1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
|
/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#ifndef INCLUDE_thread_utils_h__
#define INCLUDE_thread_utils_h__
#if defined(__GNUC__) && defined(GIT_THREADS)
# if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1))
# error Atomic primitives do not exist on this version of gcc; configure libgit2 with -DTHREADSAFE=OFF
# endif
#endif
/* Common operations even if threading has been disabled */
typedef struct {
#if defined(GIT_WIN32)
volatile long val;
#else
volatile int val;
#endif
} git_atomic;
#ifdef GIT_ARCH_64
typedef struct {
#if defined(GIT_WIN32)
__int64 val;
#else
int64_t val;
#endif
} git_atomic64;
typedef git_atomic64 git_atomic_ssize;
#define git_atomic_ssize_add git_atomic64_add
#else
typedef git_atomic git_atomic_ssize;
#define git_atomic_ssize_add git_atomic_add
#endif
#ifdef GIT_THREADS
#ifdef GIT_WIN32
# include "win32/thread.h"
#else
# include "unix/pthread.h"
#endif
GIT_INLINE(void) git_atomic_set(git_atomic *a, int val)
{
#if defined(GIT_WIN32)
InterlockedExchange(&a->val, (LONG)val);
#elif defined(__GNUC__)
__sync_lock_test_and_set(&a->val, val);
#else
# error "Unsupported architecture for atomic operations"
#endif
}
GIT_INLINE(int) git_atomic_inc(git_atomic *a)
{
#if defined(GIT_WIN32)
return InterlockedIncrement(&a->val);
#elif defined(__GNUC__)
return __sync_add_and_fetch(&a->val, 1);
#else
# error "Unsupported architecture for atomic operations"
#endif
}
GIT_INLINE(int) git_atomic_add(git_atomic *a, int32_t addend)
{
#if defined(GIT_WIN32)
return InterlockedExchangeAdd(&a->val, addend);
#elif defined(__GNUC__)
return __sync_add_and_fetch(&a->val, addend);
#else
# error "Unsupported architecture for atomic operations"
#endif
}
GIT_INLINE(int) git_atomic_dec(git_atomic *a)
{
#if defined(GIT_WIN32)
return InterlockedDecrement(&a->val);
#elif defined(__GNUC__)
return __sync_sub_and_fetch(&a->val, 1);
#else
# error "Unsupported architecture for atomic operations"
#endif
}
GIT_INLINE(void *) git___compare_and_swap(
void * volatile *ptr, void *oldval, void *newval)
{
volatile void *foundval;
#if defined(GIT_WIN32)
foundval = InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval);
#elif defined(__GNUC__)
foundval = __sync_val_compare_and_swap(ptr, oldval, newval);
#else
# error "Unsupported architecture for atomic operations"
#endif
return (foundval == oldval) ? oldval : newval;
}
GIT_INLINE(volatile void *) git___swap(
void * volatile *ptr, void *newval)
{
#if defined(GIT_WIN32)
return InterlockedExchangePointer(ptr, newval);
#else
return __sync_lock_test_and_set(ptr, newval);
#endif
}
#ifdef GIT_ARCH_64
GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend)
{
#if defined(GIT_WIN32)
return InterlockedExchangeAdd64(&a->val, addend);
#elif defined(__GNUC__)
return __sync_add_and_fetch(&a->val, addend);
#else
# error "Unsupported architecture for atomic operations"
#endif
}
#endif
#else
#define git_thread unsigned int
#define git_thread_create(thread, start_routine, arg) 0
#define git_thread_join(id, status) (void)0
/* Pthreads Mutex */
#define git_mutex unsigned int
GIT_INLINE(int) git_mutex_init(git_mutex *mutex) \
{ GIT_UNUSED(mutex); return 0; }
GIT_INLINE(int) git_mutex_lock(git_mutex *mutex) \
{ GIT_UNUSED(mutex); return 0; }
#define git_mutex_unlock(a) (void)0
#define git_mutex_free(a) (void)0
/* Pthreads condition vars */
#define git_cond unsigned int
#define git_cond_init(c, a) (void)0
#define git_cond_free(c) (void)0
#define git_cond_wait(c, l) (void)0
#define git_cond_signal(c) (void)0
#define git_cond_broadcast(c) (void)0
/* Pthreads rwlock */
#define git_rwlock unsigned int
#define git_rwlock_init(a) 0
#define git_rwlock_rdlock(a) 0
#define git_rwlock_rdunlock(a) (void)0
#define git_rwlock_wrlock(a) 0
#define git_rwlock_wrunlock(a) (void)0
#define git_rwlock_free(a) (void)0
#define GIT_RWLOCK_STATIC_INIT 0
GIT_INLINE(void) git_atomic_set(git_atomic *a, int val)
{
a->val = val;
}
GIT_INLINE(int) git_atomic_inc(git_atomic *a)
{
return ++a->val;
}
GIT_INLINE(int) git_atomic_add(git_atomic *a, int32_t addend)
{
a->val += addend;
return a->val;
}
GIT_INLINE(int) git_atomic_dec(git_atomic *a)
{
return --a->val;
}
GIT_INLINE(void *) git___compare_and_swap(
void * volatile *ptr, void *oldval, void *newval)
{
if (*ptr == oldval)
*ptr = newval;
else
oldval = newval;
return oldval;
}
GIT_INLINE(volatile void *) git___swap(
void * volatile *ptr, void *newval)
{
volatile void *old = *ptr;
*ptr = newval;
return old;
}
#ifdef GIT_ARCH_64
GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend)
{
a->val += addend;
return a->val;
}
#endif
#endif
GIT_INLINE(int) git_atomic_get(git_atomic *a)
{
return (int)a->val;
}
/* Atomically replace oldval with newval
* @return oldval if it was replaced or newval if it was not
*/
#define git__compare_and_swap(P,O,N) \
git___compare_and_swap((void * volatile *)P, O, N)
#define git__swap(ptr, val) (void *)git___swap((void * volatile *)&ptr, val)
extern int git_online_cpus(void);
#if defined(GIT_THREADS) && defined(_MSC_VER)
# define GIT_MEMORY_BARRIER MemoryBarrier()
#elif defined(GIT_THREADS)
# define GIT_MEMORY_BARRIER __sync_synchronize()
#else
# define GIT_MEMORY_BARRIER /* noop */
#endif
#endif /* INCLUDE_thread_utils_h__ */
|
