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c25aa7cd PP |
1 | /* |
2 | * Copyright (C) the libgit2 contributors. All rights reserved. | |
3 | * | |
4 | * This file is part of libgit2, distributed under the GNU GPL v2 with | |
5 | * a Linking Exception. For full terms see the included COPYING file. | |
6 | */ | |
7 | #ifndef INCLUDE_thread_h__ | |
8 | #define INCLUDE_thread_h__ | |
9 | ||
10 | #if defined(GIT_THREADS) | |
11 | ||
12 | #if defined(__clang__) | |
13 | ||
14 | # if (__clang_major__ < 3 || (__clang_major__ == 3 && __clang_minor__ < 1)) | |
e579e0f7 | 15 | # error Atomic primitives do not exist on this version of clang; configure libgit2 with -DUSE_THREADS=OFF |
c25aa7cd PP |
16 | # else |
17 | # define GIT_BUILTIN_ATOMIC | |
18 | # endif | |
19 | ||
20 | #elif defined(__GNUC__) | |
21 | ||
22 | # if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)) | |
e579e0f7 | 23 | # error Atomic primitives do not exist on this version of gcc; configure libgit2 with -DUSE_THREADS=OFF |
c25aa7cd PP |
24 | # elif (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 7)) |
25 | # define GIT_BUILTIN_ATOMIC | |
26 | # else | |
27 | # define GIT_BUILTIN_SYNC | |
28 | # endif | |
29 | ||
30 | #endif | |
31 | ||
32 | #endif /* GIT_THREADS */ | |
33 | ||
34 | /* Common operations even if threading has been disabled */ | |
35 | typedef struct { | |
36 | #if defined(GIT_WIN32) | |
37 | volatile long val; | |
38 | #else | |
39 | volatile int val; | |
40 | #endif | |
41 | } git_atomic32; | |
42 | ||
43 | #ifdef GIT_ARCH_64 | |
44 | ||
45 | typedef struct { | |
46 | #if defined(GIT_WIN32) | |
47 | volatile __int64 val; | |
48 | #else | |
49 | volatile int64_t val; | |
50 | #endif | |
51 | } git_atomic64; | |
52 | ||
53 | typedef git_atomic64 git_atomic_ssize; | |
54 | ||
55 | #define git_atomic_ssize_set git_atomic64_set | |
56 | #define git_atomic_ssize_add git_atomic64_add | |
57 | #define git_atomic_ssize_get git_atomic64_get | |
58 | ||
59 | #else | |
60 | ||
61 | typedef git_atomic32 git_atomic_ssize; | |
62 | ||
63 | #define git_atomic_ssize_set git_atomic32_set | |
64 | #define git_atomic_ssize_add git_atomic32_add | |
65 | #define git_atomic_ssize_get git_atomic32_get | |
66 | ||
67 | #endif | |
68 | ||
69 | #ifdef GIT_THREADS | |
70 | ||
71 | #ifdef GIT_WIN32 | |
72 | # include "win32/thread.h" | |
73 | #else | |
74 | # include "unix/pthread.h" | |
75 | #endif | |
76 | ||
77 | /* | |
78 | * Atomically sets the contents of *a to be val. | |
79 | */ | |
80 | GIT_INLINE(void) git_atomic32_set(git_atomic32 *a, int val) | |
81 | { | |
82 | #if defined(GIT_WIN32) | |
83 | InterlockedExchange(&a->val, (LONG)val); | |
84 | #elif defined(GIT_BUILTIN_ATOMIC) | |
85 | __atomic_store_n(&a->val, val, __ATOMIC_SEQ_CST); | |
86 | #elif defined(GIT_BUILTIN_SYNC) | |
87 | __sync_lock_test_and_set(&a->val, val); | |
88 | #else | |
89 | # error "Unsupported architecture for atomic operations" | |
90 | #endif | |
91 | } | |
92 | ||
93 | /* | |
94 | * Atomically increments the contents of *a by 1, and stores the result back into *a. | |
95 | * @return the result of the operation. | |
96 | */ | |
97 | GIT_INLINE(int) git_atomic32_inc(git_atomic32 *a) | |
98 | { | |
99 | #if defined(GIT_WIN32) | |
100 | return InterlockedIncrement(&a->val); | |
101 | #elif defined(GIT_BUILTIN_ATOMIC) | |
