1 /**
2 * threads.c: set of generic threading related routines
3 *
4 * See Copyright for the status of this software.
5 *
6 * Gary Pennington <Gary.Pennington@uk.sun.com>
7 * daniel@veillard.com
8 */
9
10 #define IN_LIBXML
11 #include "libxml.h"
12
13 #include <string.h>
14
15 #include <libxml/threads.h>
16 #include <libxml/globals.h>
17
18 #ifdef HAVE_SYS_TYPES_H
19 #include <sys/types.h>
20 #endif
21 #ifdef HAVE_UNISTD_H
22 #include <unistd.h>
23 #endif
24 #ifdef HAVE_STDLIB_H
25 #include <stdlib.h>
26 #endif
27 #ifdef HAVE_PTHREAD_H
28 #include <pthread.h>
29 #elif defined HAVE_WIN32_THREADS
30 #include <windows.h>
31 #ifndef HAVE_COMPILER_TLS
32 #include <process.h>
33 #endif
34 #endif
35
36 #ifdef HAVE_BEOS_THREADS
37 #include <OS.h>
38 #include <TLS.h>
39 #endif
40
41 #if defined(SOLARIS)
42 #include <note.h>
43 #endif
44
45 /* #define DEBUG_THREADS */
46
47 #ifdef HAVE_PTHREAD_H
48
49 static int libxml_is_threaded = -1;
50 #ifdef __GNUC__
51 #ifdef linux
52 #if (__GNUC__ == 3 && __GNUC_MINOR__ >= 3) || (__GNUC__ > 3)
53 extern int pthread_once (pthread_once_t *__once_control,
54 void (*__init_routine) (void))
55 __attribute((weak));
56 extern void *pthread_getspecific (pthread_key_t __key)
57 __attribute((weak));
58 extern int pthread_setspecific (pthread_key_t __key,
59 __const void *__pointer)
60 __attribute((weak));
61 extern int pthread_key_create (pthread_key_t *__key,
62 void (*__destr_function) (void *))
63 __attribute((weak));
64 extern int pthread_key_delete (pthread_key_t __key)
65 __attribute((weak));
66 extern int pthread_mutex_init ()
67 __attribute((weak));
68 extern int pthread_mutex_destroy ()
69 __attribute((weak));
70 extern int pthread_mutex_lock ()
71 __attribute((weak));
72 extern int pthread_mutex_unlock ()
73 __attribute((weak));
74 extern int pthread_cond_init ()
75 __attribute((weak));
76 extern int pthread_cond_destroy ()
77 __attribute((weak));
78 extern int pthread_cond_wait ()
79 __attribute((weak));
80 extern int pthread_equal ()
81 __attribute((weak));
82 extern pthread_t pthread_self ()
83 __attribute((weak));
84 extern int pthread_key_create ()
85 __attribute((weak));
86 extern int pthread_key_delete ()
87 __attribute((weak));
88 extern int pthread_cond_signal ()
89 __attribute((weak));
90 #endif
91 #endif /* linux */
92 #endif /* __GNUC__ */
93 #endif /* HAVE_PTHREAD_H */
94
95 /*
96 * TODO: this module still uses malloc/free and not xmlMalloc/xmlFree
97 * to avoid some crazyness since xmlMalloc/xmlFree may actually
98 * be hosted on allocated blocks needing them for the allocation ...
99 */
100
101 /*
102 * xmlMutex are a simple mutual exception locks
103 */
104 struct _xmlMutex {
105 #ifdef HAVE_PTHREAD_H
106 pthread_mutex_t lock;
107 #elif defined HAVE_WIN32_THREADS
108 HANDLE mutex;
109 #elif defined HAVE_BEOS_THREADS
110 sem_id sem;
111 thread_id tid;
112 #else
113 int empty;
114 #endif
115 };
116
117 /*
118 * xmlRMutex are reentrant mutual exception locks
119 */
120 struct _xmlRMutex {
121 #ifdef HAVE_PTHREAD_H
122 pthread_mutex_t lock;
123 unsigned int held;
124 unsigned int waiters;
125 pthread_t tid;
126 pthread_cond_t cv;
127 #elif defined HAVE_WIN32_THREADS
128 CRITICAL_SECTION cs;
129 unsigned int count;
130 #elif defined HAVE_BEOS_THREADS
131 xmlMutexPtr lock;
132 thread_id tid;
133 int32 count;
134 #else
135 int empty;
136 #endif
137 };
138
139 /*
140 * This module still has some internal static data.
