1 /* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
2 *
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to
5 * deal in the Software without restriction, including without limitation the
6 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
7 * sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
9 *
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
19 * IN THE SOFTWARE.
20 */
21
22 #include <assert.h>
23 #include <limits.h>
24 #include <stdlib.h>
25
26 #if defined(__MINGW64_VERSION_MAJOR)
27 /* MemoryBarrier expands to __mm_mfence in some cases (x86+sse2), which may
28 * require this header in some versions of mingw64. */
29 #include <intrin.h>
30 #endif
31
32 #include "uv.h"
33 #include "internal.h"
34
uv__once_inner(uv_once_t * guard,void (* callback)(void))35 static void uv__once_inner(uv_once_t* guard, void (*callback)(void)) {
36 DWORD result;
37 HANDLE existing_event, created_event;
38
39 created_event = CreateEvent(NULL, 1, 0, NULL);
40 if (created_event == 0) {
41 /* Could fail in a low-memory situation? */
42 uv_fatal_error(GetLastError(), "CreateEvent");
43 }
44
45 existing_event = InterlockedCompareExchangePointer(&guard->event,
46 created_event,
47 NULL);
48
49 if (existing_event == NULL) {
50 /* We won the race */
51 callback();
52
53 result = SetEvent(created_event);
54 assert(result);
55 guard->ran = 1;
56
57 } else {
58 /* We lost the race. Destroy the event we created and wait for the existing
59 * one to become signaled. */
60 CloseHandle(created_event);
61 result = WaitForSingleObject(existing_event, INFINITE);
62 assert(result == WAIT_OBJECT_0);
63 }
64 }
65
66
uv_once(uv_once_t * guard,void (* callback)(void))67 void uv_once(uv_once_t* guard, void (*callback)(void)) {
68 /* Fast case - avoid WaitForSingleObject. */
69 if (guard->ran) {
70 return;
71 }
72
73 uv__once_inner(guard, callback);
74 }
75
76
77 /* Verify that uv_thread_t can be stored in a TLS slot. */
78 STATIC_ASSERT(sizeof(uv_thread_t) <= sizeof(void*));
79
80 static uv_key_t uv__current_thread_key;
81 static uv_once_t uv__current_thread_init_guard = UV_ONCE_INIT;
82
83
uv__init_current_thread_key(void)84 static void uv__init_current_thread_key(void) {
85 if (uv_key_create(&uv__current_thread_key))
86 abort();
87 }
88
89
90 struct thread_ctx {
91 void (*entry)(void* arg);
92 void* arg;
93 uv_thread_t self;
94 };
95
96
uv__thread_start(void * arg)97 static UINT __stdcall uv__thread_start(void* arg) {
98 struct thread_ctx *ctx_p;
99 struct thread_ctx ctx;
100
101 ctx_p = arg;
102 ctx = *ctx_p;
103 uv__free(ctx_p);
104
105 uv_once(&uv__current_thread_init_guard, uv__init_current_thread_key);
106 uv_key_set(&uv__current_thread_key, ctx.self);
107
108 ctx.entry(ctx.arg);
109
110 return 0;
111 }
112
113
uv_thread_create(uv_thread_t * tid,void (* entry)(void * arg),void * arg)114 int uv_thread_create(uv_thread_t *tid, void (*entry)(void *arg), void *arg) {
115 uv_thread_options_t params;
116 params.flags = UV_THREAD_NO_FLAGS;
117 return uv_thread_create_ex(tid, ¶ms, entry, arg);
118 }
119
uv_thread_create_ex(uv_thread_t * tid,const uv_thread_options_t * params,void (* entry)(void * arg),void * arg)120 int uv_thread_create_ex(uv_thread_t* tid,
