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comparison: ipc/chromium/src/third_party/libevent/evthread-internal.h
ipc/chromium/src/third_party/libevent/evthread-internal.h
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| 1 /* | |
| 2 * Copyright (c) 2008-2012 Niels Provos, 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 #ifndef _EVTHREAD_INTERNAL_H_ | |
| 27 #define _EVTHREAD_INTERNAL_H_ | |
| 28 | |
| 29 #ifdef __cplusplus | |
| 30 extern "C" { | |
| 31 #endif | |
| 32 | |
| 33 #include "event2/thread.h" | |
| 34 #include "event2/event-config.h" | |
| 35 #include "util-internal.h" | |
| 36 | |
| 37 struct event_base; | |
| 38 | |
| 39 #ifndef WIN32 | |
| 40 /* On Windows, the way we currently make DLLs, it's not allowed for us to | |
| 41 * have shared global structures. Thus, we only do the direct-call-to-function | |
| 42 * code path if we know that the local shared library system supports it. | |
| 43 */ | |
| 44 #define EVTHREAD_EXPOSE_STRUCTS | |
| 45 #endif | |
| 46 | |
| 47 #if ! defined(_EVENT_DISABLE_THREAD_SUPPORT) && defined(EVTHREAD_EXPOSE_STRUCTS) | |
| 48 /* Global function pointers to lock-related functions. NULL if locking isn't | |
| 49 enabled. */ | |
| 50 extern struct evthread_lock_callbacks _evthread_lock_fns; | |
| 51 extern struct evthread_condition_callbacks _evthread_cond_fns; | |
| 52 extern unsigned long (*_evthread_id_fn)(void); | |
| 53 extern int _evthread_lock_debugging_enabled; | |
| 54 | |
| 55 /** Return the ID of the current thread, or 1 if threading isn't enabled. */ | |
| 56 #define EVTHREAD_GET_ID() \ | |
| 57 (_evthread_id_fn ? _evthread_id_fn() : 1) | |
| 58 | |
| 59 /** Return true iff we're in the thread that is currently (or most recently) | |
| 60 * running a given event_base's loop. Requires lock. */ | |
| 61 #define EVBASE_IN_THREAD(base) \ | |
| 62 (_evthread_id_fn == NULL || \ | |
| 63 (base)->th_owner_id == _evthread_id_fn()) | |
| 64 | |
| 65 /** Return true iff we need to notify the base's main thread about changes to | |
| 66 * its state, because it's currently running the main loop in another | |
| 67 * thread. Requires lock. */ | |
| 68 #define EVBASE_NEED_NOTIFY(base) \ | |
| 69 (_evthread_id_fn != NULL && \ | |
| 70 (base)->running_loop && \ | |
| 71 (base)->th_owner_id != _evthread_id_fn()) | |
| 72 | |
| 73 /** Allocate a new lock, and store it in lockvar, a void*. Sets lockvar to | |
| 74 NULL if locking is not enabled. */ | |
| 75 #define EVTHREAD_ALLOC_LOCK(lockvar, locktype) \ | |
| 76 ((lockvar) = _evthread_lock_fns.alloc ? \ | |
| 77 _evthread_lock_fns.alloc(locktype) : NULL) | |
| 78 | |
| 79 /** Free a given lock, if it is present and locking is enabled. */ | |
| 80 #define EVTHREAD_FREE_LOCK(lockvar, locktype) \ | |
| 81 do { \ | |
| 82 void *_lock_tmp_ = (lockvar); \ | |
| 83 if (_lock_tmp_ && _evthread_lock_fns.free) \ | |
| 84 _evthread_lock_fns.free(_lock_tmp_, (locktype)); \ | |
| 85 } while (0) | |
| 86 | |
| 87 /** Acquire a lock. */ | |
| 88 #define EVLOCK_LOCK(lockvar,mode) \ | |
| 89 do { \ | |
| 90 if (lockvar) \ | |
| 91 _evthread_lock_fns.lock(mode, lockvar); \ | |
