1 #ifndef QEMU_THREAD_H
2 #define QEMU_THREAD_H
3
4 #include "qemu/processor.h"
5 #include "qemu/atomic.h"
6 #include "qemu/clang-tsa.h"
7
8 typedef struct QemuCond QemuCond;
9 typedef struct QemuSemaphore QemuSemaphore;
10 typedef struct QemuEvent QemuEvent;
11 typedef struct QemuLockCnt QemuLockCnt;
12 typedef struct QemuThread QemuThread;
13
14 #ifdef _WIN32
15 #include "qemu/thread-win32.h"
16 #else
17 #include "qemu/thread-posix.h"
18 #endif
19
20 /* include QSP header once QemuMutex, QemuCond etc. are defined */
21 #include "qemu/qsp.h"
22
23 #define QEMU_THREAD_JOINABLE 0
24 #define QEMU_THREAD_DETACHED 1
25
26 void qemu_mutex_init(QemuMutex *mutex);
27 void qemu_mutex_destroy(QemuMutex *mutex);
28 int TSA_NO_TSA qemu_mutex_trylock_impl(QemuMutex *mutex, const char *file,
29 const int line);
30 void TSA_NO_TSA qemu_mutex_lock_impl(QemuMutex *mutex, const char *file,
31 const int line);
32 void TSA_NO_TSA qemu_mutex_unlock_impl(QemuMutex *mutex, const char *file,
33 const int line);
34
35 void qemu_rec_mutex_init(QemuRecMutex *mutex);
36 void qemu_rec_mutex_destroy(QemuRecMutex *mutex);
37 void qemu_rec_mutex_lock_impl(QemuRecMutex *mutex, const char *file, int line);
38 int qemu_rec_mutex_trylock_impl(QemuRecMutex *mutex, const char *file, int line);
39 void qemu_rec_mutex_unlock_impl(QemuRecMutex *mutex, const char *file, int line);
40
41 typedef void (*QemuMutexLockFunc)(QemuMutex *m, const char *f, int l);
42 typedef int (*QemuMutexTrylockFunc)(QemuMutex *m, const char *f, int l);
43 typedef void (*QemuRecMutexLockFunc)(QemuRecMutex *m, const char *f, int l);
44 typedef int (*QemuRecMutexTrylockFunc)(QemuRecMutex *m, const char *f, int l);
45 typedef void (*QemuCondWaitFunc)(QemuCond *c, QemuMutex *m, const char *f,
46 int l);
47 typedef bool (*QemuCondTimedWaitFunc)(QemuCond *c, QemuMutex *m, int ms,
48 const char *f, int l);
49
50 extern QemuMutexLockFunc bql_mutex_lock_func;
51 extern QemuMutexLockFunc qemu_mutex_lock_func;
52 extern QemuMutexTrylockFunc qemu_mutex_trylock_func;
53 extern QemuRecMutexLockFunc qemu_rec_mutex_lock_func;
54 extern QemuRecMutexTrylockFunc qemu_rec_mutex_trylock_func;
55 extern QemuCondWaitFunc qemu_cond_wait_func;
56 extern QemuCondTimedWaitFunc qemu_cond_timedwait_func;
57
58 /* convenience macros to bypass the profiler */
59 #define qemu_mutex_lock__raw(m) \
60 qemu_mutex_lock_impl(m, __FILE__, __LINE__)
61 #define qemu_mutex_trylock__raw(m) \
62 qemu_mutex_trylock_impl(m, __FILE__, __LINE__)
63
64 #ifdef __COVERITY__
65 /*
66 * Coverity is severely confused by the indirect function calls,
67 * hide them.
