Home | History | Annotate | Download | only in src 
      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     pthread_mutex_lock(&global_init_lock);
    443 #elif defined HAVE_WIN32_THREADS
    444     LPCRITICAL_SECTION cs;
    445 
    446     /* Create a new critical section */
    447     if (global_init_lock == NULL) {
    448         cs = malloc(sizeof(CRITICAL_SECTION));
    449         if (cs == NULL) {
    450             xmlGenericError(xmlGenericErrorContext,
    451                             "xmlGlobalInitMutexLock: out of memory\n");
    452             return;
    453         }
    454         InitializeCriticalSection(cs);
    455 
    456         /* Swap it into the global_init_lock */
    457 #ifdef InterlockedCompareExchangePointer
    458         InterlockedCompareExchangePointer(&global_init_lock, cs, NULL);
    459 #else /* Use older void* version */
    460         InterlockedCompareExchange((void **) &global_init_lock,
    461                                    (void *) cs, NULL);
    462 #endif /* InterlockedCompareExchangePointer */
    463 
    464         /* If another thread successfully recorded its critical
    465          * section in the global_init_lock then discard the one
    466          * allocated by this thread. */
    467         if (global_init_lock != cs) {
    468             DeleteCriticalSection(cs);
    469             free(cs);
    470         }
    471     }
    472 
    473     /* Lock the chosen critical section */
    474     EnterCriticalSection(global_init_lock);
    475 #elif defined HAVE_BEOS_THREADS
    476     int32 sem;
    477 
    478     /* Allocate a new semaphore */
    479     sem = create_sem(1, "xmlGlobalinitMutex");
    480 
    481     while (global_init_lock == -1) {
    482         if (atomic_add(&global_init_count, 1) == 0) {
    483             global_init_lock = sem;
    484         } else {
    485             snooze(1);
    486             atomic_add(&global_init_count, -1);
    487         }
    488     }
    489 
    490     /* If another thread successfully recorded its critical
    491      * section in the global_init_lock then discard the one
    492      * allocated by this thread. */
    493     if (global_init_lock != sem)
    494         delete_sem(sem);
    495 
    496     /* Acquire the chosen semaphore */
    497     if (acquire_sem(global_init_lock) != B_NO_ERROR) {
    498 #ifdef DEBUG_THREADS
    499         xmlGenericError(xmlGenericErrorContext,
    500                         "xmlGlobalInitMutexLock():BeOS:Couldn't acquire semaphore\n");
    501         exit();
    502 #endif
    503     }
    504 #endif
    505 }
    506 
    507 void
    508 __xmlGlobalInitMutexUnlock(void)
    509 {
    510 #ifdef HAVE_PTHREAD_H
    511     pthread_mutex_unlock(&global_init_lock);
    512 #elif defined HAVE_WIN32_THREADS
    513     if (global_init_lock != NULL) {
    514 	LeaveCriticalSection(global_init_lock);
    515     }
    516 #elif defined HAVE_BEOS_THREADS
    517     release_sem(global_init_lock);
    518 #endif
    519 }
    520 
    521 /**
    522  * xmlGlobalInitMutexDestroy
    523  *
    524  * Makes sure that the global initialization mutex is destroyed before
    525  * application termination.
    526  */
    527 void
    528 __xmlGlobalInitMutexDestroy(void)
    529 {
    530 #ifdef HAVE_PTHREAD_H
    531 #elif defined HAVE_WIN32_THREADS
    532     if (global_init_lock != NULL) {
    533         DeleteCriticalSection(global_init_lock);
    534         free(global_init_lock);
    535         global_init_lock = NULL;
    536     }
    537 #endif
    538 }
    539 
    540 /************************************************************************
    541  *									*
    542  *			Per thread global state handling		*
    543  *									*
    544  ************************************************************************/
    545 
    546 #ifdef LIBXML_THREAD_ENABLED
    547 #ifdef xmlLastError
    548 #undef xmlLastError
    549 #endif
    550 
    551 /**
    552  * xmlFreeGlobalState:
    553  * @state:  a thread global state
    554  *
    555  * xmlFreeGlobalState() is called when a thread terminates with a non-NULL
    556  * global state. It is is used here to reclaim memory resources.
