ICU: Mark which functions are threadsafe and which ones aren't

Mark the thread-safe functions with the \threadsafe doc marker. This
includes public API, which should be thread-safe anyway.

The thread-unsafe functions are marked "\nonreentrant" already. In
addition, I renamed the functions that must be called with locked
mutexes to Unlocked, following the convention in other libraries like
libdbus-1.

Change-Id: Ibd93d1266149767f546c8e82959b73c138008469
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

src/corelib/codecs/qicucodec.cpp

@@ -52,8 +52,6 @@
 
 QT_BEGIN_NAMESPACE
 
-extern QMutex *qTextCodecsMutex();
-
 static void qIcuCodecStateFree(QTextCodec::ConverterState *state)
 {
     ucnv_close(static_cast<UConverter *>(state->d));
@@ -376,7 +374,7 @@ static QTextCodec *loadQtCodec(const char *name)
     return 0;
 }
 
-
+/// \threadsafe
 QList<QByteArray> QIcuCodec::availableCodecs()
 {
     QList<QByteArray> codecs;
@@ -412,6 +410,7 @@ QList<QByteArray> QIcuCodec::availableCodecs()
     return codecs;
 }
 
+/// \threadsafe
 QList<int> QIcuCodec::availableMibs()
 {
     QList<int> mibs;
@@ -424,7 +423,7 @@ QList<int> QIcuCodec::availableMibs()
     return mibs;
 }
 
-QTextCodec *QIcuCodec::defaultCodec()
+QTextCodec *QIcuCodec::defaultCodecUnlocked()
 {
     QCoreGlobalData *globalData = QCoreGlobalData::instance();
     if (!globalData)
@@ -438,13 +437,13 @@ QTextCodec *QIcuCodec::defaultCodec()
 #else
     const char *name = ucnv_getDefaultName();
 #endif
-    c = codecForName(name);
+    c = codecForNameUnlocked(name);
     globalData->codecForLocale.storeRelease(c);
     return c;
 }
 
 
-QTextCodec *QIcuCodec::codecForName(const char *name)
+QTextCodec *QIcuCodec::codecForNameUnlocked(const char *name)
 {
     // backwards compatibility with Qt 4.x
     if (!qstrcmp(name, "CP949"))
@@ -525,11 +524,11 @@ QTextCodec *QIcuCodec::codecForName(const char *name)
 }
 
 
-QTextCodec *QIcuCodec::codecForMib(int mib)
+QTextCodec *QIcuCodec::codecForMibUnlocked(int mib)
 {
     for (int i = 0; i < mibToNameSize; ++i) {
         if (mibToName[i].mib == mib)
-            return codecForName(mibToNameTable + mibToName[i].index);
+            return codecForNameUnlocked(mibToNameTable + mibToName[i].index);
     }
     return 0;
 }

src/corelib/codecs/qicucodec_p.h

@@ -67,10 +67,10 @@ public:
     static QList<QByteArray> availableCodecs();
     static QList<int> availableMibs();
 
-    static QTextCodec *defaultCodec();
+    static QTextCodec *defaultCodecUnlocked();
 
-    static QTextCodec *codecForName(const char *name);
-    static QTextCodec *codecForMib(int mib);
+    static QTextCodec *codecForNameUnlocked(const char *name);
+    static QTextCodec *codecForMibUnlocked(int mib);
 
     QString convertToUnicode(const char *, int, ConverterState *) const;
     QByteArray convertFromUnicode(const QChar *, int, ConverterState *) const;

src/corelib/codecs/qtextcodec.cpp

@@ -146,6 +146,7 @@ static QTextCodec *checkForCodec(const QByteArray &name) {
 
 static void setup();
 
+// \threadsafe
 // this returns the codec the method sets up as locale codec to
 // avoid a race condition in codecForLocale() when
 // setCodecForLocale(0) is called at the same time.
@@ -495,6 +496,7 @@ QTextCodec::~QTextCodec()
 */
 
 /*!
+    \threadsafe
     Searches all installed QTextCodec objects and returns the one
     which best matches \a name; the match is case-insensitive. Returns
     0 if no codec matching the name \a name could be found.
@@ -538,12 +540,13 @@ QTextCodec *QTextCodec::codecForName(const QByteArray &name)
 
     return 0;
 #else
-    return QIcuCodec::codecForName(name);
+    return QIcuCodec::codecForNameUnlocked(name);
 #endif
 }
 
 
 /*!
+    \threadsafe
     Returns the QTextCodec which matches the
     \l{QTextCodec::mibEnum()}{MIBenum} \a mib.
 */
@@ -578,13 +581,14 @@ QTextCodec* QTextCodec::codecForMib(int mib)
     }
 
 #ifdef QT_USE_ICU
-    return QIcuCodec::codecForMib(mib);
+    return QIcuCodec::codecForMibUnlocked(mib);
 #endif
 
     return 0;
 }
 
 /*!
+    \threadsafe
     Returns the list of all available codecs, by name. Call
     QTextCodec::codecForName() to obtain the QTextCodec for the name.
 
@@ -616,6 +620,7 @@ QList<QByteArray> QTextCodec::availableCodecs()
 }
 
 /*!
+    \threadsafe
     Returns the list of MIBs for all available codecs. Call
     QTextCodec::codecForMib() to obtain the QTextCodec for the MIB.
 
@@ -659,6 +664,7 @@ void QTextCodec::setCodecForLocale(QTextCodec *c)
 }
 
 /*!
+    \threadsafe
     Returns a pointer to the codec most suitable for this locale.
 
     On Windows, the codec will be based on a system locale. On Unix
@@ -677,8 +683,9 @@ QTextCodec* QTextCodec::codecForLocale()
     QTextCodec *codec = globalData->codecForLocale.loadAcquire();
     if (!codec) {
 #ifdef QT_USE_ICU
-        codec = QIcuCodec::defaultCodec();
+        codec = QIcuCodec::defaultCodecUnlocked();
 #else
+        // setupLocaleMapper locks as necessary
         codec = setupLocaleMapper();
 #endif
     }