/* GLIB - Library of useful routines for C programming

 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald

 *

 * gthread.c: thread related functions

 * Copyright 1998 Sebastian Wilhelmi; University of Karlsruhe

 * Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

 *

 * 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 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, write to the

 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

/*

 * Modified by the GLib Team and others 1997-2000.  See the AUTHORS

 * file for a list of people on the GLib Team.  See the ChangeLog

 * files for a list of changes.  These files are distributed with

 * GLib at ftp://ftp.gtk.org/pub/gtk/. 

 */

/* 

 * MT safe

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <glib.h>

#include <gthreadinit.h>

#ifdef __SYMBIAN32__

#include <glib_global.h>

#include <gthread_wsd.h>

#endif /* __SYMBIAN32__ */

#ifdef G_THREADS_ENABLED

#if EMULATOR

PLS(thread_system_already_initialized,gthread_impl,gboolean)

PLS_ARRAY(g_thread_priority_map,gthread_impl,gint)

#define thread_system_already_initialized (*FUNCTION_NAME(thread_system_already_initialized,gthread_impl)())

#define g_thread_priority_map (FUNCTION_NAME(g_thread_priority_map,gthread_impl)())

#else

static gboolean thread_system_already_initialized = FALSE;

static gint g_thread_priority_map [G_THREAD_PRIORITY_URGENT + 1];

#endif /* EMULATOR */

#include G_THREAD_SOURCE

#ifndef PRIORITY_LOW_VALUE

# define PRIORITY_LOW_VALUE 0

#endif

#ifndef PRIORITY_URGENT_VALUE

# define PRIORITY_URGENT_VALUE 0

#endif

#ifndef PRIORITY_NORMAL_VALUE

# define PRIORITY_NORMAL_VALUE						\

  ((PRIORITY_LOW_VALUE * 6 + PRIORITY_URGENT_VALUE * 4) / 10)

#endif /* PRIORITY_NORMAL_VALUE */

#ifndef PRIORITY_HIGH_VALUE

# define PRIORITY_HIGH_VALUE						\

  ((PRIORITY_NORMAL_VALUE + PRIORITY_URGENT_VALUE * 2) / 3)

#endif /* PRIORITY_HIGH_VALUE */

void g_mutex_init (void);

void g_mem_init (void);

void g_messages_init (void);

void g_convert_init (void);

void g_rand_init (void);

void g_main_thread_init (void);

#define G_MUTEX_DEBUG_INFO(mutex) (*((gpointer*)(((char*)mutex)+G_MUTEX_SIZE)))

typedef struct _ErrorCheckInfo ErrorCheckInfo;

struct _ErrorCheckInfo

{

  gchar *location;

  GThread *owner;

};

static GMutex *

g_mutex_new_errorcheck_impl (void)

{

  GMutex *retval = g_thread_functions_for_glib_use_default.mutex_new ();

  retval = g_realloc (retval, G_MUTEX_SIZE + sizeof (gpointer));

  G_MUTEX_DEBUG_INFO (retval) = NULL;

  return retval;

}

static void

g_mutex_lock_errorcheck_impl (GMutex *mutex, 

			      gulong magic,

			      gchar *location)

{

  ErrorCheckInfo *info;

  GThread *self = g_thread_self ();

  if (magic != G_MUTEX_DEBUG_MAGIC)

    location = "unknown";

  if (G_MUTEX_DEBUG_INFO (mutex) == NULL)

    {

      /* if the debug info is NULL, we have not yet locked that mutex,

       * so we do it now */

      g_thread_functions_for_glib_use_default.mutex_lock (mutex);

      /* Now we have to check again, because another thread might have

       * tried to lock the mutex at the same time we did. This

       * technique is not 100% save on systems without decent cache

       * coherence, but we have no choice */

      if (G_MUTEX_DEBUG_INFO (mutex) == NULL)

	{

	  info = G_MUTEX_DEBUG_INFO (mutex) = g_new0 (ErrorCheckInfo, 1);

	}

      g_thread_functions_for_glib_use_default.mutex_unlock (mutex);

    }

  info = G_MUTEX_DEBUG_INFO (mutex);

  if (info->owner == self)

    g_error ("Trying to recursivly lock a mutex at '%s', "