141 * - xmlLibraryLock a global lock
142 * - globalkey used for per-thread data
143 */
144
145 #ifdef HAVE_PTHREAD_H
146 static pthread_key_t globalkey;
147 static pthread_t mainthread;
148 static pthread_once_t once_control = PTHREAD_ONCE_INIT;
149 static pthread_mutex_t global_init_lock = PTHREAD_MUTEX_INITIALIZER;
150 #elif defined HAVE_WIN32_THREADS
151 #if defined(HAVE_COMPILER_TLS)
152 static __declspec(thread) xmlGlobalState tlstate;
153 static __declspec(thread) int tlstate_inited = 0;
154 #else /* HAVE_COMPILER_TLS */
155 static DWORD globalkey = TLS_OUT_OF_INDEXES;
156 #endif /* HAVE_COMPILER_TLS */
157 static DWORD mainthread;
158 static struct {
159 DWORD done;
160 DWORD control;
161 } run_once = { 0, 0};
162 static volatile LPCRITICAL_SECTION global_init_lock = NULL;
163
164 /* endif HAVE_WIN32_THREADS */
165 #elif defined HAVE_BEOS_THREADS
166 int32 globalkey = 0;
167 thread_id mainthread = 0;
168 int32 run_once_init = 0;
169 static int32 global_init_lock = -1;
170 static vint32 global_init_count = 0;
171 #endif
172
173 static xmlRMutexPtr xmlLibraryLock = NULL;
174
175 #ifdef LIBXML_THREAD_ENABLED
176 static void xmlOnceInit(void);
177 #endif
178
179 /**
180 * xmlNewMutex:
181 *
182 * xmlNewMutex() is used to allocate a libxml2 token struct for use in
183 * synchronizing access to data.
184 *
185 * Returns a new simple mutex pointer or NULL in case of error
186 */
187 xmlMutexPtr
xmlNewMutex(void)188 xmlNewMutex(void)
189 {
190 xmlMutexPtr tok;
191
192 if ((tok = malloc(sizeof(xmlMutex))) == NULL)
193 return (NULL);
194 #ifdef HAVE_PTHREAD_H
195 if (libxml_is_threaded != 0)
196 pthread_mutex_init(&tok->lock, NULL);
197 #elif defined HAVE_WIN32_THREADS
198 tok->mutex = CreateMutex(NULL, FALSE, NULL);
199 #elif defined HAVE_BEOS_THREADS
200 if ((tok->sem = create_sem(1, "xmlMutex")) < B_OK) {
201 free(tok);
202 return NULL;
203 }
204 tok->tid = -1;
205 #endif
206 return (tok);
207 }
208
209 /**
210 * xmlFreeMutex:
211 * @tok: the simple mutex
212 *
213 * xmlFreeMutex() is used to reclaim resources associated with a libxml2 token
214 * struct.
215 */
216 void
xmlFreeMutex(xmlMutexPtr tok)217 xmlFreeMutex(xmlMutexPtr tok)
218 {
219 if (tok == NULL)
220 return;
221
222 #ifdef HAVE_PTHREAD_H
223 if (libxml_is_threaded != 0)
224 pthread_mutex_destroy(&tok->lock);
225 #elif defined HAVE_WIN32_THREADS
226 CloseHandle(tok->mutex);
227 #elif defined HAVE_BEOS_THREADS
228 delete_sem(tok->sem);
229 #endif
230 free(tok);
231 }
232
233 /**
234 * xmlMutexLock:
235 * @tok: the simple mutex
236 *
237 * xmlMutexLock() is used to lock a libxml2 token.
238 */
239 void
xmlMutexLock(xmlMutexPtr tok)240 xmlMutexLock(xmlMutexPtr tok)
241 {
242 if (tok == NULL)
243 return;
244 #ifdef HAVE_PTHREAD_H
245 if (libxml_is_threaded != 0)
246 pthread_mutex_lock(&tok->lock);
247 #elif defined HAVE_WIN32_THREADS
248 WaitForSingleObject(tok->mutex, INFINITE);
249 #elif defined HAVE_BEOS_THREADS
250 if (acquire_sem(tok->sem) != B_NO_ERROR) {
251 #ifdef DEBUG_THREADS
252 xmlGenericError(xmlGenericErrorContext,
253 "xmlMutexLock():BeOS:Couldn't aquire semaphore\n");
254 exit();
255 #endif
256 }
257 tok->tid = find_thread(NULL);
258 #endif
259
260 }
261
262 /**
263 * xmlMutexUnlock:
264 * @tok: the simple mutex
265 *
266 * xmlMutexUnlock() is used to unlock a libxml2 token.