102 | return __atomic_add_fetch(&a->val, 1, __ATOMIC_SEQ_CST); | |
103 | #elif defined(GIT_BUILTIN_SYNC) | |
104 | return __sync_add_and_fetch(&a->val, 1); | |
105 | #else | |
106 | # error "Unsupported architecture for atomic operations" | |
107 | #endif | |
108 | } | |
109 | ||
110 | /* | |
111 | * Atomically adds the contents of *a and addend, and stores the result back into *a. | |
112 | * @return the result of the operation. | |
113 | */ | |
114 | GIT_INLINE(int) git_atomic32_add(git_atomic32 *a, int32_t addend) | |
115 | { | |
116 | #if defined(GIT_WIN32) | |
117 | return InterlockedAdd(&a->val, addend); | |
118 | #elif defined(GIT_BUILTIN_ATOMIC) | |
119 | return __atomic_add_fetch(&a->val, addend, __ATOMIC_SEQ_CST); | |
120 | #elif defined(GIT_BUILTIN_SYNC) | |
121 | return __sync_add_and_fetch(&a->val, addend); | |
122 | #else | |
123 | # error "Unsupported architecture for atomic operations" | |
124 | #endif | |
125 | } | |
126 | ||
127 | /* | |
128 | * Atomically decrements the contents of *a by 1, and stores the result back into *a. | |
129 | * @return the result of the operation. | |
130 | */ | |
131 | GIT_INLINE(int) git_atomic32_dec(git_atomic32 *a) | |
132 | { | |
133 | #if defined(GIT_WIN32) | |
134 | return InterlockedDecrement(&a->val); | |
135 | #elif defined(GIT_BUILTIN_ATOMIC) | |
136 | return __atomic_sub_fetch(&a->val, 1, __ATOMIC_SEQ_CST); | |
137 | #elif defined(GIT_BUILTIN_SYNC) | |
138 | return __sync_sub_and_fetch(&a->val, 1); | |
139 | #else | |
140 | # error "Unsupported architecture for atomic operations" | |
141 | #endif | |
142 | } | |
143 | ||
144 | /* | |
145 | * Atomically gets the contents of *a. | |
146 | * @return the contents of *a. | |
147 | */ | |
148 | GIT_INLINE(int) git_atomic32_get(git_atomic32 *a) | |
149 | { | |
150 | #if defined(GIT_WIN32) | |
151 | return (int)InterlockedCompareExchange(&a->val, 0, 0); | |
152 | #elif defined(GIT_BUILTIN_ATOMIC) | |
153 | return __atomic_load_n(&a->val, __ATOMIC_SEQ_CST); | |
154 | #elif defined(GIT_BUILTIN_SYNC) | |
155 | return __sync_val_compare_and_swap(&a->val, 0, 0); | |
156 | #else | |
157 | # error "Unsupported architecture for atomic operations" | |
158 | #endif | |
159 | } | |
160 | ||
161 | GIT_INLINE(void *) git_atomic__compare_and_swap( | |
162 | void * volatile *ptr, void *oldval, void *newval) | |
163 | { | |
164 | #if defined(GIT_WIN32) | |
165 | return InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval); | |
166 | #elif defined(GIT_BUILTIN_ATOMIC) | |
167 | void *foundval = oldval; | |
168 | __atomic_compare_exchange(ptr, &foundval, &newval, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST); | |
169 | return foundval; | |
170 | #elif defined(GIT_BUILTIN_SYNC) | |
171 | return __sync_val_compare_and_swap(ptr, oldval, newval); | |
172 | #else | |
173 | # error "Unsupported architecture for atomic operations" | |
174 | #endif | |
175 | } | |
176 | ||
177 | GIT_INLINE(volatile void *) git_atomic__swap( | |
178 | void * volatile *ptr, void *newval) | |
179 | { | |
180 | #if defined(GIT_WIN32) | |
181 | return InterlockedExchangePointer(ptr, newval); | |
182 | #elif defined(GIT_BUILTIN_ATOMIC) | |
e579e0f7 | 183 | void * foundval = NULL; |
c25aa7cd PP |
184 | __atomic_exchange(ptr, &newval, &foundval, __ATOMIC_SEQ_CST); |
185 | return foundval; | |