121 const uv_thread_options_t* params,
122 void (*entry)(void *arg),
123 void *arg) {
124 struct thread_ctx* ctx;
125 int err;
126 HANDLE thread;
127 SYSTEM_INFO sysinfo;
128 size_t stack_size;
129 size_t pagesize;
130
131 stack_size =
132 params->flags & UV_THREAD_HAS_STACK_SIZE ? params->stack_size : 0;
133
134 if (stack_size != 0) {
135 GetNativeSystemInfo(&sysinfo);
136 pagesize = (size_t)sysinfo.dwPageSize;
137 /* Round up to the nearest page boundary. */
138 stack_size = (stack_size + pagesize - 1) &~ (pagesize - 1);
139
140 if ((unsigned)stack_size != stack_size)
141 return UV_EINVAL;
142 }
143
144 ctx = uv__malloc(sizeof(*ctx));
145 if (ctx == NULL)
146 return UV_ENOMEM;
147
148 ctx->entry = entry;
149 ctx->arg = arg;
150
151 /* Create the thread in suspended state so we have a chance to pass
152 * its own creation handle to it */
153 thread = (HANDLE) _beginthreadex(NULL,
154 (unsigned)stack_size,
155 uv__thread_start,
156 ctx,
157 CREATE_SUSPENDED,
158 NULL);
159 if (thread == NULL) {
160 err = errno;
161 uv__free(ctx);
162 } else {
163 err = 0;
164 *tid = thread;
165 ctx->self = thread;
166 ResumeThread(thread);
167 }
168
169 switch (err) {
170 case 0:
171 return 0;
172 case EACCES:
173 return UV_EACCES;
174 case EAGAIN:
175 return UV_EAGAIN;
176 case EINVAL:
177 return UV_EINVAL;
178 }
179
180 return UV_EIO;
181 }
182
183
uv_thread_self(void)184 uv_thread_t uv_thread_self(void) {
185 uv_thread_t key;
186 uv_once(&uv__current_thread_init_guard, uv__init_current_thread_key);
187 key = uv_key_get(&uv__current_thread_key);
188 if (key == NULL) {
189 /* If the thread wasn't started by uv_thread_create (such as the main
190 * thread), we assign an id to it now. */
191 if (!DuplicateHandle(GetCurrentProcess(), GetCurrentThread(),
192 GetCurrentProcess(), &key, 0,
193 FALSE, DUPLICATE_SAME_ACCESS)) {
194 uv_fatal_error(GetLastError(), "DuplicateHandle");
195 }
196 uv_key_set(&uv__current_thread_key, key);
197 }
198 return key;
199 }
200
201
uv_thread_join(uv_thread_t * tid)202 int uv_thread_join(uv_thread_t *tid) {
203 if (WaitForSingleObject(*tid, INFINITE))
204 return uv_translate_sys_error(GetLastError());
205 else {
206 CloseHandle(*tid);
207 *tid = 0;
208 MemoryBarrier(); /* For feature parity with pthread_join(). */
209 return 0;
210 }
211 }
212
213
uv_thread_equal(const uv_thread_t * t1,const uv_thread_t * t2)214 int uv_thread_equal(const uv_thread_t* t1, const uv_thread_t* t2) {
215 return *t1 == *t2;
216 }
217
218
uv_mutex_init(uv_mutex_t * mutex)219 int uv_mutex_init(uv_mutex_t* mutex) {
220 InitializeCriticalSection(mutex);
221 return 0;
222 }
223
224
uv_mutex_init_recursive(uv_mutex_t * mutex)225 int uv_mutex_init_recursive(uv_mutex_t* mutex) {
226 return uv_mutex_init(mutex);
227 }
228
229
uv_mutex_destroy(uv_mutex_t * mutex)230 void uv_mutex_destroy(uv_mutex_t* mutex) {
231 DeleteCriticalSection(mutex);
232 }
233
234
uv_mutex_lock(uv_mutex_t * mutex)235 void uv_mutex_lock(uv_mutex_t* mutex) {
236 EnterCriticalSection(mutex);
237 }
238
239
uv_mutex_trylock(uv_mutex_t * mutex)240 int uv_mutex_trylock(uv_mutex_t* mutex) {
241 if (TryEnterCriticalSection(mutex))
242 return 0;
