/* GLIB - Library of useful routines for C programming

 * Copyright (C) 2005 Matthias Clasen

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, see <http://www.gnu.org/licenses/>.

 */

#include <stdlib.h>

#include <string.h>

#include <sys/types.h>

#include <signal.h>

#include "glib.h"

#include "gstdio.h"

#ifdef G_OS_UNIX

#include <unistd.h>

#endif

static gchar *dir, *filename, *displayname, *childname;

static gboolean stop = FALSE;

static gint parent_pid;

#ifndef G_OS_WIN32

static void

handle_usr1 (int signum)

{

  stop = TRUE;

}

#endif

static gboolean

check_stop (gpointer data)

{

  GMainLoop *loop = data;

#ifdef G_OS_WIN32

  stop = g_file_test ("STOP", G_FILE_TEST_EXISTS);

#endif

  if (stop)

    g_main_loop_quit (loop);

  return TRUE;

}

static void

write_or_die (const gchar *filename,

	      const gchar *contents,

	      gssize       length)

{

  GError *error = NULL;

  gchar *displayname;    

  if (!g_file_set_contents (filename, contents, length, &error)) 

    {

      displayname = g_filename_display_name (childname);

      g_print ("failed to write '%s': %s\n", 

	       displayname, error->message);

      exit (1);

    }

}

static GMappedFile *

map_or_die (const gchar *filename,

	    gboolean     writable)

{

  GError *error = NULL;

  GMappedFile *map;

  gchar *displayname;

  map = g_mapped_file_new (filename, writable, &error);

  if (!map)

    {

      displayname = g_filename_display_name (childname);

      g_print ("failed to map '%s' non-writable, shared: %s\n", 

	       displayname, error->message);

      exit (1);

    }

  return map;

}

static gboolean

signal_parent (gpointer data)

{

#ifndef G_OS_WIN32

  kill (parent_pid, SIGUSR1);

#endif

  return G_SOURCE_REMOVE;

}

static int

child_main (int argc, char *argv[])

{

  GMappedFile *map;

  GMainLoop *loop;

  parent_pid = atoi (argv[2]);

  map = map_or_die (filename, FALSE);

#ifndef G_OS_WIN32

  signal (SIGUSR1, handle_usr1);

#endif

  loop = g_main_loop_new (NULL, FALSE);

  g_idle_add (check_stop, loop);

  g_idle_add (signal_parent, NULL);

  g_main_loop_run (loop);

 g_message ("test_child_private: received parent signal");

  write_or_die (childname, 

		g_mapped_file_get_contents (map),

		g_mapped_file_get_length (map));

  signal_parent (NULL);

  return 0;

}

static void

test_mapping (void)

{

  GMappedFile *map;

  write_or_die (filename, "ABC", -1);

  map = map_or_die (filename, FALSE);

  g_assert (g_mapped_file_get_length (map) == 3);

  g_mapped_file_free (map);

  map = map_or_die (filename, TRUE);

  g_assert (g_mapped_file_get_length (map) == 3);

  g_mapped_file_free (map);

  g_message ("test_mapping: ok");

}

static void 

test_private (void)

{

  GError *error = NULL;

  GMappedFile *map;

  gchar *buffer;

  gsize len;

  write_or_die (filename, "ABC", -1);

  map = map_or_die (filename, TRUE);

  buffer = (gchar *)g_mapped_file_get_contents (map);

  buffer[0] = '1';

  buffer[1] = '2';

  buffer[2] = '3';

  g_mapped_file_free (map);

  if (!g_file_get_contents (filename, &buffer, &len, &error))

    {

      g_print ("failed to read '%s': %s\n", 

	       displayname, error->message);

      exit (1);

    }

  g_assert (len == 3);

  g_assert (strcmp (buffer, "ABC") == 0);

  g_free (buffer);

  g_message ("test_private: ok");

}

static void

test_child_private (gchar *argv0)

{

  GError *error = NULL;

  GMappedFile *map;

  gchar *buffer;

  gsize len;

  gchar *child_argv[4];

  GPid  child_pid;

  GMainLoop *loop;

  gchar pid[100];

#ifdef G_OS_WIN32

  g_remove ("STOP");

  g_assert (!g_file_test ("STOP", G_FILE_TEST_EXISTS));

#endif

  write_or_die (filename, "ABC", -1);

  map = map_or_die (filename, TRUE);

#ifndef G_OS_WIN32

  signal (SIGUSR1, handle_usr1);

#endif

  g_snprintf (pid, sizeof(pid), "%d", getpid ());

  child_argv[0] = argv0;

  child_argv[1] = "mapchild";

  child_argv[2] = pid;

  child_argv[3] = NULL;

  if (!g_spawn_async (dir, child_argv, NULL,

		      0, NULL, NULL, &child_pid, &error))

    {

      g_print ("failed to spawn child: %s\n", 

	       error->message);

      exit (1);            

    }

 g_message ("test_child_private: child spawned");

#ifndef G_OS_WIN32

  loop = g_main_loop_new (NULL, FALSE);

  g_idle_add (check_stop, loop);

  g_main_loop_run (loop);

  stop = FALSE;

#else

  g_usleep (2000000);

#endif

 g_message ("test_child_private: received first child signal");

  buffer = (gchar *)g_mapped_file_get_contents (map);

  buffer[0] = '1';

  buffer[1] = '2';

  buffer[2] = '3';

  g_mapped_file_free (map);

#ifndef G_OS_WIN32

  kill (child_pid, SIGUSR1);

#else

  g_file_set_contents ("STOP", "Hey there\n", -1, NULL);

#endif

#ifndef G_OS_WIN32

  g_idle_add (check_stop, loop);

  g_main_loop_run (loop);

#else

  g_usleep (2000000);

#endif

 g_message ("test_child_private: received second child signal");

  if (!g_file_get_contents (childname, &buffer, &len, &error))

    {

      gchar *name;

      name = g_filename_display_name (childname);

      g_print ("failed to read '%s': %s\n", name, error->message);

      exit (1);      

    }

  g_assert (len == 3);

  g_assert (strcmp (buffer, "ABC") == 0);

  g_free (buffer);

  g_message ("test_child_private: ok");

}

static int 

parent_main (int   argc,

	     char *argv[])

{

  /* test mapping with various flag combinations */

  test_mapping ();

  /* test private modification */

  test_private ();

  /* test multiple clients, non-shared */

  test_child_private (argv[0]);

  return 0;

}

int

main (int argc, 

      char *argv[])

{

  int ret;

#ifndef G_OS_WIN32

  sigset_t sig_mask, old_mask;

  sigemptyset (&sig_mask);

  sigaddset (&sig_mask, SIGUSR1);

  if (sigprocmask (SIG_UNBLOCK, &sig_mask, &old_mask) == 0)

    {

      if (sigismember (&old_mask, SIGUSR1))

        g_message ("SIGUSR1 was blocked, unblocking it");

    }

#endif

  dir = g_get_current_dir ();

  filename = g_build_filename (dir, "maptest", NULL);

  displayname = g_filename_display_name (filename);

  childname = g_build_filename (dir, "mapchild", NULL);

  if (argc > 1)

    ret = child_main (argc, argv);

  else 

    ret = parent_main (argc, argv);

  g_free (childname);

  g_free (filename);

  g_free (displayname);

  g_free (dir);

  return ret;

}