/**
* threads.c: set of generic threading related routines
*
* See Copyright for the status of this software.
*
* Gary Pennington <Gary.Pennington@uk.sun.com>
* daniel@veillard.com
*/
#define IN_LIBXML
#include "libxml.h"
#include <string.h>
#include <libxml/threads.h>
#include <libxml/globals.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_PTHREAD_H
#include <pthread.h>
#endif
#ifdef HAVE_WIN32_THREADS
#include <windows.h>
#ifndef HAVE_COMPILER_TLS
#include <process.h>
#endif
#endif
#ifdef HAVE_BEOS_THREADS
#include <OS.h>
#include <TLS.h>
#endif
#if defined(SOLARIS)
#include <note.h>
#endif
/* #define DEBUG_THREADS */
/*
* TODO: this module still uses malloc/free and not xmlMalloc/xmlFree
* to avoid some crazyness since xmlMalloc/xmlFree may actually
* be hosted on allocated blocks needing them for the allocation ...
*/
/*
* xmlMutex are a simple mutual exception locks
*/
struct _xmlMutex {
#ifdef HAVE_PTHREAD_H
pthread_mutex_t lock;
#elif defined HAVE_WIN32_THREADS
HANDLE mutex;
#elif defined HAVE_BEOS_THREADS
sem_id sem;
thread_id tid;
#else
int empty;
#endif
};
/*
* xmlRMutex are reentrant mutual exception locks
*/
struct _xmlRMutex {
#ifdef HAVE_PTHREAD_H
pthread_mutex_t lock;
unsigned int held;
unsigned int waiters;
pthread_t tid;
pthread_cond_t cv;
#elif defined HAVE_WIN32_THREADS
CRITICAL_SECTION cs;
unsigned int count;
#elif defined HAVE_BEOS_THREADS
xmlMutexPtr lock;
thread_id tid;
int32 count;
#else
int empty;
#endif
};
/*
* This module still has some internal static data.
* - xmlLibraryLock a global lock
* - globalkey used for per-thread data
*/
#ifdef HAVE_PTHREAD_H
static pthread_key_t globalkey;
static pthread_t mainthread;
static pthread_once_t once_control = PTHREAD_ONCE_INIT;
#elif defined HAVE_WIN32_THREADS
#if defined(HAVE_COMPILER_TLS)
static __declspec(thread) xmlGlobalState tlstate;
static __declspec(thread) int tlstate_inited = 0;
#else /* HAVE_COMPILER_TLS */
static DWORD globalkey = TLS_OUT_OF_INDEXES;
#endif /* HAVE_COMPILER_TLS */
static DWORD mainthread;
static struct
{
DWORD done;
DWORD control;
} run_once = { 0, 0 };
/* endif HAVE_WIN32_THREADS */
#elif defined HAVE_BEOS_THREADS
int32 globalkey = 0;
thread_id mainthread = 0;
int32 run_once_init = 0;
#endif
static xmlRMutexPtr xmlLibraryLock = NULL;
#ifdef LIBXML_THREAD_ENABLED
static void xmlOnceInit(void);
#endif
/**
* xmlNewMutex:
*
* xmlNewMutex() is used to allocate a libxml2 token struct for use in
* synchronizing access to data.
*
* Returns a new simple mutex pointer or NULL in case of error
*/
xmlMutexPtr
xmlNewMutex(void)
{
xmlMutexPtr tok;
if ((tok = (xmlMutex*) malloc(sizeof(xmlMutex))) == NULL)
return NULL;
#ifdef HAVE_PTHREAD_H
pthread_mutex_init(&tok->lock, NULL);
#elif defined HAVE_WIN32_THREADS
tok->mutex = CreateMutex(NULL, FALSE, NULL);
#elif defined HAVE_BEOS_THREADS
if ((tok->sem = create_sem(1, "xmlMutex")) < B_OK) {
free(tok);
return NULL;
}
tok->tid = -1;
#endif
return (tok);
}
/**
* xmlFreeMutex:
* @tok: the simple mutex
*
* xmlFreeMutex() is used to reclaim resources associated with a libxml2 token
* struct.
*/
void
xmlFreeMutex(xmlMutexPtr tok)
{
if (tok == NULL) return;
#ifdef HAVE_PTHREAD_H
pthread_mutex_destroy(&tok->lock);
#elif defined HAVE_WIN32_THREADS
CloseHandle(tok->mutex);
#elif defined HAVE_BEOS_THREADS
delete_sem(tok->sem);
#endif
free(tok);
}
/**
* xmlMutexLock:
* @tok: the simple mutex
*
* xmlMutexLock() is used to lock a libxml2 token.
