Server model that uses shared memory as a communication channel.

shserver.cpp

#include <iostream>
#include <boost/interprocess/shared_memory_object.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include "shared_data.h"
#include "server.h"

using namespace std;
using namespace boost::interprocess;

class SharedMemory {
public:
    SharedMemory() {
        shm = new shared_memory_object(
                open_or_create,  // only create
                sharedmem_key,   // name
                read_write       // read-write mode
        );
        shm->truncate(sizeof(Message));

        region = new mapped_region(*shm, read_write);
        void *addr = region->get_address();

        msg = new (addr) Message; // shared obj
    }

    ~SharedMemory() {
        delete shm;
        delete region;
        shared_memory_object::remove(sharedmem_key); // clean
    }

    mapped_region *get_region() {
        return region;
    }

    shared_memory_object *get_shm() {
        return shm;
    }

    Message *get_message() {
        return msg;
    }

private:
    mapped_region *region;
    shared_memory_object *shm;
    Message *msg;
};


static SharedMemory *sharedMemory = NULL;

static PyObject *start(PyObject *self, PyObject *args) {
    sharedMemory = new SharedMemory();
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *wait(PyObject *self, PyObject *args) {
    Message *message = sharedMemory->get_message();

    scoped_lock<interprocess_mutex> lock(message->mutex);
    message->client.wait(lock);

    return PyString_FromString(message->data);
}

static PyObject *notify_all(PyObject *self, PyObject *args) {
    Message *message = sharedMemory->get_message();
    message->server.notify_all();
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *stop(PyObject *self, PyObject *args) {
    delete sharedMemory;
    Py_INCREF(Py_None);
    return Py_None;
}

static PyMethodDef methods[] = {
    {"start", start, METH_VARARGS, "server start"},
    {"wait",  wait,  METH_VARARGS, "server wait"},
    {"notify_all",  notify_all,  METH_VARARGS, "server notify_all"},
    {"stop",  stop,  METH_VARARGS, "server stop"},
    {NULL, NULL, 0, NULL}        /* Sentinel */
};

PyMODINIT_FUNC initserver(void) {
    PyObject *mod;

    mod = Py_InitModule("server", methods);
    if (mod == NULL)
        return;

    PyObject *err = PyErr_NewException((char *) "server.error", NULL, NULL);
    Py_INCREF(err);
    PyModule_AddObject(mod, "error", err);
}