	     "previously locked at '%s'", 

	     location, info->location);

  g_thread_functions_for_glib_use_default.mutex_lock (mutex);

  info->owner = self;

  info->location = location;

}

static gboolean

g_mutex_trylock_errorcheck_impl (GMutex *mutex, 

				 gulong magic, 

				 gchar *location)

{

  ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);

  GThread *self = g_thread_self ();

  if (magic != G_MUTEX_DEBUG_MAGIC)

    location = "unknown";

  if (!info)

    {

      /* This mutex has not yet been used, so simply lock and return TRUE */

      g_mutex_lock_errorcheck_impl (mutex, magic, location);

      return TRUE;

    }

  if (info->owner == self)

    g_error ("Trying to recursivly lock a mutex at '%s', "

	     "previously locked at '%s'", 

	     location, info->location);

  if (!g_thread_functions_for_glib_use_default.mutex_trylock (mutex))

    return FALSE;

  info->owner = self;

  info->location = location;

  return TRUE;

}

static void

g_mutex_unlock_errorcheck_impl (GMutex *mutex, 

				gulong magic, 

				gchar *location)

{

  ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);

  GThread *self = g_thread_self ();

  if (magic != G_MUTEX_DEBUG_MAGIC)

    location = "unknown";

  if (!info || info->owner == NULL)

    g_error ("Trying to unlock an unlocked mutex at '%s'", location);

  if (info->owner != self)

    g_warning ("Trying to unlock a mutex at '%s', "

	       "previously locked by a different thread at '%s'",

	       location, info->location);

  info->owner = NULL;

  info->location = NULL;

  g_thread_functions_for_glib_use_default.mutex_unlock (mutex);

}

static void

g_mutex_free_errorcheck_impl (GMutex *mutex, 

			      gulong magic, 

			      gchar *location)

{

  ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);

  if (magic != G_MUTEX_DEBUG_MAGIC)

    location = "unknown";

  if (info && info->owner != NULL)

    g_error ("Trying to free a locked mutex at '%s', "

	     "which was previously locked at '%s'", 

	     location, info->location);

  g_free (G_MUTEX_DEBUG_INFO (mutex));

  g_thread_functions_for_glib_use_default.mutex_free (mutex);  

}

static void     

g_cond_wait_errorcheck_impl (GCond *cond,

			     GMutex *mutex, 

			     gulong magic, 

			     gchar *location)

{

  ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);

  GThread *self = g_thread_self ();

  if (magic != G_MUTEX_DEBUG_MAGIC)

    location = "unknown";

  if (!info || info->owner == NULL)

    g_error ("Trying to use an unlocked mutex in g_cond_wait() at '%s'",

	     location);

  if (info->owner != self)

    g_error ("Trying to use a mutex locked by another thread in "

	     "g_cond_wait() at '%s'", location);

  info->owner = NULL;

  location = info->location;

  g_thread_functions_for_glib_use_default.cond_wait (cond, mutex);

  info->owner = self;

  info->location = location;

}

static gboolean 

g_cond_timed_wait_errorcheck_impl (GCond *cond,

                                   GMutex *mutex,

                                   GTimeVal *end_time, 

				   gulong magic, 

				   gchar *location)

{

  ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);

  GThread *self = g_thread_self ();

  gboolean retval;

  if (magic != G_MUTEX_DEBUG_MAGIC)

    location = "unknown";

  if (!info || info->owner == NULL)

    g_error ("Trying to use an unlocked mutex in g_cond_timed_wait() at '%s'",

	     location);

  if (info->owner != self)

    g_error ("Trying to use a mutex locked by another thread in "

	     "g_cond_timed_wait() at '%s'", location);

  info->owner = NULL;

  location = info->location;

  retval = g_thread_functions_for_glib_use_default.cond_timed_wait (cond, 

								    mutex, 

								    end_time);

  info->owner = self;

  info->location = location;

  return retval;

}

/* unshadow function declaration. See gthread.h */

#undef g_thread_init

EXPORT_C void 

g_thread_init_with_errorcheck_mutexes (GThreadFunctions* init)

{

  GThreadFunctions errorcheck_functions;

  if (init)

    g_error ("Errorcheck mutexes can only be used for native " 

	     "thread implementations. Sorry." );

#ifdef HAVE_G_THREAD_IMPL_INIT

  /* This isn't called in g_thread_init, as it doesn't think to get

   * the default implementation, so we have to call it on our own.