    557  */
    558 static void
    559 xmlFreeGlobalState(void *state)
    560 {
    561     xmlGlobalState *gs = (xmlGlobalState *) state;
    562 
    563     /* free any memory allocated in the thread's xmlLastError */
    564     xmlResetError(&(gs->xmlLastError));
    565     free(state);
    566 }
    567 
    568 /**
    569  * xmlNewGlobalState:
    570  *
    571  * xmlNewGlobalState() allocates a global state. This structure is used to
    572  * hold all data for use by a thread when supporting backwards compatibility
    573  * of libxml2 to pre-thread-safe behaviour.
    574  *
    575  * Returns the newly allocated xmlGlobalStatePtr or NULL in case of error
    576  */
    577 static xmlGlobalStatePtr
    578 xmlNewGlobalState(void)
    579 {
    580     xmlGlobalState *gs;
    581 
    582     gs = malloc(sizeof(xmlGlobalState));
    583     if (gs == NULL) {
    584 	xmlGenericError(xmlGenericErrorContext,
    585 			"xmlGetGlobalState: out of memory\n");
    586         return (NULL);
    587     }
    588 
    589     memset(gs, 0, sizeof(xmlGlobalState));
    590     xmlInitializeGlobalState(gs);
    591     return (gs);
    592 }
    593 #endif /* LIBXML_THREAD_ENABLED */
    594 
    595 #ifdef HAVE_PTHREAD_H
    596 #elif defined HAVE_WIN32_THREADS
    597 #if !defined(HAVE_COMPILER_TLS)
    598 #if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
    599 typedef struct _xmlGlobalStateCleanupHelperParams {
    600     HANDLE thread;
    601     void *memory;
    602 } xmlGlobalStateCleanupHelperParams;
    603 
    604 static void XMLCDECL
    605 xmlGlobalStateCleanupHelper(void *p)
    606 {
    607     xmlGlobalStateCleanupHelperParams *params =
    608         (xmlGlobalStateCleanupHelperParams *) p;
    609     WaitForSingleObject(params->thread, INFINITE);
    610     CloseHandle(params->thread);
    611     xmlFreeGlobalState(params->memory);
    612     free(params);
    613     _endthread();
    614 }
    615 #else /* LIBXML_STATIC && !LIBXML_STATIC_FOR_DLL */
    616 
    617 typedef struct _xmlGlobalStateCleanupHelperParams {
    618     void *memory;
    619     struct _xmlGlobalStateCleanupHelperParams *prev;
    620     struct _xmlGlobalStateCleanupHelperParams *next;
    621 } xmlGlobalStateCleanupHelperParams;
    622 
    623 static xmlGlobalStateCleanupHelperParams *cleanup_helpers_head = NULL;
    624 static CRITICAL_SECTION cleanup_helpers_cs;
    625 
    626 #endif /* LIBXMLSTATIC && !LIBXML_STATIC_FOR_DLL */
    627 #endif /* HAVE_COMPILER_TLS */
    628 #endif /* HAVE_WIN32_THREADS */
    629 
    630 #if defined HAVE_BEOS_THREADS
    631 
    632 /**
    633  * xmlGlobalStateCleanup:
    634  * @data: unused parameter
    635  *
    636  * Used for Beos only
    637  */
    638 void
    639 xmlGlobalStateCleanup(void *data)
    640 {
    641     void *globalval = tls_get(globalkey);
    642 
    643     if (globalval != NULL)
    644         xmlFreeGlobalState(globalval);
    645 }
    646 #endif
    647 
    648 /**
    649  * xmlGetGlobalState:
    650  *
    651  * xmlGetGlobalState() is called to retrieve the global state for a thread.
