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_once_t once_control_init = PTHREAD_ONCE_INIT;
150 static pthread_mutex_t global_init_lock = PTHREAD_MUTEX_INITIALIZER;
151 #elif defined HAVE_WIN32_THREADS
152 #if defined(HAVE_COMPILER_TLS)
153 static __declspec(thread) xmlGlobalState tlstate;
154 static __declspec(thread) int tlstate_inited = 0;
155 #else /* HAVE_COMPILER_TLS */
156 static DWORD globalkey = TLS_OUT_OF_INDEXES;
157 #endif /* HAVE_COMPILER_TLS */
158 static DWORD mainthread;
159 static struct {
160 DWORD done;
161 DWORD control;
162 } run_once = { 0, 0};
163 static volatile LPCRITICAL_SECTION global_init_lock = NULL;
164
165 /* endif HAVE_WIN32_THREADS */
166 #elif defined HAVE_BEOS_THREADS
167 int32 globalkey = 0;
168 thread_id mainthread = 0;
169 int32 run_once_init = 0;
170 static int32 global_init_lock = -1;
171 static vint32 global_init_count = 0;
172 #endif
173
174 static xmlRMutexPtr xmlLibraryLock = NULL;
175
176 #ifdef LIBXML_THREAD_ENABLED
177 static void xmlOnceInit(void);
178 #endif
179
180 /**
181 * xmlNewMutex:
182 *
183 * xmlNewMutex() is used to allocate a libxml2 token struct for use in
184 * synchronizing access to data.
185 *
186 * Returns a new simple mutex pointer or NULL in case of error
187 */
188 xmlMutexPtr
xmlNewMutex(void)189 xmlNewMutex(void)
190 {
191 xmlMutexPtr tok;
192
193 if ((tok = malloc(sizeof(xmlMutex))) == NULL)
194 return (NULL);
195 #ifdef HAVE_PTHREAD_H
196 if (libxml_is_threaded != 0)
197 pthread_mutex_init(&tok->lock, NULL);
198 #elif defined HAVE_WIN32_THREADS
199 tok->mutex = CreateMutex(NULL, FALSE, NULL);
200 #elif defined HAVE_BEOS_THREADS
201 if ((tok->sem = create_sem(1, "xmlMutex")) < B_OK) {
202 free(tok);
203 return NULL;
204 }
205 tok->tid = -1;
206 #endif
207 return (tok);
208 }
209
210 /**
211 * xmlFreeMutex:
212 * @tok: the simple mutex
213 *
214 * xmlFreeMutex() is used to reclaim resources associated with a libxml2 token
215 * struct.
216 */
217 void
xmlFreeMutex(xmlMutexPtr tok)218 xmlFreeMutex(xmlMutexPtr tok)
219 {
220 if (tok == NULL)
221 return;
222
223 #ifdef HAVE_PTHREAD_H
224 if (libxml_is_threaded != 0)
225 pthread_mutex_destroy(&tok->lock);
226 #elif defined HAVE_WIN32_THREADS
227 CloseHandle(tok->mutex);
228 #elif defined HAVE_BEOS_THREADS
229 delete_sem(tok->sem);
230 #endif
231 free(tok);
232 }
233
234 /**
235 * xmlMutexLock:
236 * @tok: the simple mutex
237 *
238 * xmlMutexLock() is used to lock a libxml2 token.
239 */
240 void
xmlMutexLock(xmlMutexPtr tok)241 xmlMutexLock(xmlMutexPtr tok)
242 {
243 if (tok == NULL)
244 return;
245 #ifdef HAVE_PTHREAD_H
246 if (libxml_is_threaded != 0)
247 pthread_mutex_lock(&tok->lock);
248 #elif defined HAVE_WIN32_THREADS
249 WaitForSingleObject(tok->mutex, INFINITE);
250 #elif defined HAVE_BEOS_THREADS
251 if (acquire_sem(tok->sem) != B_NO_ERROR) {
252 #ifdef DEBUG_THREADS
253 xmlGenericError(xmlGenericErrorContext,
254 "xmlMutexLock():BeOS:Couldn't aquire semaphore\n");
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 != NULL)
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 #endif
503 }
504 #endif
505 }
506
507 void
__xmlGlobalInitMutexUnlock(void)508 __xmlGlobalInitMutexUnlock(void)
509 {
510 #ifdef HAVE_PTHREAD_H
511 if (pthread_mutex_unlock != NULL)
512 pthread_mutex_unlock(&global_init_lock);
513 #elif defined HAVE_WIN32_THREADS
514 if (global_init_lock != NULL) {
515 LeaveCriticalSection(global_init_lock);
516 }
517 #elif defined HAVE_BEOS_THREADS
518 release_sem(global_init_lock);
519 #endif
520 }
521
522 /**
523 * xmlGlobalInitMutexDestroy
524 *
525 * Makes sure that the global initialization mutex is destroyed before
526 * application termination.