267 */
268 void
xmlMutexUnlock(xmlMutexPtr tok)269 xmlMutexUnlock(xmlMutexPtr tok)
270 {
271 if (tok == NULL)
272 return;
273 #ifdef HAVE_PTHREAD_H
274 if (libxml_is_threaded != 0)
275 pthread_mutex_unlock(&tok->lock);
276 #elif defined HAVE_WIN32_THREADS
277 ReleaseMutex(tok->mutex);
278 #elif defined HAVE_BEOS_THREADS
279 if (tok->tid == find_thread(NULL)) {
280 tok->tid = -1;
281 release_sem(tok->sem);
282 }
283 #endif
284 }
285
286 /**
287 * xmlNewRMutex:
288 *
289 * xmlRNewMutex() is used to allocate a reentrant mutex for use in
290 * synchronizing access to data. token_r is a re-entrant lock and thus useful
291 * for synchronizing access to data structures that may be manipulated in a
292 * recursive fashion.
293 *
294 * Returns the new reentrant mutex pointer or NULL in case of error
295 */
296 xmlRMutexPtr
xmlNewRMutex(void)297 xmlNewRMutex(void)
298 {
299 xmlRMutexPtr tok;
300
301 if ((tok = malloc(sizeof(xmlRMutex))) == NULL)
302 return (NULL);
303 #ifdef HAVE_PTHREAD_H
304 if (libxml_is_threaded != 0) {
305 pthread_mutex_init(&tok->lock, NULL);
306 tok->held = 0;
307 tok->waiters = 0;
308 pthread_cond_init(&tok->cv, NULL);
309 }
310 #elif defined HAVE_WIN32_THREADS
311 InitializeCriticalSection(&tok->cs);
312 tok->count = 0;
313 #elif defined HAVE_BEOS_THREADS
314 if ((tok->lock = xmlNewMutex()) == NULL) {
315 free(tok);
316 return NULL;
317 }
318 tok->count = 0;
319 #endif
320 return (tok);
321 }
322
323 /**
324 * xmlFreeRMutex:
325 * @tok: the reentrant mutex
326 *
327 * xmlRFreeMutex() is used to reclaim resources associated with a
328 * reentrant mutex.
329 */
330 void
xmlFreeRMutex(xmlRMutexPtr tok ATTRIBUTE_UNUSED)331 xmlFreeRMutex(xmlRMutexPtr tok ATTRIBUTE_UNUSED)
332 {
333 if (tok == NULL)
334 return;
335 #ifdef HAVE_PTHREAD_H
336 if (libxml_is_threaded != 0) {
337 pthread_mutex_destroy(&tok->lock);
338 pthread_cond_destroy(&tok->cv);
339 }
340 #elif defined HAVE_WIN32_THREADS
341 DeleteCriticalSection(&tok->cs);
342 #elif defined HAVE_BEOS_THREADS
343 xmlFreeMutex(tok->lock);
344 #endif
345 free(tok);
346 }
347
348 /**
349 * xmlRMutexLock:
350 * @tok: the reentrant mutex
351 *
352 * xmlRMutexLock() is used to lock a libxml2 token_r.
353 */
354 void
xmlRMutexLock(xmlRMutexPtr tok)355 xmlRMutexLock(xmlRMutexPtr tok)
356 {
357 if (tok == NULL)
358 return;
359 #ifdef HAVE_PTHREAD_H
360 if (libxml_is_threaded == 0)
361 return;
362
363 pthread_mutex_lock(&tok->lock);
364 if (tok->held) {
365 if (pthread_equal(tok->tid, pthread_self())) {
366 tok->held++;
367 pthread_mutex_unlock(&tok->lock);
368 return;
369 } else {
370 tok->waiters++;
371 while (tok->held)
372 pthread_cond_wait(&tok->cv, &tok->lock);
373 tok->waiters--;
374 }
375 }
376 tok->tid = pthread_self();
377 tok->held = 1;
378 pthread_mutex_unlock(&tok->lock);
379 #elif defined HAVE_WIN32_THREADS
380 EnterCriticalSection(&tok->cs);
381 ++tok->count;
382 #elif defined HAVE_BEOS_THREADS
383 if (tok->lock->tid == find_thread(NULL)) {
384 tok->count++;
385 return;
386 } else {
387 xmlMutexLock(tok->lock);
388 tok->count = 1;
389 }
390 #endif
391 }
392
393 /**
394 * xmlRMutexUnlock:
395 * @tok: the reentrant mutex
396 *
397 * xmlRMutexUnlock() is used to unlock a libxml2 token_r.