    652  *
    653  * Returns the thread global state or NULL in case of error
    654  */
    655 xmlGlobalStatePtr
    656 xmlGetGlobalState(void)
    657 {
    658 #ifdef HAVE_PTHREAD_H
    659     xmlGlobalState *globalval;
    660 
    661     if (libxml_is_threaded == 0)
    662         return (NULL);
    663 
    664     pthread_once(&once_control, xmlOnceInit);
    665 
    666     if ((globalval = (xmlGlobalState *)
    667          pthread_getspecific(globalkey)) == NULL) {
    668         xmlGlobalState *tsd = xmlNewGlobalState();
    669 	if (tsd == NULL)
    670 	    return(NULL);
    671 
    672         pthread_setspecific(globalkey, tsd);
    673         return (tsd);
    674     }
    675     return (globalval);
    676 #elif defined HAVE_WIN32_THREADS
    677 #if defined(HAVE_COMPILER_TLS)
    678     if (!tlstate_inited) {
    679         tlstate_inited = 1;
    680         xmlInitializeGlobalState(&tlstate);
    681     }
    682     return &tlstate;
    683 #else /* HAVE_COMPILER_TLS */
    684     xmlGlobalState *globalval;
    685     xmlGlobalStateCleanupHelperParams *p;
    686 
    687     xmlOnceInit();
    688 #if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
    689     globalval = (xmlGlobalState *) TlsGetValue(globalkey);
    690 #else
    691     p = (xmlGlobalStateCleanupHelperParams *) TlsGetValue(globalkey);
    692     globalval = (xmlGlobalState *) (p ? p->memory : NULL);
    693 #endif
    694     if (globalval == NULL) {
    695         xmlGlobalState *tsd = xmlNewGlobalState();
    696 
    697         if (tsd == NULL)
    698 	    return(NULL);
    699         p = (xmlGlobalStateCleanupHelperParams *)
    700             malloc(sizeof(xmlGlobalStateCleanupHelperParams));
    701 	if (p == NULL) {
    702             xmlGenericError(xmlGenericErrorContext,
    703                             "xmlGetGlobalState: out of memory\n");
    704             xmlFreeGlobalState(tsd);
    705 	    return(NULL);
    706 	}
    707         p->memory = tsd;
    708 #if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
    709         DuplicateHandle(GetCurrentProcess(), GetCurrentThread(),
    710                         GetCurrentProcess(), &p->thread, 0, TRUE,
    711                         DUPLICATE_SAME_ACCESS);
    712         TlsSetValue(globalkey, tsd);
    713         _beginthread(xmlGlobalStateCleanupHelper, 0, p);
    714 #else
    715         EnterCriticalSection(&cleanup_helpers_cs);
    716         if (cleanup_helpers_head != NULL) {
    717             cleanup_helpers_head->prev = p;
    718         }
    719         p->next = cleanup_helpers_head;
    720         p->prev = NULL;
    721         cleanup_helpers_head = p;
    722         TlsSetValue(globalkey, p);
    723         LeaveCriticalSection(&cleanup_helpers_cs);
    724 #endif
    725 
    726         return (tsd);
    727     }
    728     return (globalval);
    729 #endif /* HAVE_COMPILER_TLS */
    730 #elif defined HAVE_BEOS_THREADS
    731     xmlGlobalState *globalval;
    732 
    733     xmlOnceInit();
    734 
    735     if ((globalval = (xmlGlobalState *) tls_get(globalkey)) == NULL) {
    736         xmlGlobalState *tsd = xmlNewGlobalState();
    737 	if (tsd == NULL)
    738 	    return (NULL);
    739 
    740         tls_set(globalkey, tsd);
    741         on_exit_thread(xmlGlobalStateCleanup, NULL);
    742         return (tsd);
    743     }
    744     return (globalval);
    745 #else
    746     return (NULL);
    747 #endif
    748 }
    749 
    750 /************************************************************************
    751  *									*
    752  *			Library wide thread interfaces			*
    753  *									*
    754  ************************************************************************/
    755 
    756 /**
    757  * xmlGetThreadId:
    758  *
    759  * xmlGetThreadId() find the current thread ID number
    760  * Note that this is likely to be broken on some platforms using pthreads
    761  * as the specification doesn't mandate pthread_t to be an integer type
    762  *
    763  * Returns the current thread ID number
    764  */
    765 int
    766 xmlGetThreadId(void)
    767 {
    768 #ifdef HAVE_PTHREAD_H
    769     pthread_t id;
    770     int ret;
    771 
    772     if (libxml_is_threaded == 0)
    773         return (0);
    774     id = pthread_self();
    775     /* horrible but preserves compat, see warning above */
    776     memcpy(&ret, &id, sizeof(ret));
    777     return (ret);
    778 #elif defined HAVE_WIN32_THREADS
    779     return GetCurrentThreadId();
    780 #elif defined HAVE_BEOS_THREADS
    781     return find_thread(NULL);
    782 #else
    783     return ((int) 0);
    784 #endif
    785 }
    786 
    787 /**
    788  * xmlIsMainThread:
    789  *
    790  * xmlIsMainThread() check whether the current thread is the main thread.
