examples/libs/l4re/streammap/client.cc

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

Client/Server example showing how to map a page to another task – Client 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 <l4/sys/err.h>
#include <l4/sys/types.h>
#include <l4/re/env>
#include <l4/re/util/cap_alloc>
#include <l4/cxx/ipc_stream>
 
#include <stdio.h>
 
#include "shared.h"
 
static int
func_smap_call(L4::Cap<void> const &server)
{
  L4::Ipc::Iostream s(l4_utcb());
  l4_addr_t addr = 0;
  int err;
 
  if ((err = L4Re::Env::env()->rm()->reserve_area(&addr, L4_PAGESIZE,
                                                  L4Re::Rm::F::Search_addr)))
    {
      printf("The reservation of one page within our virtual memory failed with %d\n", err);
      return 1;
    }
 
  s << L4::Opcode(Mapper::Do_map)
    << (l4_addr_t)addr;
  s << L4::Ipc::Rcv_fpage::mem((l4_addr_t)addr, L4_PAGESHIFT, 0);
  int r = l4_error(s.call(server.cap(), Mapper::Protocol));
  if (r)
    return r; // failure
 
  printf("String sent by server: %s\n", (char *)addr);
 
  return 0; // ok
}
 
int
main()
{
 
  L4::Cap<void> server = L4Re::Env::env()->get_cap<void>("smap");
  if (!server.is_valid())
    {
      printf("Could not get capability slot!\n");
      return 1;
    }
 
 
  printf("Asking for page from server\n");
 
  if (func_smap_call(server))
    {
      printf("Error talking to server\n");
      return 1;
    }
  printf("It worked!\n");
 
  L4Re::Util::cap_alloc.free(server, L4Re::This_task);
 
  return 0;
}