398 */
399 void
xmlRMutexUnlock(xmlRMutexPtr tok ATTRIBUTE_UNUSED)400 xmlRMutexUnlock(xmlRMutexPtr tok ATTRIBUTE_UNUSED)
401 {
402 if (tok == NULL)
403 return;
404 #ifdef HAVE_PTHREAD_H
405 if (libxml_is_threaded == 0)
406 return;
407
408 pthread_mutex_lock(&tok->lock);
409 tok->held--;
410 if (tok->held == 0) {
411 if (tok->waiters)
412 pthread_cond_signal(&tok->cv);
413 memset(&tok->tid, 0, sizeof(tok->tid));
414 }
415 pthread_mutex_unlock(&tok->lock);
416 #elif defined HAVE_WIN32_THREADS
417 if (!--tok->count)
418 LeaveCriticalSection(&tok->cs);
419 #elif defined HAVE_BEOS_THREADS
420 if (tok->lock->tid == find_thread(NULL)) {
421 tok->count--;
422 if (tok->count == 0) {
423 xmlMutexUnlock(tok->lock);
424 }
425 return;
426 }
427 #endif
428 }
429
430 /**
431 * xmlGlobalInitMutexLock
432 *
433 * Makes sure that the global initialization mutex is initialized and
434 * locks it.
435 */
436 void
__xmlGlobalInitMutexLock(void)437 __xmlGlobalInitMutexLock(void)
438 {
439 /* Make sure the global init lock is initialized and then lock it. */
440 #ifdef HAVE_PTHREAD_H
441 /* The mutex is statically initialized, so we just lock it. */
442 if (pthread_mutex_lock)
443 pthread_mutex_lock(&global_init_lock);
444 #elif defined HAVE_WIN32_THREADS
445 LPCRITICAL_SECTION cs;
446
447 /* Create a new critical section */
448 if (global_init_lock == NULL) {
449 cs = malloc(sizeof(CRITICAL_SECTION));
450 if (cs == NULL) {
451 xmlGenericError(xmlGenericErrorContext,
452 "xmlGlobalInitMutexLock: out of memory\n");
453 return;
454 }
455 InitializeCriticalSection(cs);
456
457 /* Swap it into the global_init_lock */
458 #ifdef InterlockedCompareExchangePointer
459 InterlockedCompareExchangePointer(&global_init_lock, cs, NULL);
460 #else /* Use older void* version */
461 InterlockedCompareExchange((void **) &global_init_lock,
462 (void *) cs, NULL);
463 #endif /* InterlockedCompareExchangePointer */
464
465 /* If another thread successfully recorded its critical
466 * section in the global_init_lock then discard the one
467 * allocated by this thread. */
468 if (global_init_lock != cs) {
469 DeleteCriticalSection(cs);
470 free(cs);
471 }
472 }
473
474 /* Lock the chosen critical section */
475 EnterCriticalSection(global_init_lock);
476 #elif defined HAVE_BEOS_THREADS
477 int32 sem;
478
479 /* Allocate a new semaphore */
480 sem = create_sem(1, "xmlGlobalinitMutex");
481
482 while (global_init_lock == -1) {
483 if (atomic_add(&global_init_count, 1) == 0) {
484 global_init_lock = sem;
485 } else {
486 snooze(1);
487 atomic_add(&global_init_count, -1);
488 }
489 }
490
491 /* If another thread successfully recorded its critical
492 * section in the global_init_lock then discard the one
493 * allocated by this thread. */
494 if (global_init_lock != sem)
495 delete_sem(sem);
496
497 /* Acquire the chosen semaphore */
498 if (acquire_sem(global_init_lock) != B_NO_ERROR) {
499 #ifdef DEBUG_THREADS
500 xmlGenericError(xmlGenericErrorContext,
501 "xmlGlobalInitMutexLock():BeOS:Couldn't acquire semaphore\n");
502 exit();
503 #endif
504 }
505 #endif
506 }
507
508 void
__xmlGlobalInitMutexUnlock(void)509 __xmlGlobalInitMutexUnlock(void)
510 {
511 #ifdef HAVE_PTHREAD_H
512 if (pthread_mutex_unlock)
513 pthread_mutex_unlock(&global_init_lock);
514 #elif defined HAVE_WIN32_THREADS
515 if (global_init_lock != NULL) {
516 LeaveCriticalSection(global_init_lock);
517 }
518 #elif defined HAVE_BEOS_THREADS
519 release_sem(global_init_lock);
520 #endif
521 }
522
523 /**
524 * xmlGlobalInitMutexDestroy
525 *
526 * Makes sure that the global initialization mutex is destroyed before
527 * application termination.