| 92 } while (0) | |
| 93 | |
| 94 /** Release a lock */ | |
| 95 #define EVLOCK_UNLOCK(lockvar,mode) \ | |
| 96 do { \ | |
| 97 if (lockvar) \ | |
| 98 _evthread_lock_fns.unlock(mode, lockvar); \ | |
| 99 } while (0) | |
| 100 | |
| 101 /** Helper: put lockvar1 and lockvar2 into pointerwise ascending order. */ | |
| 102 #define _EVLOCK_SORTLOCKS(lockvar1, lockvar2) \ | |
| 103 do { \ | |
| 104 if (lockvar1 && lockvar2 && lockvar1 > lockvar2) { \ | |
| 105 void *tmp = lockvar1; \ | |
| 106 lockvar1 = lockvar2; \ | |
| 107 lockvar2 = tmp; \ | |
| 108 } \ | |
| 109 } while (0) | |
| 110 | |
| 111 /** Lock an event_base, if it is set up for locking. Acquires the lock | |
| 112 in the base structure whose field is named 'lockvar'. */ | |
| 113 #define EVBASE_ACQUIRE_LOCK(base, lockvar) do { \ | |
| 114 EVLOCK_LOCK((base)->lockvar, 0); \ | |
| 115 } while (0) | |
| 116 | |
| 117 /** Unlock an event_base, if it is set up for locking. */ | |
| 118 #define EVBASE_RELEASE_LOCK(base, lockvar) do { \ | |
| 119 EVLOCK_UNLOCK((base)->lockvar, 0); \ | |
| 120 } while (0) | |
| 121 | |
| 122 /** If lock debugging is enabled, and lock is non-null, assert that 'lock' is | |
| 123 * locked and held by us. */ | |
| 124 #define EVLOCK_ASSERT_LOCKED(lock) \ | |
| 125 do { \ | |
| 126 if ((lock) && _evthread_lock_debugging_enabled) { \ | |
| 127 EVUTIL_ASSERT(_evthread_is_debug_lock_held(lock)); \ | |
| 128 } \ | |
| 129 } while (0) | |
| 130 | |
| 131 /** Try to grab the lock for 'lockvar' without blocking, and return 1 if we | |
| 132 * manage to get it. */ | |
| 133 static inline int EVLOCK_TRY_LOCK(void *lock); | |
| 134 static inline int | |
| 135 EVLOCK_TRY_LOCK(void *lock) | |
| 136 { | |
| 137 if (lock && _evthread_lock_fns.lock) { | |
| 138 int r = _evthread_lock_fns.lock(EVTHREAD_TRY, lock); | |
| 139 return !r; | |
| 140 } else { | |
| 141 /* Locking is disabled either globally or for this thing; | |
| 142 * of course we count as having the lock. */ | |
| 143 return 1; | |
| 144 } | |
| 145 } | |
| 146 | |
| 147 /** Allocate a new condition variable and store it in the void *, condvar */ | |
| 148 #define EVTHREAD_ALLOC_COND(condvar) \ | |
| 149 do { \ | |
| 150 (condvar) = _evthread_cond_fns.alloc_condition ? \ | |
| 151 _evthread_cond_fns.alloc_condition(0) : NULL; \ | |
| 152 } while (0) | |
| 153 /** Deallocate and free a condition variable in condvar */ | |
| 154 #define EVTHREAD_FREE_COND(cond) \ | |
| 155 do { \ | |
| 156 if (cond) \ | |
| 157 _evthread_cond_fns.free_condition((cond)); \ | |
| 158 } while (0) | |
| 159 /** Signal one thread waiting on cond */ | |
| 160 #define EVTHREAD_COND_SIGNAL(cond) \ | |
| 161 ( (cond) ? _evthread_cond_fns.signal_condition((cond), 0) : 0 ) | |
| 162 /** Signal all threads waiting on cond */ | |
| 163 #define EVTHREAD_COND_BROADCAST(cond) \ | |
| 164 ( (cond) ? _evthread_cond_fns.signal_condition((cond), 1) : 0 ) | |
| 165 /** Wait until the condition 'cond' is signalled. Must be called while | |
| 166 * holding 'lock'. The lock will be released until the condition is | |
