1 /* Copyright (c) 2000, 2014, Oracle and/or its affiliates.
2 Copyright (c) 2009, 2020, MariaDB Corporation.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; version 2 of the License.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12
13 You should have received a copy of the GNU General Public License
14 along with this program; if not, write to the Free Software
15 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
16
17 /* Defines to make different thread packages compatible */
18
19 #ifndef _my_pthread_h
20 #define _my_pthread_h
21
22 #ifndef ETIME
23 #define ETIME ETIMEDOUT /* For FreeBSD */
24 #endif
25
26 #ifdef __cplusplus
27 #define EXTERNC extern "C"
28 extern "C" {
29 #else
30 #define EXTERNC
31 #endif /* __cplusplus */
32
33 #if defined(__WIN__)
34 typedef CRITICAL_SECTION pthread_mutex_t;
35 typedef DWORD pthread_t;
36 typedef struct thread_attr {
37 DWORD dwStackSize ;
38 DWORD dwCreatingFlag ;
39 } pthread_attr_t ;
40
41 typedef struct { int dummy; } pthread_condattr_t;
42
43 /* Implementation of posix conditions */
44
45 typedef struct st_pthread_link {
46 DWORD thread_id;
47 struct st_pthread_link *next;
48 } pthread_link;
49
50 /**
51 Implementation of Windows condition variables.
52 We use native conditions on Vista and later, and fallback to own
53 implementation on earlier OS version.
54 */
55 typedef CONDITION_VARIABLE pthread_cond_t;
56
57
58 typedef int pthread_mutexattr_t;
59 #define pthread_self() GetCurrentThreadId()
60 #define pthread_handler_t EXTERNC void * __cdecl
61 typedef void * (__cdecl *pthread_handler)(void *);
62
63 typedef INIT_ONCE my_pthread_once_t;
64 #define MY_PTHREAD_ONCE_INIT INIT_ONCE_STATIC_INIT;
65
66 #if !STRUCT_TIMESPEC_HAS_TV_SEC || !STRUCT_TIMESPEC_HAS_TV_NSEC
67 struct timespec {
68 time_t tv_sec;
69 long tv_nsec;
70 };
71 #endif
72
73 int win_pthread_mutex_trylock(pthread_mutex_t *mutex);
74 int pthread_create(pthread_t *, const pthread_attr_t *, pthread_handler, void *);
75 int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr);
76 int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex);
77 int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
78 const struct timespec *abstime);
79 int pthread_cond_signal(pthread_cond_t *cond);
80 int pthread_cond_broadcast(pthread_cond_t *cond);
81 int pthread_cond_destroy(pthread_cond_t *cond);
82 int pthread_attr_init(pthread_attr_t *connect_att);
83 int pthread_attr_setstacksize(pthread_attr_t *connect_att,size_t stack);
84 int pthread_attr_destroy(pthread_attr_t *connect_att);
85 int my_pthread_once(my_pthread_once_t *once_control,void (*init_routine)(void));
86
localtime_r(const time_t * timep,struct tm * tmp)87 static inline struct tm *localtime_r(const time_t *timep, struct tm *tmp)
88 {
89 localtime_s(tmp, timep);
90 return tmp;
91 }
92
gmtime_r(const time_t * clock,struct tm * res)93 static inline struct tm *gmtime_r(const time_t *clock, struct tm *res)
94 {
95 gmtime_s(res, clock);
96 return res;
97 }
98
99 void pthread_exit(void *a);
100 int pthread_join(pthread_t thread, void **value_ptr);
101 int pthread_cancel(pthread_t thread);
102
103 #ifndef ETIMEDOUT
104 #define ETIMEDOUT 145 /* Win32 doesn't have this */
105 #endif
106
107 #define getpid() GetCurrentThreadId()
108 #define HAVE_LOCALTIME_R 1
109 #define _REENTRANT 1
110 #define HAVE_PTHREAD_ATTR_SETSTACKSIZE 1
111
112 #undef SAFE_MUTEX /* This will cause conflicts */
113 #define pthread_key(T,V) DWORD V
114 #define pthread_key_create(A,B) ((*A=TlsAlloc())==0xFFFFFFFF)
115 #define pthread_key_delete(A) TlsFree(A)
116 #define my_pthread_setspecific_ptr(T,V) (!TlsSetValue((T),(V)))
117 #define pthread_setspecific(A,B) (!TlsSetValue((A),(B)))
