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      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 (at) uk.sun.com>
      7  * daniel (at) 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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
   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