1 #ifndef QEMU_THREAD_H 2 #define QEMU_THREAD_H 3 4 #include "qemu/processor.h" 5 #include "qemu/atomic.h" 6 7 typedef struct QemuCond QemuCond; 8 typedef struct QemuSemaphore QemuSemaphore; 9 typedef struct QemuEvent QemuEvent; 10 typedef struct QemuLockCnt QemuLockCnt; 11 typedef struct QemuThread QemuThread; 12 13 #ifdef _WIN32 14 #include "qemu/thread-win32.h" 15 #else 16 #include "qemu/thread-posix.h" 17 #endif 18 19 /* include QSP header once QemuMutex, QemuCond etc. are defined */ 20 #include "qemu/qsp.h" 21 22 #define QEMU_THREAD_JOINABLE 0 23 #define QEMU_THREAD_DETACHED 1 24 25 void qemu_mutex_init(QemuMutex *mutex); 26 void qemu_mutex_destroy(QemuMutex *mutex); 27 int qemu_mutex_trylock_impl(QemuMutex *mutex, const char *file, const int line); 28 void qemu_mutex_lock_impl(QemuMutex *mutex, const char *file, const int line); 29 void qemu_mutex_unlock_impl(QemuMutex *mutex, const char *file, const int line); 30 31 void qemu_rec_mutex_init(QemuRecMutex *mutex); 32 void qemu_rec_mutex_destroy(QemuRecMutex *mutex); 33 void qemu_rec_mutex_lock_impl(QemuRecMutex *mutex, const char *file, int line); 34 int qemu_rec_mutex_trylock_impl(QemuRecMutex *mutex, const char *file, int line); 35 void qemu_rec_mutex_unlock_impl(QemuRecMutex *mutex, const char *file, int line); 36 37 typedef void (*QemuMutexLockFunc)(QemuMutex *m, const char *f, int l); 38 typedef int (*QemuMutexTrylockFunc)(QemuMutex *m, const char *f, int l); 39 typedef void (*QemuRecMutexLockFunc)(QemuRecMutex *m, const char *f, int l); 40 typedef int (*QemuRecMutexTrylockFunc)(QemuRecMutex *m, const char *f, int l); 41 typedef void (*QemuCondWaitFunc)(QemuCond *c, QemuMutex *m, const char *f, 42 int l); 43 typedef bool (*QemuCondTimedWaitFunc)(QemuCond *c, QemuMutex *m, int ms, 44 const char *f, int l); 45 46 extern QemuMutexLockFunc qemu_bql_mutex_lock_func; 47 extern QemuMutexLockFunc qemu_mutex_lock_func; 48 extern QemuMutexTrylockFunc qemu_mutex_trylock_func; 49 extern QemuRecMutexLockFunc qemu_rec_mutex_lock_func; 50 extern QemuRecMutexTrylockFunc qemu_rec_mutex_trylock_func; 51 extern QemuCondWaitFunc qemu_cond_wait_func; 52 extern QemuCondTimedWaitFunc qemu_cond_timedwait_func; 53 54 /* convenience macros to bypass the profiler */ 55 #define qemu_mutex_lock__raw(m) \ 56 qemu_mutex_lock_impl(m, __FILE__, __LINE__) 57 #define qemu_mutex_trylock__raw(m) \ 58 qemu_mutex_trylock_impl(m, __FILE__, __LINE__) 59 60 #ifdef __COVERITY__ 61 /* 62 * Coverity is severely confused by the indirect function calls, 63 * hide them. 64 */ 65 #define qemu_mutex_lock(m) \ 66 qemu_mutex_lock_impl(m, __FILE__, __LINE__) 67 #define qemu_mutex_trylock(m) \ 68 qemu_mutex_trylock_impl(m, __FILE__, __LINE__) 69 #define qemu_rec_mutex_lock(m) \ 70 qemu_rec_mutex_lock_impl(m, __FILE__, __LINE__) 71 #define qemu_rec_mutex_trylock(m) \ 72 qemu_rec_mutex_trylock_impl(m, __FILE__, __LINE__) 73 #define qemu_cond_wait(c, m) \ 74 qemu_cond_wait_impl(c, m, __FILE__, __LINE__) 75 #define qemu_cond_timedwait(c, m, ms) \ 76 qemu_cond_timedwait_impl(c, m, ms, __FILE__, __LINE__) 77 #else 78 #define qemu_mutex_lock(m) ({ \ 79 QemuMutexLockFunc _f = qatomic_read(&qemu_mutex_lock_func); \ 80 _f(m, __FILE__, __LINE__); \ 81 }) 82 