Fix a number of threading data races

Add proper thread termination handler
This partially resolves Bug 1508

4 files changed, 292 insertions, 85 deletions

diff --git a/src/tools/qshared.h b/src/tools/qshared.h
index 290592c..7fe2593 100644
--- a/src/tools/qshared.h
+++ b/src/tools/qshared.h
@@ -45,7 +45,6 @@
 #include "qglobal.h"
 #endif // QT_H
 
-
 struct Q_EXPORT QShared
 {
     QShared() : count( 1 ) { }
diff --git a/src/tools/qstring.cpp b/src/tools/qstring.cpp
index 8717f6a..0630cd3 100644
--- a/src/tools/qstring.cpp
+++ b/src/tools/qstring.cpp
@@ -87,6 +87,12 @@
 #define ULLONG_MAX Q_UINT64_C(18446744073709551615)
 #endif
 
+#ifdef QT_THREAD_SUPPORT
+#include "qmutex.h"
+#endif // QT_THREAD_SUPPORT
+
+extern QMutex *qt_sharedStringMutex;
+
 static int ucstrcmp( const QString &as, const QString &bs )
 {
     const QChar *a = as.unicode();
@@ -1033,12 +1039,54 @@ static inline bool format(QChar::Decomposition tag, QString & str,
 } // format()
 #endif
 
+QStringData::QStringData() : QShared(),
+	unicode(0),
+	ascii(0),
+	len(0),
+	issimpletext(TRUE),
+	maxl(0),
+	islatin1(FALSE),
+	security_unpaged(FALSE) {
+#ifdef QT_THREAD_SUPPORT
+	mutex = new QMutex( TRUE );
+	mutex->lock();
+#endif // QT_THREAD_SUPPORT
+	ref();
+#ifdef QT_THREAD_SUPPORT
+	mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+}
+
+QStringData::QStringData(QChar *u, uint l, uint m) : QShared(),
+	unicode(u),
+	ascii(0),
+	len(l),
+	issimpletext(FALSE),
+	maxl(m),
+	islatin1(FALSE),
+	security_unpaged(FALSE) {
+#ifdef QT_THREAD_SUPPORT
+	mutex = new QMutex( TRUE );
+#endif // QT_THREAD_SUPPORT
+}
+
 QStringData::~QStringData() {
-    if ( unicode ) delete[] ((char*)unicode);
-    if ( ascii && security_unpaged ) {
-	munlock(ascii, LINUX_MEMLOCK_LIMIT_BYTES);
-    }
-    if ( ascii ) delete[] ascii;
+	if ( unicode ) delete[] ((char*)unicode);
+	if ( ascii && security_unpaged ) {
+		munlock(ascii, LINUX_MEMLOCK_LIMIT_BYTES);
+	}
+	if ( ascii ) delete[] ascii;
+#ifdef QT_THREAD_SUPPORT
+	if ( mutex ) delete mutex;
+#endif // QT_THREAD_SUPPORT
+}
+
+void QStringData::setDirty() {
+	if ( ascii ) {
+		delete [] ascii;
+		ascii = 0;
+	}
+	issimpletext = FALSE;
 }
 
 /*
@@ -1194,27 +1242,30 @@ QChar* QString::latin1ToUnicode( const char *str, uint* len, uint maxlen )
     return result;
 }
 
-static QChar* internalLatin1ToUnicode( const char *str, uint* len,
-				      uint maxlen = (uint)-1 )
+static QChar* internalLatin1ToUnicode( const char *str, uint* len, uint maxlen = (uint)-1 )
 {
     QChar* result = 0;
     uint l = 0;
     if ( str ) {
 	if ( maxlen != (uint)-1 ) {
-	    while ( l < maxlen && str[l] )
+	    while ( l < maxlen && str[l] ) {
 		l++;
-	} else {
+	    }
+	}
+	else {
 	    // Faster?
 	    l = int(strlen( str ));
 	}
 	QChar *uc = QT_ALLOC_QCHAR_VEC( l );
 	result = uc;
 	uint i = l;
-	while ( i-- )
+	while ( i-- ) {
 	    *uc++ = *str++;
+	}
     }
-    if ( len )
+    if ( len ) {
 	*len = l;
+    }
     return result;
 }
 
@@ -1395,11 +1446,26 @@ QT_STATIC_CONST_IMPL QChar QChar::nbsp((ushort)0x00a0);
 