   *

   * We must call this before copying

   * g_thread_functions_for_glib_use_default as the

   * implementation-specific init function might modify the contents

   * of g_thread_functions_for_glib_use_default based on operating

   * system version, C library version, or whatever. */

  g_thread_impl_init();

#endif /* HAVE_G_THREAD_IMPL_INIT */

  errorcheck_functions = g_thread_functions_for_glib_use_default;

  errorcheck_functions.mutex_new = g_mutex_new_errorcheck_impl;

  errorcheck_functions.mutex_lock = 

    (void (*)(GMutex *)) g_mutex_lock_errorcheck_impl;

  errorcheck_functions.mutex_trylock = 

    (gboolean (*)(GMutex *)) g_mutex_trylock_errorcheck_impl;

  errorcheck_functions.mutex_unlock = 

    (void (*)(GMutex *)) g_mutex_unlock_errorcheck_impl;

  errorcheck_functions.mutex_free = 

    (void (*)(GMutex *)) g_mutex_free_errorcheck_impl;

  errorcheck_functions.cond_wait = 

    (void (*)(GCond *, GMutex *)) g_cond_wait_errorcheck_impl;

  errorcheck_functions.cond_timed_wait = 

    (gboolean (*)(GCond *, GMutex *, GTimeVal *)) 

    g_cond_timed_wait_errorcheck_impl;

  g_thread_init (&errorcheck_functions);

}

EXPORT_C void

g_thread_init (GThreadFunctions* init)

{

  gboolean supported;

  if (thread_system_already_initialized)

    g_error ("GThread system may only be initialized once.");

  thread_system_already_initialized = TRUE;

  if (init == NULL)

    {

#ifdef HAVE_G_THREAD_IMPL_INIT

      /* now do any initialization stuff required by the

       * implementation, but only if called with a NULL argument, of

       * course. Otherwise it's up to the user to do so. */

      g_thread_impl_init();

#endif /* HAVE_G_THREAD_IMPL_INIT */

      init = (GThreadFunctions*)&g_thread_functions_for_glib_use_default;

    }

  else

    g_thread_use_default_impl = FALSE;

  g_thread_functions_for_glib_use = *init;

  supported = (init->mutex_new &&  

	       init->mutex_lock && 

	       init->mutex_trylock && 

	       init->mutex_unlock && 

	       init->mutex_free && 

	       init->cond_new && 

	       init->cond_signal && 

	       init->cond_broadcast && 

	       init->cond_wait && 

	       init->cond_timed_wait &&

	       init->cond_free &&

	       init->private_new &&

	       init->private_get &&

	       init->private_set &&

	       init->thread_create &&

	       init->thread_yield &&

	       init->thread_join &&

	       init->thread_exit &&

	       init->thread_set_priority &&

	       init->thread_self);

  /* if somebody is calling g_thread_init (), it means that he wants to

   * have thread support, so check this

   */

  if (!supported)

    {

      if (g_thread_use_default_impl)

	g_error ("Threads are not supported on this platform.");

      else

	g_error ("The supplied thread function vector is invalid.");

    }

  g_thread_priority_map [G_THREAD_PRIORITY_LOW] = PRIORITY_LOW_VALUE;

  g_thread_priority_map [G_THREAD_PRIORITY_NORMAL] = PRIORITY_NORMAL_VALUE;

  g_thread_priority_map [G_THREAD_PRIORITY_HIGH] = PRIORITY_HIGH_VALUE;

  g_thread_priority_map [G_THREAD_PRIORITY_URGENT] = PRIORITY_URGENT_VALUE;

  g_thread_init_glib ();

}

#else /* !G_THREADS_ENABLED */

void

EXPORT_C g_thread_init (GThreadFunctions* init)

{

  g_error ("GLib thread support is disabled.");

}

#endif /* !G_THREADS_ENABLED */