83 #define qemu_mutex_trylock(m) ({ \ 84 QemuMutexTrylockFunc _f = qatomic_read(&qemu_mutex_trylock_func); \ 85 _f(m, __FILE__, __LINE__); \ 86 }) 87 88 #define qemu_rec_mutex_lock(m) ({ \ 89 QemuRecMutexLockFunc _f = qatomic_read(&qemu_rec_mutex_lock_func);\ 90 _f(m, __FILE__, __LINE__); \ 91 }) 92 93 #define qemu_rec_mutex_trylock(m) ({ \ 94 QemuRecMutexTrylockFunc _f; \ 95 _f = qatomic_read(&qemu_rec_mutex_trylock_func); \ 96 _f(m, __FILE__, __LINE__); \ 97 }) 98 99 #define qemu_cond_wait(c, m) ({ \ 100 QemuCondWaitFunc _f = qatomic_read(&qemu_cond_wait_func); \ 101 _f(c, m, __FILE__, __LINE__); \ 102 }) 103 104 #define qemu_cond_timedwait(c, m, ms) ({ \ 105 QemuCondTimedWaitFunc _f = qatomic_read(&qemu_cond_timedwait_func);\ 106 _f(c, m, ms, __FILE__, __LINE__); \ 107 }) 108 #endif 109 110 #define qemu_mutex_unlock(mutex) \ 111 qemu_mutex_unlock_impl(mutex, __FILE__, __LINE__) 112 113 #define qemu_rec_mutex_unlock(mutex) \ 114 qemu_rec_mutex_unlock_impl(mutex, __FILE__, __LINE__) 115 116 static inline void (qemu_mutex_lock)(QemuMutex *mutex) 117 { 118 qemu_mutex_lock(mutex); 119 } 120 121 static inline int (qemu_mutex_trylock)(QemuMutex *mutex) 122 { 123 return qemu_mutex_trylock(mutex); 124 } 125 126 static inline void (qemu_mutex_unlock)(QemuMutex *mutex) 127 { 128 qemu_mutex_unlock(mutex); 129 } 130 131 static inline void (qemu_rec_mutex_lock)(QemuRecMutex *mutex) 132 { 133 qemu_rec_mutex_lock(mutex); 134 } 135 136 static inline int (qemu_rec_mutex_trylock)(QemuRecMutex *mutex) 137 { 138 return qemu_rec_mutex_trylock(mutex); 139 } 140 141 static inline void (qemu_rec_mutex_unlock)(QemuRecMutex *mutex) 142 { 143 qemu_rec_mutex_unlock(mutex); 144 } 145 146 void qemu_cond_init(QemuCond *cond); 147 void qemu_cond_destroy(QemuCond *cond); 148 149 /* 150 * IMPORTANT: The implementation does not guarantee that pthread_cond_signal 151 * and pthread_cond_broadcast can be called except while the same mutex is 152 * held as in the corresponding pthread_cond_wait calls! 153 */ 154 void qemu_cond_signal(QemuCond *cond); 155 void qemu_cond_broadcast(QemuCond *cond); 156 void qemu_cond_wait_impl(QemuCond *cond, QemuMutex *mutex, 157 const char *file, const int line); 158 bool qemu_cond_timedwait_impl(QemuCond *cond, QemuMutex *mutex, int ms, 159 const char *file, const int line); 160 161 static inline void (qemu_cond_wait)(QemuCond *cond, QemuMutex *mutex) 162 { 163 qemu_cond_wait(cond, mutex); 164 } 165 166 /* Returns true if timeout has not expired, and false otherwise */ 167 static inline bool (qemu_cond_timedwait)(QemuCond *cond, QemuMutex *mutex, 168 int ms) 169 { 170 return qemu_cond_timedwait(cond, mutex, ms); 171 } 172 173 void qemu_sem_init(QemuSemaphore *sem, int init); 174 void qemu_sem_post(QemuSemaphore *sem); 175 void qemu_sem_wait(QemuSemaphore *sem); 176 int qemu_sem_timedwait(QemuSemaphore *sem, int ms); 177 void qemu_sem_destroy(QemuSemaphore *sem); 178 179 void qemu_event_init(QemuEvent *ev, bool init); 180 void qemu_event_set(QemuEvent *ev); 181 void qemu_event_reset(QemuEvent *ev); 182 void qemu_event_wait(QemuEvent *ev); 183 void qemu_event_destroy(QemuEvent *ev); 184 185 void qemu_thread_create(QemuThread *thread, const char *name, 186 