fontconfig/src/fcmutex.h

128 lines
4.3 KiB
C

/*
* Atomic int and pointer operations. Originally copied from HarfBuzz.
*
* Copyright © 2007 Chris Wilson
* Copyright © 2009,2010 Red Hat, Inc.
* Copyright © 2011,2012,2013 Google, Inc.
*
* 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 _FCMUTEX_H_
#define _FCMUTEX_H_
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#define FC_STMT_START do
#define FC_STMT_END while (0)
/* mutex */
/* We need external help for these */
#if 0
#elif !defined(FC_NO_MT) && defined(_MSC_VER) || defined(__MINGW32__)
#include "fcwindows.h"
typedef CRITICAL_SECTION fc_mutex_impl_t;
#define FC_MUTEX_IMPL_INIT { NULL, 0, 0, NULL, NULL, 0 }
#define fc_mutex_impl_init(M) InitializeCriticalSection (M)
#define fc_mutex_impl_lock(M) EnterCriticalSection (M)
#define fc_mutex_impl_unlock(M) LeaveCriticalSection (M)
#define fc_mutex_impl_finish(M) DeleteCriticalSection (M)
#elif !defined(FC_NO_MT) && (defined(HAVE_PTHREAD) || defined(__APPLE__))
#include <pthread.h>
typedef pthread_mutex_t fc_mutex_impl_t;
#define FC_MUTEX_IMPL_INIT PTHREAD_MUTEX_INITIALIZER
#define fc_mutex_impl_init(M) pthread_mutex_init (M, NULL)
#define fc_mutex_impl_lock(M) pthread_mutex_lock (M)
#define fc_mutex_impl_unlock(M) pthread_mutex_unlock (M)
#define fc_mutex_impl_finish(M) pthread_mutex_destroy (M)
#elif !defined(FC_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)
#if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_YIELD)
# include <sched.h>
# define FC_SCHED_YIELD() sched_yield ()
#else
# define FC_SCHED_YIELD() FC_STMT_START {} FC_STMT_END
#endif
/* This actually is not a totally awful implementation. */
typedef volatile int fc_mutex_impl_t;
#define FC_MUTEX_IMPL_INIT 0
#define fc_mutex_impl_init(M) *(M) = 0
#define fc_mutex_impl_lock(M) FC_STMT_START { while (__sync_lock_test_and_set((M), 1)) FC_SCHED_YIELD (); } FC_STMT_END
#define fc_mutex_impl_unlock(M) __sync_lock_release (M)
#define fc_mutex_impl_finish(M) FC_STMT_START {} FC_STMT_END
#elif !defined(FC_NO_MT)
#if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_YIELD)
# include <sched.h>
# define FC_SCHED_YIELD() sched_yield ()
#else
# define FC_SCHED_YIELD() FC_STMT_START {} FC_STMT_END
#endif
#define FC_MUTEX_INT_NIL 1 /* Warn that fallback implementation is in use. */
typedef volatile int fc_mutex_impl_t;
#define FC_MUTEX_IMPL_INIT 0
#define fc_mutex_impl_init(M) *(M) = 0
#define fc_mutex_impl_lock(M) FC_STMT_START { while (*(M)) FC_SCHED_YIELD (); (*(M))++; } FC_STMT_END
#define fc_mutex_impl_unlock(M) (*(M))--;
#define fc_mutex_impl_finish(M) FC_STMT_START {} FC_STMT_END
#else /* FC_NO_MT */
typedef int fc_mutex_impl_t;
#define FC_MUTEX_IMPL_INIT 0
#define fc_mutex_impl_init(M) FC_STMT_START {} FC_STMT_END
#define fc_mutex_impl_lock(M) FC_STMT_START {} FC_STMT_END
#define fc_mutex_impl_unlock(M) FC_STMT_START {} FC_STMT_END
#define fc_mutex_impl_finish(M) FC_STMT_START {} FC_STMT_END
#endif
#define FC_MUTEX_INIT {FC_MUTEX_IMPL_INIT}
typedef fc_mutex_impl_t FcMutex;
static inline void FcMutexInit (FcMutex *m) { fc_mutex_impl_init (m); }
static inline void FcMutexLock (FcMutex *m) { fc_mutex_impl_lock (m); }
static inline void FcMutexUnlock (FcMutex *m) { fc_mutex_impl_unlock (m); }
static inline void FcMutexFinish (FcMutex *m) { fc_mutex_impl_finish (m); }
#endif /* _FCMUTEX_H_ */