| 167 * signalled, at which point it will be acquired again. Returns 0 for | |
| 168 * success, -1 for failure. */ | |
| 169 #define EVTHREAD_COND_WAIT(cond, lock) \ | |
| 170 ( (cond) ? _evthread_cond_fns.wait_condition((cond), (lock), NULL) : 0 ) | |
| 171 /** As EVTHREAD_COND_WAIT, but gives up after 'tv' has elapsed. Returns 1 | |
| 172 * on timeout. */ | |
| 173 #define EVTHREAD_COND_WAIT_TIMED(cond, lock, tv) \ | |
| 174 ( (cond) ? _evthread_cond_fns.wait_condition((cond), (lock), (tv)) : 0 ) | |
| 175 | |
| 176 /** True iff locking functions have been configured. */ | |
| 177 #define EVTHREAD_LOCKING_ENABLED() \ | |
| 178 (_evthread_lock_fns.lock != NULL) | |
| 179 | |
| 180 #elif ! defined(_EVENT_DISABLE_THREAD_SUPPORT) | |
| 181 | |
| 182 unsigned long _evthreadimpl_get_id(void); | |
| 183 int _evthreadimpl_is_lock_debugging_enabled(void); | |
| 184 void *_evthreadimpl_lock_alloc(unsigned locktype); | |
| 185 void _evthreadimpl_lock_free(void *lock, unsigned locktype); | |
| 186 int _evthreadimpl_lock_lock(unsigned mode, void *lock); | |
| 187 int _evthreadimpl_lock_unlock(unsigned mode, void *lock); | |
| 188 void *_evthreadimpl_cond_alloc(unsigned condtype); | |
| 189 void _evthreadimpl_cond_free(void *cond); | |
| 190 int _evthreadimpl_cond_signal(void *cond, int broadcast); | |
| 191 int _evthreadimpl_cond_wait(void *cond, void *lock, const struct timeval *tv); | |
| 192 int _evthreadimpl_locking_enabled(void); | |
| 193 | |
| 194 #define EVTHREAD_GET_ID() _evthreadimpl_get_id() | |
| 195 #define EVBASE_IN_THREAD(base) \ | |
| 196 ((base)->th_owner_id == _evthreadimpl_get_id()) | |
| 197 #define EVBASE_NEED_NOTIFY(base) \ | |
| 198 ((base)->running_loop && \ | |
| 199 ((base)->th_owner_id != _evthreadimpl_get_id())) | |
| 200 | |
| 201 #define EVTHREAD_ALLOC_LOCK(lockvar, locktype) \ | |
| 202 ((lockvar) = _evthreadimpl_lock_alloc(locktype)) | |
| 203 | |
| 204 #define EVTHREAD_FREE_LOCK(lockvar, locktype) \ | |
| 205 do { \ | |
| 206 void *_lock_tmp_ = (lockvar); \ | |
| 207 if (_lock_tmp_) \ | |
| 208 _evthreadimpl_lock_free(_lock_tmp_, (locktype)); \ | |
| 209 } while (0) | |
| 210 | |
| 211 /** Acquire a lock. */ | |
| 212 #define EVLOCK_LOCK(lockvar,mode) \ | |
| 213 do { \ | |
| 214 if (lockvar) \ | |
| 215 _evthreadimpl_lock_lock(mode, lockvar); \ | |
| 216 } while (0) | |
| 217 | |
| 218 /** Release a lock */ | |
| 219 #define EVLOCK_UNLOCK(lockvar,mode) \ | |
| 220 do { \ | |
| 221 if (lockvar) \ | |
| 222 _evthreadimpl_lock_unlock(mode, lockvar); \ | |
| 223 } while (0) | |
| 224 | |
| 225 /** Lock an event_base, if it is set up for locking. Acquires the lock | |
| 226 in the base structure whose field is named 'lockvar'. */ | |
| 227 #define EVBASE_ACQUIRE_LOCK(base, lockvar) do { \ | |
| 228 EVLOCK_LOCK((base)->lockvar, 0); \ | |
| 229 } while (0) | |
| 230 | |
| 231 /** Unlock an event_base, if it is set up for locking. */ | |
| 232 #define EVBASE_RELEASE_LOCK(base, lockvar) do { \ | |
| 233 EVLOCK_UNLOCK((base)->lockvar, 0); \ | |
| 234 } while (0) | |
| 235 | |
| 236 /** If lock debugging is enabled, and lock is non-null, assert that 'lock' is | |