    791  *
    792  * Returns 1 if the current thread is the main thread, 0 otherwise
    793  */
    794 int
    795 xmlIsMainThread(void)
    796 {
    797 #ifdef HAVE_PTHREAD_H
    798     if (libxml_is_threaded == -1)
    799         xmlInitThreads();
    800     if (libxml_is_threaded == 0)
    801         return (1);
    802     pthread_once(&once_control, xmlOnceInit);
    803 #elif defined HAVE_WIN32_THREADS
    804     xmlOnceInit();
    805 #elif defined HAVE_BEOS_THREADS
    806     xmlOnceInit();
    807 #endif
    808 
    809 #ifdef DEBUG_THREADS
    810     xmlGenericError(xmlGenericErrorContext, "xmlIsMainThread()\n");
    811 #endif
    812 #ifdef HAVE_PTHREAD_H
    813     return (pthread_equal(mainthread,pthread_self()));
    814 #elif defined HAVE_WIN32_THREADS
    815     return (mainthread == GetCurrentThreadId());
    816 #elif defined HAVE_BEOS_THREADS
    817     return (mainthread == find_thread(NULL));
    818 #else
    819     return (1);
    820 #endif
    821 }
    822 
    823 /**
    824  * xmlLockLibrary:
    825  *
    826  * xmlLockLibrary() is used to take out a re-entrant lock on the libxml2
    827  * library.
    828  */
    829 void
    830 xmlLockLibrary(void)
    831 {
    832 #ifdef DEBUG_THREADS
    833     xmlGenericError(xmlGenericErrorContext, "xmlLockLibrary()\n");
    834 #endif
    835     xmlRMutexLock(xmlLibraryLock);
    836 }
    837 
    838 /**
    839  * xmlUnlockLibrary:
    840  *
    841  * xmlUnlockLibrary() is used to release a re-entrant lock on the libxml2
    842  * library.
    843  */
    844 void
    845 xmlUnlockLibrary(void)
    846 {
    847 #ifdef DEBUG_THREADS
    848     xmlGenericError(xmlGenericErrorContext, "xmlUnlockLibrary()\n");
    849 #endif
    850     xmlRMutexUnlock(xmlLibraryLock);
    851 }
    852 
    853 /**
    854  * xmlInitThreads:
    855  *
    856  * xmlInitThreads() is used to to initialize all the thread related
    857  * data of the libxml2 library.
    858  */
    859 void
    860 xmlInitThreads(void)
    861 {
    862 #ifdef HAVE_PTHREAD_H
    863     if (libxml_is_threaded == -1) {
    864         if ((pthread_once != NULL) &&
    865             (pthread_getspecific != NULL) &&
    866             (pthread_setspecific != NULL) &&
    867             (pthread_key_create != NULL) &&
    868             (pthread_key_delete != NULL) &&
    869             (pthread_mutex_init != NULL) &&
    870             (pthread_mutex_destroy != NULL) &&
    871             (pthread_mutex_lock != NULL) &&
    872             (pthread_mutex_unlock != NULL) &&
    873             (pthread_cond_init != NULL) &&
    874             (pthread_cond_destroy != NULL) &&
    875             (pthread_cond_wait != NULL) &&
    876             (pthread_equal != NULL) &&
    877             (pthread_self != NULL) &&
    878             (pthread_cond_signal != NULL)) {
    879             libxml_is_threaded = 1;
    880 
    881 /* fprintf(stderr, "Running multithreaded\n"); */
    882         } else {
    883 
    884 /* fprintf(stderr, "Running without multithread\n"); */
    885             libxml_is_threaded = 0;
    886         }
    887     }
    888 #elif defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
    889     InitializeCriticalSection(&cleanup_helpers_cs);
    890 #endif
    891 }
    892 
    893 /**
    894  * xmlCleanupThreads:
    895  *
    896  * xmlCleanupThreads() is used to to cleanup all the thread related
    897  * data of the libxml2 library once processing has ended.
    898  *
    899  * WARNING: if your application is multithreaded or has plugin support
    900  *          calling this may crash the application if another thread or
    901  *          a plugin is still using libxml2. It's sometimes very hard to
    902  *          guess if libxml2 is in use in the application, some libraries
    903  *          or plugins may use it without notice. In case of doubt abstain
    904  *          from calling this function or do it just before calling exit()
    905  *          to avoid leak reports from valgrind !