243 else
244 return UV_EBUSY;
245 }
246
247
uv_mutex_unlock(uv_mutex_t * mutex)248 void uv_mutex_unlock(uv_mutex_t* mutex) {
249 LeaveCriticalSection(mutex);
250 }
251
252 /* Ensure that the ABI for this type remains stable in v1.x */
253 #ifdef _WIN64
254 STATIC_ASSERT(sizeof(uv_rwlock_t) == 80);
255 #else
256 STATIC_ASSERT(sizeof(uv_rwlock_t) == 48);
257 #endif
258
uv_rwlock_init(uv_rwlock_t * rwlock)259 int uv_rwlock_init(uv_rwlock_t* rwlock) {
260 memset(rwlock, 0, sizeof(*rwlock));
261 InitializeSRWLock(&rwlock->read_write_lock_);
262
263 return 0;
264 }
265
266
uv_rwlock_destroy(uv_rwlock_t * rwlock)267 void uv_rwlock_destroy(uv_rwlock_t* rwlock) {
268 /* SRWLock does not need explicit destruction so long as there are no waiting threads
269 See: https://docs.microsoft.com/windows/win32/api/synchapi/nf-synchapi-initializesrwlock#remarks */
270 }
271
272
uv_rwlock_rdlock(uv_rwlock_t * rwlock)273 void uv_rwlock_rdlock(uv_rwlock_t* rwlock) {
274 AcquireSRWLockShared(&rwlock->read_write_lock_);
275 }
276
277
uv_rwlock_tryrdlock(uv_rwlock_t * rwlock)278 int uv_rwlock_tryrdlock(uv_rwlock_t* rwlock) {
279 if (!TryAcquireSRWLockShared(&rwlock->read_write_lock_))
280 return UV_EBUSY;
281
282 return 0;
283 }
284
285
uv_rwlock_rdunlock(uv_rwlock_t * rwlock)286 void uv_rwlock_rdunlock(uv_rwlock_t* rwlock) {
287 ReleaseSRWLockShared(&rwlock->read_write_lock_);
288 }
289
290
uv_rwlock_wrlock(uv_rwlock_t * rwlock)291 void uv_rwlock_wrlock(uv_rwlock_t* rwlock) {
292 AcquireSRWLockExclusive(&rwlock->read_write_lock_);
293 }
294
295
uv_rwlock_trywrlock(uv_rwlock_t * rwlock)296 int uv_rwlock_trywrlock(uv_rwlock_t* rwlock) {
297 if (!TryAcquireSRWLockExclusive(&rwlock->read_write_lock_))
298 return UV_EBUSY;
299
300 return 0;
301 }
302
303
uv_rwlock_wrunlock(uv_rwlock_t * rwlock)304 void uv_rwlock_wrunlock(uv_rwlock_t* rwlock) {
305 ReleaseSRWLockExclusive(&rwlock->read_write_lock_);
306 }
307
308
uv_sem_init(uv_sem_t * sem,unsigned int value)309 int uv_sem_init(uv_sem_t* sem, unsigned int value) {
310 *sem = CreateSemaphore(NULL, value, INT_MAX, NULL);
311 if (*sem == NULL)
312 return uv_translate_sys_error(GetLastError());
313 else
314 return 0;
315 }
316
317
uv_sem_destroy(uv_sem_t * sem)318 void uv_sem_destroy(uv_sem_t* sem) {
319 if (!CloseHandle(*sem))
320 abort();
321 }
322
323
uv_sem_post(uv_sem_t * sem)324 void uv_sem_post(uv_sem_t* sem) {
325 if (!ReleaseSemaphore(*sem, 1, NULL))
326 abort();
327 }
328
329
uv_sem_wait(uv_sem_t * sem)330 void uv_sem_wait(uv_sem_t* sem) {
331 if (WaitForSingleObject(*sem, INFINITE) != WAIT_OBJECT_0)
332 abort();
333 }
334
335
uv_sem_trywait(uv_sem_t * sem)336 int uv_sem_trywait(uv_sem_t* sem) {
337 DWORD r = WaitForSingleObject(*sem, 0);
338
339 if (r == WAIT_OBJECT_0)
340 return 0;
341
342 if (r == WAIT_TIMEOUT)
343 return UV_EAGAIN;
344
345 abort();
346 return -1; /* Satisfy the compiler. */
347 }
348
349
uv_cond_init(uv_cond_t * cond)350 int uv_cond_init(uv_cond_t* cond) {
351 InitializeConditionVariable(&cond->cond_var);
352 return 0;
353 }
354
355
uv_cond_destroy(uv_cond_t * cond)356 void uv_cond_destroy(uv_cond_t* cond) {
357 /* nothing to do */
358 (void) &cond;
359 }
360
361