void *(*start_routine)(void *), 187 void *arg, int mode); 188 void *qemu_thread_join(QemuThread *thread); 189 void qemu_thread_get_self(QemuThread *thread); 190 bool qemu_thread_is_self(QemuThread *thread); 191 G_NORETURN void qemu_thread_exit(void *retval); 192 void qemu_thread_naming(bool enable); 193 194 struct Notifier; 195 /** 196 * qemu_thread_atexit_add: 197 * @notifier: Notifier to add 198 * 199 * Add the specified notifier to a list which will be run via 200 * notifier_list_notify() when this thread exits (either by calling 201 * qemu_thread_exit() or by returning from its start_routine). 202 * The usual usage is that the caller passes a Notifier which is 203 * a per-thread variable; it can then use the callback to free 204 * other per-thread data. 205 * 206 * If the thread exits as part of the entire process exiting, 207 * it is unspecified whether notifiers are called or not. 208 */ 209 void qemu_thread_atexit_add(struct Notifier *notifier); 210 /** 211 * qemu_thread_atexit_remove: 212 * @notifier: Notifier to remove 213 * 214 * Remove the specified notifier from the thread-exit notification 215 * list. It is not valid to try to remove a notifier which is not 216 * on the list. 217 */ 218 void qemu_thread_atexit_remove(struct Notifier *notifier); 219 220 #ifdef CONFIG_TSAN 221 #include <sanitizer/tsan_interface.h> 222 #endif 223 224 struct QemuSpin { 225 int value; 226 }; 227 228 static inline void qemu_spin_init(QemuSpin *spin) 229 { 230 __sync_lock_release(&spin->value); 231 #ifdef CONFIG_TSAN 232 __tsan_mutex_create(spin, __tsan_mutex_not_static); 233 #endif 234 } 235 236 /* const parameter because the only purpose here is the TSAN annotation */ 237 static inline void qemu_spin_destroy(const QemuSpin *spin) 238 { 239 #ifdef CONFIG_TSAN 240 __tsan_mutex_destroy((void *)spin, __tsan_mutex_not_static); 241 #endif 242 } 243 244 static inline void qemu_spin_lock(QemuSpin *spin) 245 { 246 #ifdef CONFIG_TSAN 247 __tsan_mutex_pre_lock(spin, 0); 248 #endif 249 while (unlikely(__sync_lock_test_and_set(&spin->value, true))) { 250 while (qatomic_read(&spin->value)) { 251 cpu_relax(); 252 } 253 } 254 #ifdef CONFIG_TSAN 255 __tsan_mutex_post_lock(spin, 0, 0); 256 #endif 257 } 258 259 static inline bool qemu_spin_trylock(QemuSpin *spin) 260 { 261 #ifdef CONFIG_TSAN 262 __tsan_mutex_pre_lock(spin, __tsan_mutex_try_lock); 263 #endif 264 bool busy = __sync_lock_test_and_set(&spin->value, true); 265 #ifdef CONFIG_TSAN 266 unsigned flags = __tsan_mutex_try_lock; 267 flags |= busy ? __tsan_mutex_try_lock_failed : 0; 268 __tsan_mutex_post_lock(spin, flags, 0); 269 #endif 270 return busy; 271 } 272 273 static inline bool qemu_spin_locked(QemuSpin *spin) 274 { 275 return qatomic_read(&spin->value); 276 } 277 278 static inline void qemu_spin_unlock(QemuSpin *spin) 279 { 280 #ifdef CONFIG_TSAN 281 __tsan_mutex_pre_unlock(spin, 0); 282 #endif 283 __sync_lock_release(&spin->value); 284 #ifdef CONFIG_TSAN 285 __tsan_mutex_post_unlock(spin, 0); 286 #endif 287 } 288 289 struct QemuLockCnt { 290 #ifndef CONFIG_LINUX 291 QemuMutex mutex; 292 #endif 293 unsigned count; 294 }; 295 296 /** 297 * qemu_lockcnt_init: initialize a QemuLockcnt 298 * @lockcnt: the lockcnt to initialize 299 * 300 * Initialize lockcnt's counter to zero and prepare its mutex 301 * for usage. 