*/
void
xmlMutexLock(xmlMutexPtr tok)
{
if (tok == NULL)
return;
#ifdef HAVE_PTHREAD_H
pthread_mutex_lock(&tok->lock);
#elif defined HAVE_WIN32_THREADS
WaitForSingleObject(tok->mutex, INFINITE);
#elif defined HAVE_BEOS_THREADS
if (acquire_sem(tok->sem) != B_NO_ERROR) {
#ifdef DEBUG_THREADS
xmlGenericError(xmlGenericErrorContext, "xmlMutexLock():BeOS:Couldn't aquire semaphore\n");
exit();
#endif
}
tok->tid = find_thread(NULL);
#endif
}
/**
* xmlMutexUnlock:
* @tok: the simple mutex
*
* xmlMutexUnlock() is used to unlock a libxml2 token.
*/
void
xmlMutexUnlock(xmlMutexPtr tok)
{
if (tok == NULL)
return;
#ifdef HAVE_PTHREAD_H
pthread_mutex_unlock(&tok->lock);
#elif defined HAVE_WIN32_THREADS
ReleaseMutex(tok->mutex);
#elif defined HAVE_BEOS_THREADS
if (tok->tid == find_thread(NULL)) {
tok->tid = -1;
release_sem(tok->sem);
}
#endif
}
/**
* xmlNewRMutex:
*
* xmlRNewMutex() is used to allocate a reentrant mutex for use in
* synchronizing access to data. token_r is a re-entrant lock and thus useful
* for synchronizing access to data structures that may be manipulated in a
* recursive fashion.
*
* Returns the new reentrant mutex pointer or NULL in case of error
*/
xmlRMutexPtr
xmlNewRMutex(void)
{
xmlRMutexPtr tok;
if ((tok = (xmlRMutex*) malloc(sizeof(xmlRMutex))) == NULL)
return (NULL);
#ifdef HAVE_PTHREAD_H
pthread_mutex_init(&tok->lock, NULL);
tok->held = 0;
tok->waiters = 0;
pthread_cond_init(&tok->cv, NULL);
#elif defined HAVE_WIN32_THREADS
InitializeCriticalSection(&tok->cs);
tok->count = 0;
#elif defined HAVE_BEOS_THREADS
if ((tok->lock = xmlNewMutex()) == NULL) {
free(tok);
return NULL;
}
tok->count = 0;
#endif
return (tok);
}
/**
* xmlFreeRMutex:
* @tok: the reentrant mutex
*
* xmlRFreeMutex() is used to reclaim resources associated with a
* reentrant mutex.
*/
void
xmlFreeRMutex(xmlRMutexPtr tok ATTRIBUTE_UNUSED)
{
#ifdef HAVE_PTHREAD_H
pthread_mutex_destroy(&tok->lock);
#elif defined HAVE_WIN32_THREADS
DeleteCriticalSection(&tok->cs);
#elif defined HAVE_BEOS_THREADS
xmlFreeMutex(tok->lock);
#endif
free(tok);
}
/**
* xmlRMutexLock:
* @tok: the reentrant mutex
*
* xmlRMutexLock() is used to lock a libxml2 token_r.
*/
void
xmlRMutexLock(xmlRMutexPtr tok)
{
if (tok == NULL)
return;
#ifdef HAVE_PTHREAD_H
pthread_mutex_lock(&tok->lock);
if (tok->held) {
if (pthread_equal(tok->tid, pthread_self())) {
tok->held++;
pthread_mutex_unlock(&tok->lock);
return;
} else {
tok->waiters++;
while (tok->held)
pthread_cond_wait(&tok->cv, &tok->lock);
tok->waiters--;
}
}
tok->tid = pthread_self();
tok->held = 1;
pthread_mutex_unlock(&tok->lock);
#elif defined HAVE_WIN32_THREADS
EnterCriticalSection(&tok->cs);
++tok->count;
#elif defined HAVE_BEOS_THREADS
if (tok->lock->tid == find_thread(NULL)) {
tok->count++;
return;
} else {
xmlMutexLock(tok->lock);
tok->count = 1;
}
#endif
}
/**
* xmlRMutexUnlock:
* @tok: the reentrant mutex
*
* xmlRMutexUnlock() is used to unlock a libxml2 token_r.