118 #define pthread_getspecific(A) (TlsGetValue(A))
119 #define my_pthread_getspecific(T,A) ((T) TlsGetValue(A))
120 #define my_pthread_getspecific_ptr(T,V) ((T) TlsGetValue(V))
121
122 #define pthread_equal(A,B) ((A) == (B))
123 #define pthread_mutex_init(A,B) (InitializeCriticalSection(A),0)
124 #define pthread_mutex_lock(A) (EnterCriticalSection(A),0)
125 #define pthread_mutex_trylock(A) win_pthread_mutex_trylock((A))
126 #define pthread_mutex_unlock(A) (LeaveCriticalSection(A), 0)
127 #define pthread_mutex_destroy(A) (DeleteCriticalSection(A), 0)
128 #define pthread_kill(A,B) pthread_dummy((A) ? 0 : ESRCH)
129
130
131 /* Dummy defines for easier code */
132 #define pthread_attr_setdetachstate(A,B) pthread_dummy(0)
133 #define pthread_attr_setscope(A,B)
134 #define pthread_detach_this_thread()
135 #define pthread_condattr_init(A)
136 #define pthread_condattr_destroy(A)
137 #define pthread_yield() SwitchToThread()
138 #define my_sigset(A,B) signal(A,B)
139
140 #else /* Normal threads */
141
142 #ifdef HAVE_rts_threads
143 #define sigwait org_sigwait
144 #include <signal.h>
145 #undef sigwait
146 #endif
147 #include <pthread.h>
148 #ifndef _REENTRANT
149 #define _REENTRANT
150 #endif
151 #ifdef HAVE_THR_SETCONCURRENCY
152 #include <thread.h> /* Probably solaris */
153 #endif
154 #ifdef HAVE_SCHED_H
155 #include <sched.h>
156 #endif
157 #ifdef HAVE_SYNCH_H
158 #include <synch.h>
159 #endif
160
161 #define pthread_key(T,V) pthread_key_t V
162 #define my_pthread_getspecific_ptr(T,V) my_pthread_getspecific(T,(V))
163 #define my_pthread_setspecific_ptr(T,V) pthread_setspecific(T,(void*) (V))
164 #define pthread_detach_this_thread()
165 #define pthread_handler_t EXTERNC void *
166 typedef void *(* pthread_handler)(void *);
167
168 #define my_pthread_once_t pthread_once_t
169 #if defined(PTHREAD_ONCE_INITIALIZER)
170 #define MY_PTHREAD_ONCE_INIT PTHREAD_ONCE_INITIALIZER
171 #else
172 #define MY_PTHREAD_ONCE_INIT PTHREAD_ONCE_INIT
173 #endif
174 #define my_pthread_once(C,F) pthread_once(C,F)
175
176 /* Test first for RTS or FSU threads */
177
178 #if defined(PTHREAD_SCOPE_GLOBAL) && !defined(PTHREAD_SCOPE_SYSTEM)
179 #define HAVE_rts_threads
180 extern int my_pthread_create_detached;
181 #define pthread_sigmask(A,B,C) sigprocmask((A),(B),(C))
182 #define PTHREAD_CREATE_DETACHED &my_pthread_create_detached
183 #define PTHREAD_SCOPE_SYSTEM PTHREAD_SCOPE_GLOBAL
184 #define PTHREAD_SCOPE_PROCESS PTHREAD_SCOPE_LOCAL
185 #define USE_ALARM_THREAD
186 #endif /* defined(PTHREAD_SCOPE_GLOBAL) && !defined(PTHREAD_SCOPE_SYSTEM) */
187
188 #if defined(_BSDI_VERSION) && _BSDI_VERSION < 199910
189 int sigwait(sigset_t *set, int *sig);
190 #endif
191
192 static inline int my_sigwait(sigset_t *set, int *sig, int *code)
193 {
194 #ifdef HAVE_SIGWAITINFO
195 siginfo_t siginfo;
196 *sig= sigwaitinfo(set, &siginfo);
197 *code= siginfo.si_code;
198 return *sig < 0 ? errno : 0;
199 /* XXX */
200 #ifndef SI_KERNEL
201 #define SI_KERNEL 128
202 #endif
203 #else
204 *code= 0;
205 return sigwait(set, sig);
206 #endif
207 }
208
209 #if defined(HAVE_SIGTHREADMASK) && !defined(HAVE_PTHREAD_SIGMASK)
210 #define pthread_sigmask(A,B,C) sigthreadmask((A),(B),(C))
211 #endif
212
213 #if !defined(HAVE_SIGWAIT) && !defined(HAVE_rts_threads) && !defined(sigwait) && !defined(alpha_linux_port) && !defined(_AIX)
214 int sigwait(sigset_t *setp, int *sigp); /* Use our implementation */
215 #endif
216
217
218 /*
219 We define my_sigset() and use that instead of the system sigset() so that
220 we can favor an implementation based on sigaction(). On some systems, such
221 as Mac OS X, sigset() results in flags such as SA_RESTART being set, and
222 we want to make sure that no such flags are set.
