started integrating the core of the thread support not activated yet but

* Makefile.am include/libxml/Makefile.am
  include/libxml/globals.h globals.c  include/libxml/threads.h
  threads.c build_glob.py global.data xmlcatalog.c acconfig.h
  configure.in: started integrating the core of the thread support
  not activated yet but half integrated. The code should still
  compile and work anyway.
Daniel

1 files changed, 372 insertions, 0 deletions

diff --git a/threads.c b/threads.c
new file mode 100644
index 00000000..9b0a3464
--- /dev/null
+++ b/threads.c
@@ -0,0 +1,372 @@
+/**
+ * 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
+ */
+
+#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
+
+#if defined(SOLARIS)
+#include <note.h>
+#endif
+
+
+/*
+ * 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;
+#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;
+#else
+    int empty;
+#endif
+};
+/*
+ * This module still has some internal static data.
+ *   - xmlLibraryLock a global lock
+ *   - globalkey used for per-thread data
+ *   - keylock protecting globalkey
+ *   - keyonce to mark initialization of globalkey
+ */
+#ifdef HAVE_PTHREAD_H
+static pthread_mutex_t	keylock;
+static pthread_key_t	globalkey;
+static int		keyonce = 0;
+#endif
+static xmlRMutexPtr	xmlLibraryLock = NULL;
+
+#if defined(SOLARIS)
+NOTE(DATA_READABLE_WITHOUT_LOCK(keyonce))
+#endif
+
+/**
+ * xmlMutexPtr:
+ *
+ * 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 = malloc(sizeof(xmlMutex))) == NULL)
+        return (NULL);
+#ifdef HAVE_PTHREAD_H
+    pthread_mutex_init(&tok->lock, NULL);
+#endif
+    return (tok);
+}
+
+/**
+ * xmlFreeMutex:
+ * @tok:  the simple mutex
+ *
+ * xmlFreeMutex() is used to reclaim resources associated with a libxml2 token
+ * struct.
+ */
+void
+xmlFreeMutex(xmlMutexPtr tok)
+{
+#ifdef HAVE_PTHREAD_H
+    pthread_mutex_destroy(&tok->lock);
+#endif
+    free(tok);
+}
+
+/**
+ * xmlMutexLock:
+ * @tok:  the simple mutex
+ *
+ * xmlMutexLock() is used to lock a libxml2 token.
+ */
+void
+xmlMutexLock(xmlMutexPtr tok)
+{
+#ifdef HAVE_PTHREAD_H
+    pthread_mutex_lock(&tok->lock);
+#endif
+
+}
+
+/**
+ * xmlMutexUnlock:
+ * @tok:  the simple mutex
+ *
+ * xmlMutexUnlock() is used to unlock a libxml2 token.
+ */
+void
+xmlMutexUnlock(xmlMutexPtr tok)
+{
+#ifdef HAVE_PTHREAD_H
+    pthread_mutex_unlock(&tok->lock);
+#endif
+}
+
+/**
+ * xmlRNewMutex:
+ *
+ * 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 = malloc(sizeof(xmlRMutex))) == NULL)
+        return (NULL);
+#ifdef HAVE_PTHREAD_H
+    pthread_mutex_init(&tok->lock, NULL);
+    tok->held = 0;
+    tok->waiters = 0;
+#endif
+    return (tok);
+}
+
+/**
+ * xmlRFreeMutex:
+ * @tok:  the reentrant mutex
+ *
+ * xmlRFreeMutex() is used to reclaim resources associated with a
+ * reentrant mutex.
+ */
+void
+xmlFreeRMutex(xmlRMutexPtr tok)
+{
+#ifdef HAVE_PTHREAD_H
+    pthread_mutex_destroy(&tok->lock);
+#endif
+    free(tok);
+}
+
+/**
+ * xmlRMutexLock:
+ * @tok:  the reentrant mutex
+ *
+ * xmlRMutexLock() is used to lock a libxml2 token_r.
+ */
+void
+xmlRMutexLock(xmlRMutexPtr tok)
+{
+#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);
+#endif
+}
+
+/**
+ * xmlRMutexUnlock:
+ * @tok:  the reentrant mutex
+ *
+ * xmlRMutexUnlock() is used to unlock a libxml2 token_r.
+ */
+void
+xmlRMutexUnlock(xmlRMutexPtr tok)
+{
+#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);
+#endif
+}
+
+/************************************************************************
+ *									*
+ *			Per thread global state handling		*
+ *									*
+ ************************************************************************/
+
+/**
+ * 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)
+{
+    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 libmxml2 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(gs));
+    xmlInitializeGlobalState(gs);
+    return (gs);
+}
+
+
+/**
+ * xmlGetGlobalState:
+ *
+ * xmlGetGlobalState() is called to retrieve the global state for a thread.
+ * keyonce will only be set once during a library invocation and is used
+ * to create globalkey, the key used to store each thread's TSD.
+ *
+ * Note: it should not be called for the "main" thread as this thread uses
+ *       the existing global variables defined in the library.
+ *
+ * Returns the thread global state or NULL in case of error
+ */
+xmlGlobalStatePtr
+xmlGetGlobalState(void)
+{
+#ifdef HAVE_PTHREAD_H
+    xmlGlobalState *globalval;
+
+    if (keyonce == 0) {
+        (void) pthread_mutex_lock(&keylock);
+        if (keyonce == 0) {
+            keyonce++;
+            (void) pthread_key_create(&globalkey, xmlFreeGlobalState);
+        }
+        (void) pthread_mutex_unlock(&keylock);
+    }
+    if ((globalval = (xmlGlobalState *)
+         pthread_getspecific(globalkey)) == NULL) {
+        xmlGlobalState *tsd = xmlNewGlobalState();
+
+        pthread_setspecific(globalkey, tsd);
+        return (tsd);
+    } else
+        return (globalval);
+#endif
+}
+
+
+/************************************************************************
+ *									*
+ *			Library wide thread interfaces			*
+ *									*
+ ************************************************************************/
+
+/**
+ * xmlLockLibrary:
+ *
+ * xmlLockLibrary() is used to take out a re-entrant lock on the libxml2
+ * library.
+ */
+void
+xmlLockLibrary(void)
+{
+    xmlRMutexLock(xmlLibraryLock);
+}
+
+/**
+ * xmlUnlockLibrary:
+ *
+ * xmlUnlockLibrary() is used to release a re-entrant lock on the libxml2
+ * library.
+ */
+void
+xmlUnlockLibrary(void)
+{
+    xmlRMutexUnlock(xmlLibraryLock);
+}
+
+/**
+ * xmlInitThreads:
+ *
+ * xmlInitThreads() is used to to initialize all the thread related
+ * data of the libxml2 library.
+ */
+void
+xmlInitThreads(void)
+{
+}
+
+/**
+ * xmlCleanupThreads:
+ *
+ * xmlCleanupThreads() is used to to cleanup all the thread related
+ * data of the libxml2 library once processing has ended.
+ */
+void
+xmlCleanupThreads(void)
+{
+}