528 */
529 void
__xmlGlobalInitMutexDestroy(void)530 __xmlGlobalInitMutexDestroy(void)
531 {
532 #ifdef HAVE_PTHREAD_H
533 #elif defined HAVE_WIN32_THREADS
534 if (global_init_lock != NULL) {
535 DeleteCriticalSection(global_init_lock);
536 free(global_init_lock);
537 global_init_lock = NULL;
538 }
539 #endif
540 }
541
542 /************************************************************************
543 * *
544 * Per thread global state handling *
545 * *
546 ************************************************************************/
547
548 #ifdef LIBXML_THREAD_ENABLED
549 #ifdef xmlLastError
550 #undef xmlLastError
551 #endif
552
553 /**
554 * xmlFreeGlobalState:
555 * @state: a thread global state
556 *
557 * xmlFreeGlobalState() is called when a thread terminates with a non-NULL
558 * global state. It is is used here to reclaim memory resources.
559 */
560 static void
xmlFreeGlobalState(void * state)561 xmlFreeGlobalState(void *state)
562 {
563 xmlGlobalState *gs = (xmlGlobalState *) state;
564
565 /* free any memory allocated in the thread's xmlLastError */
566 xmlResetError(&(gs->xmlLastError));
567 free(state);
568 }
569
570 /**
571 * xmlNewGlobalState:
572 *
573 * xmlNewGlobalState() allocates a global state. This structure is used to
574 * hold all data for use by a thread when supporting backwards compatibility
575 * of libxml2 to pre-thread-safe behaviour.
576 *
577 * Returns the newly allocated xmlGlobalStatePtr or NULL in case of error
578 */
579 static xmlGlobalStatePtr
xmlNewGlobalState(void)580 xmlNewGlobalState(void)
581 {
582 xmlGlobalState *gs;
583
584 gs = malloc(sizeof(xmlGlobalState));
585 if (gs == NULL) {
586 xmlGenericError(xmlGenericErrorContext,
587 "xmlGetGlobalState: out of memory\n");
588 return (NULL);
589 }
590
591 memset(gs, 0, sizeof(xmlGlobalState));
592 xmlInitializeGlobalState(gs);
593 return (gs);
594 }
595 #endif /* LIBXML_THREAD_ENABLED */
596
597 #ifdef HAVE_PTHREAD_H
598 #elif defined HAVE_WIN32_THREADS
599 #if !defined(HAVE_COMPILER_TLS)
600 #if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
601 typedef struct _xmlGlobalStateCleanupHelperParams {
602 HANDLE thread;
603 void *memory;
604 } xmlGlobalStateCleanupHelperParams;
605
606 static void XMLCDECL
xmlGlobalStateCleanupHelper(void * p)607 xmlGlobalStateCleanupHelper(void *p)
608 {
609 xmlGlobalStateCleanupHelperParams *params =
610 (xmlGlobalStateCleanupHelperParams *) p;
611 WaitForSingleObject(params->thread, INFINITE);
612 CloseHandle(params->thread);
613 xmlFreeGlobalState(params->memory);
614 free(params);
615 _endthread();
616 }
617 #else /* LIBXML_STATIC && !LIBXML_STATIC_FOR_DLL */
618
619 typedef struct _xmlGlobalStateCleanupHelperParams {
620 void *memory;
621 struct _xmlGlobalStateCleanupHelperParams *prev;
622 struct _xmlGlobalStateCleanupHelperParams *next;
623 } xmlGlobalStateCleanupHelperParams;
624
625 static xmlGlobalStateCleanupHelperParams *cleanup_helpers_head = NULL;
626 static CRITICAL_SECTION cleanup_helpers_cs;
627
628 #endif /* LIBXMLSTATIC && !LIBXML_STATIC_FOR_DLL */
629 #endif /* HAVE_COMPILER_TLS */
630 #endif /* HAVE_WIN32_THREADS */
631
632 #if defined HAVE_BEOS_THREADS
633
634 /**
635 * xmlGlobalStateCleanup:
636 * @data: unused parameter
637 *
638 * Used for Beos only
639 */
640 void
xmlGlobalStateCleanup(void * data)641 xmlGlobalStateCleanup(void *data)
642 {
643 void *globalval = tls_get(globalkey);
644
645 if (globalval != NULL)
646 xmlFreeGlobalState(globalval);
647 }
648 #endif
649
650 /**
651 * xmlGetGlobalState:
652 *
653 * xmlGetGlobalState() is called to retrieve the global state for a thread.