68 */
69 #define qemu_mutex_lock(m) \
70 qemu_mutex_lock_impl(m, __FILE__, __LINE__)
71 #define qemu_mutex_trylock(m) \
72 qemu_mutex_trylock_impl(m, __FILE__, __LINE__)
73 #define qemu_rec_mutex_lock(m) \
74 qemu_rec_mutex_lock_impl(m, __FILE__, __LINE__)
75 #define qemu_rec_mutex_trylock(m) \
76 qemu_rec_mutex_trylock_impl(m, __FILE__, __LINE__)
77 #define qemu_cond_wait(c, m) \
78 qemu_cond_wait_impl(c, m, __FILE__, __LINE__)
79 #define qemu_cond_timedwait(c, m, ms) \
80 qemu_cond_timedwait_impl(c, m, ms, __FILE__, __LINE__)
81 #else
82 #define qemu_mutex_lock(m) ({ \
83 QemuMutexLockFunc _f = qatomic_read(&qemu_mutex_lock_func); \
84 _f(m, __FILE__, __LINE__); \
85 })
86
87 #define qemu_mutex_trylock(m) ({ \
88 QemuMutexTrylockFunc _f = qatomic_read(&qemu_mutex_trylock_func); \
89 _f(m, __FILE__, __LINE__); \
90 })
91
92 #define qemu_rec_mutex_lock(m) ({ \
93 QemuRecMutexLockFunc _f = qatomic_read(&qemu_rec_mutex_lock_func);\
94 _f(m, __FILE__, __LINE__); \
95 })
96
97 #define qemu_rec_mutex_trylock(m) ({ \
98 QemuRecMutexTrylockFunc _f; \
99 _f = qatomic_read(&qemu_rec_mutex_trylock_func); \
100 _f(m, __FILE__, __LINE__); \
101 })
102
103 #define qemu_cond_wait(c, m) ({ \
104 QemuCondWaitFunc _f = qatomic_read(&qemu_cond_wait_func); \
105 _f(c, m, __FILE__, __LINE__); \
106 })
107
108 #define qemu_cond_timedwait(c, m, ms) ({ \
109 QemuCondTimedWaitFunc _f = qatomic_read(&qemu_cond_timedwait_func);\
110 _f(c, m, ms, __FILE__, __LINE__); \
111 })
112 #endif
113
114 #define qemu_mutex_unlock(mutex) \
115 qemu_mutex_unlock_impl(mutex, __FILE__, __LINE__)
116
117 #define qemu_rec_mutex_unlock(mutex) \
118 qemu_rec_mutex_unlock_impl(mutex, __FILE__, __LINE__)
119
120 static inline void (qemu_mutex_lock)(QemuMutex *mutex)
121 {
122 qemu_mutex_lock(mutex);
123 }
124
125 static inline int (qemu_mutex_trylock)(QemuMutex *mutex)
126 {
127 return qemu_mutex_trylock(mutex);
128 }
129
130 static inline void (qemu_mutex_unlock)(QemuMutex *mutex)
131 {
132 qemu_mutex_unlock(mutex);
133 }
134
135 static inline void (qemu_rec_mutex_lock)(QemuRecMutex *mutex)
136 {
137 qemu_rec_mutex_lock(mutex);
138 }
139
140 static inline int (qemu_rec_mutex_trylock)(QemuRecMutex *mutex)
141 {
142 return qemu_rec_mutex_trylock(mutex);
143 }
144
145 static inline void (qemu_rec_mutex_unlock)(QemuRecMutex *mutex)
146 {
147 qemu_rec_mutex_unlock(mutex);
148 }
149
150 void qemu_cond_init(QemuCond *cond);
151 void qemu_cond_destroy(QemuCond *cond);
152
153 /*
154 * IMPORTANT: The implementation does not guarantee that pthread_cond_signal
155 * and pthread_cond_broadcast can be called except while the same mutex is
156 * held as in the corresponding pthread_cond_wait calls!
157 */
158 void qemu_cond_signal(QemuCond *cond);
159 void qemu_cond_broadcast(QemuCond *cond);
160 void TSA_NO_TSA qemu_cond_wait_impl(QemuCond *cond, QemuMutex *mutex,
161 const char *file, const int line);
162 bool qemu_cond_timedwait_impl(QemuCond *cond, QemuMutex *mutex, int ms,
163 const char *file, const int line);
164
165 static inline void (qemu_cond_wait)(QemuCond *cond, QemuMutex *mutex)
166 {
167 qemu_cond_wait(cond, mutex);
168 }
169
170 /* Returns true if timeout has not expired, and false otherwise */
171 static inline bool (qemu_cond_timedwait)(QemuCond *cond, QemuMutex *mutex,
172 int ms)
173 {
174 return qemu_cond_timedwait(cond, mutex, ms);
175 }
176
177 void qemu_sem_init(QemuSemaphore *sem, int init);
178 void qemu_sem_post(QemuSemaphore *sem);
179 void qemu_sem_wait(QemuSemaphore *sem);
180 int qemu_sem_timedwait(QemuSemaphore *sem, int ms);
181 void qemu_sem_destroy(QemuSemaphore *sem);
182
183 void qemu_event_init(QemuEvent *ev, bool init);
184 void qemu_event_set(QemuEvent *ev);
185 void qemu_event_reset(QemuEvent *ev);
186 void qemu_event_wait(QemuEvent *ev);
187 void qemu_event_destroy(QemuEvent *ev);
188
189 void qemu_thread_create(QemuThread *thread, const char *name,
190 void *(*start_routine)(void *),
191 void *arg, int mode);
192 int qemu_thread_set_affinity(QemuThread *thread, unsigned long *host_cpus,
193 unsigned long nbits);
194 int qemu_thread_get_affinity(QemuThread *thread, unsigned long **host_cpus,
195 unsigned long *nbits);
196 void *qemu_thread_join(QemuThread *thread);
197 void qemu_thread_get_self(QemuThread *thread);
198 bool qemu_thread_is_self(QemuThread *thread);
199 G_NORETURN void qemu_thread_exit(void *retval);
200 void qemu_thread_naming(bool enable);
201
202 struct Notifier;
203 /**
204 * qemu_thread_atexit_add:
205 * @notifier: Notifier to add
206 *
207 * Add the specified notifier to a list which will be run via
208 * notifier_list_notify() when this thread exits (either by calling
209 * qemu_thread_exit() or by returning from its start_routine).
