1 /* $NetBSD: evthread_win32.c,v 1.1.1.1 2013/04/11 16:43:26 christos Exp $ */ 2 /* 3 * Copyright 2009-2012 Niels Provos and Nick Mathewson 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 #include "event2/event-config.h" 28 #include <sys/cdefs.h> 29 __RCSID("$NetBSD: evthread_win32.c,v 1.1.1.1 2013/04/11 16:43:26 christos Exp $"); 30 31 #ifdef WIN32 32 #ifndef _WIN32_WINNT 33 /* Minimum required for InitializeCriticalSectionAndSpinCount */ 34 #define _WIN32_WINNT 0x0403 35 #endif 36 #include <winsock2.h> 37 #define WIN32_LEAN_AND_MEAN 38 #include <windows.h> 39 #undef WIN32_LEAN_AND_MEAN 40 #include <sys/locking.h> 41 #endif 42 43 struct event_base; 44 #include "event2/thread.h" 45 46 #include "mm-internal.h" 47 #include "evthread-internal.h" 48 49 #define SPIN_COUNT 2000 50 51 static void * 52 evthread_win32_lock_create(unsigned locktype) 53 { 54 CRITICAL_SECTION *lock = mm_malloc(sizeof(CRITICAL_SECTION)); 55 if (!lock) 56 return NULL; 57 if (InitializeCriticalSectionAndSpinCount(lock, SPIN_COUNT) == 0) { 58 mm_free(lock); 59 return NULL; 60 } 61 return lock; 62 } 63 64 static void 65 evthread_win32_lock_free(void *_lock, unsigned locktype) 66 { 67 CRITICAL_SECTION *lock = _lock; 68 DeleteCriticalSection(lock); 69 mm_free(lock); 70 } 71 72 static int 73 evthread_win32_lock(unsigned mode, void *_lock) 74 { 75 CRITICAL_SECTION *lock = _lock; 76 if ((mode & EVTHREAD_TRY)) { 77 return ! TryEnterCriticalSection(lock); 78 } else { 79 EnterCriticalSection(lock); 80 return 0; 81 } 82 } 83 84 static int 85 evthread_win32_unlock(unsigned mode, void *_lock) 86 { 87 CRITICAL_SECTION *lock = _lock; 88 LeaveCriticalSection(lock); 89 return 0; 90 } 91 92 static unsigned long 93 evthread_win32_get_id(void) 94 { 95 return (unsigned long) GetCurrentThreadId(); 96 } 97 98 #ifdef WIN32_HAVE_CONDITION_VARIABLES 99 static void WINAPI (*InitializeConditionVariable_fn)(PCONDITION_VARIABLE) 100 = NULL; 101 static BOOL WINAPI (*SleepConditionVariableCS_fn)( 102 PCONDITION_VARIABLE, PCRITICAL_SECTION, DWORD) = NULL; 103 static void WINAPI (*WakeAllConditionVariable_fn)(PCONDITION_VARIABLE) = NULL; 104 static void WINAPI (*WakeConditionVariable_fn)(PCONDITION_VARIABLE) = NULL; 105 106 static int 107 evthread_win32_condvar_init(void) 108 { 109 HANDLE lib; 110 111 lib = GetModuleHandle(TEXT("kernel32.dll")); 112 if (lib == NULL) 113 return 0; 114 115 #define LOAD(name) \ 116 name##_fn = GetProcAddress(lib, #name) 117 LOAD(InitializeConditionVariable); 118 LOAD(SleepConditionVariable); 119 LOAD(WakeAllConditionVariable); 120 LOAD(WakeConditionVariable); 121 122 return InitializeConditionVariable_fn && SleepConditionVariableCS_fn && 123 WakeAllConditionVariable_fn && WakeConditionVariable_fn; 124 } 125 126 /* XXXX Even if we can build this, we don't necessarily want to: the functions 127 * in question didn't exist before Vista, so we'd better LoadProc them. */ 128 static void * 129 evthread_win32_condvar_alloc(unsigned condflags) 130 { 131 CONDITION_VARIABLE *cond = mm_malloc(sizeof(CONDITION_VARIABLE)); 132 if (!cond) 133 return NULL; 134 InitializeConditionVariable_fn(cond); 135 return cond; 136 } 137 138 static void 139 evthread_win32_condvar_free(void *_cond) 140 { 141 CONDITION_VARIABLE *cond = _cond; 142 /* There doesn't _seem_ to be a cleaup fn here... */ 143 mm_free(cond); 144 } 145 146 static int 147 evthread_win32_condvar_signal(void *_cond, int broadcast) 148 { 149 CONDITION_VARIABLE *cond = _cond; 150 if (broadcast) 151 WakeAllConditionVariable_fn(cond); 152 else 153 WakeConditionVariable_fn(cond); 154 return 0; 155 } 156 157 static int 158 evthread_win32_condvar_wait(void *_cond, void *_lock, const struct timeval *tv) 159 { 160 CONDITION_VARIABLE *cond = _cond; 161 CRITICAL_SECTION *lock = _lock; 162 DWORD ms, err; 163 BOOL result; 164 165 if (tv) 166 ms = evutil_tv_to_msec(tv); 167 else 168 ms = INFINITE; 169 result = SleepConditionVariableCS_fn(cond, lock, ms); 170 if (result) { 171 if (GetLastError() == WAIT_TIMEOUT) 172 return 1; 173 else 174 return -1; 175 } else { 176 return 0; 177 } 178 } 179 #endif 180 181 struct evthread_win32_cond { 182 HANDLE event; 183 184 CRITICAL_SECTION lock; 185 int n_waiting; 186 int n_to_wake; 187 int generation; 188 }; 189 190 static void * 191 evthread_win32_cond_alloc(unsigned flags) 192 { 193 struct evthread_win32_cond *cond; 194 if (!