| 237 * locked and held by us. */ | |
| 238 #define EVLOCK_ASSERT_LOCKED(lock) \ | |
| 239 do { \ | |
| 240 if ((lock) && _evthreadimpl_is_lock_debugging_enabled()) { \ | |
| 241 EVUTIL_ASSERT(_evthread_is_debug_lock_held(lock)); \ | |
| 242 } \ | |
| 243 } while (0) | |
| 244 | |
| 245 /** Try to grab the lock for 'lockvar' without blocking, and return 1 if we | |
| 246 * manage to get it. */ | |
| 247 static inline int EVLOCK_TRY_LOCK(void *lock); | |
| 248 static inline int | |
| 249 EVLOCK_TRY_LOCK(void *lock) | |
| 250 { | |
| 251 if (lock) { | |
| 252 int r = _evthreadimpl_lock_lock(EVTHREAD_TRY, lock); | |
| 253 return !r; | |
| 254 } else { | |
| 255 /* Locking is disabled either globally or for this thing; | |
| 256 * of course we count as having the lock. */ | |
| 257 return 1; | |
| 258 } | |
| 259 } | |
| 260 | |
| 261 /** Allocate a new condition variable and store it in the void *, condvar */ | |
| 262 #define EVTHREAD_ALLOC_COND(condvar) \ | |
| 263 do { \ | |
| 264 (condvar) = _evthreadimpl_cond_alloc(0); \ | |
| 265 } while (0) | |
| 266 /** Deallocate and free a condition variable in condvar */ | |
| 267 #define EVTHREAD_FREE_COND(cond) \ | |
| 268 do { \ | |
| 269 if (cond) \ | |
| 270 _evthreadimpl_cond_free((cond)); \ | |
| 271 } while (0) | |
| 272 /** Signal one thread waiting on cond */ | |
| 273 #define EVTHREAD_COND_SIGNAL(cond) \ | |
| 274 ( (cond) ? _evthreadimpl_cond_signal((cond), 0) : 0 ) | |
| 275 /** Signal all threads waiting on cond */ | |
| 276 #define EVTHREAD_COND_BROADCAST(cond) \ | |
| 277 ( (cond) ? _evthreadimpl_cond_signal((cond), 1) : 0 ) | |
| 278 /** Wait until the condition 'cond' is signalled. Must be called while | |
| 279 * holding 'lock'. The lock will be released until the condition is | |
| 280 * signalled, at which point it will be acquired again. Returns 0 for | |
| 281 * success, -1 for failure. */ | |
| 282 #define EVTHREAD_COND_WAIT(cond, lock) \ | |
| 283 ( (cond) ? _evthreadimpl_cond_wait((cond), (lock), NULL) : 0 ) | |
| 284 /** As EVTHREAD_COND_WAIT, but gives up after 'tv' has elapsed. Returns 1 | |
| 285 * on timeout. */ | |
| 286 #define EVTHREAD_COND_WAIT_TIMED(cond, lock, tv) \ | |
| 287 ( (cond) ? _evthreadimpl_cond_wait((cond), (lock), (tv)) : 0 ) | |
| 288 | |
| 289 #define EVTHREAD_LOCKING_ENABLED() \ | |
| 290 (_evthreadimpl_locking_enabled()) | |
| 291 | |
| 292 #else /* _EVENT_DISABLE_THREAD_SUPPORT */ | |
| 293 | |
| 294 #define EVTHREAD_GET_ID() 1 | |
| 295 #define EVTHREAD_ALLOC_LOCK(lockvar, locktype) _EVUTIL_NIL_STMT | |
| 296 #define EVTHREAD_FREE_LOCK(lockvar, locktype) _EVUTIL_NIL_STMT | |
| 297 | |
| 298 #define EVLOCK_LOCK(lockvar, mode) _EVUTIL_NIL_STMT | |
| 299 #define EVLOCK_UNLOCK(lockvar, mode) _EVUTIL_NIL_STMT | |
| 300 #define EVLOCK_LOCK2(lock1,lock2,mode1,mode2) _EVUTIL_NIL_STMT | |
| 301 #define EVLOCK_UNLOCK2(lock1,lock2,mode1,mode2) _EVUTIL_NIL_STMT | |
| 302 | |
| 303 #define EVBASE_IN_THREAD(base) 1 | |
| 304 #define EVBASE_NEED_NOTIFY(base) 0 | |
| 305 #define EVBASE_ACQUIRE_LOCK(base, lock) _EVUTIL_NIL_STMT | |
