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 #define WIN32_LEAN_AND_MEAN
  48 #include <windows.h>
  49 typedef CRITICAL_SECTION hb_mutex_impl_t;
  50 #define HB_MUTEX_IMPL_INIT      { NULL, 0, 0, NULL, NULL, 0 }
  51 #define hb_mutex_impl_init(M)   InitializeCriticalSection (M)
  52 #define hb_mutex_impl_lock(M)   EnterCriticalSection (M)
  53 #define hb_mutex_impl_unlock(M) LeaveCriticalSection (M)
  54 #define hb_mutex_impl_finish(M) DeleteCriticalSection (M)
  55
  56
  57 #elif !defined(HB_NO_MT) && (defined(HAVE_PTHREAD) || defined(__APPLE__))
  58
  59 #include <pthread.h>
  60 typedef pthread_mutex_t hb_mutex_impl_t;
  61 #define HB_MUTEX_IMPL_INIT      PTHREAD_MUTEX_INITIALIZER
  62 #define hb_mutex_impl_init(M)   pthread_mutex_init (M, NULL)
  63 #define hb_mutex_impl_lock(M)   pthread_mutex_lock (M)
  64 #define hb_mutex_impl_unlock(M) pthread_mutex_unlock (M)
  65 #define hb_mutex_impl_finish(M) pthread_mutex_destroy (M)
  66
  67
  68 #elif !defined(HB_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)
  69
  70 #if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_YIELD)
  71 # include <sched.h>
  72 # define HB_SCHED_YIELD() sched_yield ()
  73 #else
  74 # define HB_SCHED_YIELD() HB_STMT_START {} HB_STMT_END
  75 #endif
  76
  77 /* This actually is not a totally awful implementation. */
  78 typedef volatile int hb_mutex_impl_t;
  79 #define HB_MUTEX_IMPL_INIT      0
  80 #define hb_mutex_impl_init(M)   *(M) = 0
  81 #define hb_mutex_impl_lock(M)   HB_STMT_START { while (__sync_lock_test_and_set((M), 1)) HB_SCHED_YIELD (); } HB_STMT_END
  82 #define hb_mutex_impl_unlock(M) __sync_lock_release (M)
  83 #define hb_mutex_impl_finish(M) HB_STMT_START {} HB_STMT_END
  84
  85
  86 #elif !defined(HB_NO_MT)
  87
  88 #if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_YIELD)
  89 # include <sched.h>
  90 # define HB_SCHED_YIELD() sched_yield ()
  91 #else
  92 # define HB_SCHED_YIELD() HB_STMT_START {} HB_STMT_END
  93 #endif
  94
  95 #define HB_MUTEX_INT_NIL 1 /* Warn that fallback implementation is in use. */
  96 typedef volatile int hb_mutex_impl_t;
  97 #define HB_MUTEX_IMPL_INIT      0
  98 #define hb_mutex_impl_init(M)   *(M) = 0
  99 #define hb_mutex_impl_lock(M)   HB_STMT_START { while (*(M)) HB_SCHED_YIELD (); (*(M))++; } HB_STMT_END
 100 #define hb_mutex_impl_unlock(M) (*(M))--;
 101 #define hb_mutex_impl_finish(M) HB_STMT_START {} HB_STMT_END
 102
 103
 104 #else /* HB_NO_MT */
 105
 106 typedef int hb_mutex_impl_t;
 107 #define HB_MUTEX_IMPL_INIT      0
 108 #define hb_mutex_impl_init(M)   HB_STMT_START {} HB_STMT_END
 109 #define hb_mutex_impl_lock(M)   HB_STMT_START {} HB_STMT_END
 110 #define hb_mutex_impl_unlock(M) HB_STMT_START {} HB_STMT_END
 111 #define hb_mutex_impl_finish(M) HB_STMT_START {} HB_STMT_END
 112
 113 #endif
 114
 115
 116 #define HB_MUTEX_INIT           {HB_MUTEX_IMPL_INIT}
 117 struct hb_mutex_t
 118 {
 119   /* TODO Add tracing. */
 120
 121   hb_mutex_impl_t m;
 122
 123   inline void init   (void) { hb_mutex_impl_init   (&m); }
 124   inline void lock   (void) { hb_mutex_impl_lock   (&m); }
 125   inline void unlock (void) { hb_mutex_impl_unlock (&m); }
 126   inline void finish (void) { hb_mutex_impl_finish (&m); }
 127 };
 128
 129
 130 #endif /* HB_MUTEX_PRIVATE_HH */