223 */
224 #if defined(HAVE_SIGACTION) && !defined(my_sigset)
225 #define my_sigset(A,B) do { struct sigaction l_s; sigset_t l_set; \
226 DBUG_ASSERT((A) != 0); \
227 sigemptyset(&l_set); \
228 l_s.sa_handler = (B); \
229 l_s.sa_mask = l_set; \
230 l_s.sa_flags = 0; \
231 sigaction((A), &l_s, NULL); \
232 } while (0)
233 #elif defined(HAVE_SIGSET) && !defined(my_sigset)
234 #define my_sigset(A,B) sigset((A),(B))
235 #elif !defined(my_sigset)
236 #define my_sigset(A,B) signal((A),(B))
237 #endif
238
239 #if !defined(HAVE_PTHREAD_ATTR_SETSCOPE)
240 #define pthread_attr_setscope(A,B)
241 #undef HAVE_GETHOSTBYADDR_R /* No definition */
242 #endif
243
244 #define my_pthread_getspecific(A,B) ((A) pthread_getspecific(B))
245
246 #ifndef HAVE_LOCALTIME_R
247 struct tm *localtime_r(const time_t *clock, struct tm *res);
248 #endif
249
250 #ifndef HAVE_GMTIME_R
251 struct tm *gmtime_r(const time_t *clock, struct tm *res);
252 #endif
253
254 #ifdef HAVE_PTHREAD_CONDATTR_CREATE
255 /* DCE threads on HPUX 10.20 */
256 #define pthread_condattr_init pthread_condattr_create
257 #define pthread_condattr_destroy pthread_condattr_delete
258 #endif
259
260 /* FSU THREADS */
261 #if !defined(HAVE_PTHREAD_KEY_DELETE) && !defined(pthread_key_delete)
262 #define pthread_key_delete(A) pthread_dummy(0)
263 #endif
264
265 #if defined(HAVE_PTHREAD_ATTR_CREATE) && !defined(HAVE_SIGWAIT)
266 /* This is set on AIX_3_2 and Siemens unix (and DEC OSF/1 3.2 too) */
267 #define pthread_key_create(A,B) \
268 pthread_keycreate(A,(B) ?\
269 (pthread_destructor_t) (B) :\
270 (pthread_destructor_t) pthread_dummy)
271 #define pthread_attr_init(A) pthread_attr_create(A)
272 #define pthread_attr_destroy(A) pthread_attr_delete(A)
273 #define pthread_attr_setdetachstate(A,B) pthread_dummy(0)
274 #define pthread_create(A,B,C,D) pthread_create((A),*(B),(C),(D))
275 #ifndef pthread_sigmask
276 #define pthread_sigmask(A,B,C) sigprocmask((A),(B),(C))
277 #endif
278 #define pthread_kill(A,B) pthread_dummy((A) ? 0 : ESRCH)
279 #undef pthread_detach_this_thread
280 #define pthread_detach_this_thread() { pthread_t tmp=pthread_self() ; pthread_detach(&tmp); }
281 #else /* HAVE_PTHREAD_ATTR_CREATE && !HAVE_SIGWAIT */
282 #define HAVE_PTHREAD_KILL 1
283 #endif
284
285 #endif /* defined(__WIN__) */
286
287 #if defined(HPUX10) && !defined(DONT_REMAP_PTHREAD_FUNCTIONS)
288 #undef pthread_cond_timedwait
289 #define pthread_cond_timedwait(a,b,c) my_pthread_cond_timedwait((a),(b),(c))
290 int my_pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
291 struct timespec *abstime);
292 #endif
293
294 #if defined(HPUX10)
295 #define pthread_attr_getstacksize(A,B) my_pthread_attr_getstacksize(A,B)
296 void my_pthread_attr_getstacksize(pthread_attr_t *attrib, size_t *size);
297 #endif
298
299 #if defined(HAVE_POSIX1003_4a_MUTEX) && !defined(DONT_REMAP_PTHREAD_FUNCTIONS)
300 #undef pthread_mutex_trylock
301 #define pthread_mutex_trylock(a) my_pthread_mutex_trylock((a))
302 int my_pthread_mutex_trylock(pthread_mutex_t *mutex);
303 #endif
304
305 #ifdef HAVE_SCHED_YIELD
306 #define pthread_yield() sched_yield()
307 #else
308 #if !defined(HAVE_PTHREAD_YIELD_ZERO_ARG)
309 /* no pthread_yield() available */
310 #if defined(HAVE_PTHREAD_YIELD_NP) /* can be Mac OS X */
311 #define pthread_yield() pthread_yield_np()
312 #elif defined(HAVE_THR_YIELD)
313 #define pthread_yield() thr_yield()
314 #endif //defined(HAVE_PTHREAD_YIELD_NP)
315 #endif //!defined(HAVE_PTHREAD_YIELD_ZERO_ARG)
316 #endif //HAVE_SCHED_YIELD
317
318 /*
319 The defines set_timespec and set_timespec_nsec should be used
320 for calculating an absolute time at which
321 pthread_cond_timedwait should timeout
322 */
323 #define set_timespec(ABSTIME,SEC) set_timespec_nsec((ABSTIME),(SEC)*1000000000ULL)
324
325 #ifndef set_timespec_nsec
326 #define set_timespec_nsec(ABSTIME,NSEC) \
327 set_timespec_time_nsec((ABSTIME), my_hrtime_coarse().val*1000 + (NSEC))
