dbus-threads.c

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-threads.h  D-Bus threads handling
 *
 * Copyright (C) 2002, 2003, 2006 Red Hat Inc.
 *
 * SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later
 *
 * Licensed under the Academic Free License version 2.1
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */
#include <config.h>
#include "dbus-threads.h"
#include "dbus-internals.h"
#include "dbus-threads-internal.h"
#include "dbus-list.h"
 
/* Protected by _dbus_threads_lock_platform_specific() */
static int thread_init_generation = 0;
 
void
_dbus_rmutex_new_at_location (DBusRMutex **location_p)
{
  _dbus_assert (location_p != NULL);
 
  if (!dbus_threads_init_default ())
    {
      *location_p = NULL;
      return;
    }
 
  *location_p = _dbus_platform_rmutex_new ();
}
 
void
_dbus_cmutex_new_at_location (DBusCMutex **location_p)
{
  _dbus_assert (location_p != NULL);
 
  if (!dbus_threads_init_default ())
    {
      *location_p = NULL;
      return;
    }
 
  *location_p = _dbus_platform_cmutex_new ();
}
 
void
_dbus_rmutex_free_at_location (DBusRMutex **location_p)
{
  if (location_p == NULL)
    return;
 
  if (*location_p != NULL)
    _dbus_platform_rmutex_free (*location_p);
}
 
void
_dbus_cmutex_free_at_location (DBusCMutex **location_p)
{
  if (location_p == NULL)
    return;
 
  if (*location_p != NULL)
    _dbus_platform_cmutex_free (*location_p);
}
 
void
_dbus_rmutex_lock (DBusRMutex *mutex)
{
  if (mutex == NULL)
    return;
 
  _dbus_platform_rmutex_lock (mutex);
}
 
void
_dbus_cmutex_lock (DBusCMutex *mutex)
{
  if (mutex == NULL)
    return;
 
  _dbus_platform_cmutex_lock (mutex);
}
 
void
_dbus_rmutex_unlock (DBusRMutex *mutex)
{
  if (mutex == NULL)
    return;
 
  _dbus_platform_rmutex_unlock (mutex);
}
 
void
_dbus_cmutex_unlock (DBusCMutex *mutex)
{
  if (mutex == NULL)
    return;
 
  _dbus_platform_cmutex_unlock (mutex);
}
 
DBusCondVar *
_dbus_condvar_new (void)
{
  if (!dbus_threads_init_default ())
    return NULL;
 
  return _dbus_platform_condvar_new ();
}
 
 
void 
_dbus_condvar_new_at_location (DBusCondVar **location_p)
{
  _dbus_assert (location_p != NULL);
 
  *location_p = _dbus_condvar_new();
}
 
 
void
_dbus_condvar_free (DBusCondVar *cond)
{
  if (cond == NULL)
    return;
 
  _dbus_platform_condvar_free (cond);
}
 
void
_dbus_condvar_free_at_location (DBusCondVar **location_p)
{
  if (location_p == NULL)
    return;
 
  if (*location_p != NULL)
    _dbus_platform_condvar_free (*location_p);
}
 
void
_dbus_condvar_wait (DBusCondVar *cond,
                    DBusCMutex  *mutex)
{
  if (cond == NULL || mutex == NULL)
    return;
 
  _dbus_platform_condvar_wait (cond, mutex);
}
 
dbus_bool_t
_dbus_condvar_wait_timeout (DBusCondVar               *cond,
                            DBusCMutex                *mutex,
                            int                        timeout_milliseconds)
{
  if (cond == NULL || mutex == NULL)
    return TRUE;
 
  return _dbus_platform_condvar_wait_timeout (cond, mutex,
      timeout_milliseconds);
}
 
void
_dbus_condvar_wake_one (DBusCondVar *cond)
{
  if (cond == NULL)
    return;
 
  _dbus_platform_condvar_wake_one (cond);
}
 
/* Protected by _dbus_threads_lock_platform_specific() */
static DBusRMutex *global_locks[_DBUS_N_GLOBAL_LOCKS] = { NULL };
 
static void
shutdown_global_locks (void *nil)
{
  int i;
 
  for (i = 0; i < _DBUS_N_GLOBAL_LOCKS; i++)
    {
      _dbus_assert (global_locks[i] != NULL);
      _dbus_platform_rmutex_free (global_locks[i]);
      global_locks[i] = NULL;
    }
}
 
static dbus_bool_t
init_global_locks (void)
{
  int i;
  dbus_bool_t ok;
 
  for (i = 0; i < _DBUS_N_GLOBAL_LOCKS; i++)
    {
      _dbus_assert (global_locks[i] == NULL);
 
      global_locks[i] = _dbus_platform_rmutex_new ();
 
      if (global_locks[i] == NULL)
        goto failed;
    }
 
  _dbus_platform_rmutex_lock (global_locks[_DBUS_LOCK_shutdown_funcs]);
  ok = _dbus_register_shutdown_func_unlocked (shutdown_global_locks, NULL);
  _dbus_platform_rmutex_unlock (global_locks[_DBUS_LOCK_shutdown_funcs]);
 
  if (!ok)
    goto failed;
 
  return TRUE;
 
 failed:
  for (i = i - 1; i >= 0; i--)
    {
      _dbus_platform_rmutex_free (global_locks[i]);
      global_locks[i] = NULL;
    }
 
  return FALSE;
}
 
dbus_bool_t
_dbus_lock (DBusGlobalLock lock)
{
  _dbus_assert (lock >= 0);
  _dbus_assert (lock < _DBUS_N_GLOBAL_LOCKS);
 
  if (thread_init_generation != _dbus_current_generation &&
      !dbus_threads_init_default ())
    return FALSE;
 
  _dbus_platform_rmutex_lock (global_locks[lock]);
  return TRUE;
}
 
void
_dbus_unlock (DBusGlobalLock lock)
{
  _dbus_assert (lock >= 0);
  _dbus_assert (lock < _DBUS_N_GLOBAL_LOCKS);
 
  _dbus_platform_rmutex_unlock (global_locks[lock]);
}
 
 
dbus_bool_t
dbus_threads_init (const DBusThreadFunctions *functions)
{
  _dbus_threads_lock_platform_specific ();
 
  if (thread_init_generation == _dbus_current_generation)
    {
      _dbus_threads_unlock_platform_specific ();
      return TRUE;
    }
 
  if (!_dbus_threads_init_platform_specific() ||
      !init_global_locks ())
    {
      _dbus_threads_unlock_platform_specific ();
      return FALSE;
    }
 
  thread_init_generation = _dbus_current_generation;
 
  _dbus_threads_unlock_platform_specific ();
  return TRUE;
}
 
 
 
/* Default thread implemenation */
 
dbus_bool_t
dbus_threads_init_default (void)
{
  return dbus_threads_init (NULL);
}
 
 
#ifdef DBUS_ENABLE_EMBEDDED_TESTS
 
#endif /* DBUS_ENABLE_EMBEDDED_TESTS */