uv_cond_signal(uv_cond_t * cond)362 void uv_cond_signal(uv_cond_t* cond) {
363 WakeConditionVariable(&cond->cond_var);
364 }
365
366
uv_cond_broadcast(uv_cond_t * cond)367 void uv_cond_broadcast(uv_cond_t* cond) {
368 WakeAllConditionVariable(&cond->cond_var);
369 }
370
371
uv_cond_wait(uv_cond_t * cond,uv_mutex_t * mutex)372 void uv_cond_wait(uv_cond_t* cond, uv_mutex_t* mutex) {
373 if (!SleepConditionVariableCS(&cond->cond_var, mutex, INFINITE))
374 abort();
375 }
376
uv_cond_timedwait(uv_cond_t * cond,uv_mutex_t * mutex,uint64_t timeout)377 int uv_cond_timedwait(uv_cond_t* cond, uv_mutex_t* mutex, uint64_t timeout) {
378 if (SleepConditionVariableCS(&cond->cond_var, mutex, (DWORD)(timeout / 1e6)))
379 return 0;
380 if (GetLastError() != ERROR_TIMEOUT)
381 abort();
382 return UV_ETIMEDOUT;
383 }
384
385
uv_barrier_init(uv_barrier_t * barrier,unsigned int count)386 int uv_barrier_init(uv_barrier_t* barrier, unsigned int count) {
387 int err;
388
389 barrier->n = count;
390 barrier->count = 0;
391
392 err = uv_mutex_init(&barrier->mutex);
393 if (err)
394 return err;
395
396 err = uv_sem_init(&barrier->turnstile1, 0);
397 if (err)
398 goto error2;
399
400 err = uv_sem_init(&barrier->turnstile2, 1);
401 if (err)
402 goto error;
403
404 return 0;
405
406 error:
407 uv_sem_destroy(&barrier->turnstile1);
408 error2:
409 uv_mutex_destroy(&barrier->mutex);
410 return err;
411
412 }
413
414
uv_barrier_destroy(uv_barrier_t * barrier)415 void uv_barrier_destroy(uv_barrier_t* barrier) {
416 uv_sem_destroy(&barrier->turnstile2);
417 uv_sem_destroy(&barrier->turnstile1);
418 uv_mutex_destroy(&barrier->mutex);
419 }
420
421
uv_barrier_wait(uv_barrier_t * barrier)422 int uv_barrier_wait(uv_barrier_t* barrier) {
423 int serial_thread;
424
425 uv_mutex_lock(&barrier->mutex);
426 if (++barrier->count == barrier->n) {
427 uv_sem_wait(&barrier->turnstile2);
428 uv_sem_post(&barrier->turnstile1);
429 }
430 uv_mutex_unlock(&barrier->mutex);
431
432 uv_sem_wait(&barrier->turnstile1);
433 uv_sem_post(&barrier->turnstile1);
434
435 uv_mutex_lock(&barrier->mutex);
436 serial_thread = (--barrier->count == 0);
437 if (serial_thread) {
438 uv_sem_wait(&barrier->turnstile1);
439 uv_sem_post(&barrier->turnstile2);
440 }
441 uv_mutex_unlock(&barrier->mutex);
442
443 uv_sem_wait(&barrier->turnstile2);
444 uv_sem_post(&barrier->turnstile2);
445 return serial_thread;
446 }
447
448
uv_key_create(uv_key_t * key)449 int uv_key_create(uv_key_t* key) {
450 key->tls_index = TlsAlloc();
451 if (key->tls_index == TLS_OUT_OF_INDEXES)
452 return UV_ENOMEM;
453 return 0;
454 }
455
456
uv_key_delete(uv_key_t * key)457 void uv_key_delete(uv_key_t* key) {
458 if (TlsFree(key->tls_index) == FALSE)
459 abort();
460 key->tls_index = TLS_OUT_OF_INDEXES;
461 }
462
463
uv_key_get(uv_key_t * key)464 void* uv_key_get(uv_key_t* key) {
465 void* value;
466
467 value = TlsGetValue(key->tls_index);
468 if (value == NULL)
469 if (GetLastError() != ERROR_SUCCESS)
470 abort();
471
472 return value;
473 }
474
475
uv_key_set(uv_key_t * key,void * value)476 void uv_key_set(uv_key_t* key, void* value) {
477 if (TlsSetValue(key->tls_index, value) == FALSE)
478 abort();
479 }
480