328 #endif /* !set_timespec_nsec */
329
330 /* adapt for two different flavors of struct timespec */
331 #ifdef HAVE_TIMESPEC_TS_SEC
332 #define MY_tv_sec ts_sec
333 #define MY_tv_nsec ts_nsec
334 #else
335 #define MY_tv_sec tv_sec
336 #define MY_tv_nsec tv_nsec
337 #endif /* HAVE_TIMESPEC_TS_SEC */
338
339 /**
340 Compare two timespec structs.
341
342 @retval 1 If TS1 ends after TS2.
343
344 @retval 0 If TS1 is equal to TS2.
345
346 @retval -1 If TS1 ends before TS2.
347 */
348 #ifndef cmp_timespec
349 #define cmp_timespec(TS1, TS2) \
350 ((TS1.MY_tv_sec > TS2.MY_tv_sec || \
351 (TS1.MY_tv_sec == TS2.MY_tv_sec && TS1.MY_tv_nsec > TS2.MY_tv_nsec)) ? 1 : \
352 ((TS1.MY_tv_sec < TS2.MY_tv_sec || \
353 (TS1.MY_tv_sec == TS2.MY_tv_sec && TS1.MY_tv_nsec < TS2.MY_tv_nsec)) ? -1 : 0))
354 #endif /* !cmp_timespec */
355
356 #ifndef set_timespec_time_nsec
357 #define set_timespec_time_nsec(ABSTIME,NSEC) do { \
358 ulonglong _now_= (NSEC); \
359 (ABSTIME).MY_tv_sec= (_now_ / 1000000000ULL); \
360 (ABSTIME).MY_tv_nsec= (_now_ % 1000000000ULL); \
361 } while(0)
362 #endif /* !set_timespec_time_nsec */
363
364 #ifdef MYSQL_CLIENT
365 #define _current_thd() NULL
366 #elif defined(_WIN32)
367 #ifdef __cplusplus
368 extern "C"
369 #endif
370 MYSQL_THD _current_thd_noinline();
371 #define _current_thd() _current_thd_noinline()
372 #else
373 /*
374 THR_THD is a key which will be used to set/get THD* for a thread,
375 using my_pthread_setspecific_ptr()/my_thread_getspecific_ptr().
376 */
377 extern pthread_key(MYSQL_THD, THR_THD);
_current_thd(void)378 static inline MYSQL_THD _current_thd(void)
379 {
380 return my_pthread_getspecific_ptr(MYSQL_THD,THR_THD);
381 }
382 #endif
383
384 /* safe_mutex adds checking to mutex for easier debugging */
385 struct st_hash;
386 typedef struct st_safe_mutex_t
387 {
388 pthread_mutex_t global,mutex;
389 const char *file, *name;
390 uint line,count;
391 myf create_flags, active_flags;
392 ulong id;
393 pthread_t thread;
394 struct st_hash *locked_mutex, *used_mutex;
395 struct st_safe_mutex_t *prev, *next;
396 #ifdef SAFE_MUTEX_DETECT_DESTROY
397 struct st_safe_mutex_info_t *info; /* to track destroying of mutexes */
398 #endif
399 } safe_mutex_t;
400
401 typedef struct st_safe_mutex_deadlock_t
402 {
403 const char *file, *name;
404 safe_mutex_t *mutex;
405 uint line;
406 ulong count;
407 ulong id;
408 my_bool warning_only;
409 } safe_mutex_deadlock_t;
410
411 #ifdef SAFE_MUTEX_DETECT_DESTROY
412 /*
413 Used to track the destroying of mutexes. This needs to be a separate
414 structure because the safe_mutex_t structure could be freed before
415 the mutexes are destroyed.
