Home | History | Annotate | Download | only in libxml2 
      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_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
    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
    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
    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
    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)
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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