302 */ 303 void qemu_lockcnt_init(QemuLockCnt *lockcnt); 304 305 /** 306 * qemu_lockcnt_destroy: destroy a QemuLockcnt 307 * @lockcnt: the lockcnt to destruct 308 * 309 * Destroy lockcnt's mutex. 310 */ 311 void qemu_lockcnt_destroy(QemuLockCnt *lockcnt); 312 313 /** 314 * qemu_lockcnt_inc: increment a QemuLockCnt's counter 315 * @lockcnt: the lockcnt to operate on 316 * 317 * If the lockcnt's count is zero, wait for critical sections 318 * to finish and increment lockcnt's count to 1. If the count 319 * is not zero, just increment it. 320 * 321 * Because this function can wait on the mutex, it must not be 322 * called while the lockcnt's mutex is held by the current thread. 323 * For the same reason, qemu_lockcnt_inc can also contribute to 324 * AB-BA deadlocks. This is a sample deadlock scenario: 325 * 326 * thread 1 thread 2 327 * ------------------------------------------------------- 328 * qemu_lockcnt_lock(&lc1); 329 * qemu_lockcnt_lock(&lc2); 330 * qemu_lockcnt_inc(&lc2); 331 * qemu_lockcnt_inc(&lc1); 332 */ 333 void qemu_lockcnt_inc(QemuLockCnt *lockcnt); 334 335 /** 336 * qemu_lockcnt_dec: decrement a QemuLockCnt's counter 337 * @lockcnt: the lockcnt to operate on 338 */ 339 void qemu_lockcnt_dec(QemuLockCnt *lockcnt); 340 341 /** 342 * qemu_lockcnt_dec_and_lock: decrement a QemuLockCnt's counter and 343 * possibly lock it. 344 * @lockcnt: the lockcnt to operate on 345 * 346 * Decrement lockcnt's count. If the new count is zero, lock 347 * the mutex and return true. Otherwise, return false. 348 */ 349 bool qemu_lockcnt_dec_and_lock(QemuLockCnt *lockcnt); 350 351 /** 352 * qemu_lockcnt_dec_if_lock: possibly decrement a QemuLockCnt's counter and 353 * lock it. 354 * @lockcnt: the lockcnt to operate on 355 * 356 * If the count is 1, decrement the count to zero, lock 357 * the mutex and return true. Otherwise, return false. 358 */ 359 bool qemu_lockcnt_dec_if_lock(QemuLockCnt *lockcnt); 360 361 /** 362 * qemu_lockcnt_lock: lock a QemuLockCnt's mutex. 363 * @lockcnt: the lockcnt to operate on 364 * 365 * Remember that concurrent visits are not blocked unless the count is 366 * also zero. You can use qemu_lockcnt_count to check for this inside a 367 * critical section. 368 */ 369 void qemu_lockcnt_lock(QemuLockCnt *lockcnt); 370 371 /** 372 * qemu_lockcnt_unlock: release a QemuLockCnt's mutex. 373 * @lockcnt: the lockcnt to operate on. 374 */ 375 void qemu_lockcnt_unlock(QemuLockCnt *lockcnt); 376 377 /** 378 * qemu_lockcnt_inc_and_unlock: combined unlock/increment on a QemuLockCnt. 379 * @lockcnt: the lockcnt to operate on. 380 * 381 * This is the same as 382 * 383 * qemu_lockcnt_unlock(lockcnt); 384 * qemu_lockcnt_inc(lockcnt); 385 * 386 * but more efficient. 387 */ 388 void qemu_lockcnt_inc_and_unlock(QemuLockCnt *lockcnt); 389 390 /** 391 * qemu_lockcnt_count: query a LockCnt's count. 392 * @lockcnt: the lockcnt to query. 393 * 394 * Note that the count can change at any time. Still, while the 395 * lockcnt is locked, one can usefully check whether the count 396 * is non-zero. 397 */ 398 unsigned qemu_lockcnt_count(QemuLockCnt *lockcnt); 399 400 #endif 401