416 */
417
418 typedef struct st_safe_mutex_info_t
419 {
420 struct st_safe_mutex_info_t *next;
421 struct st_safe_mutex_info_t *prev;
422 const char *init_file;
423 uint32 init_line;
424 } safe_mutex_info_t;
425 #endif /* SAFE_MUTEX_DETECT_DESTROY */
426
427 int safe_mutex_init(safe_mutex_t *mp, const pthread_mutexattr_t *attr,
428 const char *name, const char *file, uint line);
429 int safe_mutex_lock(safe_mutex_t *mp, myf my_flags, const char *file,
430 uint line);
431 int safe_mutex_unlock(safe_mutex_t *mp,const char *file, uint line);
432 int safe_mutex_destroy(safe_mutex_t *mp,const char *file, uint line);
433 int safe_cond_wait(pthread_cond_t *cond, safe_mutex_t *mp,const char *file,
434 uint line);
435 int safe_cond_timedwait(pthread_cond_t *cond, safe_mutex_t *mp,
436 const struct timespec *abstime,
437 const char *file, uint line);
438 void safe_mutex_global_init(void);
439 void safe_mutex_end(FILE *file);
440 void safe_mutex_free_deadlock_data(safe_mutex_t *mp);
441
442 /* Wrappers if safe mutex is actually used */
443 #define MYF_TRY_LOCK 1
444 #define MYF_NO_DEADLOCK_DETECTION 2
445
446 #ifdef SAFE_MUTEX
447 #define safe_mutex_assert_owner(mp) \
448 DBUG_ASSERT((mp)->count > 0 && \
449 pthread_equal(pthread_self(), (mp)->thread))
450 #define safe_mutex_assert_not_owner(mp) \
451 DBUG_ASSERT(! (mp)->count || \
452 ! pthread_equal(pthread_self(), (mp)->thread))
453 #define safe_mutex_setflags(mp, F) do { (mp)->create_flags|= (F); } while (0)
454 #define my_cond_timedwait(A,B,C) safe_cond_timedwait((A),(B),(C),__FILE__,__LINE__)
455 #define my_cond_wait(A,B) safe_cond_wait((A), (B), __FILE__, __LINE__)
456 #else
457
458 #define safe_mutex_assert_owner(mp) do {} while (0)
459 #define safe_mutex_assert_not_owner(mp) do {} while (0)
460 #define safe_mutex_setflags(mp, F) do {} while (0)
461
462 #define my_cond_timedwait(A,B,C) pthread_cond_timedwait((A),(B),(C))
463 #define my_cond_wait(A,B) pthread_cond_wait((A), (B))
464 #endif /* !SAFE_MUTEX */
465
466 /* READ-WRITE thread locking */
467
468 #if defined(USE_MUTEX_INSTEAD_OF_RW_LOCKS)
469 /* use these defs for simple mutex locking */
470 #define rw_lock_t pthread_mutex_t
471 #define my_rwlock_init(A,B) pthread_mutex_init((A),(B))
472 #define rw_rdlock(A) pthread_mutex_lock((A))
473 #define rw_wrlock(A) pthread_mutex_lock((A))
474 #define rw_tryrdlock(A) pthread_mutex_trylock((A))
475 #define rw_trywrlock(A) pthread_mutex_trylock((A))
476 #define rw_unlock(A) pthread_mutex_unlock((A))
477 #define rwlock_destroy(A) pthread_mutex_destroy((A))
478 #elif defined(HAVE_PTHREAD_RWLOCK_RDLOCK)
479 #define rw_lock_t pthread_rwlock_t
480 #define my_rwlock_init(A,B) pthread_rwlock_init((A),(B))
481 #define rw_rdlock(A) pthread_rwlock_rdlock(A)
482 #define rw_wrlock(A) pthread_rwlock_wrlock(A)
483 #define rw_tryrdlock(A) pthread_rwlock_tryrdlock((A))
484 #define rw_trywrlock(A) pthread_rwlock_trywrlock((A))
485 #define rw_unlock(A) pthread_rwlock_unlock(A)
486 #define rwlock_destroy(A) pthread_rwlock_destroy(A)
487 #elif defined(HAVE_RWLOCK_INIT)
488 #ifdef HAVE_RWLOCK_T /* For example Solaris 2.6-> */
489 #define rw_lock_t rwlock_t
490 #endif
491 #define my_rwlock_init(A,B) rwlock_init((A),USYNC_THREAD,0)
492 #else
493 /* Use our own version of read/write locks */
494 #define NEED_MY_RW_LOCK 1
495 #define rw_lock_t my_rw_lock_t
496 #define my_rwlock_init(A,B) my_rw_init((A))
497 #define rw_rdlock(A) my_rw_rdlock((A))
498 #define rw_wrlock(A) my_rw_wrlock((A))
499 #define rw_tryrdlock(A) my_rw_tryrdlock((A))
500 #define rw_trywrlock(A) my_rw_trywrlock((A))
501 #define rw_unlock(A) my_rw_unlock((A))
502 #define rwlock_destroy(A) my_rw_destroy((A))
503 #define rw_lock_assert_write_owner(A) my_rw_lock_assert_write_owner((A))
504 #define rw_lock_assert_not_write_owner(A) my_rw_lock_assert_not_write_owner((A))
505 #endif /* USE_MUTEX_INSTEAD_OF_RW_LOCKS */
506
507
508 /**
509 Portable implementation of special type of read-write locks.
510
511 These locks have two properties which are unusual for rwlocks:
512 1) They "prefer readers" in the sense that they do not allow
513 situations in which rwlock is rd-locked and there is a
514 pending rd-lock which is blocked (e.g. due to pending
515 request for wr-lock).
