third_party/harfbuzz-ng/src/hb-mutex-private.hh

   1 /*
   2  * Copyright © 2007  Chris Wilson
   3  * Copyright © 2009,2010  Red Hat, Inc.
   4  * Copyright © 2011,2012  Google, Inc.
   5  *
   6  *  This is part of HarfBuzz, a text shaping library.
   7  *
   8  * Permission is hereby granted, without written agreement and without
   9  * license or royalty fees, to use, copy, modify, and distribute this
  10  * software and its documentation for any purpose, provided that the
  11  * above copyright notice and the following two paragraphs appear in
  12  * all copies of this software.
  13  *
  14  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  15  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  16  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  17  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  18  * DAMAGE.
  19  *
  20  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  21  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  22  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  23  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  24  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  25  *
  26  * Contributor(s):
  27  *      Chris Wilson <chris@chris-wilson.co.uk>
  28  * Red Hat Author(s): Behdad Esfahbod
  29  * Google Author(s): Behdad Esfahbod
  30  */
  31
  32 #ifndef HB_MUTEX_PRIVATE_HH
  33 #define HB_MUTEX_PRIVATE_HH
  34
  35 #include "hb-private.hh"
  36
  37
  38 /* mutex */
  39
  40 /* We need external help for these */
  41
  42 #if 0
  43
  44
  45 #elif !defined(HB_NO_MT) && (defined(_WIN32) || defined(__CYGWIN__))
  46
  47 #include <windows.h>
  48 typedef CRITICAL_SECTION hb_mutex_impl_t;
  49 #define HB_MUTEX_IMPL_INIT      {0}
  50 #define hb_mutex_impl_init(M)   InitializeCriticalSection (M)
  51 #define hb_mutex_impl_lock(M)   EnterCriticalSection (M)
  52 #define hb_mutex_impl_unlock(M) LeaveCriticalSection (M)
  53 #define hb_mutex_impl_finish(M) DeleteCriticalSection (M)
  54
  55
  56 #elif !defined(HB_NO_MT) && (defined(HAVE_PTHREAD) || defined(__APPLE__))
  57
  58 #include <pthread.h>
  59 typedef pthread_mutex_t hb_mutex_impl_t;
  60 #define HB_MUTEX_IMPL_INIT      PTHREAD_MUTEX_INITIALIZER
  61 #define hb_mutex_impl_init(M)   pthread_mutex_init (M, NULL)
  62 #define hb_mutex_impl_lock(M)   pthread_mutex_lock (M)
  63 #define hb_mutex_impl_unlock(M) pthread_mutex_unlock (M)
  64 #define hb_mutex_impl_finish(M) pthread_mutex_destroy (M)
  65
  66
  67 #elif !defined(HB_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)
  68
  69 #if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_YIELD)
  70 # include <sched.h>
  71 # define HB_SCHED_YIELD() sched_yield ()
  72 #else
  73 # define HB_SCHED_YIELD() HB_STMT_START {} HB_STMT_END
  74 #endif
  75
  76 /* This actually is not a totally awful implementation. */
  77 typedef volatile int hb_mutex_impl_t;
  78 #define HB_MUTEX_IMPL_INIT      0
  79 #define hb_mutex_impl_init(M)   *(M) = 0
  80 #define hb_mutex_impl_lock(M)   HB_STMT_START { while (__sync_lock_test_and_set((M), 1)) HB_SCHED_YIELD (); } HB_STMT_END
  81 #define hb_mutex_impl_unlock(M) __sync_lock_release (M)
  82 #define hb_mutex_impl_finish(M) HB_STMT_START {} HB_STMT_END
  83
  84
  85 #elif !defined(HB_NO_MT)
  86
  87 #if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_YIELD)
  88 # include <sched.h>
  89 # define HB_SCHED_YIELD() sched_yield ()
  90 #else
  91 # define HB_SCHED_YIELD() HB_STMT_START {} HB_STMT_END
  92 #endif
  93
  94 #define HB_MUTEX_INT_NIL 1 /* Warn that fallback implementation is in use. */
  95 typedef volatile int hb_mutex_impl_t;
  96 #define HB_MUTEX_IMPL_INIT      0
  97 #define hb_mutex_impl_init(M)   *(M) = 0
  98 #define hb_mutex_impl_lock(M)   HB_STMT_START { while (*(M)) HB_SCHED_YIELD (); (*(M))++; } HB_STMT_END
  99 #define hb_mutex_impl_unlock(M) (*(M))--;
 100 #define hb_mutex_impl_finish(M) HB_STMT_START {} HB_STMT_END
 101
 102
 103 #else /* HB_NO_MT */
 104
 105 typedef int hb_mutex_impl_t;
 106 #define HB_MUTEX_IMPL_INIT      0
 107 #define hb_mutex_impl_init(M)   HB_STMT_START {} HB_STMT_END
 108 #define hb_mutex_impl_lock(M)   HB_STMT_START {} HB_STMT_END
 109 #define hb_mutex_impl_unlock(M) HB_STMT_START {} HB_STMT_END
 110 #define hb_mutex_impl_finish(M) HB_STMT_START {} HB_STMT_END
 111
 112 #endif
 113
 114
 115 #define HB_MUTEX_INIT           {HB_MUTEX_IMPL_INIT}
 116 struct hb_mutex_t
 117 {
 118   /* TODO Add tracing. */
 119
 120   hb_mutex_impl_t m;
 121
 122   inline void init   (void) { hb_mutex_impl_init   (&m); }
 123   inline void lock   (void) { hb_mutex_impl_lock   (&m); }
 124   inline void unlock (void) { hb_mutex_impl_unlock (&m); }
 125   inline void finish (void) { hb_mutex_impl_finish (&m); }
 126 };
 127
 128
 129 #endif /* HB_MUTEX_PRIVATE_HH */