 QStringData* QString::makeSharedNull()
 {
+#ifdef QT_THREAD_SUPPORT
+    if (qt_sharedStringMutex) qt_sharedStringMutex->lock();
+#endif // QT_THREAD_SUPPORT
+
+    if (QString::shared_null) {
+#ifdef QT_THREAD_SUPPORT
+	if (qt_sharedStringMutex) qt_sharedStringMutex->unlock();
+#endif // QT_THREAD_SUPPORT
+	return QString::shared_null;
+    }
+
     QString::shared_null = new QStringData;
 #if defined( Q_OS_MAC ) || defined(Q_OS_SOLARIS) || defined(Q_OS_HPUX) || defined(Q_OS_AIX)
     QString *that = const_cast<QString *>(&QString::null);
     that->d = QString::shared_null;
 #endif
+
+#ifdef QT_THREAD_SUPPORT
+    if (qt_sharedStringMutex) qt_sharedStringMutex->unlock();
+#endif // QT_THREAD_SUPPORT
     return QString::shared_null;
 }
 
@@ -1412,6 +1478,24 @@ QStringData* QString::makeSharedNull()
     \sa isNull()
 */
 
+// FIXME
+// Original Qt3 code stated that there is
+// "No safe way to pre-init shared_null on ALL compilers/linkers"
+// Is this still true?
+
+QString::QString() :
+    d(0)
+{
+	d = shared_null ? shared_null : makeSharedNull();
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
+	d->ref();
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+}
+
 /*!
     Constructs a string of length one, containing the character \a ch.
 */
@@ -1428,7 +1512,15 @@ QString::QString( QChar ch )
 QString::QString( const QString &s ) :
     d(s.d)
 {
+#ifdef QT_THREAD_SUPPORT
+    d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
+
     d->ref();
+
+#ifdef QT_THREAD_SUPPORT
+    d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
 }
 
 /*!
@@ -1451,7 +1543,13 @@ QString::QString( int size, bool /*dummy*/ )
 	d = new QStringData( uc, 0, l );
     } else {
 	d = shared_null ? shared_null : (shared_null=new QStringData);
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
 	d->ref();
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
     }
 }
 
@@ -1493,11 +1591,19 @@ QString::QString( const QChar* unicode, uint length )
 {
     if ( !unicode && !length ) {
 	d = shared_null ? shared_null : makeSharedNull();
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
 	d->ref();
-    } else {
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+    }
+    else {
 	QChar* uc = QT_ALLOC_QCHAR_VEC( length );
-	if ( unicode )
+	if ( unicode ) {
 	    memcpy(uc, unicode, length*sizeof(QChar));
+	}
 	d = new QStringData(uc,unicode ? length : 0,length);
     }
 }
@@ -1556,6 +1662,10 @@ QString::QString( const std::string &str )
 }
 #endif
 
+QString::QString( QStringData* dd, bool /* dummy */ ) {
+	d = dd;
+}
+
 /*!
     \fn QString::~QString()
 
@@ -1563,6 +1673,31 @@ QString::QString( const std::string &str )
     last reference to the string.
 */
 
+QString::~QString()
+{
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
+	if ( d->deref() ) {
+		if ( d != shared_null ) {
+#ifdef QT_THREAD_SUPPORT
+			d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+			d->deleteSelf();
+		}
+		else {
+#ifdef QT_THREAD_SUPPORT
+			d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+		}
+	}
+	else {
+#ifdef QT_THREAD_SUPPORT
+		d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+	}
+}
+
 
 /*!
     Deallocates any space reserved solely by this QString.
@@ -1580,11 +1715,25 @@ void QString::real_detach()
 
 void QString::deref()
 {
-    if ( d && d->deref() ) {
-	if ( d != shared_null )
-	    delete d;
-	d = 0;
-    }
+	if ( d ) {
+#ifdef QT_THREAD_SUPPORT
+		d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
+		if ( d->deref() ) {
+#ifdef QT_THREAD_SUPPORT
+			d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+			if ( d != shared_null ) {
+				delete d;
+			}
+			d = 0;
+		}
+		else {
+#ifdef QT_THREAD_SUPPORT
+			d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+		}
+	}
 }
 
 void QStringData::deleteSelf()
@@ -1624,9 +1773,16 @@ void QStringData::deleteSelf()
 */
 QString &QString::operator=( const QString &s )
 {
+#ifdef QT_THREAD_SUPPORT
+    s.d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
     s.d->ref();
+#ifdef QT_THREAD_SUPPORT
+    s.d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
     deref();
     d = s.d;
+
     return *this;
 }
 