516 This is a stronger guarantee than one which is provided for
517 PTHREAD_RWLOCK_PREFER_READER_NP rwlocks in Linux.
518 MDL subsystem deadlock detector relies on this property for
519 its correctness.
520 2) They are optimized for uncontended wr-lock/unlock case.
521 This is a scenario in which they are most often used
522 within MDL subsystem. Optimizing for it gives significant
523 performance improvements in some of the tests involving many
524 connections.
525
526 Another important requirement imposed on this type of rwlock
527 by the MDL subsystem is that it should be OK to destroy rwlock
528 object which is in unlocked state even though some threads might
529 have not yet fully left unlock operation for it (of course there
530 is an external guarantee that no thread will try to lock rwlock
531 which is destroyed).
532 Putting it another way the unlock operation should not access
533 rwlock data after changing its state to unlocked.
534
535 TODO/FIXME: We should consider alleviating this requirement as
536 it blocks us from doing certain performance optimizations.
537 */
538
539 typedef struct st_rw_pr_lock_t {
540 /**
541 Lock which protects the structure.
542 Also held for the duration of wr-lock.
543 */
544 pthread_mutex_t lock;
545 /**
546 Condition variable which is used to wake-up
547 writers waiting for readers to go away.
548 */
549 pthread_cond_t no_active_readers;
550 /** Number of active readers. */
551 uint active_readers;
552 /** Number of writers waiting for readers to go away. */
553 uint writers_waiting_readers;
554 /** Indicates whether there is an active writer. */
555 my_bool active_writer;
556 #ifdef SAFE_MUTEX
557 /** Thread holding wr-lock (for debug purposes only). */
558 pthread_t writer_thread;
559 #endif
560 } rw_pr_lock_t;
561
562 extern int rw_pr_init(rw_pr_lock_t *);
563 extern int rw_pr_rdlock(rw_pr_lock_t *);
564 extern int rw_pr_wrlock(rw_pr_lock_t *);
565 extern int rw_pr_unlock(rw_pr_lock_t *);
566 extern int rw_pr_destroy(rw_pr_lock_t *);
567 #ifdef SAFE_MUTEX
568 #define rw_pr_lock_assert_write_owner(A) \
569 DBUG_ASSERT((A)->active_writer && pthread_equal(pthread_self(), \
570 (A)->writer_thread))
571 #define rw_pr_lock_assert_not_write_owner(A) \
572 DBUG_ASSERT(! (A)->active_writer || ! pthread_equal(pthread_self(), \
573 (A)->writer_thread))
574 #else
575 #define rw_pr_lock_assert_write_owner(A)
576 #define rw_pr_lock_assert_not_write_owner(A)
577 #endif /* SAFE_MUTEX */
578
579
580 #ifdef NEED_MY_RW_LOCK
581
582 #ifdef _WIN32
583
584 /**
585 Implementation of Windows rwlock.
586
587 We use native (slim) rwlocks on Win7 and later, and fallback to portable
588 implementation on earlier Windows.
589
590 slim rwlock are also available on Vista/WS2008, but we do not use it
591 ("trylock" APIs are missing on Vista)
592 */
593 typedef union
594 {
595 /* Native rwlock (is_srwlock == TRUE) */
596 struct
597 {
598 SRWLOCK srwlock; /* native reader writer lock */
599 BOOL have_exclusive_srwlock; /* used for unlock */
600 };
601
602 /*
603 Portable implementation (is_srwlock == FALSE)
604 Fields are identical with Unix my_rw_lock_t fields.
605 */
606 struct
607 {
608 pthread_mutex_t lock; /* lock for structure */
609 pthread_cond_t readers; /* waiting readers */
610 pthread_cond_t writers; /* waiting writers */
611 int state; /* -1:writer,0:free,>0:readers */
612 int waiters; /* number of waiting writers */
613 #ifdef SAFE_MUTEX
614 pthread_t write_thread;
615 #endif
616 };
617 } my_rw_lock_t;
618
619
620 #else /* _WIN32 */
621
622 /*
623 On systems which don't support native read/write locks we have
624 to use own implementation.
