ipc/chromium/src/third_party/libevent/evthread_win32.c@6474c204b198
ipc/chromium/src/third_party/libevent/evthread_win32.c
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
1 /*
2 * Copyright 2009-2012 Niels Provos and Nick Mathewson
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. The name of the author may not be used to endorse or promote products
13 * derived from this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26 #include "event2/event-config.h"
28 #ifdef WIN32
29 #ifndef _WIN32_WINNT
30 /* Minimum required for InitializeCriticalSectionAndSpinCount */
31 #define _WIN32_WINNT 0x0403
32 #endif
33 #include <winsock2.h>
34 #define WIN32_LEAN_AND_MEAN
35 #include <windows.h>
36 #undef WIN32_LEAN_AND_MEAN
37 #include <sys/locking.h>
38 #endif
40 struct event_base;
41 #include "event2/thread.h"
43 #include "mm-internal.h"
44 #include "evthread-internal.h"
46 #define SPIN_COUNT 2000
48 static void *
49 evthread_win32_lock_create(unsigned locktype)
50 {
51 CRITICAL_SECTION *lock = mm_malloc(sizeof(CRITICAL_SECTION));
52 if (!lock)
53 return NULL;
54 if (InitializeCriticalSectionAndSpinCount(lock, SPIN_COUNT) == 0) {
55 mm_free(lock);
56 return NULL;
57 }
58 return lock;
59 }
61 static void
62 evthread_win32_lock_free(void *_lock, unsigned locktype)
63 {
64 CRITICAL_SECTION *lock = _lock;
65 DeleteCriticalSection(lock);
66 mm_free(lock);
67 }
69 static int
70 evthread_win32_lock(unsigned mode, void *_lock)
71 {
72 CRITICAL_SECTION *lock = _lock;
73 if ((mode & EVTHREAD_TRY)) {
74 return ! TryEnterCriticalSection(lock);
75 } else {
76 EnterCriticalSection(lock);
77 return 0;
78 }
79 }
81 static int
82 evthread_win32_unlock(unsigned mode, void *_lock)
83 {
84 CRITICAL_SECTION *lock = _lock;
85 LeaveCriticalSection(lock);
86 return 0;
87 }
89 static unsigned long
90 evthread_win32_get_id(void)
91 {
92 return (unsigned long) GetCurrentThreadId();
93 }
95 #ifdef WIN32_HAVE_CONDITION_VARIABLES
96 static void WINAPI (*InitializeConditionVariable_fn)(PCONDITION_VARIABLE)
97 = NULL;
98 static BOOL WINAPI (*SleepConditionVariableCS_fn)(
99 PCONDITION_VARIABLE, PCRITICAL_SECTION, DWORD) = NULL;
100 static void WINAPI (*WakeAllConditionVariable_fn)(PCONDITION_VARIABLE) = NULL;
101 static void WINAPI (*WakeConditionVariable_fn)(PCONDITION_VARIABLE) = NULL;
103 static int
104 evthread_win32_condvar_init(void)
105 {
106 HANDLE lib;
108 lib = GetModuleHandle(TEXT("kernel32.dll"));
109 if (lib == NULL)
110 return 0;
112 #define LOAD(name) \
113 name##_fn = GetProcAddress(lib, #name)
114 LOAD(InitializeConditionVariable);
115 LOAD(SleepConditionVariable);
116 LOAD(WakeAllConditionVariable);
117 LOAD(WakeConditionVariable);
119 return InitializeConditionVariable_fn && SleepConditionVariableCS_fn &&
120 WakeAllConditionVariable_fn && WakeConditionVariable_fn;
121 }
123 /* XXXX Even if we can build this, we don't necessarily want to: the functions
124 * in question didn't exist before Vista, so we'd better LoadProc them. */
125 static void *
126 evthread_win32_condvar_alloc(unsigned condflags)
127 {
128 CONDITION_VARIABLE *cond = mm_malloc(sizeof(CONDITION_VARIABLE));
129 if (!cond)
130 return NULL;
131 InitializeConditionVariable_fn(cond);
132 return cond;
133 }
135 static void
136 evthread_win32_condvar_free(void *_cond)
137 {
138 CONDITION_VARIABLE *cond = _cond;
139 /* There doesn't _seem_ to be a cleaup fn here... */
140 mm_free(cond);
141 }
143 static int
144 evthread_win32_condvar_signal(void *_cond, int broadcast)
145 {
146 CONDITION_VARIABLE *cond = _cond;
147 if (broadcast)
148 WakeAllConditionVariable_fn(cond);
149 else
150 WakeConditionVariable_fn(cond);
151 return 0;
152 }
154 static int
155 evthread_win32_condvar_wait(void *_cond, void *_lock, const struct timeval *tv)
156 {
157 CONDITION_VARIABLE *cond = _cond;
158 CRITICAL_SECTION *lock = _lock;
159 DWORD ms, err;
160 BOOL result;
162 if (tv)
163 ms = evutil_tv_to_msec(tv);
164 else
165 ms = INFINITE;
166 result = SleepConditionVariableCS_fn(cond, lock, ms);
167 if (result) {
168 if (GetLastError() == WAIT_TIMEOUT)
169 return 1;
170 else
171 return -1;
172 } else {