186 | #elif defined(GIT_BUILTIN_SYNC) | |
187 | return (volatile void *)__sync_lock_test_and_set(ptr, newval); | |
188 | #else | |
189 | # error "Unsupported architecture for atomic operations" | |
190 | #endif | |
191 | } | |
192 | ||
193 | GIT_INLINE(volatile void *) git_atomic__load(void * volatile *ptr) | |
194 | { | |
195 | #if defined(GIT_WIN32) | |
196 | void *newval = NULL, *oldval = NULL; | |
197 | return (volatile void *)InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval); | |
198 | #elif defined(GIT_BUILTIN_ATOMIC) | |
199 | return (volatile void *)__atomic_load_n(ptr, __ATOMIC_SEQ_CST); | |
200 | #elif defined(GIT_BUILTIN_SYNC) | |
201 | return (volatile void *)__sync_val_compare_and_swap(ptr, 0, 0); | |
202 | #else | |
203 | # error "Unsupported architecture for atomic operations" | |
204 | #endif | |
205 | } | |
206 | ||
207 | #ifdef GIT_ARCH_64 | |
208 | ||
209 | /* | |
210 | * Atomically adds the contents of *a and addend, and stores the result back into *a. | |
211 | * @return the result of the operation. | |
212 | */ | |
213 | GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend) | |
214 | { | |
215 | #if defined(GIT_WIN32) | |
216 | return InterlockedAdd64(&a->val, addend); | |
217 | #elif defined(GIT_BUILTIN_ATOMIC) | |
218 | return __atomic_add_fetch(&a->val, addend, __ATOMIC_SEQ_CST); | |
219 | #elif defined(GIT_BUILTIN_SYNC) | |
220 | return __sync_add_and_fetch(&a->val, addend); | |
221 | #else | |
222 | # error "Unsupported architecture for atomic operations" | |
223 | #endif | |
224 | } | |
225 | ||
226 | /* | |
227 | * Atomically sets the contents of *a to be val. | |
228 | */ | |
229 | GIT_INLINE(void) git_atomic64_set(git_atomic64 *a, int64_t val) | |
230 | { | |
231 | #if defined(GIT_WIN32) | |
232 | InterlockedExchange64(&a->val, val); | |
233 | #elif defined(GIT_BUILTIN_ATOMIC) | |
234 | __atomic_store_n(&a->val, val, __ATOMIC_SEQ_CST); | |
235 | #elif defined(GIT_BUILTIN_SYNC) | |
236 | __sync_lock_test_and_set(&a->val, val); | |
237 | #else | |
238 | # error "Unsupported architecture for atomic operations" | |
239 | #endif | |
240 | } | |
241 | ||
242 | /* | |
243 | * Atomically gets the contents of *a. | |
244 | * @return the contents of *a. | |
245 | */ | |
246 | GIT_INLINE(int64_t) git_atomic64_get(git_atomic64 *a) | |
247 | { | |
248 | #if defined(GIT_WIN32) | |
249 | return (int64_t)InterlockedCompareExchange64(&a->val, 0, 0); | |
250 | #elif defined(GIT_BUILTIN_ATOMIC) | |
251 | return __atomic_load_n(&a->val, __ATOMIC_SEQ_CST); | |
252 | #elif defined(GIT_BUILTIN_SYNC) | |
253 | return __sync_val_compare_and_swap(&a->val, 0, 0); | |
254 | #else | |
255 | # error "Unsupported architecture for atomic operations" | |
256 | #endif | |
257 | } | |
258 | ||
259 | #endif | |
260 | ||
261 | #else | |
262 | ||
263 | #define git_threads_global_init git__noop | |
264 | ||
265 | #define git_thread unsigned int | |
266 | #define git_thread_create(thread, start_routine, arg) git__noop() | |
267 | #define git_thread_join(id, status) git__noop() | |
268 | ||
269 | /* Pthreads Mutex */ | |
270 | #define git_mutex unsigned int | |
271 | #define git_mutex_init(a) git__noop() | |
272 | #define git_mutex_init(a) git__noop() | |
273 | #define git_mutex_lock(a) git__noop() | |
274 | #define git_mutex_unlock(a) git__noop() | |
275 | #define git_mutex_free(a) git__noop() | |