625 */
626 typedef struct st_my_rw_lock_t {
627 pthread_mutex_t lock; /* lock for structure */
628 pthread_cond_t readers; /* waiting readers */
629 pthread_cond_t writers; /* waiting writers */
630 int state; /* -1:writer,0:free,>0:readers */
631 int waiters; /* number of waiting writers */
632 #ifdef SAFE_MUTEX
633 pthread_t write_thread;
634 #endif
635 } my_rw_lock_t;
636
637 #endif /*! _WIN32 */
638
639 extern int my_rw_init(my_rw_lock_t *);
640 extern int my_rw_destroy(my_rw_lock_t *);
641 extern int my_rw_rdlock(my_rw_lock_t *);
642 extern int my_rw_wrlock(my_rw_lock_t *);
643 extern int my_rw_unlock(my_rw_lock_t *);
644 extern int my_rw_tryrdlock(my_rw_lock_t *);
645 extern int my_rw_trywrlock(my_rw_lock_t *);
646 #ifdef SAFE_MUTEX
647 #define my_rw_lock_assert_write_owner(A) \
648 DBUG_ASSERT((A)->state == -1 && pthread_equal(pthread_self(), \
649 (A)->write_thread))
650 #define my_rw_lock_assert_not_write_owner(A) \
651 DBUG_ASSERT((A)->state >= 0 || ! pthread_equal(pthread_self(), \
652 (A)->write_thread))
653 #else
654 #define my_rw_lock_assert_write_owner(A)
655 #define my_rw_lock_assert_not_write_owner(A)
656 #endif
657 #endif /* NEED_MY_RW_LOCK */
658
659
660 #define GETHOSTBYADDR_BUFF_SIZE 2048
661
662 #ifndef HAVE_THR_SETCONCURRENCY
663 #define thr_setconcurrency(A) pthread_dummy(0)
664 #endif
665 #if !defined(HAVE_PTHREAD_ATTR_SETSTACKSIZE) && ! defined(pthread_attr_setstacksize)
666 #define pthread_attr_setstacksize(A,B) pthread_dummy(0)
667 #endif
668
669 /* Define mutex types, see my_thr_init.c */
670 #define MY_MUTEX_INIT_SLOW NULL
671 #ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
672 extern pthread_mutexattr_t my_fast_mutexattr;
673 #define MY_MUTEX_INIT_FAST &my_fast_mutexattr
674 #else
675 #define MY_MUTEX_INIT_FAST NULL
676 #endif
677 #ifdef PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
678 extern pthread_mutexattr_t my_errorcheck_mutexattr;
679 #define MY_MUTEX_INIT_ERRCHK &my_errorcheck_mutexattr
680 #else
681 #define MY_MUTEX_INIT_ERRCHK NULL
682 #endif
683
684 #ifndef ESRCH
685 /* Define it to something */
686 #define ESRCH 1
687 #endif
688
689 typedef uint64 my_thread_id;
690
691 extern void my_threadattr_global_init(void);
692 extern my_bool my_thread_global_init(void);
693 extern void my_thread_global_reinit(void);
694 extern void my_thread_global_end(void);
695 extern my_bool my_thread_init(void);
696 extern void my_thread_end(void);
697 extern const char *my_thread_name(void);
698 extern my_thread_id my_thread_dbug_id(void);
699 extern int pthread_dummy(int);
700 extern void my_mutex_init(void);
701 extern void my_mutex_end(void);
702
703 /* All thread specific variables are in the following struct */
704
705 #define THREAD_NAME_SIZE 10
706 #ifndef DEFAULT_THREAD_STACK
707 /*
708 We need to have at least 256K stack to handle calls to myisamchk_init()
709 with the current number of keys and key parts.