173 return 0;
174 }
175 }
176 #endif
178 struct evthread_win32_cond {
179 HANDLE event;
181 CRITICAL_SECTION lock;
182 int n_waiting;
183 int n_to_wake;
184 int generation;
185 };
187 static void *
188 evthread_win32_cond_alloc(unsigned flags)
189 {
190 struct evthread_win32_cond *cond;
191 if (!(cond = mm_malloc(sizeof(struct evthread_win32_cond))))
192 return NULL;
193 if (InitializeCriticalSectionAndSpinCount(&cond->lock, SPIN_COUNT)==0) {
194 mm_free(cond);
195 return NULL;
196 }
197 if ((cond->event = CreateEvent(NULL,TRUE,FALSE,NULL)) == NULL) {
198 DeleteCriticalSection(&cond->lock);
199 mm_free(cond);
200 return NULL;
201 }
202 cond->n_waiting = cond->n_to_wake = cond->generation = 0;
203 return cond;
204 }
206 static void
207 evthread_win32_cond_free(void *_cond)
208 {
209 struct evthread_win32_cond *cond = _cond;
210 DeleteCriticalSection(&cond->lock);
211 CloseHandle(cond->event);
212 mm_free(cond);
213 }
215 static int
216 evthread_win32_cond_signal(void *_cond, int broadcast)
217 {
218 struct evthread_win32_cond *cond = _cond;
219 EnterCriticalSection(&cond->lock);
220 if (broadcast)
221 cond->n_to_wake = cond->n_waiting;
222 else
223 ++cond->n_to_wake;
224 cond->generation++;
225 SetEvent(cond->event);
226 LeaveCriticalSection(&cond->lock);
227 return 0;
228 }
230 static int
231 evthread_win32_cond_wait(void *_cond, void *_lock, const struct timeval *tv)
232 {
233 struct evthread_win32_cond *cond = _cond;
234 CRITICAL_SECTION *lock = _lock;
235 int generation_at_start;
236 int waiting = 1;
237 int result = -1;
238 DWORD ms = INFINITE, ms_orig = INFINITE, startTime, endTime;
239 if (tv)
240 ms_orig = ms = evutil_tv_to_msec(tv);
242 EnterCriticalSection(&cond->lock);
243 ++cond->n_waiting;
244 generation_at_start = cond->generation;
245 LeaveCriticalSection(&cond->lock);
247 LeaveCriticalSection(lock);
249 startTime = GetTickCount();
250 do {
251 DWORD res;
252 res = WaitForSingleObject(cond->event, ms);
253 EnterCriticalSection(&cond->lock);
254 if (cond->n_to_wake &&
255 cond->generation != generation_at_start) {
256 --cond->n_to_wake;
257 --cond->n_waiting;
258 result = 0;
259 waiting = 0;
260 goto out;
261 } else if (res != WAIT_OBJECT_0) {
262 result = (res==WAIT_TIMEOUT) ? 1 : -1;
263 --cond->n_waiting;
264 waiting = 0;
265 goto out;
266 } else if (ms != INFINITE) {
267 endTime = GetTickCount();
268 if (startTime + ms_orig <= endTime) {
269 result = 1; /* Timeout */
270 --cond->n_waiting;
271 waiting = 0;
272 goto out;
273 } else {
274 ms = startTime + ms_orig - endTime;
275 }
276 }
277 /* If we make it here, we are still waiting. */
278 if (cond->n_to_wake == 0) {
279 /* There is nobody else who should wake up; reset
280 * the event. */
281 ResetEvent(cond->event);
282 }
283 out:
284 LeaveCriticalSection(&cond->lock);
285 } while (waiting);
287 EnterCriticalSection(lock);
289 EnterCriticalSection(&cond->lock);
290 if (!cond->n_waiting)
291 ResetEvent(cond->event);
292 LeaveCriticalSection(&cond->lock);
294 return result;
295 }
297 int
298 evthread_use_windows_threads(void)
299 {
300 struct evthread_lock_callbacks cbs = {
301 EVTHREAD_LOCK_API_VERSION,
302 EVTHREAD_LOCKTYPE_RECURSIVE,
303 evthread_win32_lock_create,
304 evthread_win32_lock_free,
305 evthread_win32_lock,
306 evthread_win32_unlock
307 };
310 struct evthread_condition_callbacks cond_cbs = {
311 EVTHREAD_CONDITION_API_VERSION,
312 evthread_win32_cond_alloc,
313 evthread_win32_cond_free,
314 evthread_win32_cond_signal,
315 evthread_win32_cond_wait
316 };
317 #ifdef WIN32_HAVE_CONDITION_VARIABLES
318 struct evthread_condition_callbacks condvar_cbs = {
319 EVTHREAD_CONDITION_API_VERSION,
320 evthread_win32_condvar_alloc,
321 evthread_win32_condvar_free,
322 evthread_win32_condvar_signal,
323 evthread_win32_condvar_wait
324 };
325 #endif
327 evthread_set_lock_callbacks(&cbs);
328 evthread_set_id_callback(evthread_win32_get_id);
329 #ifdef WIN32_HAVE_CONDITION_VARIABLES
330 if (evthread_win32_condvar_init()) {
331 evthread_set_condition_callbacks(&condvar_cbs);
332 return 0;
333 }
334 #endif
335 evthread_set_condition_callbacks(&cond_cbs);
337 return 0;
338 }