276 | ||
277 | /* Pthreads condition vars */ | |
278 | #define git_cond unsigned int | |
279 | #define git_cond_init(c) git__noop() | |
280 | #define git_cond_free(c) git__noop() | |
281 | #define git_cond_wait(c, l) git__noop() | |
282 | #define git_cond_signal(c) git__noop() | |
283 | #define git_cond_broadcast(c) git__noop() | |
284 | ||
285 | /* Pthreads rwlock */ | |
286 | #define git_rwlock unsigned int | |
287 | #define git_rwlock_init(a) git__noop() | |
288 | #define git_rwlock_rdlock(a) git__noop() | |
289 | #define git_rwlock_rdunlock(a) git__noop() | |
290 | #define git_rwlock_wrlock(a) git__noop() | |
291 | #define git_rwlock_wrunlock(a) git__noop() | |
292 | #define git_rwlock_free(a) git__noop() | |
293 | #define GIT_RWLOCK_STATIC_INIT 0 | |
294 | ||
295 | ||
296 | GIT_INLINE(void) git_atomic32_set(git_atomic32 *a, int val) | |
297 | { | |
298 | a->val = val; | |
299 | } | |
300 | ||
301 | GIT_INLINE(int) git_atomic32_inc(git_atomic32 *a) | |
302 | { | |
303 | return ++a->val; | |
304 | } | |
305 | ||
306 | GIT_INLINE(int) git_atomic32_add(git_atomic32 *a, int32_t addend) | |
307 | { | |
308 | a->val += addend; | |
309 | return a->val; | |
310 | } | |
311 | ||
312 | GIT_INLINE(int) git_atomic32_dec(git_atomic32 *a) | |
313 | { | |
314 | return --a->val; | |
315 | } | |
316 | ||
317 | GIT_INLINE(int) git_atomic32_get(git_atomic32 *a) | |
318 | { | |
319 | return (int)a->val; | |
320 | } | |
321 | ||
322 | GIT_INLINE(void *) git_atomic__compare_and_swap( | |
323 | void * volatile *ptr, void *oldval, void *newval) | |
324 | { | |
325 | void *foundval = *ptr; | |
326 | if (foundval == oldval) | |
327 | *ptr = newval; | |
328 | return foundval; | |
329 | } | |
330 | ||
331 | GIT_INLINE(volatile void *) git_atomic__swap( | |
332 | void * volatile *ptr, void *newval) | |
333 | { | |
334 | volatile void *old = *ptr; | |
335 | *ptr = newval; | |
336 | return old; | |
337 | } | |
338 | ||
339 | GIT_INLINE(volatile void *) git_atomic__load(void * volatile *ptr) | |
340 | { | |
341 | return *ptr; | |
342 | } | |
343 | ||
344 | #ifdef GIT_ARCH_64 | |
345 | ||
346 | GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend) | |
347 | { | |
348 | a->val += addend; | |
349 | return a->val; | |
350 | } | |
351 | ||
352 | GIT_INLINE(void) git_atomic64_set(git_atomic64 *a, int64_t val) | |
353 | { | |
354 | a->val = val; | |
355 | } | |
356 | ||
357 | GIT_INLINE(int64_t) git_atomic64_get(git_atomic64 *a) | |
358 | { | |
359 | return (int64_t)a->val; | |
360 | } | |
361 | ||
362 | #endif | |
363 | ||
364 | #endif | |
365 | ||
366 | /* | |
367 | * Atomically replace the contents of *ptr (if they are equal to oldval) with | |
368 | * newval. ptr must point to a pointer or a value that is the same size as a | |
369 | * pointer. This is semantically compatible with: | |
370 | * | |
371 | * #define git_atomic_compare_and_swap(ptr, oldval, newval) \ | |
372 | * ({ \ | |
373 | * void *foundval = *ptr; \ | |
374 | * if (foundval == oldval) \ | |
375 | * *ptr = newval; \ | |
376 | * foundval; \ | |
377 | * }) | |
378 | * | |
379 | * @return the original contents of *ptr. | |
380 | */ | |
381 | #define git_atomic_compare_and_swap(ptr, oldval, newval) \ | |
382 | git_atomic__compare_and_swap((void * volatile *)ptr, oldval, newval) | |
383 | ||
384 | /* | |