654 *
655 * Returns the thread global state or NULL in case of error
656 */
657 xmlGlobalStatePtr
xmlGetGlobalState(void)658 xmlGetGlobalState(void)
659 {
660 #ifdef HAVE_PTHREAD_H
661 xmlGlobalState *globalval;
662
663 if (libxml_is_threaded == 0)
664 return (NULL);
665
666 pthread_once(&once_control, xmlOnceInit);
667
668 if ((globalval = (xmlGlobalState *)
669 pthread_getspecific(globalkey)) == NULL) {
670 xmlGlobalState *tsd = xmlNewGlobalState();
671 if (tsd == NULL)
672 return(NULL);
673
674 pthread_setspecific(globalkey, tsd);
675 return (tsd);
676 }
677 return (globalval);
678 #elif defined HAVE_WIN32_THREADS
679 #if defined(HAVE_COMPILER_TLS)
680 if (!tlstate_inited) {
681 tlstate_inited = 1;
682 xmlInitializeGlobalState(&tlstate);
683 }
684 return &tlstate;
685 #else /* HAVE_COMPILER_TLS */
686 xmlGlobalState *globalval;
687 xmlGlobalStateCleanupHelperParams *p;
688
689 xmlOnceInit();
690 #if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
691 globalval = (xmlGlobalState *) TlsGetValue(globalkey);
692 #else
693 p = (xmlGlobalStateCleanupHelperParams *) TlsGetValue(globalkey);
694 globalval = (xmlGlobalState *) (p ? p->memory : NULL);
695 #endif
696 if (globalval == NULL) {
697 xmlGlobalState *tsd = xmlNewGlobalState();
698
699 if (tsd == NULL)
700 return(NULL);
701 p = (xmlGlobalStateCleanupHelperParams *)
702 malloc(sizeof(xmlGlobalStateCleanupHelperParams));
703 if (p == NULL) {
704 xmlGenericError(xmlGenericErrorContext,
705 "xmlGetGlobalState: out of memory\n");
706 xmlFreeGlobalState(tsd);
707 return(NULL);
708 }
709 p->memory = tsd;
710 #if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
711 DuplicateHandle(GetCurrentProcess(), GetCurrentThread(),
712 GetCurrentProcess(), &p->thread, 0, TRUE,
713 DUPLICATE_SAME_ACCESS);
714 TlsSetValue(globalkey, tsd);
715 _beginthread(xmlGlobalStateCleanupHelper, 0, p);
716 #else
717 EnterCriticalSection(&cleanup_helpers_cs);
718 if (cleanup_helpers_head != NULL) {
719 cleanup_helpers_head->prev = p;
720 }
721 p->next = cleanup_helpers_head;
722 p->prev = NULL;
723 cleanup_helpers_head = p;
724 TlsSetValue(globalkey, p);
725 LeaveCriticalSection(&cleanup_helpers_cs);
726 #endif
727
728 return (tsd);
729 }
730 return (globalval);
731 #endif /* HAVE_COMPILER_TLS */
732 #elif defined HAVE_BEOS_THREADS
733 xmlGlobalState *globalval;
734
735 xmlOnceInit();
736
737 if ((globalval = (xmlGlobalState *) tls_get(globalkey)) == NULL) {
738 xmlGlobalState *tsd = xmlNewGlobalState();
739 if (tsd == NULL)
740 return (NULL);
741
742 tls_set(globalkey, tsd);
743 on_exit_thread(xmlGlobalStateCleanup, NULL);
744 return (tsd);
745 }
746 return (globalval);
747 #else
748 return (NULL);
749 #endif
750 }
751
752 /************************************************************************
753 * *
754 * Library wide thread interfaces *
755 * *
756 ************************************************************************/
757
758 /**
759 * xmlGetThreadId:
760 *
761 * xmlGetThreadId() find the current thread ID number
762 * Note that this is likely to be broken on some platforms using pthreads
763 * as the specification doesn't mandate pthread_t to be an integer type
764 *
765 * Returns the current thread ID number
766 */
767 int
xmlGetThreadId(void)768 xmlGetThreadId(void)
769 {
770 #ifdef HAVE_PTHREAD_H
771 pthread_t id;
772 int ret;
773
774 if (libxml_is_threaded == 0)
775 return (0);
776 id = pthread_self();
777 /* horrible but preserves compat, see warning above */
778 memcpy(&ret, &id, sizeof(ret));
779 return (ret);
780 #elif defined HAVE_WIN32_THREADS
781 return GetCurrentThreadId();
782 #elif defined HAVE_BEOS_THREADS
783 return find_thread(NULL);
784 #else
785 return ((int) 0);
786 #endif
787 }
788
789 /**
790 * xmlIsMainThread:
791 *
792 * xmlIsMainThread() check whether the current thread is the main thread.
