/*

 * Copyright © 2007  Chris Wilson

 * Copyright © 2009,2010  Red Hat, Inc.

 * Copyright © 2011,2012  Google, Inc.

 *

 *  This is part of HarfBuzz, a text shaping library.

 *

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 *

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 *

 * Contributor(s):

 *  Chris Wilson <chris@chris-wilson.co.uk>

 * Red Hat Author(s): Behdad Esfahbod

 * Google Author(s): Behdad Esfahbod

 */

#ifndef HB_MUTEX_HH

#define HB_MUTEX_HH

#include "hb.hh"

/* mutex */

/* We need external help for these */

#if defined(hb_mutex_impl_init) \

 && defined(hb_mutex_impl_lock) \

 && defined(hb_mutex_impl_unlock) \

 && defined(hb_mutex_impl_finish)

/* Defined externally, i.e. in config.h; must have typedef'ed hb_mutex_impl_t as well. */

#elif !defined(HB_NO_MT) && !defined(HB_MUTEX_IMPL_STD_MUTEX) && (defined(HAVE_PTHREAD) || defined(__APPLE__))

#include <pthread.h>

typedef pthread_mutex_t hb_mutex_impl_t;

#define hb_mutex_impl_init(M) pthread_mutex_init (M, nullptr)

#define hb_mutex_impl_lock(M) pthread_mutex_lock (M)

#define hb_mutex_impl_unlock(M) pthread_mutex_unlock (M)

#define hb_mutex_impl_finish(M) pthread_mutex_destroy (M)

#elif !defined(HB_NO_MT) && !defined(HB_MUTEX_IMPL_STD_MUTEX) && defined(_WIN32)

typedef CRITICAL_SECTION hb_mutex_impl_t;

#if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)

#define hb_mutex_impl_init(M) InitializeCriticalSectionEx (M, 0, 0)

#else

#define hb_mutex_impl_init(M) InitializeCriticalSection (M)

#endif

#define hb_mutex_impl_lock(M) EnterCriticalSection (M)

#define hb_mutex_impl_unlock(M) LeaveCriticalSection (M)

#define hb_mutex_impl_finish(M) DeleteCriticalSection (M)

#elif !defined(HB_NO_MT)

#include <mutex>

typedef std::mutex              hb_mutex_impl_t;

#define hb_mutex_impl_init(M)   HB_STMT_START { new (M) hb_mutex_impl_t; } HB_STMT_END

#define hb_mutex_impl_lock(M)   (M)->lock ()

#define hb_mutex_impl_unlock(M) (M)->unlock ()

#define hb_mutex_impl_finish(M) HB_STMT_START { (M)->~hb_mutex_impl_t(); } HB_STMT_END

#else /* defined(HB_NO_MT) */

typedef int hb_mutex_impl_t;

#define hb_mutex_impl_init(M) HB_STMT_START {} HB_STMT_END

#define hb_mutex_impl_lock(M) HB_STMT_START {} HB_STMT_END

#define hb_mutex_impl_unlock(M) HB_STMT_START {} HB_STMT_END

#define hb_mutex_impl_finish(M) HB_STMT_START {} HB_STMT_END

#endif

struct hb_mutex_t

{

  /* Create space for, but do not initialize m. */

  alignas(hb_mutex_impl_t) char m[sizeof (hb_mutex_impl_t)];

  hb_mutex_t () { init (); }

  ~hb_mutex_t () { fini (); }

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wcast-align"

  void init   () { hb_mutex_impl_init   ((hb_mutex_impl_t *) m); }

  void lock   () { hb_mutex_impl_lock   ((hb_mutex_impl_t *) m); }

  void unlock () { hb_mutex_impl_unlock ((hb_mutex_impl_t *) m); }

  void fini   () { hb_mutex_impl_finish ((hb_mutex_impl_t *) m); }

#pragma GCC diagnostic pop

};

struct hb_lock_t

{

  hb_lock_t (hb_mutex_t &mutex_) : mutex (&mutex_) { mutex->lock (); }

  hb_lock_t (hb_mutex_t *mutex_) : mutex (mutex_) { if (mutex) mutex->lock (); }

  ~hb_lock_t () { if (mutex) mutex->unlock (); }

  private:

  hb_mutex_t *mutex;

};

#endif /* HB_MUTEX_HH */