385 | * Atomically replace the contents of v with newval. v must be the same size as | |
386 | * a pointer. This is semantically compatible with: | |
387 | * | |
388 | * #define git_atomic_swap(v, newval) \ | |
389 | * ({ \ | |
390 | * volatile void *old = v; \ | |
391 | * v = newval; \ | |
392 | * old; \ | |
393 | * }) | |
394 | * | |
395 | * @return the original contents of v. | |
396 | */ | |
397 | #define git_atomic_swap(v, newval) \ | |
398 | (void *)git_atomic__swap((void * volatile *)&(v), newval) | |
399 | ||
400 | /* | |
401 | * Atomically reads the contents of v. v must be the same size as a pointer. | |
402 | * This is semantically compatible with: | |
403 | * | |
404 | * #define git_atomic_load(v) v | |
405 | * | |
406 | * @return the contents of v. | |
407 | */ | |
408 | #define git_atomic_load(v) \ | |
409 | (void *)git_atomic__load((void * volatile *)&(v)) | |
410 | ||
411 | #if defined(GIT_THREADS) | |
412 | ||
413 | # if defined(GIT_WIN32) | |
414 | # define GIT_MEMORY_BARRIER MemoryBarrier() | |
415 | # elif defined(GIT_BUILTIN_ATOMIC) | |
416 | # define GIT_MEMORY_BARRIER __atomic_thread_fence(__ATOMIC_SEQ_CST) | |
417 | # elif defined(GIT_BUILTIN_SYNC) | |
418 | # define GIT_MEMORY_BARRIER __sync_synchronize() | |
419 | # endif | |
420 | ||
421 | #else | |
422 | ||
423 | # define GIT_MEMORY_BARRIER /* noop */ | |
424 | ||
425 | #endif | |
426 | ||
427 | /* Thread-local data */ | |
428 | ||
429 | #if !defined(GIT_THREADS) | |
430 | # define git_tlsdata_key int | |
431 | #elif defined(GIT_WIN32) | |
432 | # define git_tlsdata_key DWORD | |
433 | #elif defined(_POSIX_THREADS) | |
434 | # define git_tlsdata_key pthread_key_t | |
435 | #else | |
436 | # error unknown threading model | |
437 | #endif | |
438 | ||
439 | /** | |
440 | * Create a thread-local data key. The destroy function will be | |
441 | * called upon thread exit. On some platforms, it may be called | |
442 | * when all threads have deleted their keys. | |
443 | * | |
444 | * Note that the tlsdata functions do not set an error message on | |
445 | * failure; this is because the error handling in libgit2 is itself | |
446 | * handled by thread-local data storage. | |
447 | * | |
448 | * @param key the tlsdata key | |
449 | * @param destroy_fn function pointer called upon thread exit | |
450 | * @return 0 on success, non-zero on failure | |
451 | */ | |
452 | int git_tlsdata_init(git_tlsdata_key *key, void (GIT_SYSTEM_CALL *destroy_fn)(void *)); | |
453 | ||
454 | /** | |
455 | * Set a the thread-local value for the given key. | |
456 | * | |
457 | * @param key the tlsdata key to store data on | |
458 | * @param value the pointer to store | |
459 | * @return 0 on success, non-zero on failure | |
460 | */ | |
461 | int git_tlsdata_set(git_tlsdata_key key, void *value); | |
462 | ||
463 | /** | |
464 | * Get the thread-local value for the given key. | |
465 | * | |
466 | * @param key the tlsdata key to retrieve the value of | |
467 | * @return the pointer stored with git_tlsdata_set | |
468 | */ | |
469 | void *git_tlsdata_get(git_tlsdata_key key); | |
470 | ||
471 | /** | |
472 | * Delete the given thread-local key. | |
473 | * | |
474 | * @param key the tlsdata key to dispose | |
475 | * @return 0 on success, non-zero on failure | |
476 | */ | |
477 | int git_tlsdata_dispose(git_tlsdata_key key); | |
478 | ||
479 | #endif |