QJSEngine: optimize isInterrupted handling

The isInterrupted flag is just that: a flag, so it doesn't require
acquire/release semantics when loading/storing.

Use relaxed loads and stores instead.

Change-Id: I6d733a6bebcfc7f2b786265fc28f9ba7e25bb1c7
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

4 files changed, 10 insertions, 10 deletions

diff --git a/src/qml/jsapi/qjsengine.cpp b/src/qml/jsapi/qjsengine.cpp
index f66488e04c..7e52dc2e4d 100644
--- a/src/qml/jsapi/qjsengine.cpp
+++ b/src/qml/jsapi/qjsengine.cpp
@@ -478,7 +478,7 @@ void QJSEngine::installExtensions(QJSEngine::Extensions extensions, const QJSVal
 */
 void QJSEngine::setInterrupted(bool interrupted)
 {
-    m_v4Engine->isInterrupted = interrupted;
+    m_v4Engine->isInterrupted.storeRelaxed(interrupted);
 }
 
 /*!
@@ -489,7 +489,7 @@ void QJSEngine::setInterrupted(bool interrupted)
 */
 bool QJSEngine::isInterrupted() const
 {
-    return m_v4Engine->isInterrupted.loadAcquire();
+    return m_v4Engine->isInterrupted.loadRelaxed();
 }
 
 static QUrl urlForFileName(const QString &fileName)
@@ -571,7 +571,7 @@ QJSValue QJSEngine::evaluate(const QString& program, const QString& fileName, in
                                       );
         }
     }
-    if (v4->isInterrupted.loadAcquire())
+    if (v4->isInterrupted.loadRelaxed())
         result = v4->newErrorObject(QStringLiteral("Interrupted"));
 
     return QJSValuePrivate::fromReturnedValue(result->asReturnedValue());
@@ -611,7 +611,7 @@ QJSValue QJSEngine::importModule(const QString &fileName)
     if (m_v4Engine->hasException)
         return QJSValuePrivate::fromReturnedValue(m_v4Engine->catchException());
     moduleUnit->evaluate();
-    if (!m_v4Engine->isInterrupted.loadAcquire())
+    if (!m_v4Engine->isInterrupted.loadRelaxed())
         return QJSValuePrivate::fromReturnedValue(moduleNamespace->asReturnedValue());
 
     return QJSValuePrivate::fromReturnedValue(
diff --git a/src/qml/jsapi/qjsvalue.cpp b/src/qml/jsapi/qjsvalue.cpp
index 03cd1e9aa9..c79953130e 100644
--- a/src/qml/jsapi/qjsvalue.cpp
+++ b/src/qml/jsapi/qjsvalue.cpp
@@ -713,7 +713,7 @@ QJSValue QJSValue::call(const QJSValueList &args) const
     ScopedValue result(scope, f->call(jsCallData));
     if (engine->hasException)
         result = engine->catchException();
-    if (engine->isInterrupted.loadAcquire())
+    if (engine->isInterrupted.loadRelaxed())
         result = engine->newErrorObject(QStringLiteral("Interrupted"));
 
     return QJSValuePrivate::fromReturnedValue(result->asReturnedValue());
@@ -767,7 +767,7 @@ QJSValue QJSValue::callWithInstance(const QJSValue &instance, const QJSValueList
     ScopedValue result(scope, f->call(jsCallData));
     if (engine->hasException)
         result = engine->catchException();
-    if (engine->isInterrupted.loadAcquire())
+    if (engine->isInterrupted.loadRelaxed())
         result = engine->newErrorObject(QStringLiteral("Interrupted"));
 
     return QJSValuePrivate::fromReturnedValue(result->asReturnedValue());
@@ -813,7 +813,7 @@ QJSValue QJSValue::callAsConstructor(const QJSValueList &args) const
     ScopedValue result(scope, f->callAsConstructor(jsCallData));
     if (engine->hasException)
         result = engine->catchException();
-    if (engine->isInterrupted.loadAcquire())
+    if (engine->isInterrupted.loadRelaxed())
         result = engine->newErrorObject(QStringLiteral("Interrupted"));
 
     return QJSValuePrivate::fromReturnedValue(result->asReturnedValue());
diff --git a/src/qml/jsruntime/qv4scopedvalue_p.h b/src/qml/jsruntime/qv4scopedvalue_p.h
index beb8315225..5b6abfd819 100644
--- a/src/qml/jsruntime/qv4scopedvalue_p.h
+++ b/src/qml/jsruntime/qv4scopedvalue_p.h
@@ -70,7 +70,7 @@ struct ScopedValue;
 
 #define CHECK_EXCEPTION() \
     do { \
-        if (scope.hasException() || scope.engine->isInterrupted.loadAcquire()) { \
+        if (scope.hasException() || scope.engine->isInterrupted.loadRelaxed()) { \
             return QV4::Encode::undefined(); \
         } \
     } while (false)
diff --git a/src/qml/jsruntime/qv4vme_moth.cpp b/src/qml/jsruntime/qv4vme_moth.cpp
index e8d4f0a09c..d161ed53a2 100644
--- a/src/qml/jsruntime/qv4vme_moth.cpp
+++ b/src/qml/jsruntime/qv4vme_moth.cpp
@@ -360,7 +360,7 @@ static inline QV4::Value &stackValue(QV4::Value *stack, size_t slot, const JSTyp
 #undef CHECK_EXCEPTION
 #endif
 #define CHECK_EXCEPTION \
-    if (engine->hasException || engine->isInterrupted.loadAcquire()) \
+    if (engine->hasException || engine->isInterrupted.loadRelaxed()) \
         goto handleUnwind
 
 static inline Heap::CallContext *getScope(QV4::Value *stack, int level)
@@ -1525,7 +1525,7 @@ QV4::ReturnedValue VME::interpret(JSTypesStackFrame *frame, ExecutionEngine *eng
         // We do start the exception handler in case of isInterrupted. The exception handler will
         // immediately abort, due to the same isInterrupted. We don't skip the exception handler
         // because the current behavior is easier to implement in the JIT.
-        Q_ASSERT(engine->hasException || engine->isInterrupted.loadAcquire() || frame->unwindLevel);
+        Q_ASSERT(engine->hasException || engine->isInterrupted.loadRelaxed() || frame->unwindLevel);
         if (!frame->unwindHandler) {
             acc = Encode::undefined();
             return acc;