| 306 #define EVBASE_RELEASE_LOCK(base, lock) _EVUTIL_NIL_STMT | |
| 307 #define EVLOCK_ASSERT_LOCKED(lock) _EVUTIL_NIL_STMT | |
| 308 | |
| 309 #define EVLOCK_TRY_LOCK(lock) 1 | |
| 310 | |
| 311 #define EVTHREAD_ALLOC_COND(condvar) _EVUTIL_NIL_STMT | |
| 312 #define EVTHREAD_FREE_COND(cond) _EVUTIL_NIL_STMT | |
| 313 #define EVTHREAD_COND_SIGNAL(cond) _EVUTIL_NIL_STMT | |
| 314 #define EVTHREAD_COND_BROADCAST(cond) _EVUTIL_NIL_STMT | |
| 315 #define EVTHREAD_COND_WAIT(cond, lock) _EVUTIL_NIL_STMT | |
| 316 #define EVTHREAD_COND_WAIT_TIMED(cond, lock, howlong) _EVUTIL_NIL_STMT | |
| 317 | |
| 318 #define EVTHREAD_LOCKING_ENABLED() 0 | |
| 319 | |
| 320 #endif | |
| 321 | |
| 322 /* This code is shared between both lock impls */ | |
| 323 #if ! defined(_EVENT_DISABLE_THREAD_SUPPORT) | |
| 324 /** Helper: put lockvar1 and lockvar2 into pointerwise ascending order. */ | |
| 325 #define _EVLOCK_SORTLOCKS(lockvar1, lockvar2) \ | |
| 326 do { \ | |
| 327 if (lockvar1 && lockvar2 && lockvar1 > lockvar2) { \ | |
| 328 void *tmp = lockvar1; \ | |
| 329 lockvar1 = lockvar2; \ | |
| 330 lockvar2 = tmp; \ | |
| 331 } \ | |
| 332 } while (0) | |
| 333 | |
| 334 /** Acquire both lock1 and lock2. Always allocates locks in the same order, | |
| 335 * so that two threads locking two locks with LOCK2 will not deadlock. */ | |
| 336 #define EVLOCK_LOCK2(lock1,lock2,mode1,mode2) \ | |
| 337 do { \ | |
| 338 void *_lock1_tmplock = (lock1); \ | |
| 339 void *_lock2_tmplock = (lock2); \ | |
| 340 _EVLOCK_SORTLOCKS(_lock1_tmplock,_lock2_tmplock); \ | |
| 341 EVLOCK_LOCK(_lock1_tmplock,mode1); \ | |
| 342 if (_lock2_tmplock != _lock1_tmplock) \ | |
| 343 EVLOCK_LOCK(_lock2_tmplock,mode2); \ | |
| 344 } while (0) | |
| 345 /** Release both lock1 and lock2. */ | |
| 346 #define EVLOCK_UNLOCK2(lock1,lock2,mode1,mode2) \ | |
| 347 do { \ | |
| 348 void *_lock1_tmplock = (lock1); \ | |
| 349 void *_lock2_tmplock = (lock2); \ | |
| 350 _EVLOCK_SORTLOCKS(_lock1_tmplock,_lock2_tmplock); \ | |
| 351 if (_lock2_tmplock != _lock1_tmplock) \ | |
| 352 EVLOCK_UNLOCK(_lock2_tmplock,mode2); \ | |
| 353 EVLOCK_UNLOCK(_lock1_tmplock,mode1); \ | |
| 354 } while (0) | |
| 355 | |
| 356 int _evthread_is_debug_lock_held(void *lock); | |
| 357 void *_evthread_debug_get_real_lock(void *lock); | |
| 358 | |
| 359 void *evthread_setup_global_lock_(void *lock_, unsigned locktype, | |
| 360 int enable_locks); | |
| 361 | |
| 362 #define EVTHREAD_SETUP_GLOBAL_LOCK(lockvar, locktype) \ | |
| 363 do { \ | |
| 364 lockvar = evthread_setup_global_lock_(lockvar, \ | |
| 365 (locktype), enable_locks); \ | |
| 366 if (!lockvar) { \ | |
| 367 event_warn("Couldn't allocate %s", #lockvar); \ | |
| 368 return -1; \ | |
| 369 } \ | |
| 370 } while (0); | |
| 371 | |
| 372 int event_global_setup_locks_(const int enable_locks); | |
| 373 int evsig_global_setup_locks_(const int enable_locks); | |
| 374 int evutil_secure_rng_global_setup_locks_(const int enable_locks); | |
| 375 | |
| 376 #endif | |
| 377 | |
| 378 #ifdef __cplusplus | |
| 379 } | |
| 380 #endif | |
| 381 | |
| 382 #endif /* _EVTHREAD_INTERNAL_H_ */ |