*/
void
xmlRMutexUnlock(xmlRMutexPtr tok ATTRIBUTE_UNUSED)
{
if (tok == NULL)
return;
#ifdef HAVE_PTHREAD_H
pthread_mutex_lock(&tok->lock);
tok->held--;
if (tok->held == 0) {
if (tok->waiters)
pthread_cond_signal(&tok->cv);
tok->tid = 0;
}
pthread_mutex_unlock(&tok->lock);
#elif defined HAVE_WIN32_THREADS
if (!--tok->count)
LeaveCriticalSection(&tok->cs);
#elif defined HAVE_BEOS_THREADS
if (tok->lock->tid == find_thread(NULL)) {
tok->count--;
if (tok->count == 0) {
xmlMutexUnlock(tok->lock);
}
return;
}
#endif
}
/************************************************************************
* *
* Per thread global state handling *
* *
************************************************************************/
#ifdef LIBXML_THREAD_ENABLED
#ifdef xmlLastError
#undef xmlLastError
#endif
/**
* xmlFreeGlobalState:
* @state: a thread global state
*
* xmlFreeGlobalState() is called when a thread terminates with a non-NULL
* global state. It is is used here to reclaim memory resources.
*/
static void
xmlFreeGlobalState(void *state)
{
xmlGlobalState *gs = (xmlGlobalState *) state;
/* free any memory allocated in the thread's xmlLastError */
xmlResetError(&(gs->xmlLastError));
free(state);
}
/**
* xmlNewGlobalState:
*
* xmlNewGlobalState() allocates a global state. This structure is used to
* hold all data for use by a thread when supporting backwards compatibility
* of libxml2 to pre-thread-safe behaviour.
*
* Returns the newly allocated xmlGlobalStatePtr or NULL in case of error
*/
static xmlGlobalStatePtr
xmlNewGlobalState(void)
{
xmlGlobalState *gs;
gs = malloc(sizeof(xmlGlobalState));
if (gs == NULL)
return(NULL);
memset(gs, 0, sizeof(xmlGlobalState));
xmlInitializeGlobalState(gs);
return (gs);
}
#endif /* LIBXML_THREAD_ENABLED */
#ifdef HAVE_WIN32_THREADS
#if !defined(HAVE_COMPILER_TLS)
#if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
typedef struct _xmlGlobalStateCleanupHelperParams
{
HANDLE thread;
void *memory;
} xmlGlobalStateCleanupHelperParams;
static void xmlGlobalStateCleanupHelper (void *p)
{
xmlGlobalStateCleanupHelperParams *params = (xmlGlobalStateCleanupHelperParams *) p;
WaitForSingleObject(params->thread, INFINITE);
CloseHandle(params->thread);
xmlFreeGlobalState(params->memory);
free(params);
_endthread();
}
#else /* LIBXML_STATIC && !LIBXML_STATIC_FOR_DLL */
typedef struct _xmlGlobalStateCleanupHelperParams
{
void *memory;
struct _xmlGlobalStateCleanupHelperParams * prev;
struct _xmlGlobalStateCleanupHelperParams * next;
} xmlGlobalStateCleanupHelperParams;
static xmlGlobalStateCleanupHelperParams * cleanup_helpers_head = NULL;
static CRITICAL_SECTION cleanup_helpers_cs;
#endif /* LIBXMLSTATIC && !LIBXML_STATIC_FOR_DLL */
#endif /* HAVE_COMPILER_TLS */
#endif /* HAVE_WIN32_THREADS */
#if defined HAVE_BEOS_THREADS
/**
* xmlGlobalStateCleanup:
* @data: unused parameter
*
* Used for Beos only
*/
void xmlGlobalStateCleanup(void *data)
{
void *globalval = tls_get(globalkey);
if (globalval != NULL)
xmlFreeGlobalState(globalval);
}
#endif
/**
* xmlGetGlobalState:
*
* xmlGetGlobalState() is called to retrieve the global state for a thread.