    906  */
    907 void
    908 xmlCleanupThreads(void)
    909 {
    910 #ifdef DEBUG_THREADS
    911     xmlGenericError(xmlGenericErrorContext, "xmlCleanupThreads()\n");
    912 #endif
    913 #ifdef HAVE_PTHREAD_H
    914     if ((libxml_is_threaded)  && (pthread_key_delete != NULL))
    915         pthread_key_delete(globalkey);
    916 #elif defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
    917     if (globalkey != TLS_OUT_OF_INDEXES) {
    918         xmlGlobalStateCleanupHelperParams *p;
    919 
    920         EnterCriticalSection(&cleanup_helpers_cs);
    921         p = cleanup_helpers_head;
    922         while (p != NULL) {
    923             xmlGlobalStateCleanupHelperParams *temp = p;
    924 
    925             p = p->next;
    926             xmlFreeGlobalState(temp->memory);
    927             free(temp);
    928         }
    929         cleanup_helpers_head = 0;
    930         LeaveCriticalSection(&cleanup_helpers_cs);
    931         TlsFree(globalkey);
    932         globalkey = TLS_OUT_OF_INDEXES;
    933     }
    934     DeleteCriticalSection(&cleanup_helpers_cs);
    935 #endif
    936 }
    937 
    938 #ifdef LIBXML_THREAD_ENABLED
    939 
    940 /**
    941  * xmlOnceInit
    942  *
    943  * xmlOnceInit() is used to initialize the value of mainthread for use
    944  * in other routines. This function should only be called using
    945  * pthread_once() in association with the once_control variable to ensure
    946  * that the function is only called once. See man pthread_once for more
    947  * details.
    948  */
    949 static void
    950 xmlOnceInit(void)
    951 {
    952 #ifdef HAVE_PTHREAD_H
    953     (void) pthread_key_create(&globalkey, xmlFreeGlobalState);
    954     mainthread = pthread_self();
    955 #elif defined(HAVE_WIN32_THREADS)
    956     if (!run_once.done) {
    957         if (InterlockedIncrement(&run_once.control) == 1) {
    958 #if !defined(HAVE_COMPILER_TLS)
    959             globalkey = TlsAlloc();
    960 #endif
    961             mainthread = GetCurrentThreadId();
    962             run_once.done = 1;
    963         } else {
    964             /* Another thread is working; give up our slice and
    965              * wait until they're done. */
    966             while (!run_once.done)
    967                 Sleep(0);
    968         }
    969     }
    970 #elif defined HAVE_BEOS_THREADS
    971     if (atomic_add(&run_once_init, 1) == 0) {
    972         globalkey = tls_allocate();
    973         tls_set(globalkey, NULL);
    974         mainthread = find_thread(NULL);
    975     } else
    976         atomic_add(&run_once_init, -1);
    977 #endif
    978 }
    979 #endif
    980 
    981 /**
    982  * DllMain:
    983  * @hinstDLL: handle to DLL instance
    984  * @fdwReason: Reason code for entry
    985  * @lpvReserved: generic pointer (depends upon reason code)
    986  *
    987  * Entry point for Windows library. It is being used to free thread-specific
    988  * storage.
    989  *
    990  * Returns TRUE always
    991  */
    992 #ifdef HAVE_PTHREAD_H
    993 #elif defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
    994 #if defined(LIBXML_STATIC_FOR_DLL)
    995 BOOL XMLCALL
    996 xmlDllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
    997 #else
    998 BOOL WINAPI
    999 DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
   1000 #endif
   1001 {
   1002     switch (fdwReason) {
   1003         case DLL_THREAD_DETACH:
   1004             if (globalkey != TLS_OUT_OF_INDEXES) {
   1005                 xmlGlobalState *globalval = NULL;
   1006                 xmlGlobalStateCleanupHelperParams *p =
   1007                     (xmlGlobalStateCleanupHelperParams *)
   1008                     TlsGetValue(globalkey);
   1009                 globalval = (xmlGlobalState *) (p ? p->memory : NULL);
   1010                 if (globalval) {
   1011                     xmlFreeGlobalState(globalval);
   1012                     TlsSetValue(globalkey, NULL);
   1013                 }
   1014                 if (p) {
   1015                     EnterCriticalSection(&cleanup_helpers_cs);
   1016                     if (p == cleanup_helpers_head)
   1017                         cleanup_helpers_head = p->next;
   1018                     else
   1019                         p->prev->next = p->next;
   1020                     if (p->next != NULL)
   1021                         p->next->prev = p->prev;
   1022                     LeaveCriticalSection(&cleanup_helpers_cs);
   1023                     free(p);
   1024                 }
   1025             }
   1026             break;
   1027     }
   1028     return TRUE;
   1029 }
   1030 #endif
   1031 #define bottom_threads
   1032 #include "elfgcchack.h"
   1033