michael@0: /*
michael@0:  * Copyright © 2007  Chris Wilson
michael@0:  * Copyright © 2009,2010  Red Hat, Inc.
michael@0:  * Copyright © 2011,2012  Google, Inc.
michael@0:  *
michael@0:  *  This is part of HarfBuzz, a text shaping library.
michael@0:  *
michael@0:  * Permission is hereby granted, without written agreement and without
michael@0:  * license or royalty fees, to use, copy, modify, and distribute this
michael@0:  * software and its documentation for any purpose, provided that the
michael@0:  * above copyright notice and the following two paragraphs appear in
michael@0:  * all copies of this software.
michael@0:  *
michael@0:  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
michael@0:  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
michael@0:  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
michael@0:  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
michael@0:  * DAMAGE.
michael@0:  *
michael@0:  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
michael@0:  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
michael@0:  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
michael@0:  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
michael@0:  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
michael@0:  *
michael@0:  * Contributor(s):
michael@0:  *	Chris Wilson <chris@chris-wilson.co.uk>
michael@0:  * Red Hat Author(s): Behdad Esfahbod
michael@0:  * Google Author(s): Behdad Esfahbod
michael@0:  */
michael@0: 
michael@0: #ifndef HB_MUTEX_PRIVATE_HH
michael@0: #define HB_MUTEX_PRIVATE_HH
michael@0: 
michael@0: #include "hb-private.hh"
michael@0: 
michael@0: 
michael@0: /* mutex */
michael@0: 
michael@0: /* We need external help for these */
michael@0: 
michael@0: #if 0
michael@0: 
michael@0: 
michael@0: #elif !defined(HB_NO_MT) && (defined(_WIN32) || defined(__CYGWIN__))
michael@0: 
michael@0: #define WIN32_LEAN_AND_MEAN
michael@0: #include <windows.h>
michael@0: typedef CRITICAL_SECTION hb_mutex_impl_t;
michael@0: #define HB_MUTEX_IMPL_INIT	{ NULL, 0, 0, NULL, NULL, 0 }
michael@0: #define hb_mutex_impl_init(M)	InitializeCriticalSection (M)
michael@0: #define hb_mutex_impl_lock(M)	EnterCriticalSection (M)
michael@0: #define hb_mutex_impl_unlock(M)	LeaveCriticalSection (M)
michael@0: #define hb_mutex_impl_finish(M)	DeleteCriticalSection (M)
michael@0: 
michael@0: 
michael@0: #elif !defined(HB_NO_MT) && (defined(HAVE_PTHREAD) || defined(__APPLE__))
michael@0: 
michael@0: #include <pthread.h>
michael@0: typedef pthread_mutex_t hb_mutex_impl_t;
michael@0: #define HB_MUTEX_IMPL_INIT	PTHREAD_MUTEX_INITIALIZER
michael@0: #define hb_mutex_impl_init(M)	pthread_mutex_init (M, NULL)
michael@0: #define hb_mutex_impl_lock(M)	pthread_mutex_lock (M)
michael@0: #define hb_mutex_impl_unlock(M)	pthread_mutex_unlock (M)
michael@0: #define hb_mutex_impl_finish(M)	pthread_mutex_destroy (M)
michael@0: 
michael@0: 
michael@0: #elif !defined(HB_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)
michael@0: 
michael@0: #if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_YIELD)
michael@0: # include <sched.h>
michael@0: # define HB_SCHED_YIELD() sched_yield ()
michael@0: #else
michael@0: # define HB_SCHED_YIELD() HB_STMT_START {} HB_STMT_END
michael@0: #endif
michael@0: 
michael@0: /* This actually is not a totally awful implementation. */
michael@0: typedef volatile int hb_mutex_impl_t;
michael@0: #define HB_MUTEX_IMPL_INIT	0
michael@0: #define hb_mutex_impl_init(M)	*(M) = 0
michael@0: #define hb_mutex_impl_lock(M)	HB_STMT_START { while (__sync_lock_test_and_set((M), 1)) HB_SCHED_YIELD (); } HB_STMT_END
michael@0: #define hb_mutex_impl_unlock(M)	__sync_lock_release (M)
michael@0: #define hb_mutex_impl_finish(M)	HB_STMT_START {} HB_STMT_END
michael@0: 
michael@0: 
michael@0: #elif !defined(HB_NO_MT)
michael@0: 
michael@0: #if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_YIELD)
michael@0: # include <sched.h>
michael@0: # define HB_SCHED_YIELD() sched_yield ()
michael@0: #else
michael@0: # define HB_SCHED_YIELD() HB_STMT_START {} HB_STMT_END
michael@0: #endif
michael@0: 
michael@0: #define HB_MUTEX_INT_NIL 1 /* Warn that fallback implementation is in use. */
michael@0: typedef volatile int hb_mutex_impl_t;
michael@0: #define HB_MUTEX_IMPL_INIT	0
michael@0: #define hb_mutex_impl_init(M)	*(M) = 0
michael@0: #define hb_mutex_impl_lock(M)	HB_STMT_START { while (*(M)) HB_SCHED_YIELD (); (*(M))++; } HB_STMT_END
michael@0: #define hb_mutex_impl_unlock(M)	(*(M))--;
michael@0: #define hb_mutex_impl_finish(M)	HB_STMT_START {} HB_STMT_END
michael@0: 
michael@0: 
michael@0: #else /* HB_NO_MT */
michael@0: 
michael@0: typedef int hb_mutex_impl_t;
michael@0: #define HB_MUTEX_IMPL_INIT	0
michael@0: #define hb_mutex_impl_init(M)	HB_STMT_START {} HB_STMT_END
michael@0: #define hb_mutex_impl_lock(M)	HB_STMT_START {} HB_STMT_END
michael@0: #define hb_mutex_impl_unlock(M)	HB_STMT_START {} HB_STMT_END
michael@0: #define hb_mutex_impl_finish(M)	HB_STMT_START {} HB_STMT_END
michael@0: 
michael@0: #endif
michael@0: 
michael@0: 
michael@0: #define HB_MUTEX_INIT		{HB_MUTEX_IMPL_INIT}
michael@0: struct hb_mutex_t
michael@0: {
michael@0:   /* TODO Add tracing. */
michael@0: 
michael@0:   hb_mutex_impl_t m;
michael@0: 
michael@0:   inline void init   (void) { hb_mutex_impl_init   (&m); }
michael@0:   inline void lock   (void) { hb_mutex_impl_lock   (&m); }
michael@0:   inline void unlock (void) { hb_mutex_impl_unlock (&m); }
michael@0:   inline void finish (void) { hb_mutex_impl_finish (&m); }
michael@0: };
michael@0: 
michael@0: 
michael@0: #endif /* HB_MUTEX_PRIVATE_HH */