containers compatible with shared memory/memory-mapped files.
• STL-like allocators ready for shared memory/memory-mapped files implementing several memory allocation patterns (like pooling).

Boost.Interprocess has been tested in the following compilers/platforms:

• Visual 7.1 Windows XP
• Visual 8.0 Windows XP
• GCC 4.1.1 MinGW
• GCC 3.4.4 Cygwin
• Intel 9.1 Windows XP
• GCC 4.1.2 Linux
• GCC 3.4.3 Solaris 11
• GCC 4.0 MacOs 10.4.1