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_HH
33#define HB_MUTEX_HH
34
35#include "hb.hh"
36
37
38/* mutex */
39
40/* We need external help for these */
41
42#if defined(HB_MUTEX_IMPL_INIT) \
43 && defined(hb_mutex_impl_init) \
44 && defined(hb_mutex_impl_lock) \
45 && defined(hb_mutex_impl_unlock) \
46 && defined(hb_mutex_impl_finish)
47
48/* Defined externally, i.e. in config.h; must have typedef'ed hb_mutex_impl_t as well. */
49
50
51#elif !defined(HB_NO_MT) && (defined(HAVE_PTHREAD) || defined(__APPLE__))
52
53#include <pthread.h>
54typedef pthread_mutex_t hb_mutex_impl_t;
55#define HB_MUTEX_IMPL_INIT PTHREAD_MUTEX_INITIALIZER
56#define hb_mutex_impl_init(M) pthread_mutex_init (M, nullptr)
57#define hb_mutex_impl_lock(M) pthread_mutex_lock (M)
58#define hb_mutex_impl_unlock(M) pthread_mutex_unlock (M)
59#define hb_mutex_impl_finish(M) pthread_mutex_destroy (M)
60
61
62#elif !defined(HB_NO_MT) && defined(_WIN32)
63
64typedef CRITICAL_SECTION hb_mutex_impl_t;
65#define HB_MUTEX_IMPL_INIT {0}
66#if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
67#define hb_mutex_impl_init(M) InitializeCriticalSectionEx (M, 0, 0)
68#else
69#define hb_mutex_impl_init(M) InitializeCriticalSection (M)
70#endif
71#define hb_mutex_impl_lock(M) EnterCriticalSection (M)
72#define hb_mutex_impl_unlock(M) LeaveCriticalSection (M)
73#define hb_mutex_impl_finish(M) DeleteCriticalSection (M)
74
75
76#elif !defined(HB_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)
77
78#if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_YIELD)
79# include <sched.h>
80# define HB_SCHED_YIELD() sched_yield ()
81#else
82# define HB_SCHED_YIELD() HB_STMT_START {} HB_STMT_END
83#endif
84
85/* This actually is not a totally awful implementation. */
86typedef volatile int hb_mutex_impl_t;
87#define HB_MUTEX_IMPL_INIT 0
88#define hb_mutex_impl_init(M) *(M) = 0
89#define hb_mutex_impl_lock(M) HB_STMT_START { while (__sync_lock_test_and_set((M), 1)) HB_SCHED_YIELD (); } HB_STMT_END
90#define hb_mutex_impl_unlock(M) __sync_lock_release (M)
91#define hb_mutex_impl_finish(M) HB_STMT_START {} HB_STMT_END
92
93
94#elif defined(HB_NO_MT)
95
96typedef int hb_mutex_impl_t;
97#define HB_MUTEX_IMPL_INIT 0
98#define hb_mutex_impl_init(M) HB_STMT_START {} HB_STMT_END
99#define hb_mutex_impl_lock(M) HB_STMT_START {} HB_STMT_END
100#define hb_mutex_impl_unlock(M) HB_STMT_START {} HB_STMT_END
101#define hb_mutex_impl_finish(M) HB_STMT_START {} HB_STMT_END
102
103
104#else
105
106#error "Could not find any system to define mutex macros."
107#error "Check hb-mutex.hh for possible resolutions."
108
109#endif
110
111
112#define HB_MUTEX_INIT {HB_MUTEX_IMPL_INIT}
113
114struct hb_mutex_t
115{
116 hb_mutex_impl_t m;
117
118 void init () { hb_mutex_impl_init (&m); }
119 void lock () { hb_mutex_impl_lock (&m); }
120 void unlock () { hb_mutex_impl_unlock (&m); }
121 void fini () { hb_mutex_impl_finish (&m); }
122};
123
124struct hb_lock_t
125{
126 hb_lock_t (hb_mutex_t &mutex_) : mutex (mutex_) { mutex.lock (); }
127 ~hb_lock_t () { mutex.unlock (); }
128 private:
129 hb_mutex_t &mutex;
130};
131
132
133#endif /* HB_MUTEX_HH */
134