210 * The usual usage is that the caller passes a Notifier which is
211 * a per-thread variable; it can then use the callback to free
212 * other per-thread data.
213 *
214 * If the thread exits as part of the entire process exiting,
215 * it is unspecified whether notifiers are called or not.
216 */
217 void qemu_thread_atexit_add(struct Notifier *notifier);
218 /**
219 * qemu_thread_atexit_remove:
220 * @notifier: Notifier to remove
221 *
222 * Remove the specified notifier from the thread-exit notification
223 * list. It is not valid to try to remove a notifier which is not
224 * on the list.
225 */
226 void qemu_thread_atexit_remove(struct Notifier *notifier);
227
228 #ifdef CONFIG_TSAN
229 #include <sanitizer/tsan_interface.h>
230 #endif
231
232 struct QemuSpin {
233 int value;
234 };
235
qemu_spin_init(QemuSpin * spin)236 static inline void qemu_spin_init(QemuSpin *spin)
237 {
238 qatomic_set(&spin->value, 0);
239 #ifdef CONFIG_TSAN
240 __tsan_mutex_create(spin, __tsan_mutex_not_static);
241 #endif
242 }
243
qemu_spin_destroy(QemuSpin * spin)244 static inline void qemu_spin_destroy(QemuSpin *spin)
245 {
246 #ifdef CONFIG_TSAN
247 __tsan_mutex_destroy(spin, __tsan_mutex_not_static);
248 #endif
249 }
250
qemu_spin_lock(QemuSpin * spin)251 static inline void qemu_spin_lock(QemuSpin *spin)
252 {
253 #ifdef CONFIG_TSAN
254 __tsan_mutex_pre_lock(spin, 0);
255 #endif
256 while (unlikely(qatomic_xchg(&spin->value, 1))) {
257 while (qatomic_read(&spin->value)) {
258 cpu_relax();
259 }
260 }
261 #ifdef CONFIG_TSAN
262 __tsan_mutex_post_lock(spin, 0, 0);
263 #endif
264 }
265
qemu_spin_trylock(QemuSpin * spin)266 static inline bool qemu_spin_trylock(QemuSpin *spin)
267 {
268 #ifdef CONFIG_TSAN
269 __tsan_mutex_pre_lock(spin, __tsan_mutex_try_lock);
270 #endif
271 bool busy = qatomic_xchg(&spin->value, true);
272 #ifdef CONFIG_TSAN
273 unsigned flags = __tsan_mutex_try_lock;
274 flags |= busy ? __tsan_mutex_try_lock_failed : 0;
275 __tsan_mutex_post_lock(spin, flags, 0);
276 #endif
277 return busy;
278 }
279
qemu_spin_locked(QemuSpin * spin)280 static inline bool qemu_spin_locked(QemuSpin *spin)
281 {
282 return qatomic_read(&spin->value);
283 }
284
qemu_spin_unlock(QemuSpin * spin)285 static inline void qemu_spin_unlock(QemuSpin *spin)
286 {
287 #ifdef CONFIG_TSAN
288 __tsan_mutex_pre_unlock(spin, 0);
289 #endif
290 qatomic_store_release(&spin->value, 0);
291 #ifdef CONFIG_TSAN
292 __tsan_mutex_post_unlock(spin, 0);
293 #endif
294 }
295
296 struct QemuLockCnt {
297 #ifndef CONFIG_LINUX
298 QemuMutex mutex;
299 #endif
300 unsigned count;
301 };
302
303 /**
304 * qemu_lockcnt_init: initialize a QemuLockcnt
305 * @lockcnt: the lockcnt to initialize
306 *
307 * Initialize lockcnt's counter to zero and prepare its mutex
308 * for usage.