793 *
794 * Returns 1 if the current thread is the main thread, 0 otherwise
795 */
796 int
xmlIsMainThread(void)797 xmlIsMainThread(void)
798 {
799 #ifdef HAVE_PTHREAD_H
800 if (libxml_is_threaded == -1)
801 xmlInitThreads();
802 if (libxml_is_threaded == 0)
803 return (1);
804 pthread_once(&once_control, xmlOnceInit);
805 #elif defined HAVE_WIN32_THREADS
806 xmlOnceInit();
807 #elif defined HAVE_BEOS_THREADS
808 xmlOnceInit();
809 #endif
810
811 #ifdef DEBUG_THREADS
812 xmlGenericError(xmlGenericErrorContext, "xmlIsMainThread()\n");
813 #endif
814 #ifdef HAVE_PTHREAD_H
815 return (pthread_equal(mainthread,pthread_self()));
816 #elif defined HAVE_WIN32_THREADS
817 return (mainthread == GetCurrentThreadId());
818 #elif defined HAVE_BEOS_THREADS
819 return (mainthread == find_thread(NULL));
820 #else
821 return (1);
822 #endif
823 }
824
825 /**
826 * xmlLockLibrary:
827 *
828 * xmlLockLibrary() is used to take out a re-entrant lock on the libxml2
829 * library.
830 */
831 void
xmlLockLibrary(void)832 xmlLockLibrary(void)
833 {
834 #ifdef DEBUG_THREADS
835 xmlGenericError(xmlGenericErrorContext, "xmlLockLibrary()\n");
836 #endif
837 xmlRMutexLock(xmlLibraryLock);
838 }
839
840 /**
841 * xmlUnlockLibrary:
842 *
843 * xmlUnlockLibrary() is used to release a re-entrant lock on the libxml2
844 * library.
845 */
846 void
xmlUnlockLibrary(void)847 xmlUnlockLibrary(void)
848 {
849 #ifdef DEBUG_THREADS
850 xmlGenericError(xmlGenericErrorContext, "xmlUnlockLibrary()\n");
851 #endif
852 xmlRMutexUnlock(xmlLibraryLock);
853 }
854
855 /**
856 * xmlInitThreads:
857 *
858 * xmlInitThreads() is used to to initialize all the thread related
859 * data of the libxml2 library.
860 */
861 void
xmlInitThreads(void)862 xmlInitThreads(void)
863 {
864 #ifdef HAVE_PTHREAD_H
865 if (libxml_is_threaded == -1) {
866 if ((pthread_once != NULL) &&
867 (pthread_getspecific != NULL) &&
868 (pthread_setspecific != NULL) &&
869 (pthread_key_create != NULL) &&
870 (pthread_key_delete != NULL) &&
871 (pthread_mutex_init != NULL) &&
872 (pthread_mutex_destroy != NULL) &&
873 (pthread_mutex_lock != NULL) &&
874 (pthread_mutex_unlock != NULL) &&
875 (pthread_cond_init != NULL) &&
876 (pthread_cond_destroy != NULL) &&
877 (pthread_cond_wait != NULL) &&
878 (pthread_equal != NULL) &&
879 (pthread_self != NULL) &&
880 (pthread_cond_signal != NULL)) {
881 libxml_is_threaded = 1;
882
883 /* fprintf(stderr, "Running multithreaded\n"); */
884 } else {
885
886 /* fprintf(stderr, "Running without multithread\n"); */
887 libxml_is_threaded = 0;
888 }
889 }
890 #elif defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
891 InitializeCriticalSection(&cleanup_helpers_cs);
892 #endif
893 }
894
895 /**
896 * xmlCleanupThreads:
897 *
898 * xmlCleanupThreads() is used to to cleanup all the thread related
899 * data of the libxml2 library once processing has ended.
900 *
901 * WARNING: if your application is multithreaded or has plugin support
902 * calling this may crash the application if another thread or
903 * a plugin is still using libxml2. It's sometimes very hard to
904 * guess if libxml2 is in use in the application, some libraries
905 * or plugins may use it without notice. In case of doubt abstain
906 * from calling this function or do it just before calling exit()
907 * to avoid leak reports from valgrind !