*
* Returns the thread global state or NULL in case of error
*/
xmlGlobalStatePtr
xmlGetGlobalState(void)
{
#ifdef HAVE_PTHREAD_H
xmlGlobalState *globalval;
pthread_once(&once_control, xmlOnceInit);
if ((globalval = (xmlGlobalState *)
pthread_getspecific(globalkey)) == NULL) {
xmlGlobalState *tsd = xmlNewGlobalState();
pthread_setspecific(globalkey, tsd);
return (tsd);
}
return (globalval);
#elif defined HAVE_WIN32_THREADS
#if defined(HAVE_COMPILER_TLS)
if (!tlstate_inited) {
tlstate_inited = 1;
xmlInitializeGlobalState(&tlstate);
}
return &tlstate;
#else /* HAVE_COMPILER_TLS */
xmlGlobalState *globalval;
xmlGlobalStateCleanupHelperParams * p;
xmlOnceInit();
#if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
globalval = (xmlGlobalState *)TlsGetValue(globalkey);
#else
p = (xmlGlobalStateCleanupHelperParams*)TlsGetValue(globalkey);
globalval = (xmlGlobalState *)(p ? p->memory : NULL);
#endif
if (globalval == NULL) {
xmlGlobalState *tsd = xmlNewGlobalState();
p = (xmlGlobalStateCleanupHelperParams *) malloc(sizeof(xmlGlobalStateCleanupHelperParams));
p->memory = tsd;
#if defined(LIBXML_STATIC) && !defined(LIBXML_STATIC_FOR_DLL)
DuplicateHandle(GetCurrentProcess(), GetCurrentThread(),
GetCurrentProcess(), &p->thread, 0, TRUE, DUPLICATE_SAME_ACCESS);
TlsSetValue(globalkey, tsd);
_beginthread(xmlGlobalStateCleanupHelper, 0, p);
#else
EnterCriticalSection(&cleanup_helpers_cs);
if (cleanup_helpers_head != NULL) {
cleanup_helpers_head->prev = p;
}
p->next = cleanup_helpers_head;
p->prev = NULL;
cleanup_helpers_head = p;
TlsSetValue(globalkey, p);
LeaveCriticalSection(&cleanup_helpers_cs);
#endif
return (tsd);
}
return (globalval);
#endif /* HAVE_COMPILER_TLS */
#elif defined HAVE_BEOS_THREADS
xmlGlobalState *globalval;
xmlOnceInit();
if ((globalval = (xmlGlobalState *)
tls_get(globalkey)) == NULL) {
xmlGlobalState *tsd = xmlNewGlobalState();
tls_set(globalkey, tsd);
on_exit_thread(xmlGlobalStateCleanup, NULL);
return (tsd);
}
return (globalval);
#else
return(NULL);
#endif
}
/************************************************************************
* *
* Library wide thread interfaces *
* *
************************************************************************/
/**
* xmlGetThreadId:
*
* xmlGetThreadId() find the current thread ID number
*
* Returns the current thread ID number
*/
int
xmlGetThreadId(void)
{
#ifdef HAVE_PTHREAD_H
return((int) pthread_self());
#elif defined HAVE_WIN32_THREADS
return GetCurrentThreadId();
#elif defined HAVE_BEOS_THREADS
return find_thread(NULL);
#else
return((int) 0);
#endif
}
/**
* xmlIsMainThread:
*
* xmlIsMainThread() check whether the current thread is the main thread.
*
* Returns 1 if the current thread is the main thread, 0 otherwise
*/
int
xmlIsMainThread(void)
{
#ifdef HAVE_PTHREAD_H
pthread_once(&once_control, xmlOnceInit);
#elif defined HAVE_WIN32_THREADS
xmlOnceInit ();
#elif defined HAVE_BEOS_THREADS
xmlOnceInit();
#endif
#ifdef DEBUG_THREADS
xmlGenericError(xmlGenericErrorContext, "xmlIsMainThread()\n");
#endif
#ifdef HAVE_PTHREAD_H
return(mainthread == pthread_self());
#elif defined HAVE_WIN32_THREADS
return(mainthread == GetCurrentThreadId ());
#elif defined HAVE_BEOS_THREADS
return(mainthread == find_thread(NULL));
#else
return(1);
#endif
}
/**
* xmlLockLibrary:
*
* xmlLockLibrary() is used to take out a re-entrant lock on the libxml2
* library.
*/
void
xmlLockLibrary(void)
{
#ifdef DEBUG_THREADS
xmlGenericError(xmlGenericErrorContext, "xmlLockLibrary()\n");
#endif
xmlRMutexLock(xmlLibraryLock);
}
/**
* xmlUnlockLibrary:
*
* xmlUnlockLibrary() is used to release a re-entrant lock on the libxml2
* library.