@@ -1730,6 +1886,10 @@ void QString::truncate( uint newLen )
 */
 void QString::setLength( uint newLen )
 {
+#ifdef QT_THREAD_SUPPORT
+    d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
+
     if ( d->count != 1 || newLen > d->maxl ||
 	 ( newLen * 4 < d->maxl && d->maxl > 4 ) ) {
 	// detach, grow or shrink
@@ -1739,12 +1899,24 @@ void QString::setLength( uint newLen )
 	    uint len = QMIN( d->len, newLen );
 	    memcpy( nd, d->unicode, sizeof(QChar) * len );
 	    bool unpaged = d->security_unpaged;
+#ifdef QT_THREAD_SUPPORT
+	    d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
 	    deref();
 	    d = new QStringData( nd, newLen, newMax );
 	    setSecurityUnPaged(unpaged);
 	}
-    } else {
+	else {
+#ifdef QT_THREAD_SUPPORT
+	    d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+	}
+    }
+    else {
 	d->len = newLen;
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
 	d->setDirty();
     }
 }
@@ -1830,10 +2002,21 @@ void QString::squeeze()
 */
 void QString::grow( uint newLen )
 {
+#ifdef QT_THREAD_SUPPORT
+    d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
+
     if ( d->count != 1 || newLen > d->maxl ) {
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
 	setLength( newLen );
-    } else {
+    }
+    else {
 	d->len = newLen;
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
 	d->setDirty();
     }
 }
@@ -5868,13 +6051,15 @@ static QChar *addOne(QChar *qch, QString &str)
 */
 QString QString::fromUtf8( const char* utf8, int len )
 {
-    if ( !utf8 )
+    if ( !utf8 ) {
 	return QString::null;
+    }
 
     int slen = 0;
     if (len >= 0) {
-	while (slen < len && utf8[slen])
+	while (slen < len && utf8[slen]) {
 		slen++;
+	}
     } else {
         slen = int(strlen(utf8));
     }
@@ -6012,10 +6197,13 @@ QString QString::fromLatin1( const char* chars, int len )
 {
     uint l;
     QChar *uc;
-    if ( len < 0 )
+    if ( len < 0 ) {
 	 len = -1;
+    }
     uc = internalLatin1ToUnicode( chars, &l, len );
-    return QString( new QStringData(uc, l, l), TRUE );
+    QString ret( new QStringData(uc, l, l), TRUE );
+
+    return ret;
 }
 
 /*!
@@ -6178,7 +6366,8 @@ QString QString::fromUcs2( const unsigned short *str )
 	    length++;
 	QChar* uc = QT_ALLOC_QCHAR_VEC( length );
 	memcpy( uc, str, length*sizeof(QChar) );
-	return QString( new QStringData( uc, length, length ), TRUE );
+	QString ret( new QStringData( uc, length, length ), TRUE );
+	return ret;
     }
 }
 
@@ -6225,6 +6414,25 @@ QString QString::fromUcs2( const unsigned short *str )
     \sa constref()
 */
 
+QChar& QString::ref(uint i) {
+#ifdef QT_THREAD_SUPPORT
+	d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
+	if ( (d->count != 1) || (i >= d->len) ) {
+#ifdef QT_THREAD_SUPPORT
+		d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+		subat( i );
+	}
+	else {
+#ifdef QT_THREAD_SUPPORT
+		d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+	}
+	d->setDirty();
+	return d->unicode[i];
+}
+
 /*!
     \fn QChar QString::operator[]( int ) const
 
@@ -6300,27 +6508,48 @@ void QString::subat( uint i )
 
 QString& QString::setUnicode( const QChar *unicode, uint len )
 {
-    if ( len == 0 ) {                           // set to null string
-	if ( d != shared_null ) {               // beware of nullstring being set to nullstring
-	    deref();
-	    d = shared_null ? shared_null : makeSharedNull();
-	    d->ref();
+	if ( len == 0 ) {                       // set to null string
+		if ( d != shared_null ) {       // beware of nullstring being set to nullstring
+			deref();
+			d = shared_null ? shared_null : makeSharedNull();
+#ifdef QT_THREAD_SUPPORT
+			d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
+			d->ref();
+#ifdef QT_THREAD_SUPPORT
+			d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+		}
 	}
-    } else if ( d->count != 1 || len > d->maxl ||
-		( len * 4 < d->maxl && d->maxl > 4 ) ) {
-	// detach, grown or shrink
-	uint newMax = computeNewMax( len );
-	QChar* nd = QT_ALLOC_QCHAR_VEC( newMax );
-	if ( unicode )
-	    memcpy( nd, unicode, sizeof(QChar)*len );
-	deref();
-	d = new QStringData( nd, len, newMax );
-    } else {
-	d->len = len;
-	d->setDirty();
-	if ( unicode )
-	    memcpy( d->unicode, unicode, sizeof(QChar)*len );
-    }
+	else {
+#ifdef QT_THREAD_SUPPORT
+		d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
+		if ( d->count != 1 || len > d->maxl || ( len * 4 < d->maxl && d->maxl > 4 ) ) {
+			// detach, grown or shrink
+			uint newMax = computeNewMax( len );
+			QChar* nd = QT_ALLOC_QCHAR_VEC( newMax );
+			if ( unicode ) {
+				memcpy( nd, unicode, sizeof(QChar)*len );
+			}
+#ifdef QT_THREAD_SUPPORT
+			d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+			deref();
+			d = new QStringData( nd, len, newMax );
+		}
+		else {
+			d->len = len;
+#ifdef QT_THREAD_SUPPORT
+			d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
+			d->setDirty();
+			if ( unicode ) {
+				memcpy( d->unicode, unicode, sizeof(QChar)*len );
+			}
+		}
+	}
+
     return *this;
 }
 