908 */
909 void
xmlCleanupThreads(void)910 xmlCleanupThreads(void)
911 {
912 #ifdef DEBUG_THREADS
913 xmlGenericError(xmlGenericErrorContext, "xmlCleanupThreads()\n");
914 #endif
915 #ifdef HAVE_PTHREAD_H
916 if ((libxml_is_threaded) && (pthread_key_delete != NULL))
917 pthread_key_delete(globalkey);
918 #elif defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
919 if (globalkey != TLS_OUT_OF_INDEXES) {
920 xmlGlobalStateCleanupHelperParams *p;
921
922 EnterCriticalSection(&cleanup_helpers_cs);
923 p = cleanup_helpers_head;
924 while (p != NULL) {
925 xmlGlobalStateCleanupHelperParams *temp = p;
926
927 p = p->next;
928 xmlFreeGlobalState(temp->memory);
929 free(temp);
930 }
931 cleanup_helpers_head = 0;
932 LeaveCriticalSection(&cleanup_helpers_cs);
933 TlsFree(globalkey);
934 globalkey = TLS_OUT_OF_INDEXES;
935 }
936 DeleteCriticalSection(&cleanup_helpers_cs);
937 #endif
938 }
939
940 #ifdef LIBXML_THREAD_ENABLED
941
942 /**
943 * xmlOnceInit
944 *
945 * xmlOnceInit() is used to initialize the value of mainthread for use
946 * in other routines. This function should only be called using
947 * pthread_once() in association with the once_control variable to ensure
948 * that the function is only called once. See man pthread_once for more
949 * details.
950 */
951 static void
xmlOnceInit(void)952 xmlOnceInit(void)
953 {
954 #ifdef HAVE_PTHREAD_H
955 (void) pthread_key_create(&globalkey, xmlFreeGlobalState);
956 mainthread = pthread_self();
957 #elif defined(HAVE_WIN32_THREADS)
958 if (!run_once.done) {
959 if (InterlockedIncrement(&run_once.control) == 1) {
960 #if !defined(HAVE_COMPILER_TLS)
961 globalkey = TlsAlloc();
962 #endif
963 mainthread = GetCurrentThreadId();
964 run_once.done = 1;
965 } else {
966 /* Another thread is working; give up our slice and
967 * wait until they're done. */
968 while (!run_once.done)
969 Sleep(0);
970 }
971 }
972 #elif defined HAVE_BEOS_THREADS
973 if (atomic_add(&run_once_init, 1) == 0) {
974 globalkey = tls_allocate();
975 tls_set(globalkey, NULL);
976 mainthread = find_thread(NULL);
977 } else
978 atomic_add(&run_once_init, -1);
979 #endif
980 }
981 #endif
982
983 /**
984 * DllMain:
985 * @hinstDLL: handle to DLL instance
986 * @fdwReason: Reason code for entry
987 * @lpvReserved: generic pointer (depends upon reason code)
988 *
989 * Entry point for Windows library. It is being used to free thread-specific
990 * storage.
991 *
992 * Returns TRUE always
993 */
994 #ifdef HAVE_PTHREAD_H
995 #elif defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
996 #if defined(LIBXML_STATIC_FOR_DLL)
997 BOOL XMLCALL
xmlDllMain(HINSTANCE hinstDLL,DWORD fdwReason,LPVOID lpvReserved)998 xmlDllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
999 #else
1000 BOOL WINAPI
1001 DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
1002 #endif
1003 {
1004 switch (fdwReason) {
1005 case DLL_THREAD_DETACH:
1006 if (globalkey != TLS_OUT_OF_INDEXES) {
1007 xmlGlobalState *globalval = NULL;
1008 xmlGlobalStateCleanupHelperParams *p =
1009 (xmlGlobalStateCleanupHelperParams *)
1010 TlsGetValue(globalkey);
1011 globalval = (xmlGlobalState *) (p ? p->memory : NULL);
1012 if (globalval) {
1013 xmlFreeGlobalState(globalval);
1014 TlsSetValue(globalkey, NULL);
1015 }
1016 if (p) {
1017 EnterCriticalSection(&cleanup_helpers_cs);
1018 if (p == cleanup_helpers_head)
1019 cleanup_helpers_head = p->next;
1020 else
1021 p->prev->next = p->next;
1022 if (p->next != NULL)
1023 p->next->prev = p->prev;
1024 LeaveCriticalSection(&cleanup_helpers_cs);
1025 free(p);
1026 }
1027 }
1028 break;
1029 }
1030 return TRUE;
1031 }
1032 #endif
1033 #define bottom_threads
1034 #include "elfgcchack.h"
1035