527 */
528 void
__xmlGlobalInitMutexDestroy(void)529 __xmlGlobalInitMutexDestroy(void)
530 {
531 #ifdef HAVE_PTHREAD_H
532 #elif defined HAVE_WIN32_THREADS
533 if (global_init_lock != NULL) {
534 DeleteCriticalSection(global_init_lock);
535 free(global_init_lock);
536 global_init_lock = NULL;
537 }
538 #endif
539 }
540
541 /************************************************************************
542 * *
543 * Per thread global state handling *
544 * *
545 ************************************************************************/
546
547 #ifdef LIBXML_THREAD_ENABLED
548 #ifdef xmlLastError
549 #undef xmlLastError
550 #endif
551
552 /**
553 * xmlFreeGlobalState:
554 * @state: a thread global state
555 *
556 * xmlFreeGlobalState() is called when a thread terminates with a non-NULL
557 * global state. It is is used here to reclaim memory resources.
558 */
559 static void
xmlFreeGlobalState(void * state)560 xmlFreeGlobalState(void *state)
561 {
562 xmlGlobalState *gs = (xmlGlobalState *) state;
563
564 /* free any memory allocated in the thread's xmlLastError */
565 xmlResetError(&(gs->xmlLastError));
566 free(state);
567 }
568
569 /**
570 * xmlNewGlobalState:
571 *
572 * xmlNewGlobalState() allocates a global state. This structure is used to
573 * hold all data for use by a thread when supporting backwards compatibility
574 * of libxml2 to pre-thread-safe behaviour.
575 *
576 * Returns the newly allocated xmlGlobalStatePtr or NULL in case of error
577 */
578 static xmlGlobalStatePtr
xmlNewGlobalState(void)579 xmlNewGlobalState(void)
580 {
581 xmlGlobalState *gs;
582
583 gs = malloc(sizeof(xmlGlobalState));
584 if (gs == NULL) {
585 xmlGenericError(xmlGenericErrorContext,
586 "xmlGetGlobalState: out of memory\n");
587 return (NULL);
588 }
589
590 memset(gs, 0, sizeof(xmlGlobalState));
591 xmlInitializeGlobalState(gs);
592 return (gs);
593 }
594 #endif /* LIBXML_THREAD_ENABLED */
595
596 #ifdef HAVE_PTHREAD_H
597 #elif defined HAVE_WIN32_THREADS
598 #if !defined(HAVE_COMPILER_TLS)
599 #if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
600 typedef struct _xmlGlobalStateCleanupHelperParams {
601 HANDLE thread;
602 void *memory;
603 } xmlGlobalStateCleanupHelperParams;
604
605 static void XMLCDECL
xmlGlobalStateCleanupHelper(void * p)606 xmlGlobalStateCleanupHelper(void *p)
607 {
608 xmlGlobalStateCleanupHelperParams *params =
609 (xmlGlobalStateCleanupHelperParams *) p;
610 WaitForSingleObject(params->thread, INFINITE);
611 CloseHandle(params->thread);
612 xmlFreeGlobalState(params->memory);
613 free(params);
614 _endthread();
615 }
616 #else /* LIBXML_STATIC && !LIBXML_STATIC_FOR_DLL */
617
618 typedef struct _xmlGlobalStateCleanupHelperParams {
619 void *memory;
620 struct _xmlGlobalStateCleanupHelperParams *prev;
621 struct _xmlGlobalStateCleanupHelperParams *next;
622 } xmlGlobalStateCleanupHelperParams;
623
624 static xmlGlobalStateCleanupHelperParams *cleanup_helpers_head = NULL;
625 static CRITICAL_SECTION cleanup_helpers_cs;
626
627 #endif /* LIBXMLSTATIC && !LIBXML_STATIC_FOR_DLL */
628 #endif /* HAVE_COMPILER_TLS */
629 #endif /* HAVE_WIN32_THREADS */
630
631 #if defined HAVE_BEOS_THREADS
632
633 /**
634 * xmlGlobalStateCleanup:
635 * @data: unused parameter
636 *
637 * Used for Beos only
638 */
639 void
xmlGlobalStateCleanup(void * data)640 xmlGlobalStateCleanup(void *data)
641 {
642 void *globalval = tls_get(globalkey);
643
644 if (globalval != NULL)
645 xmlFreeGlobalState(globalval);
646 }
647 #endif
648
649 /**
650 * xmlGetGlobalState:
651 *
652 * xmlGetGlobalState() is called to retrieve the global state for a thread.