@@ -7024,15 +7253,23 @@ QConstString::QConstString( const QChar* unicode, uint length ) :
 */
 QConstString::~QConstString()
 {
+#ifdef QT_THREAD_SUPPORT
+    d->mutex->lock();
+#endif // QT_THREAD_SUPPORT
+
     if ( d->count > 1 ) {
 	QChar* cp = QT_ALLOC_QCHAR_VEC( d->len );
 	memcpy( cp, d->unicode, d->len*sizeof(QChar) );
 	d->unicode = cp;
-    } else {
+    }
+    else {
 	d->unicode = 0;
     }
 
     // The original d->unicode is now unlinked.
+#ifdef QT_THREAD_SUPPORT
+    d->mutex->unlock();
+#endif // QT_THREAD_SUPPORT
 }
 
 /*!
diff --git a/src/tools/qstring.h b/src/tools/qstring.h
index 58830db..8715395 100644
--- a/src/tools/qstring.h
+++ b/src/tools/qstring.h
@@ -71,6 +71,7 @@
 class QRegExp;
 class QString;
 class QCharRef;
+class QMutex;
 template <class T> class QDeepCopy;
 
 class Q_EXPORT QChar {
@@ -359,22 +360,14 @@ inline bool operator>( QChar c1, QChar c2 ) { return !(c2>=c1); }
 
 // internal
 struct Q_EXPORT QStringData : public QShared {
-    QStringData() :
-        QShared(), unicode(0), ascii(0), len(0), issimpletext(TRUE), maxl(0), islatin1(FALSE), security_unpaged(FALSE) { ref(); }
-    QStringData(QChar *u, uint l, uint m) :
-        QShared(), unicode(u), ascii(0), len(l), issimpletext(FALSE), maxl(m), islatin1(FALSE), security_unpaged(FALSE) { }
+    QStringData();
+    QStringData(QChar *u, uint l, uint m);
     ~QStringData();
 
     void deleteSelf();
     QChar *unicode;
     char *ascii;
-    void setDirty() {
-	if ( ascii ) {
-	    delete [] ascii;
-	    ascii = 0;
-	}
-	issimpletext = FALSE;
-    }
+    void setDirty();
 #ifdef Q_OS_MAC9
     uint len;
 #else
@@ -390,6 +383,8 @@ struct Q_EXPORT QStringData : public QShared {
 
     bool security_unpaged : 1;
 
+    QMutex* mutex;
+
 private:
 #if defined(Q_DISABLE_COPY)
     QStringData( const QStringData& );
@@ -646,13 +641,7 @@ public:
 
     QChar constref(uint i) const
         { return at(i); }
-    QChar& ref(uint i)
-        { // Optimized for easy-inlining by simple compilers.
-            if ( d->count != 1 || i >= d->len )
-                subat( i );
-            d->setDirty();
-            return d->unicode[i];
-        }
+    QChar& ref(uint i);
 
     const QChar* unicode() const { return d->unicode; }
     const char* ascii() const;
@@ -747,7 +736,7 @@ private:
 
     friend class QConstString;
     friend class QTextStream;
-    QString( QStringData* dd, bool /* dummy */ ) : d(dd) { }
+    QString( QStringData* dd, bool /* dummy */ );
 
     // needed for QDeepCopy
     void detach();
@@ -839,25 +828,6 @@ Q_EXPORT QDataStream &operator>>( QDataStream &, QString & );
   QString inline functions
  *****************************************************************************/
 
-// These two move code into makeSharedNull() and deletesData()
-// to improve cache-coherence (and reduce code bloat), while
-// keeping the common cases fast.
-//
-// No safe way to pre-init shared_null on ALL compilers/linkers.
-inline QString::QString() :
-    d(shared_null ? shared_null : makeSharedNull())
-{
-    d->ref();
-}
-//
-inline QString::~QString()
-{
-    if ( d->deref() ) {
-        if ( d != shared_null )
-	    d->deleteSelf();
-    }
-}
-
 // needed for QDeepCopy
 inline void QString::detach()
 { real_detach(); }
diff --git a/src/tools/qthreadinstance_p.h b/src/tools/qthreadinstance_p.h
index 7580b25..34550a8 100644
--- a/src/tools/qthreadinstance_p.h
+++ b/src/tools/qthreadinstance_p.h
@@ -101,6 +101,7 @@ public:
 #endif // Q_OS_WIN32
 
     QEventLoop* eventLoop;
+    int cleanupType;
 };
 
 #endif // QT_THREAD_SUPPORT