309 */
310 void qemu_lockcnt_init(QemuLockCnt *lockcnt);
311
312 /**
313 * qemu_lockcnt_destroy: destroy a QemuLockcnt
314 * @lockcnt: the lockcnt to destruct
315 *
316 * Destroy lockcnt's mutex.
317 */
318 void qemu_lockcnt_destroy(QemuLockCnt *lockcnt);
319
320 /**
321 * qemu_lockcnt_inc: increment a QemuLockCnt's counter
322 * @lockcnt: the lockcnt to operate on
323 *
324 * If the lockcnt's count is zero, wait for critical sections
325 * to finish and increment lockcnt's count to 1. If the count
326 * is not zero, just increment it.
327 *
328 * Because this function can wait on the mutex, it must not be
329 * called while the lockcnt's mutex is held by the current thread.
330 * For the same reason, qemu_lockcnt_inc can also contribute to
331 * AB-BA deadlocks. This is a sample deadlock scenario:
332 *
333 * thread 1 thread 2
334 * -------------------------------------------------------
335 * qemu_lockcnt_lock(&lc1);
336 * qemu_lockcnt_lock(&lc2);
337 * qemu_lockcnt_inc(&lc2);
338 * qemu_lockcnt_inc(&lc1);
339 */
340 void qemu_lockcnt_inc(QemuLockCnt *lockcnt);
341
342 /**
343 * qemu_lockcnt_dec: decrement a QemuLockCnt's counter
344 * @lockcnt: the lockcnt to operate on
345 */
346 void qemu_lockcnt_dec(QemuLockCnt *lockcnt);
347
348 /**
349 * qemu_lockcnt_dec_and_lock: decrement a QemuLockCnt's counter and
350 * possibly lock it.
351 * @lockcnt: the lockcnt to operate on
352 *
353 * Decrement lockcnt's count. If the new count is zero, lock
354 * the mutex and return true. Otherwise, return false.
355 */
356 bool qemu_lockcnt_dec_and_lock(QemuLockCnt *lockcnt);
357
358 /**
359 * qemu_lockcnt_dec_if_lock: possibly decrement a QemuLockCnt's counter and
360 * lock it.
361 * @lockcnt: the lockcnt to operate on
362 *
363 * If the count is 1, decrement the count to zero, lock
364 * the mutex and return true. Otherwise, return false.
365 */
366 bool qemu_lockcnt_dec_if_lock(QemuLockCnt *lockcnt);
367
368 /**
369 * qemu_lockcnt_lock: lock a QemuLockCnt's mutex.
370 * @lockcnt: the lockcnt to operate on
371 *
372 * Remember that concurrent visits are not blocked unless the count is
373 * also zero. You can use qemu_lockcnt_count to check for this inside a
374 * critical section.
375 */
376 void qemu_lockcnt_lock(QemuLockCnt *lockcnt);
377
378 /**
379 * qemu_lockcnt_unlock: release a QemuLockCnt's mutex.
380 * @lockcnt: the lockcnt to operate on.
381 */
382 void qemu_lockcnt_unlock(QemuLockCnt *lockcnt);
383
384 /**
385 * qemu_lockcnt_inc_and_unlock: combined unlock/increment on a QemuLockCnt.
386 * @lockcnt: the lockcnt to operate on.
387 *
388 * This is the same as
389 *
390 * qemu_lockcnt_unlock(lockcnt);
391 * qemu_lockcnt_inc(lockcnt);
392 *
393 * but more efficient.
394 */
395 void qemu_lockcnt_inc_and_unlock(QemuLockCnt *lockcnt);
396
397 /**
398 * qemu_lockcnt_count: query a LockCnt's count.
399 * @lockcnt: the lockcnt to query.
400 *
401 * Note that the count can change at any time. Still, while the
402 * lockcnt is locked, one can usefully check whether the count
403 * is non-zero.
404 */
405 unsigned qemu_lockcnt_count(QemuLockCnt *lockcnt);
406
407 #endif
408