653 *
654 * Returns the thread global state or NULL in case of error
655 */
656 xmlGlobalStatePtr
xmlGetGlobalState(void)657 xmlGetGlobalState(void)
658 {
659 #ifdef HAVE_PTHREAD_H
660 xmlGlobalState *globalval;
661
662 if (libxml_is_threaded == 0)
663 return (NULL);
664
665 pthread_once(&once_control, xmlOnceInit);
666
667 if ((globalval = (xmlGlobalState *)
668 pthread_getspecific(globalkey)) == NULL) {
669 xmlGlobalState *tsd = xmlNewGlobalState();
670 if (tsd == NULL)
671 return(NULL);
672
673 pthread_setspecific(globalkey, tsd);
674 return (tsd);
675 }
676 return (globalval);
677 #elif defined HAVE_WIN32_THREADS
678 #if defined(HAVE_COMPILER_TLS)
679 if (!tlstate_inited) {
680 tlstate_inited = 1;
681 xmlInitializeGlobalState(&tlstate);
682 }
683 return &tlstate;
684 #else /* HAVE_COMPILER_TLS */
685 xmlGlobalState *globalval;
686 xmlGlobalStateCleanupHelperParams *p;
687
688 xmlOnceInit();
689 #if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
690 globalval = (xmlGlobalState *) TlsGetValue(globalkey);
691 #else
692 p = (xmlGlobalStateCleanupHelperParams *) TlsGetValue(globalkey);
693 globalval = (xmlGlobalState *) (p ? p->memory : NULL);
694 #endif
695 if (globalval == NULL) {
696 xmlGlobalState *tsd = xmlNewGlobalState();
697
698 if (tsd == NULL)
699 return(NULL);
700 p = (xmlGlobalStateCleanupHelperParams *)
701 malloc(sizeof(xmlGlobalStateCleanupHelperParams));
702 if (p == NULL) {
703 xmlGenericError(xmlGenericErrorContext,
704 "xmlGetGlobalState: out of memory\n");
705 xmlFreeGlobalState(tsd);
706 return(NULL);
707 }
708 p->memory = tsd;
709 #if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
710 DuplicateHandle(GetCurrentProcess(), GetCurrentThread(),
711 GetCurrentProcess(), &p->thread, 0, TRUE,
712 DUPLICATE_SAME_ACCESS);
713 TlsSetValue(globalkey, tsd);
714 _beginthread(xmlGlobalStateCleanupHelper, 0, p);
715 #else
716 EnterCriticalSection(&cleanup_helpers_cs);
717 if (cleanup_helpers_head != NULL) {
718 cleanup_helpers_head->prev = p;
719 }
720 p->next = cleanup_helpers_head;
721 p->prev = NULL;
722 cleanup_helpers_head = p;
723 TlsSetValue(globalkey, p);
724 LeaveCriticalSection(&cleanup_helpers_cs);
725 #endif
726
727 return (tsd);
728 }
729 return (globalval);
730 #endif /* HAVE_COMPILER_TLS */
731 #elif defined HAVE_BEOS_THREADS
732 xmlGlobalState *globalval;
733
734 xmlOnceInit();
735
736 if ((globalval = (xmlGlobalState *) tls_get(globalkey)) == NULL) {
737 xmlGlobalState *tsd = xmlNewGlobalState();
738 if (tsd == NULL)
739 return (NULL);
740
741 tls_set(globalkey, tsd);
742 on_exit_thread(xmlGlobalStateCleanup, NULL);
743 return (tsd);
744 }
745 return (globalval);
746 #else
747 return (NULL);
748 #endif
749 }
750
751 /************************************************************************
752 * *
753 * Library wide thread interfaces *
754 * *
755 ************************************************************************/
756
757 /**
758 * xmlGetThreadId:
759 *
760 * xmlGetThreadId() find the current thread ID number
761 * Note that this is likely to be broken on some platforms using pthreads
762 * as the specification doesn't mandate pthread_t to be an integer type
763 *
764 * Returns the current thread ID number
765 */
766 int
xmlGetThreadId(void)767 xmlGetThreadId(void)
768 {
769 #ifdef HAVE_PTHREAD_H
770 pthread_t id;
771 int ret;
772
773 if (libxml_is_threaded == 0)
774 return (0);
775 id = pthread_self();
776 /* horrible but preserves compat, see warning above */
777 memcpy(&ret, &id, sizeof(ret));
778 return (ret);
779 #elif defined HAVE_WIN32_THREADS
780 return GetCurrentThreadId();
781 #elif defined HAVE_BEOS_THREADS
782 return find_thread(NULL);
783 #else
784 return ((int) 0);
785 #endif
786 }
787
788 /**
789 * xmlIsMainThread:
790 *
791 * xmlIsMainThread() check whether the current thread is the main thread.
