examples/libs/l4re/streammap/server.cc

Client/Server example showing how to map a page to another task – Server implementation.

Client/Server example showing how to map a page to another task – Server implementation. Note that there's also a shared memory library that supplies this functionality in more convenient way.

/*
 * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
 *               Alexander Warg <warg@os.inf.tu-dresden.de>
 *     economic rights: Technische Universität Dresden (Germany)
 *
 * This file is part of TUD:OS and distributed under the terms of the
 * GNU General Public License 2.
 * Please see the COPYING-GPL-2 file for details.
 */
#include <stdio.h>
#include <l4/re/env>
#include <l4/re/util/cap_alloc>
#include <l4/re/util/object_registry>
#include <l4/cxx/ipc_server>
 
#include "shared.h"
 
static char page_to_map[L4_PAGESIZE] __attribute__((aligned(L4_PAGESIZE)));
 
static L4Re::Util::Registry_server<> server;
 
class Smap_server : public L4::Server_object_t<Mapper>
{
public:
  int dispatch(l4_umword_t obj, L4::Ipc::Iostream &ios);
};
 
int
Smap_server::dispatch(l4_umword_t, L4::Ipc::Iostream &ios)
{
  l4_msgtag_t t;
  ios >> t;
 
  // We're only talking the Map_example protocol
  if (t.label() != Mapper::Protocol)
    return -L4_EBADPROTO;
 
  L4::Opcode opcode;
  ios >> opcode;
 
  switch (opcode)
    {
    case Mapper::Do_map:
      l4_addr_t snd_base;
      ios >> snd_base;
      // put something into the page to read it out at the other side
      snprintf(page_to_map, sizeof(page_to_map), "Hello from the server!");
      printf("Sending to client\n");
      // send page
      ios << L4::Ipc::Snd_fpage::mem((l4_addr_t)page_to_map, L4_PAGESHIFT,
                                L4_FPAGE_RO, snd_base);
      return L4_EOK;
    default:
      return -L4_ENOSYS;
    }
}
 
int
main()
{
  static Smap_server smap;
 
  // Register server
  if (!server.registry()->register_obj(&smap, "smap").is_valid())
    {
      printf("Could not register my service, read-only namespace?\n");
      return 1;
    }
 
  printf("Welcome to the memory map example server!\n");
 
  // Wait for client requests
  server.loop();
 
  return 0;
}