*/
void
xmlUnlockLibrary(void)
{
#ifdef DEBUG_THREADS
xmlGenericError(xmlGenericErrorContext, "xmlUnlockLibrary()\n");
#endif
xmlRMutexUnlock(xmlLibraryLock);
}
/**
* xmlInitThreads:
*
* xmlInitThreads() is used to to initialize all the thread related
* data of the libxml2 library.
*/
void
xmlInitThreads(void)
{
#ifdef DEBUG_THREADS
xmlGenericError(xmlGenericErrorContext, "xmlInitThreads()\n");
#endif
#if defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
InitializeCriticalSection(&cleanup_helpers_cs);
#endif
}
/**
* xmlCleanupThreads:
*
* xmlCleanupThreads() is used to to cleanup all the thread related
* data of the libxml2 library once processing has ended.
*/
void
xmlCleanupThreads(void)
{
#ifdef DEBUG_THREADS
xmlGenericError(xmlGenericErrorContext, "xmlCleanupThreads()\n");
#endif
#if defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
if (globalkey != TLS_OUT_OF_INDEXES) {
xmlGlobalStateCleanupHelperParams * p;
EnterCriticalSection(&cleanup_helpers_cs);
p = cleanup_helpers_head;
while (p != NULL) {
xmlGlobalStateCleanupHelperParams * temp = p;
p = p->next;
xmlFreeGlobalState(temp->memory);
free(temp);
}
cleanup_helpers_head = 0;
LeaveCriticalSection(&cleanup_helpers_cs);
TlsFree(globalkey);
globalkey = TLS_OUT_OF_INDEXES;
}
DeleteCriticalSection(&cleanup_helpers_cs);
#endif
}
#ifdef LIBXML_THREAD_ENABLED
/**
* xmlOnceInit
*
* xmlOnceInit() is used to initialize the value of mainthread for use
* in other routines. This function should only be called using
* pthread_once() in association with the once_control variable to ensure
* that the function is only called once. See man pthread_once for more
* details.
*/
static void
xmlOnceInit(void) {
#ifdef HAVE_PTHREAD_H
(void) pthread_key_create(&globalkey, xmlFreeGlobalState);
mainthread = pthread_self();
#endif
#if defined(HAVE_WIN32_THREADS)
if (!run_once.done) {
if (InterlockedIncrement(&run_once.control) == 1)
{
#if !defined(HAVE_COMPILER_TLS)
globalkey = TlsAlloc();
#endif
mainthread = GetCurrentThreadId();
run_once.done = 1;
}
else {
/* Another thread is working; give up our slice and
* wait until they're done. */
while (!run_once.done)
Sleep(0);
}
}
#endif
#ifdef HAVE_BEOS_THREADS
if (atomic_add(&run_once_init, 1) == 0) {
globalkey = tls_allocate();
tls_set(globalkey, NULL);
mainthread = find_thread(NULL);
} else
atomic_add(&run_once_init, -1);
#endif
}
#endif
/**
* DllMain:
* @hinstDLL: handle to DLL instance
* @fdwReason: Reason code for entry
* @lpvReserved: generic pointer (depends upon reason code)
*
* Entry point for Windows library. It is being used to free thread-specific
* storage.
*
* Returns TRUE always
*/
#if defined(HAVE_WIN32_THREADS) && !defined(HAVE_COMPILER_TLS) && (!defined(LIBXML_STATIC) || defined(LIBXML_STATIC_FOR_DLL))
#if defined(LIBXML_STATIC_FOR_DLL)
BOOL WINAPI xmlDllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
#else
BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
#endif
{
switch(fdwReason) {
case DLL_THREAD_DETACH:
if (globalkey != TLS_OUT_OF_INDEXES) {
xmlGlobalState *globalval = NULL;
xmlGlobalStateCleanupHelperParams * p =
(xmlGlobalStateCleanupHelperParams*)TlsGetValue(globalkey);
globalval = (xmlGlobalState *)(p ? p->memory : NULL);
if (globalval) {
xmlFreeGlobalState(globalval);
TlsSetValue(globalkey,NULL);
}
if (p)
{
EnterCriticalSection(&cleanup_helpers_cs);
if (p == cleanup_helpers_head)
cleanup_helpers_head = p->next;
else
p->prev->next = p->next;
if (p->next != NULL)
p->next->prev = p->prev;
LeaveCriticalSection(&cleanup_helpers_cs);
free(p);
}
}
break;
}
return TRUE;
}
#endif
#define bottom_threads
#include "elfgcchack.h"
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