792 *
793 * Returns 1 if the current thread is the main thread, 0 otherwise
794 */
795 int
xmlIsMainThread(void)796 xmlIsMainThread(void)
797 {
798 #ifdef HAVE_PTHREAD_H
799 if (libxml_is_threaded == -1)
800 xmlInitThreads();
801 if (libxml_is_threaded == 0)
802 return (1);
803 pthread_once(&once_control, xmlOnceInit);
804 #elif defined HAVE_WIN32_THREADS
805 xmlOnceInit();
806 #elif defined HAVE_BEOS_THREADS
807 xmlOnceInit();
808 #endif
809
810 #ifdef DEBUG_THREADS
811 xmlGenericError(xmlGenericErrorContext, "xmlIsMainThread()\n");
812 #endif
813 #ifdef HAVE_PTHREAD_H
814 return (pthread_equal(mainthread,pthread_self()));
815 #elif defined HAVE_WIN32_THREADS
816 return (mainthread == GetCurrentThreadId());
817 #elif defined HAVE_BEOS_THREADS
818 return (mainthread == find_thread(NULL));
819 #else
820 return (1);
821 #endif
822 }
823
824 /**
825 * xmlLockLibrary:
826 *
827 * xmlLockLibrary() is used to take out a re-entrant lock on the libxml2
828 * library.
829 */
830 void
xmlLockLibrary(void)831 xmlLockLibrary(void)
832 {
833 #ifdef DEBUG_THREADS
834 xmlGenericError(xmlGenericErrorContext, "xmlLockLibrary()\n");
835 #endif
836 xmlRMutexLock(xmlLibraryLock);
837 }
838
839 /**
840 * xmlUnlockLibrary:
841 *
842 * xmlUnlockLibrary() is used to release a re-entrant lock on the libxml2
843 * library.
844 */
845 void
xmlUnlockLibrary(void)846 xmlUnlockLibrary(void)
847 {
848 #ifdef DEBUG_THREADS
849 xmlGenericError(xmlGenericErrorContext, "xmlUnlockLibrary()\n");
850 #endif
851 xmlRMutexUnlock(xmlLibraryLock);
852 }
853
854 /**
855 * xmlInitThreads:
856 *
857 * xmlInitThreads() is used to to initialize all the thread related
858 * data of the libxml2 library.
859 */
860 void
xmlInitThreads(void)861 xmlInitThreads(void)
862 {
863 #ifdef HAVE_PTHREAD_H
864 if (libxml_is_threaded == -1) {
865 if ((pthread_once != NULL) &&
866 (pthread_getspecific != NULL) &&
867 (pthread_setspecific != NULL) &&
868 (pthread_key_create != NULL) &&
869 (pthread_key_delete != NULL) &&
870 (pthread_mutex_init != NULL) &&
871 (pthread_mutex_destroy != NULL) &&
872 (pthread_mutex_lock != NULL) &&
873 (pthread_mutex_unlock != NULL) &&
874 (pthread_cond_init != NULL) &&
875 (pthread_cond_destroy != NULL) &&
876 (pthread_cond_wait != NULL) &&
877 (pthread_equal != NULL) &&
878 (pthread_self != NULL) &&
879 (pthread_cond_signal != NULL)) {
880 libxml_is_threaded = 1;
881
882 /* fprintf(stderr, "Running multithreaded\n"); */
883 } else {
884
885 /* fprintf(stderr, "Running without multithread\n"); */
886 libxml_is_threaded = 0;
887 }
888 }
889 #elif defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
890 InitializeCriticalSection(&cleanup_helpers_cs);
891 #endif
892 }
893
894 /**
895 * xmlCleanupThreads:
896 *
897 * xmlCleanupThreads() is used to to cleanup all the thread related
898 * data of the libxml2 library once processing has ended.