710 */
711 #if defined(__SANITIZE_ADDRESS__) || defined(WITH_UBSAN)
712 #define DEFAULT_THREAD_STACK (383*1024L) /* 392192 */
713 #else
714 #define DEFAULT_THREAD_STACK (292*1024L) /* 299008 */
715 #endif
716 #endif
717
718 #define MY_PTHREAD_LOCK_READ 0
719 #define MY_PTHREAD_LOCK_WRITE 1
720
721 #include <mysql/psi/mysql_thread.h>
722
723 #define INSTRUMENT_ME 0
724
725 struct st_my_thread_var
726 {
727 int thr_errno;
728 mysql_cond_t suspend;
729 mysql_mutex_t mutex;
730 mysql_mutex_t * volatile current_mutex;
731 mysql_cond_t * volatile current_cond;
732 pthread_t pthread_self;
733 my_thread_id id, dbug_id;
734 int volatile abort;
735 my_bool init;
736 struct st_my_thread_var *next,**prev;
737 void *keycache_link;
738 uint lock_type; /* used by conditional release the queue */
739 void *stack_ends_here;
740 safe_mutex_t *mutex_in_use;
741 #ifndef DBUG_OFF
742 void *dbug;
743 char name[THREAD_NAME_SIZE+1];
744 #endif
745 };
746
747 struct st_my_thread_var *_my_thread_var(void);
748 extern void **my_thread_var_dbug(void);
749 extern safe_mutex_t **my_thread_var_mutex_in_use(void);
750 extern uint my_thread_end_wait_time;
751 extern my_bool safe_mutex_deadlock_detector;
752 #define my_thread_var (_my_thread_var())
753 #define my_errno my_thread_var->thr_errno
754 int set_mysys_var(struct st_my_thread_var *mysys_var);
755 /*
756 Keep track of shutdown,signal, and main threads so that my_end() will not
757 report errors with them
758 */
759
760 /* Which kind of thread library is in use */
761
762 #define THD_LIB_OTHER 1
763 #define THD_LIB_NPTL 2
764 #define THD_LIB_LT 4
765
766 extern uint thd_lib_detected;
767
768 /*
769 thread_safe_xxx functions are for critical statistic or counters.
770 The implementation is guaranteed to be thread safe, on all platforms.
771 Note that the calling code should *not* assume the counter is protected
772 by the mutex given, as the implementation of these helpers may change
773 to use my_atomic operations instead.
774 */
775
776 #ifndef thread_safe_increment
777 #ifdef _WIN32
778 #define thread_safe_increment(V,L) InterlockedIncrement((long*) &(V))
779 #define thread_safe_decrement(V,L) InterlockedDecrement((long*) &(V))
780 #else
781 #define thread_safe_increment(V,L) \
782 (mysql_mutex_lock((L)), (V)++, mysql_mutex_unlock((L)))
783 #define thread_safe_decrement(V,L) \
784 (mysql_mutex_lock((L)), (V)--, mysql_mutex_unlock((L)))
785 #endif
786 #endif
787
788 #ifndef thread_safe_add
789 #ifdef _WIN32
790 #define thread_safe_add(V,C,L) InterlockedExchangeAdd((long*) &(V),(C))
791 #define thread_safe_sub(V,C,L) InterlockedExchangeAdd((long*) &(V),-(long) (C))
792 #else
793 #define thread_safe_add(V,C,L) \
794 (mysql_mutex_lock((L)), (V)+=(C), mysql_mutex_unlock((L)))
795 #define thread_safe_sub(V,C,L) \
796 (mysql_mutex_lock((L)), (V)-=(C), mysql_mutex_unlock((L)))
797 #endif
798 #endif
799
800
801 /*
802 statistics_xxx functions are for non critical statistic,
803 maintained in global variables.
804 When compiling with SAFE_STATISTICS:
805 - race conditions can not occur.
806 - some locking occurs, which may cause performance degradation.
807
808 When compiling without SAFE_STATISTICS:
809 - race conditions can occur, making the result slightly inaccurate.
810 - the lock given is not honored.
811 */
812 #ifdef SAFE_STATISTICS
813 #define statistic_increment(V,L) thread_safe_increment((V),(L))
814 #define statistic_decrement(V,L) thread_safe_decrement((V),(L))
815 #define statistic_add(V,C,L) thread_safe_add((V),(C),(L))
816 #define statistic_sub(V,C,L) thread_safe_sub((V),(C),(L))
817 #else
818 #define statistic_decrement(V,L) (V)--
819 #define statistic_increment(V,L) (V)++
820 #define statistic_add(V,C,L) (V)+=(C)
821 #define statistic_sub(V,C,L) (V)-=(C)
822 #endif /* SAFE_STATISTICS */
823
824 /*
825 No locking needed, the counter is owned by the thread
826 */
827 #define status_var_increment(V) (V)++
828 #define status_var_decrement(V) (V)--
829 #define status_var_add(V,C) (V)+=(C)
830 #define status_var_sub(V,C) (V)-=(C)
831
832 #ifdef SAFE_MUTEX
833 #define mysql_mutex_record_order(A,B) \
834 do { \
835 mysql_mutex_lock(A); mysql_mutex_lock(B); \
836 mysql_mutex_unlock(B); mysql_mutex_unlock(A); \
837 } while(0)
838 #else
839 #define mysql_mutex_record_order(A,B) do { } while(0)
840 #endif
841
842 /* At least Windows and NetBSD do not have this definition */
843 #ifndef PTHREAD_STACK_MIN
844 #define PTHREAD_STACK_MIN 65536
845 #endif
846
847 #ifdef __cplusplus
848 }
849 #endif
850 #endif /* _my_ptread_h */
851