(cond = mm_malloc(sizeof(struct evthread_win32_cond)))) 195 return NULL; 196 if (InitializeCriticalSectionAndSpinCount(&cond->lock, SPIN_COUNT)==0) { 197 mm_free(cond); 198 return NULL; 199 } 200 if ((cond->event = CreateEvent(NULL,TRUE,FALSE,NULL)) == NULL) { 201 DeleteCriticalSection(&cond->lock); 202 mm_free(cond); 203 return NULL; 204 } 205 cond->n_waiting = cond->n_to_wake = cond->generation = 0; 206 return cond; 207 } 208 209 static void 210 evthread_win32_cond_free(void *_cond) 211 { 212 struct evthread_win32_cond *cond = _cond; 213 DeleteCriticalSection(&cond->lock); 214 CloseHandle(cond->event); 215 mm_free(cond); 216 } 217 218 static int 219 evthread_win32_cond_signal(void *_cond, int broadcast) 220 { 221 struct evthread_win32_cond *cond = _cond; 222 EnterCriticalSection(&cond->lock); 223 if (broadcast) 224 cond->n_to_wake = cond->n_waiting; 225 else 226 ++cond->n_to_wake; 227 cond->generation++; 228 SetEvent(cond->event); 229 LeaveCriticalSection(&cond->lock); 230 return 0; 231 } 232 233 static int 234 evthread_win32_cond_wait(void *_cond, void *_lock, const struct timeval *tv) 235 { 236 struct evthread_win32_cond *cond = _cond; 237 CRITICAL_SECTION *lock = _lock; 238 int generation_at_start; 239 int waiting = 1; 240 int result = -1; 241 DWORD ms = INFINITE, ms_orig = INFINITE, startTime, endTime; 242 if (tv) 243 ms_orig = ms = evutil_tv_to_msec(tv); 244 245 EnterCriticalSection(&cond->lock); 246 ++cond->n_waiting; 247 generation_at_start = cond->generation; 248 LeaveCriticalSection(&cond->lock); 249 250 LeaveCriticalSection(lock); 251 252 startTime = GetTickCount(); 253 do { 254 DWORD res; 255 res = WaitForSingleObject(cond->event, ms); 256 EnterCriticalSection(&cond->lock); 257 if (cond->n_to_wake && 258 cond->generation != generation_at_start) { 259 --cond->n_to_wake; 260 --cond->n_waiting; 261 result = 0; 262 waiting = 0; 263 goto out; 264 } else if (res != WAIT_OBJECT_0) { 265 result = (res==WAIT_TIMEOUT) ? 1 : -1; 266 --cond->n_waiting; 267 waiting = 0; 268 goto out; 269 } else if (ms != INFINITE) { 270 endTime = GetTickCount(); 271 if (startTime + ms_orig <= endTime) { 272 result = 1; /* Timeout */ 273 --cond->n_waiting; 274 waiting = 0; 275 goto out; 276 } else { 277 ms = startTime + ms_orig - endTime; 278 } 279 } 280 /* If we make it here, we are still waiting. */ 281 if (cond->n_to_wake == 0) { 282 /* There is nobody else who should wake up; reset 283 * the event. */ 284 ResetEvent(cond->event); 285 } 286 out: 287 LeaveCriticalSection(&cond->lock); 288 } while (waiting); 289 290 EnterCriticalSection(lock); 291 292 EnterCriticalSection(&cond->lock); 293 if (!cond->n_waiting) 294 ResetEvent(cond->event); 295 LeaveCriticalSection(&cond->lock); 296 297 return result; 298 } 299 300 int 301 evthread_use_windows_threads(void) 302 { 303 struct evthread_lock_callbacks cbs = { 304 EVTHREAD_LOCK_API_VERSION, 305 EVTHREAD_LOCKTYPE_RECURSIVE, 306 evthread_win32_lock_create, 307 evthread_win32_lock_free, 308 evthread_win32_lock, 309 evthread_win32_unlock 310 }; 311 312 313 struct evthread_condition_callbacks cond_cbs = { 314 EVTHREAD_CONDITION_API_VERSION, 315 evthread_win32_cond_alloc, 316 evthread_win32_cond_free, 317 evthread_win32_cond_signal, 318 evthread_win32_cond_wait 319 }; 320 #ifdef WIN32_HAVE_CONDITION_VARIABLES 321 struct evthread_condition_callbacks condvar_cbs = { 322 EVTHREAD_CONDITION_API_VERSION, 323 evthread_win32_condvar_alloc, 324 evthread_win32_condvar_free, 325 evthread_win32_condvar_signal, 326 evthread_win32_condvar_wait 327 }; 328 #endif 329 330 evthread_set_lock_callbacks(&cbs); 331 evthread_set_id_callback(evthread_win32_get_id); 332 #ifdef WIN32_HAVE_CONDITION_VARIABLES 333 if (evthread_win32_condvar_init()) { 334 evthread_set_condition_callbacks(&condvar_cbs); 335 return 0; 336 } 337 #endif 338 evthread_set_condition_callbacks(&cond_cbs); 339 340 return 0; 341 } 342 343