899 *
900 * WARNING: if your application is multithreaded or has plugin support
901 * calling this may crash the application if another thread or
902 * a plugin is still using libxml2. It's sometimes very hard to
903 * guess if libxml2 is in use in the application, some libraries
904 * or plugins may use it without notice. In case of doubt abstain
905 * from calling this function or do it just before calling exit()
906 * to avoid leak reports from valgrind !
907 */
908 void
xmlCleanupThreads(void)909 xmlCleanupThreads(void)
910 {
911 #ifdef DEBUG_THREADS
912 xmlGenericError(xmlGenericErrorContext, "xmlCleanupThreads()\n");
913 #endif
914 #ifdef HAVE_PTHREAD_H
915 if ((libxml_is_threaded) && (pthread_key_delete != NULL))
916 pthread_key_delete(globalkey);
917 once_control = once_control_init;
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 __xmlInitializeDict();
958 #elif defined(HAVE_WIN32_THREADS)
959 if (!run_once.done) {
960 if (InterlockedIncrement(&run_once.control) == 1) {
961 #if !defined(HAVE_COMPILER_TLS)
962 globalkey = TlsAlloc();
963 #endif
964 mainthread = GetCurrentThreadId();
965 __xmlInitializeDict();
966 run_once.done = 1;
967 } else {
968 /* Another thread is working; give up our slice and
969 * wait until they're done. */
970 while (!run_once.done)
971 Sleep(0);
972 }
973 }
974 #elif defined HAVE_BEOS_THREADS
975 if (atomic_add(&run_once_init, 1) == 0) {
976 globalkey = tls_allocate();
977 tls_set(globalkey, NULL);
978 mainthread = find_thread(NULL);
979 __xmlInitializeDict();
980 } else
981 atomic_add(&run_once_init, -1);
982 #endif
983 }
984 #endif
985
986 /**
987 * DllMain:
988 * @hinstDLL: handle to DLL instance
989 * @fdwReason: Reason code for entry
990 * @lpvReserved: generic pointer (depends upon reason code)
991 *
992 * Entry point for Windows library. It is being used to free thread-specific
993 * storage.
994 *
995 * Returns TRUE always
996 */
997 #ifdef HAVE_PTHREAD_H
998 #elif defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
999 #if defined(LIBXML_STATIC_FOR_DLL)
1000 BOOL XMLCALL
xmlDllMain(HINSTANCE hinstDLL,DWORD fdwReason,LPVOID lpvReserved)1001 xmlDllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
1002 #else
1003 BOOL WINAPI
1004 DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
1005 #endif
1006 {
1007 switch (fdwReason) {
1008 case DLL_THREAD_DETACH:
1009 if (globalkey != TLS_OUT_OF_INDEXES) {
1010 xmlGlobalState *globalval = NULL;
1011 xmlGlobalStateCleanupHelperParams *p =
1012 (xmlGlobalStateCleanupHelperParams *)
1013 TlsGetValue(globalkey);
1014 globalval = (xmlGlobalState *) (p ? p->memory : NULL);
1015 if (globalval) {
1016 xmlFreeGlobalState(globalval);
1017 TlsSetValue(globalkey, NULL);
1018 }
1019 if (p) {
1020 EnterCriticalSection(&cleanup_helpers_cs);
1021 if (p == cleanup_helpers_head)
1022 cleanup_helpers_head = p->next;
1023 else
1024 p->prev->next = p->next;
1025 if (p->next != NULL)
1026 p->next->prev = p->prev;
1027 LeaveCriticalSection(&cleanup_helpers_cs);
1028 free(p);
1029 }
1030 }
1031 break;
1032 }
1033 return TRUE;
1034 }
1035 #endif
1036 #define bottom_threads
1037 #include "elfgcchack.h"
1038